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Feature Paper Collection of Topical Advisory Members

A special issue of Materials (ISSN 1996-1944).

Deadline for manuscript submissions: closed (31 July 2022) | Viewed by 54851

Special Issue Editor

Dr. George Wardeh

E-Mail Website
Guest Editor
CY Cergy-paris University, 5 Mail Gay Lussac-Neuville sur Oise, 95031 Cergy Pontoise, CEDEX, France
Interests: thermo-hydro-mechanical behavior of porous construction materials; mix design and mechanical characterization of recycled aggregate concrete materials and structural elements; post-cracking behavior of construction materials; requalification of masonry structures
Special Issues, Collections and Topics in MDPI journals

Special Issue Information

Dear Colleagues,

This Feature Paper Collection for Topical Advisory Members is from the Materials Journal (ISSN 1996-1944) and is dedicated to collecting manuscripts from Topical Advisory Members and Editorial Board Members. The collection covers research articles and reviews on all aspects of materials science and engineering. Topics of interest include, but are not limited to the following:

  • Materials Processing and Characterization
  • Materials Simulation and Design
  • Biomaterials
  • Ceramics
  • Liquid Crystals
  • Metamaterials
  • Polymers
  • Energy Materials 
  • Metals
  • Nanotechnology
  • Semiconductors
  • Composites

Dr. George Wardeh
Guest Editor

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Keywords

  • materials science and engineering
  • topic editors
  • editorial board members

Published Papers (28 papers)

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18 pages, 5271 KiB  
Article
Effect of the Preparation Conditions on the Catalytic Properties of CoPt for Highly Efficient 4-Nitrophenol Reduction
by Oana-Georgiana Dragos-Pinzaru, Gabriela Buema, Daniel Gherca, Ibro Tabakovic and Nicoleta Lupu
Materials 2022, 15(18), 6250; https://doi.org/10.3390/ma15186250 - 08 Sep 2022
Cited by 5 | Viewed by 1356
Abstract
CoPt alloys with Pt contents from 15 to 90% were prepared using low-cost electrochemical deposition. Different samples were synthesized from electrochemical baths at pH = 2.5 and 5.5 in a solution with and without saccharin as an additive. The morphology, composition and crystalline [...] Read more.
CoPt alloys with Pt contents from 15 to 90% were prepared using low-cost electrochemical deposition. Different samples were synthesized from electrochemical baths at pH = 2.5 and 5.5 in a solution with and without saccharin as an additive. The morphology, composition and crystalline structure of the as-prepared samples were investigated by High Resolution—Scanning Electron Microscopy (HR-SEM), Atomic Force Microscopy (AFM), Ultra-high Resolution—Transmission Electron Microscopy (UHR-TEM), Energy-Dispersive X-ray Spectroscopy (EDX), and X-ray Diffraction (XRD). XRD investigations revealed that fcc crystalline structure transforms into hcp crystalline structure when the pH of the electrochemical bath is increased from 2.5 to 5.5 as well as when saccharin is added to the electrochemical bath. The catalytic performance of the CoPt alloys for the nitro to amino phenol compounds conversion was investigated for all the prepared samples, and the results show that the conversion degree increases (from 11.4 to 96.5%) even though the Pt content in the samples decreases. From the samples prepared from the electrochemical bath with saccharin, a study regarding the effect of contact time was performed. The results indicated that after only 5 min, the CoPt sample prepared at pH = 5.5 in the presence of saccharin completely converted the nitro compound to an amino compound. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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19 pages, 10689 KiB  
Article
Microstructure, Shrinkage, and Mechanical Properties of Concrete with Fibers and Experiments of Reinforced Concrete Beams without Shear Reinforcement
by Oldrich Sucharda, Zuzana Marcalikova and Radoslav Gandel
Materials 2022, 15(16), 5707; https://doi.org/10.3390/ma15165707 - 18 Aug 2022
Cited by 10 | Viewed by 1308
Abstract
The current findings on concrete with fibers show that research has focused primarily on individual aspects, especially in terms of mechanical properties and structural uses. However, no broader view of the problems solved has been provided. In this study, we present a conceptual [...] Read more.
The current findings on concrete with fibers show that research has focused primarily on individual aspects, especially in terms of mechanical properties and structural uses. However, no broader view of the problems solved has been provided. In this study, we present a conceptual overview of a new, comprehensive experimental program for the assessment of fiber-reinforced concrete, which includes the analysis of microstructural and structural elements, as well as specific features such as shrinkage and resistance to pressurized water. The proposed experimental program included several variants of schemes for the dosing of fibers into concrete, using steel fibers that were short and straight. Fiber dosing was performed up to 110 kg/m3. The basic tests performed included tests of the compressive strength of concrete, and of the split and flexural tensile strength for different dosing amounts. Within the structural tests of reinforced concrete beams without shear reinforcement, two variants of spans with different degrees of reinforcement were implemented. Herein, the test results are evaluated graphically with a detailed analysis of the positive effect of fibers, and we also provide general recommendations for the structural uses of the fibers used and the design of fiber-reinforced concrete structures. Among the important results of this experimental program was the observation of a significant increase (of the order of tens) of the percentage of the split tensile strength and an increase of the overall load-bearing capacity of the reinforced concrete beams without shear reinforcement. Among the important aspects of our findings is the fact that a fine-grained concrete mixture was used, which increased resistance to pressure water seepage, and therefore, the effect of shrinkage can be influenced by the method of production and the treatment of the concrete used. We also provide detailed figures of the microstructure. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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19 pages, 13052 KiB  
Article
Perspectives of Microstructure Refinement of Aluminum and Its Alloys by the Reciprocating Extrusion (Cyclic Extrusion Compression—CEC)
by Maria Richert, Rafał Hubicki and Piotr Łebkowski
Materials 2022, 15(11), 4006; https://doi.org/10.3390/ma15114006 - 04 Jun 2022
Cited by 1 | Viewed by 1324
Abstract
This paper presents a study on the perspectives of structure refinement of aluminum and its alloys by reciprocating extrusion (cyclic extrusion compression—CEC). The study included Al99.5 and Al99.992 aluminum and AlMg5 and AlCu4Zr alloy. Aluminum and alloys were deformed by reciprocating extrusion (CEC) [...] Read more.
This paper presents a study on the perspectives of structure refinement of aluminum and its alloys by reciprocating extrusion (cyclic extrusion compression—CEC). The study included Al99.5 and Al99.992 aluminum and AlMg5 and AlCu4Zr alloy. Aluminum and alloys were deformed by reciprocating extrusion (CEC) in the strain range ϕ = 0.42 (1 CEC cycle) to ϕ = 59.8 (67 CEC cycles). After deformation, the structure of the specimens was investigated by optical microscopy (OM) and transmission electron microscopy (TEM), which revealