Green and Sustainable Chemistry

Topic Information

Dear Colleagues,

Pollution problems and resources shortage is of high concern for civil and scientific communities. Chemistry research today must be driven by the principle of green chemistry and sustainability. In this respect, prevention of waste or the possibility to use waste-derived precursors, maximum incorporation of the reactants into the final product, minimization of energy requirements, prevention or minimization of hazardous products, design of safer chemicals, and selection of the most appropriate solvent are integral to any research strategy. This topic will collect contributions dealing with all the above aspects. The general idea is based on the sustainability concepts, which consider both the limitation of damage and the creation of benefits. Thus, the use of waste, which needs to be eliminated, often at some cost, could be seen as a damage limitation. The production of materials from waste precursors is considered beneficial for the society and the economy. If the material is used for environmental and energy applications, the number of benefits grows further, and damage is further limited. Biomass conversion, biofuels and bioenergy, renewable energy and storage, CO₂ capture and utilization, green solvents and green catalysis, photocatalysis, environmental catalysis, and the sustainable recycling of molecules, materials, and products are just some of the topics welcomed to enrich this Topic.

Dr. Valeria La Parola
Dr. Leonarda Liotta
Topic Editors

Keywords

Participating Journals

Journal Name	Impact Factor	CiteScore	Launched Year	First Decision (median)	APC
Catalysts catalysts	3.9	6.3	2011	14.3 Days	CHF 2700
Energies energies	3.2	5.5	2008	16.1 Days	CHF 2600
Molecules molecules	4.6	6.7	1996	14.6 Days	CHF 2700
Polymers polymers	5.0	6.6	2009	13.7 Days	CHF 2700
Sustainable Chemistry suschem	-	-	2020	29.1 Days	CHF 1000

MDPI Topics is cooperating with Preprints.org and has built a direct connection between MDPI journals and Preprints.org. Authors are encouraged to enjoy the benefits by posting a preprint at Preprints.org prior to publication:

1. Immediately share your ideas ahead of publication and establish your research priority;
2. Protect your idea from being stolen with this time-stamped preprint article;
3. Enhance the exposure and impact of your research;
4. Receive feedback from your peers in advance;
5. Have it indexed in Web of Science (Preprint Citation Index), Google Scholar, Crossref, SHARE, PrePubMed, Scilit and Europe PMC.

Published Papers (38 papers)

Order results

Content type Publication Date

Result details

Normal Extended Compact

Journals

All Catalysts Energies Molecules Polymers Sustainable Chemistry

Show export options expand_more Show export options expand_less

Select all

Export citation of selected articles as:

Plain Text BibTeX BibTeX (without abstracts) Endnote Endnote (without abstracts) Tab-delimited RIS

Error

Oops... you haven't selected anything for export.

Ok

clear

13 pages, 2742 KiB  

Open AccessArticle

Catalyzed Hydrothermal Pretreatment of Oat Husks for Integrated Production of Furfural and Lignocellulosic Residue

by Maris Puke, Daniela Godina and Prans Brazdausks

Polymers 2024, 16(5), 707; https://doi.org/10.3390/polym16050707 - 05 Mar 2024

Viewed by 583

Abstract

This study presents a novel approach for biorefining oat husks into furfural, leveraging a unique pilot-scale setup. Unlike conventional furfural manufacturing processes, which often result in substantial cellulose degradation and environmental concerns associated with sulfuric acid usage, our method utilizes phosphoric acid as [...] Read more.

This study presents a novel approach for biorefining oat husks into furfural, leveraging a unique pilot-scale setup. Unlike conventional furfural manufacturing processes, which often result in substantial cellulose degradation and environmental concerns associated with sulfuric acid usage, our method utilizes phosphoric acid as a catalyst to achieve high furfural yield while minimizing cellulose destruction. Drawing on our research conducted in a distinctive pilot-scale environment, we successfully developed and implemented a tailored biorefining process for oat husks. Through meticulous experimentation, we attained a remarkable furfural yield of 11.84% from oven-dried mass, accompanied by a 2.64% yield of acetic acid. Importantly, our approach significantly mitigated cellulose degradation, preserving 88.31% of the cellulose content in oat husks. Existing catalytic (H₂SO₄) furfural manufacturing processes often lead to substantial cellulose degradation (40–50%) in lignocellulosic leftover during the pretreatment stage. As a result of the research, it was also possible to reduce the destruction of cellulose in the lignocellulose leftover to 11.69% of the output (initial) cellulose of oat husks. This research underscores the feasibility and sustainability of utilizing oat husks as a valuable feedstock for furfural production, highlighting the potential of phosphoric acid as a catalyst in biorefining processes. By showcasing our unique pilot-scale methodology, this study contributes to advancing the field of environmentally friendly biorefining technologies. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 1163 KiB)

16 pages, 3221 KiB  

Open AccessArticle

Indium-Based Silica Materials: Sustainable Syntheses Combined with a Challenging Insertion in SiO₂ Mesoporous Structures

by Amélie Maertens and Carmela Aprile

Molecules 2024, 29(1), 102; https://doi.org/10.3390/molecules29010102 - 22 Dec 2023

Viewed by 768

Abstract

Optimized sustainable procedures in both acidic and basic conditions are considered to meet some of the current environmental challenges of the scientific community. In this paper, the successful syntheses of two classes of indium-based silica nanomaterials are reported. Both procedures were conceived to [...] Read more.

Optimized sustainable procedures in both acidic and basic conditions are considered to meet some of the current environmental challenges of the scientific community. In this paper, the successful syntheses of two classes of indium-based silica nanomaterials are reported. Both procedures were conceived to enhance the sustainability of the synthesis methods and promote their preparations at room temperature while avoiding the hydrothermal treatment under static conditions at 100 °C. A fast, room-temperature synthesis of porous nanospheres was conceived together with an “acid-free” procedure for SBA-15-like materials. Moreover, the isomorphic substitution of silicon with indium was achieved. All the materials were deeply characterized to probe their structural, textural and morphological properties (e.g., transmission electron microscopy, N₂ physisorption, ss MAS NMR of ²⁹Si). The high specific surface area and the mesoporosity were always preserved even under the mild reaction conditions employed. The honeycomb structure and the spherical morphology of SBA-15-like materials and nanospheres, respectively, were also observed. The insertion of indium was confirmed via X-ray photoelectron spectroscopy (XPS) investigations. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

31 pages, 6343 KiB  

Open AccessReview

Envisioning a BHET Economy: Adding Value to PET Waste

by Clarissa C. Westover and Timothy E. Long

Sustain. Chem. 2023, 4(4), 363-393; https://doi.org/10.3390/suschem4040025 - 18 Dec 2023

Cited by 2 | Viewed by 2555

Abstract

Poly(ethylene terephthalate), the fifth most produced polymer, generates significant waste annually. This increased waste production has spurred interest in chemical and mechanical pathways for recycling. The shift from laboratory settings to larger-scale implementation creates opportunities to explore the value and recovery of recycling [...] Read more.

Poly(ethylene terephthalate), the fifth most produced polymer, generates significant waste annually. This increased waste production has spurred interest in chemical and mechanical pathways for recycling. The shift from laboratory settings to larger-scale implementation creates opportunities to explore the value and recovery of recycling products. Derived from the glycolysis of PET, bis(2-hydroxyethyl) terephthalate (BHET) exhibits versatility as a depolymerization product and valuable monomer. BHET exhibits versatility and finds application across diverse industries such as resins, coatings, foams, and tissue scaffolds. Incorporating BHET, which is a chemical recycling product, supports higher recycling rates and contributes to a more sustainable approach to generating materials. This review illuminates the opportunities for BHET as a valuable feedstock for a more circular polymer materials economy. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

attachment

Supplementary material:
Supplementary File 1 (ZIP, 5283 KiB)

11 pages, 1129 KiB  

Open AccessArticle

A Facile and General Oxidative Hydroxylation of Organoboron Compounds: Citric Acid as an Efficient Catalyst in Water to Access Phenolic and Alcoholic Motifs

by Jia-Hui Zhou, Xia Chen, Dan Yang, Chun-Yan Liu and Xiao-Yu Zhou

Molecules 2023, 28(23), 7915; https://doi.org/10.3390/molecules28237915 - 03 Dec 2023

Cited by 1 | Viewed by 747

Abstract

An efficient and convenient method for the synthesis of phenols and aliphatic alcohols is described in this paper. The oxidative hydroxylation reaction of various organoboron compounds proceeded smoothly by employing H₂O₂ as the oxidant and citric acid as the catalyst [...] Read more.

An efficient and convenient method for the synthesis of phenols and aliphatic alcohols is described in this paper. The oxidative hydroxylation reaction of various organoboron compounds proceeded smoothly by employing H₂O₂ as the oxidant and citric acid as the catalyst in water at room temperature to produce phenols and aliphatic alcohols in satisfactory to excellent yields (up to 99% yield). Various synthetically useful functional groups, such as halogen atom, cyano, and nitro groups, remain intact during the oxidative hydroxylation. The developed catalytic system also could accommodate phenylboronic pinacol ester and potassium phenyltrifluoroborate to give the target product good yields. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

16 pages, 5168 KiB  

Open AccessArticle

Exploration of the Linkages between Lignin and Carbohydrates in Kraft Pulp from Wheat Straw Using a ¹³C/²H Isotopic Tracer

by Hujun Niu, Xudong Chen, Yunbo Zhao, Junyi Zhou and Yimin Xie

Molecules 2023, 28(22), 7493; https://doi.org/10.3390/molecules28227493 - 09 Nov 2023

Viewed by 726

Abstract

To further our understanding of the change in association between lignin and carbohydrates after kraft pulping, isotope-labeled kraft pulp (KP) was prepared using ¹³C and D double-isotope-labeled wheat straw, and it was subjected to enzymatic hydrolysis and ionic liquid treatment to explore [...] Read more.

To further our understanding of the change in association between lignin and carbohydrates after kraft pulping, isotope-labeled kraft pulp (KP) was prepared using ¹³C and D double-isotope-labeled wheat straw, and it was subjected to enzymatic hydrolysis and ionic liquid treatment to explore the linkages between lignin and carbohydrate complexes in wheat straw. Isotope abundance determination showed that ¹³C and D abundances in the experimental groups were substantially higher than those in the control group, indicating that the injected exogenous coniferin-[α-¹³C], coniferin-[γ-¹³C], and d-glucose-[6-D₂] were effectively absorbed and metabolized during wheat internode growth. Solid-state CP/MAS ¹³C-NMR spectroscopy showed that lignin was mainly linked to polysaccharides via acetal, benzyl ether, and benzyl ester bonds. Kraft pulp (KP) from the labeled wheat straw was degraded by cellulase. The obtained residue was fractionated using the ionic liquid DMSO/TBAH to separate the cellulose–lignin complex (KP-CLC) and xylan–lignin complex (KP-XLC). X-ray diffractometer determination showed that the KP-CLC regenerated cellulose type II from type I after the ionic liquid conversion. The ¹³C-NMR spectrum of Ac-En-KP-CLC showed that the cellulose–lignin complex structure was chemically bonded between the lignin and cellulose through acetal and benzyl ether bonds. The ¹³C-NMR spectrum of En-KP-XLC showed a lignin–hemicellulose complex structure, wherein lignin and xylan were chemically bonded by benzyl ether and acetal bonds. These results indicate that the cross-linking between lignin and carbohydrates exists in lignocellulosic fibers even after kraft pulping. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

attachment

Supplementary material:
Supplementary File 1 (ZIP, 3262 KiB)

17 pages, 852 KiB  

Open AccessArticle

Methyl and Ethyl Ethers of Glycerol as Potential Green Low-Melting Technical Fluids

by Vadim Samoilov, Vladimir Lavrentev, Madina Sultanova, Dzhamalutdin Ramazanov, Andrey Kozhevnikov, Georgiy Shandryuk, Mariia Kniazeva and Anton Maximov

Molecules 2023, 28(22), 7483; https://doi.org/10.3390/molecules28227483 - 08 Nov 2023

Viewed by 992

Abstract

The study is dedicated to the consideration of lower alkyl ethers of glycerol as potential components of low-melting technical fluids (e.g., heat transfer fluids, hydraulic fluids, aircraft de-icing fluids, etc.). Four isomeric mixtures of glycerol ethers (GMME—monomethyl; GDME—dimethyl; GMEE—monoethyl; GDEE—diethyl) were synthesized from [...] Read more.

The study is dedicated to the consideration of lower alkyl ethers of glycerol as potential components of low-melting technical fluids (e.g., heat transfer fluids, hydraulic fluids, aircraft de-icing fluids, etc.). Four isomeric mixtures of glycerol ethers (GMME—monomethyl; GDME—dimethyl; GMEE—monoethyl; GDEE—diethyl) were synthesized from epichlorohydrin and methanol/ethanol in the presence of sodium and subjected to detailed characterization as pure compounds and as aqueous solutions (30–90 vol%). The temperature and concentration dependencies of density, viscosity, cloud point, boiling range, specific heat capacity, thermal conductivity, and rubber swelling were obtained. On the basis of the data obtained, a comparison was made between the aqueous solutions of glycerol ethers and of other common bases for low-melting liquids (glycerol, ethylene glycol, and propylene glycol). Pure glycerol ethers could potentially be used as technical fluids in a very wide temperature range—from −114 to 150 °C. It was further demonstrated that in low temperature applications (e.g., in low-temperature chiller systems) the glycerol-ether-based aqueous heat transfer fluids could provide enhanced efficiency when compared to the glycerol- or propylene-glycol-based ones due to their lower viscosities and favorable environmental properties. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

attachment

Supplementary material:
Supplementary File 1 (ZIP, 872 KiB)

19 pages, 8227 KiB  

Open AccessArticle

Integrating Fermentation Engineering and Organopalladium Chemocatalysis for the Production of Squalene from Biomass-Derived Carbohydrates as the Starting Material

by Cuicui Wu, Kaifei Tian, Xuan Guo and Yunming Fang

Catalysts 2023, 13(11), 1392; https://doi.org/10.3390/catal13111392 - 25 Oct 2023

Viewed by 1166

Abstract

The transition from fossil resources to renewable biomass for the production of valuable chemicals and biobased fuels is a crucial step towards carbon neutrality. Squalene, a valuable chemical extensively used in the energy, healthcare, and pharmaceutical fields, has traditionally been isolated from the [...] Read more.

The transition from fossil resources to renewable biomass for the production of valuable chemicals and biobased fuels is a crucial step towards carbon neutrality. Squalene, a valuable chemical extensively used in the energy, healthcare, and pharmaceutical fields, has traditionally been isolated from the liver oils of deep-sea sharks and plant seed oils. In this study, a biochemical synergistic conversion strategy was designed and realized to convert glucose to squalene by combining fermentation technology in yeast with reductive coupling treatment of dienes. First, glucose derived from hydrolysis of cellulose was used as a renewable resource, using genetically engineered Saccharomyces cerevisiae as the initial biocatalyst to produce β-farnesene with a titer of 27.6 g/L in a 2.5 L bioreactor. Subsequently, intermediate β-farnesene was successfully converted to squalene through the organopalladium-catalyzed reductive coupling reaction involving the formation of Pd(0)L₂ species. Under mild reaction conditions, impressive β-farnesene conversion (99%) and squalene selectivity (100%) were achieved over the Pd(acac)₂ catalyst at a temperature of 75 °C in an ethanol solvent after 5 h. This advancement may provide insights into broadening squalene production channels and accessing the complex skeletons of natural terpenoids from biorenewable carbon sources, offering practical significance and economic benefits. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

17 pages, 4622 KiB  

Open AccessArticle

Continuous-Flow System for Methylene Blue Removal Using a Green and Cost-Effective Starch Single-Rod Column

by Tarawee Taweekarn, Worawit Wongniramaikul, Wilasinee Sriprom, Wadcharawadee Limsakul and Aree Choodum

Polymers 2023, 15(19), 3989; https://doi.org/10.3390/polym15193989 - 04 Oct 2023

Cited by 1 | Viewed by 764

Abstract

A continuous-flow system based on a green and cost-effective monolithic starch cryogel column was successfully developed for removing methylene blue (MB). The proposed column exhibited high removal efficiency (up to 99.9%) and adsorption capacity (25.4 mg·g⁻¹) for synthetic and real samples [...] Read more.

A continuous-flow system based on a green and cost-effective monolithic starch cryogel column was successfully developed for removing methylene blue (MB). The proposed column exhibited high removal efficiency (up to 99.9%) and adsorption capacity (25.4 mg·g⁻¹) for synthetic and real samples with an adsorbent cost of USD 0.02. The influence of various operation parameters, including the flow rate, initial concentration, column height, and temperature, on the MB removal efficiency was examined and reported. The MB removal efficiency remained >99% in the presence of potential interferences, highlighting the good performance of the cryogel column. The Yoon–Nelson dynamic model explained the MB adsorption better than the Bohart–Adams model, as indicated by the higher R² values (R² = 0.9890–0.9999) exhibited by the former and current trends of its parameters. The MB removal efficiency of the cryogel column remained at 62.7% after three reuse cycles. The wastewater containing MB collected from a local batik-production community enterprise in Phuket, Thailand was applied to the proposed continuous-flow system under optimum conditions, and results indicated that 99.7% of the MB present in 2.4 L of wastewater was removed. These results validate the excellent application potential of the cryogel column for the continuous-flow adsorption of MB. This study will facilitate future industrial applications and process designs of the continuous-flow system. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

22 pages, 7280 KiB  

Open AccessArticle

A Comparative Study of Ethanol and Citric Acid Solutions for Extracting Betalains and Total Phenolic Content from Freeze-Dried Beetroot Powder

by Rahul Kumar, Lisa Methven and Maria Jose Oruna-Concha

Molecules 2023, 28(17), 6405; https://doi.org/10.3390/molecules28176405 - 02 Sep 2023

Cited by 1 | Viewed by 1617

Abstract

This research compares the extraction of betalains (betacyanin and betaxanthin) and total phenolic content using citric acid and aqueous–ethanol solutions. The aim is to find an environmentally sustainable alternative solvent for extracting these compounds from dried beetroot powder. Using citric acid solution as [...] Read more.

This research compares the extraction of betalains (betacyanin and betaxanthin) and total phenolic content using citric acid and aqueous–ethanol solutions. The aim is to find an environmentally sustainable alternative solvent for extracting these compounds from dried beetroot powder. Using citric acid solution as a solvent offers several benefits over ethanol. Citric acid is a weak organic acid found naturally in citrus fruits, making it a safe and environmentally friendly choice for certain extraction processes. Moreover, the use of citric acid as solvent offers biodegradability, non-toxicity, non-flammability, and is cost effective. A full factorial design and response surface methodology (RSM) were employed to assess the effects of extraction parameters (extraction time (5–30 min), extraction temperature (20, 30, 40 °C), pH of citric acid solution (3, 4, 5) and ethanol concentration (10, 20, 30% v/v)). The yield was determined spectrophotometrically and expressed as mg/g of dry powder. The results showed that citric acid solution yielded 85–90% of the ethanolic extract under identical conditions. The maximum yields of betacyanin, betaxanthin, and total phenolic content in citric acid solution were 3.98 ± 0.21 mg/g dry powder, 3.64 ± 0.26 mg/g dry powder, and 8.28 ± 0.34 mg/g dry powder, respectively, while aqueous–ethanol yielded 4.38 ± 0.17 mg/g dry powder, 3.95 ± 0.22 mg/g dry powder, and 8.45 ± 0.45 mg/g dry powder. Optimisation resulted in maximum extraction yields of 90% for betalains and 85% for total phenolic content. The study demonstrates the potential of citric acid as a viable alternative to polar organic solvents for extracting phytochemicals from plant material, providing comparable results to aqueous–ethanol. Artificial Neural Network (ANN) models outperformed RSM in predicting extraction yields. Overall, this research highlights the importance of exploring bio-solvents to enhance the environmental sustainability of phytochemical extraction. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

16 pages, 2862 KiB  

Open AccessArticle

Development of Iron–Silicate Composites by Waste Glass and Iron or Steel Powders

by Roxana Rada, Horatiu Vermesan, Simona Rada, Cristian Leostean, Daniela Lucia Manea and Eugen Culea

Molecules 2023, 28(17), 6296; https://doi.org/10.3390/molecules28176296 - 28 Aug 2023

Viewed by 813

Abstract

There is growing interest in the opportunities regarding construction and demolition wastes, such as glass and metal powders, for developing a circular economy and their transformation into new materials. This management and recycling of construction and demolition waste offers environmental benefits and conservation [...] Read more.

There is growing interest in the opportunities regarding construction and demolition wastes, such as glass and metal powders, for developing a circular economy and their transformation into new materials. This management and recycling of construction and demolition waste offers environmental benefits and conservation of natural resources. In this paper, new magnetic composite materials were prepared by wet chemical synthesis methods using crushed glasses and iron and steel waste powders as raw materials. The prepared iron–silicate composites were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis, infrared (IR), ultraviolet–visible, and electron paramagnetic resonance (EPR) spectroscopy, and magnetic measurements. The XRD data confirm the formation of varied crystalline phases of the iron ions. The presence of the Fe₃O₄ crystalline phase was detected in the composites containing the iron waste powders. The inspection of the SEM micrographs revealed slightly better homogeneity for the composite material containing larger amounts of iron waste and heterogeneous morphology with cracks and random crystallinity for the composite doped with steel waste. By doping with different contents of iron or steel waste powder, structural modifications in the silicate network and the formation of new bands in the IR spectra were evidenced. The UV-Vis spectra were characterized by the absorption peaks for both the tetrahedral and octahedral geometries of the Fe³⁺ ions and the octahedral coordination of the Fe²⁺ ions with oxygen anions. The EPR data show resonance lines with g ~2, 4.3, and 6.4, corresponding to the Fe³⁺ ions. Using hysteresis curves, the superparamagnetic properties of the iron–silicate composites were evidenced. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

18 pages, 2632 KiB  

Open AccessArticle

Identifying, Quantifying, and Recovering a Sorbitol-Type Petrochemical Additive in Industrial Wastewater and Its Subsequent Application in a Polymeric Matrix as a Nucleating Agent

by Joaquín Hernández-Fernández, Esneyder Puello-Polo and Edgar Marquez

Molecules 2023, 28(13), 4948; https://doi.org/10.3390/molecules28134948 - 23 Jun 2023

Cited by 1 | Viewed by 1224

Abstract

Currently, polypropylene (PP) is highlighted using sorbitol-based clarifying agents since these agents are high quality, low cost, and work as a barrier against moisture, which makes PP ideal for packaging food, beverages, and medical products, among others. The use of analytical methods capable [...] Read more.

Currently, polypropylene (PP) is highlighted using sorbitol-based clarifying agents since these agents are high quality, low cost, and work as a barrier against moisture, which makes PP ideal for packaging food, beverages, and medical products, among others. The use of analytical methods capable of recovering these additives in wastewater streams and then reusing them in the PP clarification stage represents an innovative methodology that makes a substantial contribution to the circular economy of the PP production industry. In this study, a method of extraction and recovery of the Millad NX 8000 was developed. The additive was recovered using GC-MS and extracted with an activated carbon column plus glass fiber, using an injection molded sample, obtaining a recovery rate greater than 96%. TGA, DSC, and FTIR were used to evaluate the recovered additive’s glass transitions and purity. The thermal degradation of the recovered additive was found to be between 340 and 420 °C, with a melting temperature of 246 °C, adopting the same behavior as the pure additive. In FTIR, the characteristic absorption peak of Millad NX 8000 was observed at 1073 cm⁻¹, which indicates the purity of the extracted compound. Therefore, this work develops a new additive recovery methodology with high purity to regulate the crystallization behavior and of PP. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

32 pages, 2784 KiB  

Open AccessReview

Sustainable Elastomers for Actuators: “Green” Synthetic Approaches and Material Properties

by Olga V. Filippova, Aleksey V. Maksimkin, Tarek Dayyoub, Dmitry I. Larionov and Dmitry V. Telyshev

Polymers 2023, 15(12), 2755; https://doi.org/10.3390/polym15122755 - 20 Jun 2023

Cited by 1 | Viewed by 1929

Abstract

Elastomeric materials have great application potential in actuator design and soft robot development. The most common elastomers used for these purposes are polyurethanes, silicones, and acrylic elastomers due to their outstanding physical, mechanical, and electrical properties. Currently, these types of polymers are produced [...] Read more.

Elastomeric materials have great application potential in actuator design and soft robot development. The most common elastomers used for these purposes are polyurethanes, silicones, and acrylic elastomers due to their outstanding physical, mechanical, and electrical properties. Currently, these types of polymers are produced by traditional synthetic methods, which may be harmful to the environment and hazardous to human health. The development of new synthetic routes using green chemistry principles is an important step to reduce the ecological footprint and create more sustainable biocompatible materials. Another promising trend is the synthesis of other types of elastomers from renewable bioresources, such as terpenes, lignin, chitin, various bio-oils, etc. The aim of this review is to address existing approaches to the synthesis of elastomers using “green” chemistry methods, compare the properties of sustainable elastomers with the properties of materials produced by traditional methods, and analyze the feasibility of said sustainable elastomers for the development of actuators. Finally, the advantages and challenges of existing “green” methods of elastomer synthesis will be summarized, along with an estimation of future development prospects. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

12 pages, 3794 KiB  

Open AccessArticle

Photoluminescent Copper Nanoclusters in “Turn-Off/Turn-On” Sensing of Picric Acid/Hydrogen Peroxide

by Renuka Singh, Seema Gupta, Manoj Kumar Bharty, Chandra Shekhar Pati Tripathi and Debanjan Guin

Sustain. Chem. 2023, 4(2), 224-235; https://doi.org/10.3390/suschem4020017 - 01 Jun 2023

Cited by 1 | Viewed by 1518

Abstract

In this paper, we illustrate the synthesis, characterization, and application of a Bovine Serum Albumin-stabilized copper nanocluster (BSA@CuNCs)-based photoluminescence (PL) bifunctional sensor for the selective and rapid sensing of picric acid (PA) and hydrogen peroxide (H₂O₂). Blue-emitting copper nanoclusters [...] Read more.

In this paper, we illustrate the synthesis, characterization, and application of a Bovine Serum Albumin-stabilized copper nanocluster (BSA@CuNCs)-based photoluminescence (PL) bifunctional sensor for the selective and rapid sensing of picric acid (PA) and hydrogen peroxide (H₂O₂). Blue-emitting copper nanoclusters were synthesized using one-pot synthesis at room temperature. The PL intensity of BSA@CuNCs was shown to be quenched (“Turn-off”) with an increase in the concentration of PA and intensified (“Turn-on”) with the addition of H₂O₂. The quenching of PL intensity of BSA@CuNCs was shown to be extremely selective and rapid towards PA. A linear decrease in the PL emission intensity of BSA@CuNCs was observed with a PA concentration in the range of 0–15 μM. An extremely low detection limit of 60 nM (3σ/k) was calculated. The as-prepared BSA@CuNCs also exhibited superior selectivity for PA detection in aqueous medium. The developed sensor was also utilized for the sensing of PA in natural water samples. The probe was found to be extremely sensitive towards the detection of H₂O₂. An increase in the PL intensity of BSA@CuNCs was seen with the addition of H₂O₂, with a detection limit of 0.11 μM. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 762 KiB)

15 pages, 5069 KiB  

Open AccessArticle

Adsorption Characteristics of Cetirizine on Graphene Oxide

by Tuhin Bhattacharjee, Arnab Bhattacharjee, Deepmoni Deka, Mihir Kumar Purkait, Devasish Chowdhury and Gitanjali Majumdar

Sustain. Chem. 2023, 4(2), 209-223; https://doi.org/10.3390/suschem4020016 - 30 May 2023

Cited by 1 | Viewed by 1489

Abstract

Water pollution caused by emerging contaminants such as pharmaceutical compounds is a growing problem worldwide. In this reported work, graphene oxide (GO) was directly used to remove an antihistamine drug, cetirizine. GO was prepared from graphite using a modified Hummer’s method and was [...] Read more.

Water pollution caused by emerging contaminants such as pharmaceutical compounds is a growing problem worldwide. In this reported work, graphene oxide (GO) was directly used to remove an antihistamine drug, cetirizine. GO was prepared from graphite using a modified Hummer’s method and was characterized by UV–vis spectroscopy, Fourier-transformed infrared spectroscopy (FTIR), thermogravimetric analyzer (TGA), field scanning electron microscope (FE-SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), etc. GO was demonstrated to be a highly efficient adsorbent for removing cetirizine from an aqueous solution. The adsorption of cetirizine on GO at various pH levels showed that in acidic pH with the adsorption shows faster kinetics and complete removal of cetirizine within 10 min, followed by neutral pH, which showed relatively slower kinetics but complete removal of cetirizine. However, at basic pH, GO could not completely remove cetirizine after 24 h. At a neutral pH, GO showed maximum adsorption of 81.30 mg g⁻¹ of cetirizine. The adsorption isotherm results showed good agreement with the Langmuir isotherm. The BET surface area analysis showed the presence of mesoporosity in GO. In addition, the BET analysis further revealed a type IV isotherm curve being followed. A plausible mechanism is also discussed in the paper. The recyclability experiment demonstrates an adsorption efficiency of 85% after four cycles. The thermodynamic study reveals that adsorption is thermodynamically less favorable at higher temperatures. Hence, the current study successfully demonstrates the use of GO as an efficient adsorbent in removing cetirizine. It also studies the various factors and interactions affecting adsorption. Thus, this study sheds light on the adsorption characteristics of cetirizine on graphene oxide. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 215 KiB)

16 pages, 2941 KiB  

Open AccessArticle

Enzymatic Synthesis of α-Glucosyl-Baicalin through Transglucosylation via Cyclodextrin Glucanotransferase in Water

by Carole Lambert, Perrine Lemagnen, Eglantine Don Simoni, Jane Hubert, Alexis Kotland, Chantal Paulus, Audrey De Bizemont, Sylvie Bernard, Anne Humeau, Daniel Auriol and Romain Reynaud

Molecules 2023, 28(9), 3891; https://doi.org/10.3390/molecules28093891 - 05 May 2023

Viewed by 1377

Abstract

Baicalin is a biologically active flavone glucuronide with poor water solubility that can be enhanced via glucosylation. In this study, the transglucosylation of baicalin was successfully achieved with CGTases from Thermoanaerobacter sp. and Bacillus macerans using α-cyclodextrin as a glucosyl donor. The synthesis [...] Read more.

Baicalin is a biologically active flavone glucuronide with poor water solubility that can be enhanced via glucosylation. In this study, the transglucosylation of baicalin was successfully achieved with CGTases from Thermoanaerobacter sp. and Bacillus macerans using α-cyclodextrin as a glucosyl donor. The synthesis of baicalin glucosides was optimized with CGTase from Thermoanaerobacter sp. Enzymatically modified baicalin derivatives were α-glucosylated with 1 to 17 glucose moieties. The two main glucosides were identified as Baicalein-7-O-α-D-Glucuronidyl-(1→4′)-O-α-D-Glucopyranoside (BG₁) and Baicalein-7-O-α-D-Glucuronidyl-(1→4′)-O-α-D-Maltoside (BG₂), thereby confirming recent findings reporting that glucuronyl groups are acceptors of this CGTase. Optimized conditions allowed for the attainment of yields above 85% (with a total glucoside content higher than 30 mM). BG₁ and BG₂ were purified via centrifugal partition chromatography after an enrichment through deglucosylation with amyloglucosidase. Transglucosylation increased the water solubility of BG₁ by a factor of 188 in comparison to that of baicalin (molar concentrations), while the same value for BG₂ was increased by a factor of 320. Finally, BG₁ and BG₂ were evaluated using antioxidant and anti-glycation assays. Both glucosides presented antioxidant and anti-glycation properties in the same order of magnitude as that of baicalin, thereby indicating their potential biological activity. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 1540 KiB)

12 pages, 2027 KiB  

Open AccessArticle

Lysine-Based Silicone Surfactants

by Abygail Camacho Ramirez, Miguel Melendez-Zamudio, Antonio Guerra Contreras and Michael A. Brook

Sustain. Chem. 2023, 4(2), 197-208; https://doi.org/10.3390/suschem4020015 - 04 May 2023

Cited by 2 | Viewed by 1888

Abstract

Highly efficient silicone surfactants are typically based on polyether hydrophiles. As part of a program to increase the natural content of silicones, we describe the synthesis of silicone surfactants with amino acid hydrophiles (cysteine, arginine, and lysine). The compounds were prepared using a [...] Read more.

Highly efficient silicone surfactants are typically based on polyether hydrophiles. As part of a program to increase the natural content of silicones, we describe the synthesis of silicone surfactants with amino acid hydrophiles (cysteine, arginine, and lysine). The compounds were prepared using a radial thiol–ene reaction with vinylsilicones for cysteine derivatives and a catalyst-free aza-Michael reaction with arginine and lysine. Short chain surfactants with silicone monomer:hydrophile ratios of 5:1 or less (e.g., telechelic silicones of lysine-linker-(Me₂OSi)_n-linker-lysine n = 10) were ineffective at stabilizing emulsions of silicone oil (D₄): water. However, excellent surfactants were realized as the chain length (n) increased to 25 or 50, stabilizing water-in-oil emulsions with high water content (80% or 90%). The surfactants, especially the longer chain compounds, were stable against pH except <4 or >9 and survived freeze/thaw cycles. These surfactants contain 12–25% natural materials, improving their sustainability compared to those containing synthetic hydrophiles. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 758 KiB)

19 pages, 4025 KiB  

Open AccessArticle

Synthesis of FeOOH-Loaded Aminated Polyacrylonitrile Fiber for Simultaneous Removal of Phenylphosphonic Acid and Phosphate from Aqueous Solution

by Rui Zhou, Wusong Xu, Peisen Liu, Shangyuan Zhao, Gang Xu, Qizhong Xiong, Weifeng Zhang, Chaochun Zhang and Xinxin Ye

Polymers 2023, 15(8), 1918; https://doi.org/10.3390/polym15081918 - 17 Apr 2023

Cited by 2 | Viewed by 1194

Abstract

Phosphorus is one of the important metabolic elements for living organisms, but excess phosphorus in water can lead to eutrophication. At present, the removal of phosphorus in water bodies mainly focuses on inorganic phosphorus, while there is still a lack of research on [...] Read more.

Phosphorus is one of the important metabolic elements for living organisms, but excess phosphorus in water can lead to eutrophication. At present, the removal of phosphorus in water bodies mainly focuses on inorganic phosphorus, while there is still a lack of research on the removal of organic phosphorus (OP). Therefore, the degradation of OP and synchronous recovery of the produced inorganic phosphorus has important significance for the reuse of OP resources and the prevention of water eutrophication. Herein, a novel FeOOH-loaded aminated polyacrylonitrile fiber (PAN_AF-FeOOH) was constructed to enhance the removal of OP and phosphate. Taking phenylphosphonic acid (PPOA) as an example, the results indicated that modification of the aminated fiber was beneficial to FeOOH fixation, and the PAN_AF-FeOOH prepared with 0.3 mol L⁻¹ Fe(OH)₃ colloid had the best performance for OP degradation. The PAN_AF-FeOOH efficiently activated peroxydisulfate (PDS) for the degradation of PPOA with a removal efficiency of 99%. Moreover, the PAN_AF-FeOOH maintained high removal capacity for OP over five cycles as well as strong anti-interference in a coexisting ion system. In addition, the removal mechanism of PPOA by the PAN_AF-FeOOH was mainly attributed to the enrichment effect of PPOA adsorption on the fiber surface’s special microenvironment, which was more conducive to contact with SO₄•⁻ and •OH generated by PDS activation. Furthermore, the PAN_AF-FeOOH prepared with 0.2 mol L⁻¹ Fe(OH)₃ colloid possessed excellent phosphate removal capacity with a maximal adsorption quantity of 9.92 mg P g⁻¹. The adsorption kinetics and isotherms of the PAN_AF-FeOOH for phosphate were best depicted by pseudo-quadratic kinetics and a Langmuir isotherm model, showing a monolayer chemisorption procedure. Additionally, the phosphate removal mechanism was mainly due to the strong binding force of iron and the electrostatic force of protonated amine on the PAN_AF-FeOOH. In conclusion, this study provides evidence for PAN_AF-FeOOH as a potential material for the degradation of OP and simultaneous recovery of phosphate. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

13 pages, 1744 KiB  

Open AccessOpinion

Microfluidics for Polymer Microparticles: Opinion on Sustainability and Scalability

by Hassan El Itawi, Sami Fadlallah, Patrick Perré and Florent Allais

Sustain. Chem. 2023, 4(2), 171-183; https://doi.org/10.3390/suschem4020013 - 10 Apr 2023

Viewed by 1987

Abstract

The microfluidic production of simple (microspheres) and core–shell (microcapsules) polymer microparticles, often called microencapsulation, has been the scope of several research works since the 1980s. It is a fast, thrifty, and efficient process because of its controlled properties, tuneability, and yield, which can [...] Read more.

The microfluidic production of simple (microspheres) and core–shell (microcapsules) polymer microparticles, often called microencapsulation, has been the scope of several research works since the 1980s. It is a fast, thrifty, and efficient process because of its controlled properties, tuneability, and yield, which can reach 100%. However, the question of its greenness, sustainability, and scalability remains unclear, and more awareness/education is required in this field. The sustainability of production processes using microfluidic techniques can be realized/discussed based on three pillars: (i) waste generation, (ii) the solvents employed, and (iii) raw materials. On the other hand, although the scaling-up of these processes was reported on in several papers as procedures in which hundreds or thousands of microfluidic chips are set in parallel, the sustainability of this scale-up has not been addressed to our knowledge. This opinion paper highlights the advantages of microfluidic encapsulation processes, their greenness according to the above-mentioned pillars, (i–iii) and the necessary considerations to scale them up while preserving their sustainability. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

31 pages, 1499 KiB  

Open AccessReview

Biosynthesis of Gold and Silver Nanoparticles Using Phytochemical Compounds

by Ade Zuhrotun, Dede Jihan Oktaviani and Aliya Nur Hasanah

Molecules 2023, 28(7), 3240; https://doi.org/10.3390/molecules28073240 - 05 Apr 2023

Cited by 17 | Viewed by 3271

Abstract

Gold and silver nanoparticles are nanoparticles that have been widely used in various fields and have shown good benefits. The method of nanoparticle biosynthesis utilizing plant extracts, also known as green synthesis, has become a promising method considering the advantages it has compared [...] Read more.

Gold and silver nanoparticles are nanoparticles that have been widely used in various fields and have shown good benefits. The method of nanoparticle biosynthesis utilizing plant extracts, also known as green synthesis, has become a promising method considering the advantages it has compared to other synthesis methods. This review aims to give an overview of the phytochemical compounds in plants used in the synthesis of gold and silver nanoparticles, the nanoparticle properties produced using plant extracts based on the concentration and structure of phytochemical compounds, and their applications. Phytochemical compounds play an important role as reducing agents and stabilizers in the stages of the synthesis of nanoparticles. Polyphenol compounds, reducing sugars, and proteins are the main phytochemical compounds that are responsible for the synthesis of gold and silver nanoparticles. The concentration of phytochemical compounds affects the physical properties, stability, and activity of nanoparticles. This is important to know to be able to overcome limitations in controlling the physical properties of the nanoparticles produced. Based on structure, the phytochemical compounds that have ortho-substituted hydroxyl result in a smaller size and well-defined shape, which can lead to greater activity and stability. Furthermore, the optimal condition of the biosynthesis process is required to gain a successful reaction that includes setting the metal ion concentration, temperature, reaction time, and pH. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

attachment

Supplementary material:
Supplementary File 1 (ZIP, 1115 KiB)

17 pages, 3598 KiB  

Open AccessArticle

Cyrene^™, a Sustainable Solution for Graffiti Paint Removal

by Roxana A. Milescu, Thomas J. Farmer, James Sherwood, Con R. McElroy and James H. Clark

Sustain. Chem. 2023, 4(2), 154-170; https://doi.org/10.3390/suschem4020012 - 31 Mar 2023

Cited by 3 | Viewed by 3636

Abstract

Graffiti can create detrimental aesthetic and environmental damage to city infrastructure and cultural heritage and requires improved removal methods. Incumbent laser, mechanical and chemical removal techniques are often not effective, are expensive or damage the substrate. Solvents are generally hazardous and not always [...] Read more.

Graffiti can create detrimental aesthetic and environmental damage to city infrastructure and cultural heritage and requires improved removal methods. Incumbent laser, mechanical and chemical removal techniques are often not effective, are expensive or damage the substrate. Solvents are generally hazardous and not always effective because of the insolubility of the graffiti paint. This study proposes a simple strategy for safe and effective graffiti removal, using the bio-based, non-toxic and biodegradable solvent dihydrolevoglucosenone (Cyrene™). The results showed that the type of substrate influenced the cleaning performance; in benchmark studies a non-porous substrate was easy to clean, while porous ceramic showed the presence of residual paint and yellowing when the conventional polar aprotic solvents were used. Cyrene, however, showed good removability of graffiti paint from both glazed and porous substrates, with little paint remaining in the pores of ceramic tiles. The paint suffered a reversible change in colour and a selective solubility of its components when using N-methyl-2-pyrrolidone; no changes occurred when Cyrene was used. While N-methyl-2-pyrrolidone and N,N′-dimethylformamide were only effective when neat, a Cyrene–water mixture showed some cleaning results. The performance of Cyrene was validated with Hansen solubility parameters and represents a greener and more sustainable solvent for paint removal. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

17 pages, 2821 KiB  

Open AccessArticle

Cellulosic Ethanol Production from Weed Biomass Hydrolysate of Vietnamosasa pusilla

by Suwanan Wongleang, Duangporn Premjet and Siripong Premjet

Polymers 2023, 15(5), 1103; https://doi.org/10.3390/polym15051103 - 22 Feb 2023

Cited by 1 | Viewed by 1622

Abstract

Lignocellulosic biomass can be used as a renewable and sustainable energy source to help reduce the consequences of global warming. In the new energy age, the bioconversion of lignocellulosic biomass into green and clean energy displays remarkable potential and makes efficient use of [...] Read more.

Lignocellulosic biomass can be used as a renewable and sustainable energy source to help reduce the consequences of global warming. In the new energy age, the bioconversion of lignocellulosic biomass into green and clean energy displays remarkable potential and makes efficient use of waste. Bioethanol is a biofuel that can diminish reliance on fossil fuels while minimizing carbon emissions and increasing energy efficiency. Various lignocellulosic materials and weed biomass species have been selected as potential alternative energy sources. Vietnamosasa pusilla, a weed belonging to the Poaceae family, contains more than 40% glucan. However, research on the applications of this material is limited. Thus, here we aimed to achieve maximum fermentable glucose recovery and bioethanol production from weed biomass (V. pusilla). To this end, V. pusilla feedstocks were treated with varying concentrations of H₃PO₄ and then subjected to enzymatic hydrolysis. The results indicated that after pretreatment with different concentrations of H₃PO₄, the glucose recovery and digestibility at each concentration were markedly enhanced. Moreover, 87.5% of cellulosic ethanol was obtained from V. pusilla biomass hydrolysate medium without detoxification. Overall, our findings reveal that V. pusilla biomass can be introduced into sugar-based biorefineries to produce biofuels and other valuable chemicals. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

12 pages, 1134 KiB  

Open AccessArticle

Sustainable Bio-Based UV-Cured Epoxy Vitrimer from Castor Oil

by Matteo Bergoglio, David Reisinger, Sandra Schlögl, Thomas Griesser and Marco Sangermano

Polymers 2023, 15(4), 1024; https://doi.org/10.3390/polym15041024 - 18 Feb 2023

Cited by 9 | Viewed by 2714

Abstract

Vitrimers brought new properties in thermosets by allowing their reshaping, self-healing, reprocessing, and network rearrangement without changing structural integrity. In this study, epoxidized castor oil (ECO) was successfully used for the straightforward synthesis of a bio-based solvent-free vitrimer. The synthesis was based on [...] Read more.

Vitrimers brought new properties in thermosets by allowing their reshaping, self-healing, reprocessing, and network rearrangement without changing structural integrity. In this study, epoxidized castor oil (ECO) was successfully used for the straightforward synthesis of a bio-based solvent-free vitrimer. The synthesis was based on a UV-curing process, which proceeded at low temperatures in the absence of any solvents, and within a short time. Real time Fourier-transformed infrared spectroscopy and photo-DSC were exploited to monitor the cationic photocurable process. The UV-cured polymer networks were able to efficiently undergo thermo-activated bond exchange reactions due to the presence of dibutyl phosphate as a transesterification catalyst. Mechanical properties, thermal resistance, glass transition temperature, and stress relaxation were investigated as a function of the amount of transesterification catalyst. Mechanical properties were determined by both DMTA and tensile tests. Glass transition temperature (T_g) was evaluated by DMTA. Thermal stability was assessed by thermogravimetric analysis, whilst vitrimeric properties were studied by stress relaxation experiments. Overall, the ECO-based vitrimer showed high thermal resistance (up to 200 °C) and good mechanical properties (elastic modulus of about 10 MPa) and can therefore be considered as a promising starting point for obtaining more sustainable vitrimers. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 21375 KiB)

17 pages, 2185 KiB  

Open AccessArticle

Selective and Efficient Synthesis of Pine Sterol Esters Catalyzed by Deep Eutectic Solvent

by Honggang Shi, Zeping Lu, Huajin Xu, Shushu Wang, Binbin Nian and Yi Hu

Molecules 2023, 28(3), 993; https://doi.org/10.3390/molecules28030993 - 19 Jan 2023

Cited by 1 | Viewed by 1674

Abstract

Phytosterol esters have attracted widespread academic and industrial interests due to their advantages in lowering cholesterol, as antioxidants, and in preventing or treating cancer. However, the generation of by-products limits the application of phytosterol esters in food fields. In this study, deep eutectic [...] Read more.

Phytosterol esters have attracted widespread academic and industrial interests due to their advantages in lowering cholesterol, as antioxidants, and in preventing or treating cancer. However, the generation of by-products limits the application of phytosterol esters in food fields. In this study, deep eutectic solvents (DESs), a series of green, nontoxic, low-cost and biodegradable solvents, were adopted as the catalyst for the synthesis of pine sterol esters. The results showed that the acidic DES which was prepared with choline chloride (ChCl) and p-toluene sulfonic acid monohydrate (PTSA) with a molar ratio of 1:3 performed best in the prescreening experiments. To further improve the efficiency of the pine sterol ester, the molar ratio of substrates, the amount of catalyst, the reaction temperature and the reaction time were optimized, and its yield was improved to 94.1%. Moreover, the by-products of the dehydration side reactions of the sterol can be efficiently inhibited. To make this strategy more universal, other fatty acids were also used as the substrate for the synthesis of pine sterol esters, and a yield of above 92.0% was obtained. In addition, the reusability of DES was also investigated in this study, and the efficiency of DES was well maintained within five recycled uses. Finally, DFT calculations suggested that the suitable H-bonds between ChCl and PTSA decreased the nucleophilic capacity and increased the steric hindrance of the latter, and further prevented the attack on ^βH and reduced the generation of by-products. This study developed a reliable and eco-friendly strategy for the preparation of high-quality phytosterol esters with low-dosage catalyst usage and high selectivity. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

14 pages, 4250 KiB  

Open AccessArticle

Catalytic Biomaterials for Atrazine Degradation

by Karla Diviesti and Richard C. Holz

Catalysts 2023, 13(1), 140; https://doi.org/10.3390/catal13010140 - 07 Jan 2023

Cited by 3 | Viewed by 1471

Abstract

In this paper, triazine hydrolase from Arthrobacter aurescens TC1 (TrzN) was successfully immobilized in alginate beads (TrzN:alginate), alginate beads coated in chitosan (TrzN:chitosan), and tetramethylorthosilicate (TMOS) gels using the sol–gel method (TrzN:sol–gel) for the first time. TrzN:alginate and TrzN:chitosan hydrolyzed 50 µM of [...] Read more.

In this paper, triazine hydrolase from Arthrobacter aurescens TC1 (TrzN) was successfully immobilized in alginate beads (TrzN:alginate), alginate beads coated in chitosan (TrzN:chitosan), and tetramethylorthosilicate (TMOS) gels using the sol–gel method (TrzN:sol–gel) for the first time. TrzN:alginate and TrzN:chitosan hydrolyzed 50 µM of atrazine in 6 h with negligible protein loss with an ~80% conversion rate. However, the TrzN:sol–gel biomaterial converted >95% of a 50 µM atrazine solution in an hour with negligible protein loss. The treatment of each of these biomaterials with trypsin confirmed that the catalytic activity was due to the encapsulated enzyme and not surface-bound TrzN. All three of the biomaterials showed potential for long-term storage and reuse, with the only limitation arising from the loss of protein in the storage buffer for the TrzN:alginate and TrzN:chitosan biomaterials, not the denaturation of the encapsulated TrzN. TrzN:sol–gel stood out, with ~100% activity being retained after 10 consecutive reactions. Additionally, the materials stayed active in methanol concentrations <10%, suggesting the ability to increase the solubility of atrazine with organic solvents. The structural integrity of the TrzN:alginate and TrzN:chitosan materials became limiting in extreme pH conditions, while TrzN:sol–gel outperformed WT TrzN. Overall, the TrzN:sol–gel biomaterial proved to be the best atrazine dichlorination biocatalyst. As sol–gels can be cast into any desired shape, including pellets, which can be used in columns, the TrzN:sol–gel biomaterial provides a new avenue for the design of bioremediation methodologies for the removal of atrazine from the environment. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

attachment

Supplementary material:
Supplementary File 1 (ZIP, 6480 KiB)

7 pages, 1871 KiB  

Open AccessCommunication

Electrochemical Synthesis of 1,1′-Binaphthalene-2,2′-Diamines via Transition-Metal-Free Oxidative Homocoupling

by Duona Fan, Md. Imrul Khalid, Ganesh Tatya Kamble, Hiroaki Sasai and Shinobu Takizawa

Sustain. Chem. 2022, 3(4), 551-557; https://doi.org/10.3390/suschem3040034 - 04 Dec 2022

Cited by 1 | Viewed by 2283

Abstract

The facile and green synthesis of 1,1′-binaphthalene-2,2′-diamine (BINAM) derivatives was established via the anodic dehydrogenative homo-coupling of 2-naphthylamines. The sustainable protocol provided a series of BINAMs in excellent yields of up to 98% with good current efficiency (66%) and H₂ as the [...] Read more.

The facile and green synthesis of 1,1′-binaphthalene-2,2′-diamine (BINAM) derivatives was established via the anodic dehydrogenative homo-coupling of 2-naphthylamines. The sustainable protocol provided a series of BINAMs in excellent yields of up to 98% with good current efficiency (66%) and H₂ as the sole coproduct without utilizing transition-metal reagents or stoichiometric oxidants. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

15 pages, 2465 KiB  

Open AccessArticle

The Role of Pozzolanic Activity of Siliceous Fly Ash in the Formation of the Structure of Sustainable Cementitious Composites

by Grzegorz Ludwik Golewski

Sustain. Chem. 2022, 3(4), 520-534; https://doi.org/10.3390/suschem3040032 - 01 Dec 2022

Cited by 30 | Viewed by 2177

Abstract

The following article introduces, in a thorough manner, how the chemical pozzolanic reaction takes place in cement composites containing the fly ash (FA) additive. In the research part, however, the development of phases in the structure of the cement paste in the initial [...] Read more.

The following article introduces, in a thorough manner, how the chemical pozzolanic reaction takes place in cement composites containing the fly ash (FA) additive. In the research part, however, the development of phases in the structure of the cement paste in the initial period of its curing and after 28 days from its preparation was traced. For this purpose, a Scanning Electron Microscope (SEM) was used. In order to accurately highlight all the characteristic stages of the formation of the structure of the composite containing FA, an analysis of the cement matrix was carried out between 0.5 and 28 days of their curing. Microstructural studies were complemented by tests of pozzolanic activity of FAs used. In order to conduct a full analysis of this feature, experiments were carried out using two types of research methods, i.e., chemical and physical. On the basis on the conducted studies it was found that: in cement composites with the addition of FA, in the period until the third day of curing, the development of the material structure is mainly the result of the hydration reaction, and between the seventh and fourteenth day after sample preparation, the first signs of the pozzolanic reaction on FA grains are visible; however, in the period between 14 and 28 days, there is a clear homogenization of the structure of the cement composite with the addition of FA, resulting from the change of disordered phases into compact and homogeneous forms and filling in the composite of porous places with pozzolanic reaction products. The use of cement composites based on materials whose application makes it possible to reduce GHG emissions to the atmosphere, reduce energy consumption, and reduce industrial waste landfills leads towards the development of ecological and sustainable building engineering. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 150 KiB)

8 pages, 1582 KiB  

Open AccessCommunication

Fabrication of Chitosan-Based Network Polysaccharide Nanogels

by Aina Nakamichi and Jun-ichi Kadokawa

Molecules 2022, 27(23), 8384; https://doi.org/10.3390/molecules27238384 - 01 Dec 2022

Cited by 2 | Viewed by 1386

Abstract

In this study, we developed a method to fabricate chitosan-based network polysaccharides via the condensation between amino groups in water-soluble chitosan (WSCS) and a carboxylate-terminated maltooligosaccharide crosslinker. We previously reported on the fabrication of network-polysaccharide-based macroscopic hydrogels via the chemical crosslinking of water-soluble [...] Read more.

In this study, we developed a method to fabricate chitosan-based network polysaccharides via the condensation between amino groups in water-soluble chitosan (WSCS) and a carboxylate-terminated maltooligosaccharide crosslinker. We previously reported on the fabrication of network-polysaccharide-based macroscopic hydrogels via the chemical crosslinking of water-soluble chitin (WSCh) with the crosslinker. Because the molecular weight of the WSCS was much smaller than that of the WSCh, in the present investigation, the chemical crosslinking of the WSCS with the crosslinker was observed at the nanoscale upon the condensation between amino and carboxylate groups in the presence of a condensing agent, 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide hydrochloride, and N-hydroxysuccinimide, affording nano-sized chitosan-based network polysaccharides. The occurrence of the crosslinking via the formation of amido linkages was supported by the IR analysis and ¹H NMR measurements after the dissolution via acid hydrolysis in DCl/D₂O. The products formed nanogels, whose sizes depended on the amino/carboxylate feed ratio. The nanoscale morphology and size of the products were evaluated via scanning electron microscopy, dynamic light scattering analyses, and transition electron microscopy. In the present study, we successfully developed the method to fabricate nanogel materials based on network polysaccharide structures, which can practically be applied as new polysaccharide-based 3D bionanomaterials. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

23 pages, 1428 KiB  

Open AccessReview

The Role of pH, Electrodes, Surfactants, and Electrolytes in Electrokinetic Remediation of Contaminated Soil

by Brian Gidudu and Evans M. N. Chirwa

Molecules 2022, 27(21), 7381; https://doi.org/10.3390/molecules27217381 - 30 Oct 2022

Cited by 16 | Viewed by 2682

Abstract

Electrokinetic remediation has, in recent years, shown great potential in remediating polluted environments. The technology can efficiently remove heavy metals, chlorophenols, polychlorinated biphenyls, phenols, trichloroethane, benzene, toluene, ethylbenzene, and xylene (BTEX) compounds and entire petroleum hydrocarbons. Electrokinetic remediation makes use of electrolysis, electroosmosis, [...] Read more.

Electrokinetic remediation has, in recent years, shown great potential in remediating polluted environments. The technology can efficiently remove heavy metals, chlorophenols, polychlorinated biphenyls, phenols, trichloroethane, benzene, toluene, ethylbenzene, and xylene (BTEX) compounds and entire petroleum hydrocarbons. Electrokinetic remediation makes use of electrolysis, electroosmosis, electrophoresis, diffusion, and electromigration as the five fundamental processes in achieving decontamination of polluted environments. These five processes depend on pH swings, voltage, electrodes, and electrolytes used in the electrochemical system. To apply this technology at the field scale, it is necessary to pursue the design of effective processes with low environmental impact to meet global sustainability standards. It is, therefore, imperative to understand the roles of the fundamental processes and their interactions in achieving effective and sustainable electrokinetic remediation in order to identify cleaner alternative solutions. This paper presents an overview of different processes involved in electrokinetic remediation with a focus on the effect of pH, electrodes, surfactants, and electrolytes that are applied in the remediation of contaminated soil and how these can be combined with cleaner technologies or alternative additives to achieve sustainable electrokinetic remediation. The electrokinetic phenomenon is described, followed by an evaluation of the impact of pH, surfactants, voltage, electrodes, and electrolytes in achieving effective and sustainable remediation. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 3108 KiB)

12 pages, 1823 KiB  

Open AccessArticle

A Novel Utilization of Water Extract of Suaeda Salsa in the Pd/C Catalyzed Suzuki–Miyaura Coupling Reaction

by Changyue Ren, Hang Zhang, Zhengjun Chen, Jie Gao, Mingyan Yang, Zeli Yuan and Xinmin Li

Molecules 2022, 27(19), 6623; https://doi.org/10.3390/molecules27196623 - 06 Oct 2022

Cited by 1 | Viewed by 1110

Abstract

Using biomass-derived solvents in various organic reactions is challenging for the fine chemicals industry. We herein report a Pd/C catalyzed Suzuki–Miyaura reaction in water extract of suaeda salsa (WES) without using external phosphine ligand, base, and organic solvent. The cross-coupling reactions were carried [...] Read more.

Using biomass-derived solvents in various organic reactions is challenging for the fine chemicals industry. We herein report a Pd/C catalyzed Suzuki–Miyaura reaction in water extract of suaeda salsa (WES) without using external phosphine ligand, base, and organic solvent. The cross-coupling reactions were carried out in a basic WES medium with a broad substrate scope and wide functional group tolerance. Furthermore, the high purity of solid biaryl products can be obtained by column chromatography or filtration. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

11 pages, 1412 KiB  

Open AccessArticle

Methane Production Characteristics of an Anaerobic Co-Digestion of Pig Manure and Fermented Liquid Feed

by Farida Hanum, Yoichi Atsuta and Hiroyuki Daimon

Molecules 2022, 27(19), 6509; https://doi.org/10.3390/molecules27196509 - 02 Oct 2022

Cited by 4 | Viewed by 1385

Abstract

Methane production characteristics of anaerobic co-digestion of pig manure (PM) and fermented liquid feed (FLF) were investigated in a continuous digester under mesophilic conditions. The experiment followed three phases. PM alone was digested in phase I. In phases II and III, PM and [...] Read more.

Methane production characteristics of anaerobic co-digestion of pig manure (PM) and fermented liquid feed (FLF) were investigated in a continuous digester under mesophilic conditions. The experiment followed three phases. PM alone was digested in phase I. In phases II and III, PM and FLF were mixed in a ratio of 95:5 and 90:10 (% v/v), respectively. The specific methane yields (SMYs) during phases I, II, and III were 238, 278, and 326.8 mLCH₄·gVS⁻¹-added, respectively. It was due to the effect of balancing the feedstock carbon-to-nitrogen ratio by adding FLF. This improvement can also be attributed to the readily biodegradable compounds in the FLF. The higher SMY obtained in this study showed a positive synergistic effect in the anaerobic co-digestion of PM and FLF. The results also indicate that adding the FLF positively affected and maintained a constant pH level, avoiding volatile fatty acid accumulation and ammonia inhibition in the anaerobic digestion (AD). Thus, this study provides valuable information regarding the usage of unused or wasted FLF as a co-substrate for the practical AD of PM. The production of fermented liquid additives such as FLF to improve the methane production from the AD of PM is a potential novel alternative to food waste recycling in Japan, besides compost and animal feeding. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

14 pages, 2379 KiB  

Open AccessSystematic Review

Green Template-Mediated Synthesis of Biowaste Nano-Hydroxyapatite: A Systematic Literature Review

by Ferli Septi Irwansyah, Atiek Rostika Noviyanti, Diana Rakhmawaty Eddy and Risdiana Risdiana

Molecules 2022, 27(17), 5586; https://doi.org/10.3390/molecules27175586 - 30 Aug 2022

Cited by 12 | Viewed by 3173

Abstract

Hydroxyapatite (HA) is a well-known calcium phosphate ingredient comparable to human bone tissue. HA has exciting applications in many fields, especially biomedical applications, such as drug delivery, osteogenesis, and dental implants. Unfortunately, hydroxyapatite-based nanomaterials are synthesized by conventional methods using reagents that are [...] Read more.

Hydroxyapatite (HA) is a well-known calcium phosphate ingredient comparable to human bone tissue. HA has exciting applications in many fields, especially biomedical applications, such as drug delivery, osteogenesis, and dental implants. Unfortunately, hydroxyapatite-based nanomaterials are synthesized by conventional methods using reagents that are not environmentally friendly and are expensive. Therefore, extensive efforts have been made to establish a simple, efficient, and green method to form nano-hydroxyapatite (NHA) biofunctional materials with significant biocompatibility, bioactivity, and mechanical strength. Several types of biowaste have proven to be a source of calcium in forming HA, including using chicken eggshells, fish bones, and beef bones. This systematic literature review discusses the possibility of replacing synthetic chemical reagents, synthetic pathways, and toxic capping agents with a green template to synthesize NHA. This review also shed insight on the simple green manufacture of NHA with controlled shape and size. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 808 KiB)

14 pages, 3800 KiB  

Open AccessArticle

Chitin and Silk Fibroin Biopolymers Modified by Oxone: Efficient Heterogeneous Catalysts for Knoevenagel Reaction

by Fernando B. Neves, Lucas L. Zanin, Rayanne R. Pereira, José Otávio C. S. Júnior, Roseane Maria R. Costa, André L. M. Porto, Sérgio A. Yoshioka, Alex Nazaré de Oliveira, David E. Q. Jimenez and Irlon M. Ferreira

Catalysts 2022, 12(8), 904; https://doi.org/10.3390/catal12080904 - 17 Aug 2022

Cited by 2 | Viewed by 1693

Abstract

New materials from silk fibroin (FS-Ox) and chitin (CT-Ox) functionalized with Oxone^® salt were developed for application in the synthesis of Knoevenagel adducts. The experiments were performed using benzaldehyde derivatives, malononitrile, and a mixture of water and ethanol as green solvents. The [...] Read more.

New materials from silk fibroin (FS-Ox) and chitin (CT-Ox) functionalized with Oxone^® salt were developed for application in the synthesis of Knoevenagel adducts. The experiments were performed using benzaldehyde derivatives, malononitrile, and a mixture of water and ethanol as green solvents. The efficiency of conventional and microwave irradiation as heating sources for this reaction was also investigated. When the reactions were performed for 60 min under optimized conditions with conventional heating, twelve Knoevenagel adducts 2a–l were obtained, with good yields for both catalysts (CT-Ox 60–98% and FS-Ox 71–98%). When microwave irradiation was used, the reaction periods were reduced twelvefold, with the same Knoevenagel adducts with good CT-Ox (39–99%) and FS-Ox (35–99%) yields obtained in most cases. The reuse of these materials as catalysts in successive reactions was also evaluated, and CT-Ox FS-Ox were successfully used for 4 and 2 cycles, respectively. The results presented prove the efficiency of the CT-OxFS-Ox catalyst as a promising low-cost and reusable material with suitable catalytic properties to be applied in the aldol condensation reaction in a sustainable way. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

attachment

Supplementary material:
Supplementary File 1 (ZIP, 471 KiB)

10 pages, 2030 KiB  

Open AccessCommunication

An Efficient Zr-ZSM-5-st Solid Acid Catalyst for the Polyol Esterification Reaction

by Huaigang Su, Ze Zong, Wenjing Lou, Qin Zhao, Xiaobo Wang, Xiang Feng, Yanxing Qi and Zhaoning Song

Catalysts 2022, 12(8), 901; https://doi.org/10.3390/catal12080901 - 16 Aug 2022

Cited by 2 | Viewed by 1783

Abstract

In this study, Zr active species were implanted into a ZSM-5 zeolite framework to form a solid acid catalyst through steam treatment and the liquid-solid isomorphous substitution process. The as-synthesized Zr-ZSM-5-st catalyst ensured excellent esterification of trimethylolpropane and fatty acids (FAs) to achieve [...] Read more.

In this study, Zr active species were implanted into a ZSM-5 zeolite framework to form a solid acid catalyst through steam treatment and the liquid-solid isomorphous substitution process. The as-synthesized Zr-ZSM-5-st catalyst ensured excellent esterification of trimethylolpropane and fatty acids (FAs) to achieve a polyol ester production yield of 94.41%. Combined with N₂ physisorption, X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, transmission electron microscopy mapping, X-ray photoelectron spectroscopy, NH₃ temperature-programmed desorption, and inductively coupled mass plasma spectroscopy were conducted. The results revealed that the excellent performance of Zr-ZSM-5-st catalyst could be attributed to the enhanced acidity and the developed surface area and pore structure. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

attachment

Supplementary material:
Supplementary File 1 (ZIP, 157 KiB)

18 pages, 5607 KiB  

Open AccessFeature PaperArticle

Investigation of Phosphorus Loaded V₂O₅/ZrO₂ Catalysts for the Oxidative Dehydrogenation of Propane (ODH)

by Abdellah Benzaouak, Hanane Mahir, Adnane El Hamidi, Mohamed Kacimi and Leonarda Francesca Liotta

Catalysts 2022, 12(8), 811; https://doi.org/10.3390/catal12080811 - 24 Jul 2022

Cited by 4 | Viewed by 1971

Abstract

In this study, V₂O₅/ZrO₂ samples loaded with different wt% of V₂O₅, ranging between 0% and 20% (wt% = 2.5, 3.6, 7.5, 10, and 20), were prepared and studied in the dehydrogenation of 2-butanol in [...] Read more.

In this study, V₂O₅/ZrO₂ samples loaded with different wt% of V₂O₅, ranging between 0% and 20% (wt% = 2.5, 3.6, 7.5, 10, and 20), were prepared and studied in the dehydrogenation of 2-butanol in order to investigate their acid-basic properties and to select the most interesting sample, that was identified in the 3.6 wt%V₂O₅/ZrO₂. Such a catalyst was modified by adding phosphate at different atomic ratios (P/V = 0.5, 1, and 2) and further characterized by XRD, SEM-EDX, ESR, UV-Vis-PIR diffuse reflectance. Tests of catalytic dehydrogenation of 2-butanol were also performed. Then, the so-prepared samples were investigated in the oxidative dehydrogenation (ODH) of propane that represents the reaction of main interest in this study. It has been shown that the introduction of 3.6 wt%V₂O₅ and phosphate in the zirconia matrix enhances the stability of the tetragonal structure, improves acidity, and promotes ODH activity. Compared to the unpromoted 3.6 wt%V₂O₅/ZrO₂ catalyst, the addition of phosphate increases the overall propane conversion from 12% to 20%, and also the propylene selectivity from 54% to near 64%, in the experimental conditions F °_C3H8/F°_O2/F°_total (cm³/min): 3.6/1.8/60 at the temperature of 500 °C. The influence of the reaction mixture on the ODH, in particular the oxygen flow rate, was addressed. Highlights: Phosphorus loaded V₂O₅/ZrO₂ catalysts were prepared and investigated in the oxidative dehydrogenation of propane. Addition of V₂O₅ and phosphorus to ZrO₂ stabilized the tetragonal phase with respect to the monoclinic one. Among the prepared V₂O₅/ZrO₂ samples, the most active catalyst corresponds to 3.6 wt% of V₂O₅/ ZrO₂, The addition of phosphorus to 3.6 wt% V₂O₅/ZrO₂ improves acidity and selectivity to propylene. Correlation between catalysts acidity and oxidative dehydrogenation of propane was observed. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Graphical abstract

attachment

Supplementary material:
Supplementary File 1 (ZIP, 549 KiB)

16 pages, 3397 KiB  

Open AccessArticle

Sorption of Bisphenol A as Model for Sorption Ability of Organoclays

by Issaka Garikoé, Boubié Guel and Ingmar Persson

Molecules 2022, 27(14), 4343; https://doi.org/10.3390/molecules27144343 - 06 Jul 2022

Cited by 1 | Viewed by 1499

Abstract

The arrangement of bisphenol A molecules into organoclays and their interactions with the intercalated surfactant were studied. The organoclays were prepared via solid-state intercalation of four cationic surfactants, such as dodecyltrimethyl-, tetradecyltrimethyl-, hexadecyltrimethyl-, and didodecyldimethyl-ammonium, as bromide salts, at different loading levels into [...] Read more.

The arrangement of bisphenol A molecules into organoclays and their interactions with the intercalated surfactant were studied. The organoclays were prepared via solid-state intercalation of four cationic surfactants, such as dodecyltrimethyl-, tetradecyltrimethyl-, hexadecyltrimethyl-, and didodecyldimethyl-ammonium, as bromide salts, at different loading levels into the interlayers of two natural clays. The natural clays, the prepared organoclays, and the spent organoclays were characterized by X-ray powder diffraction, infrared spectroscopy, and scanning electron microscopy. X-ray powder diffraction measurements showed successive interlayer expansions of the d₀₀₁ basal spacing due to the intercalation of the cationic surfactants and the bisphenol A sorption. The increased d₀₀₁ basal spacing of the organoclays after bisphenol A sorption indicates that the molecules are integrated between the alkyl chains of the surfactant in the organoclays interlayers. Infrared spectroscopy was employed to probe the intercalation of the cationic surfactants and the sorbed bisphenol A. New characteristic bands attributed to the bisphenol A phenol rings appear in the range 1518–1613 cm⁻¹ on the infrared spectra of the spent organoclays, proving the presence of bisphenol A in the hydrophobic interlayers. Scanning electron microscopy of the organoclays before and after BPA sorption shows that their morphology becomes fluffy and that the presence of the organic molecules expands the clay structure. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

22 pages, 8201 KiB  

Open AccessArticle

Green Synthesis of Sodium Cyanide Using Hydrogen Cyanide Extracted under Vacuum from Cassava (Manihot esculenta Crantz) Leaves

by Ilunga Monga, Vimla Paul, Sudhakar Muniyasamy and Orpah Zinyemba

Sustain. Chem. 2022, 3(3), 312-333; https://doi.org/10.3390/suschem3030020 - 05 Jul 2022

Cited by 2 | Viewed by 5359

Abstract

This study was carried out to develop a green approach to synthesising sodium cyanide (NaCN) using hydrogen cyanide (HCN) extracted from cassava (Manihot esculenta Crantz) leaves after 120 min of maceration at 30 °C and 45 min of recovery under vacuum at [...] Read more.

This study was carried out to develop a green approach to synthesising sodium cyanide (NaCN) using hydrogen cyanide (HCN) extracted from cassava (Manihot esculenta Crantz) leaves after 120 min of maceration at 30 °C and 45 min of recovery under vacuum at 35–40 °C. The CN^- ion released via autolysis was reacted with the Na⁺ ion following vacuum extraction of the former to produce NaCN by saturating the absorbing sodium hydroxide (NaOH) solution. This specific extraction method avoided direct contact between the cassava leaves homogenate and the absorbing solution. NaCN was crystallised by drying the NaCN slurry at 100 °C in an air oven. A total of 15.70 kg of fresh cassava leaves was needed to produce 32.356 g of NaCN (green-NaCN) (% NaCN yield = 0.21%). The results of X-ray diffraction, attenuated total reflectance–Fourier transform infrared spectroscopy and scanning electron microscopy with energy-dispersive X-ray spectroscopy, show that NaCN was successfully prepared using the proposed method. These spectral techniques showed that the control and green-NaCN contained sodium carbonate impurities. The latter was quantified by the titration experiments and was found to be 0.61% and 2.29% in the control and green-NaCN, respectively. Furthermore, the titration experiments revealed that the residual NaOH content was 1.63% in control NaCN and 4.68% in green-NaCN. The aim of modifying the green synthesis route for producing NaCN from cassava, developed by the Attahdaniel research group in 2013 and 2020, was achieved. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

10 pages, 2080 KiB  

Open AccessArticle

Nanostructure Sn/C Composite High-Performance Negative Electrode for Lithium Storage

by Jaffer Saddique, Honglie Shen, Jiawei Ge, Xiaomin Huo, Nasir Rahman, Ahmad Aziz Al Ahmadi and Muhammad Mushtaq

Molecules 2022, 27(13), 4083; https://doi.org/10.3390/molecules27134083 - 24 Jun 2022

Cited by 2 | Viewed by 1603

Abstract

Tin-based nanocomposite materials embedded in carbon frameworks can be used as effective negative electrode materials for lithium-ion batteries (LIBs), owing to their high theoretical capacities with stable cycle performance. In this work, a low-cost and productive facile hydrothermal method was employed for the [...] Read more.

Tin-based nanocomposite materials embedded in carbon frameworks can be used as effective negative electrode materials for lithium-ion batteries (LIBs), owing to their high theoretical capacities with stable cycle performance. In this work, a low-cost and productive facile hydrothermal method was employed for the preparation of a Sn/C nanocomposite, in which Sn particles (sized in nanometers) were uniformly dispersed in the conductive carbon matrix. The as-prepared Sn/C nanocomposite displayed a considerable reversible capacity of 877 mAhg⁻¹ at 0.1 Ag⁻¹ with a high first cycle charge/discharge coulombic efficiency of about 77%, and showed 668 mAh/g even at a relatively high current density of 0.5 Ag⁻¹ after 100 cycles. Furthermore, excellent rate capability performance was achieved for 806, 697, 630, 516, and 354 mAhg⁻¹ at current densities 0.1, 0.25, 0.5, 0.75, and 1 Ag⁻¹, respectively. This outstanding and significantly improved electrochemical performance is attributed to the good distribution of Sn nanoparticles in the carbon framework, which helped to produce Sn/C nanocomposite next-generation negative electrodes for lithium-ion storage. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

attachment

Supplementary material:
Supplementary File 1 (ZIP, 1265 KiB)

12 pages, 6576 KiB  

Open AccessArticle

Fast and Efficient Mechanosynthesis of Aldonamides by Aminolysis of Unprotected Sugar Lactones

by Abed Bil, Bemba Abdellahi, Gwladys Pourceau and Anne Wadouachi

Sustain. Chem. 2022, 3(3), 300-311; https://doi.org/10.3390/suschem3030019 - 22 Jun 2022

Cited by 3 | Viewed by 1792

Abstract

Sugar amides, such as aldonamides, are interesting, sugar-based molecules used in various fields, from detergency to medicine. Nevertheless, their valorization, especially as alternatives to petroleum-based substances, can be slowed down by their synthetic pathway, which is generally not in accordance with green chemistry [...] Read more.

Sugar amides, such as aldonamides, are interesting, sugar-based molecules used in various fields, from detergency to medicine. Nevertheless, their valorization, especially as alternatives to petroleum-based substances, can be slowed down by their synthetic pathway, which is generally not in accordance with green chemistry principles, and is also not economically competitive. We propose herein a fast procedure for the synthesis of aldonamide-derived glycoconjugates with mechanochemistry. The conditions were first optimized with galactonolactone, used as a model lactone, and dodecylamine. After only 5 min of grinding of stoechiometric amounts of amine and lactone, in the presence of water used as a Liquid Assisted Grinding (LAG) agent, the corresponding galactonamide was isolated with a high yield (90%) after a simple aqueous work-up. The optimized conditions were then applied to a wide variety of amines and sugar lactones, showing the versatility of the methodology. Gluco- and ribono-lactone exhibited similarly excellent reactivity, showing that the procedure is not sugar-dependent. Furthermore, the procedure was shown to be compatible with various functional groups such as alkene, alkyne, thiol, ester and hydroxyl. Full article

(This article belongs to the Topic Green and Sustainable Chemistry)

►▼ Show Figures

Figure 1

Show export options expand_more Show export options expand_less

Select all

Export citation of selected articles as:

Plain Text BibTeX BibTeX (without abstracts) Endnote Endnote (without abstracts) Tab-delimited RIS

 

Error

Oops... you haven't selected anything for export.

Ok

clear

Displaying articles 1-38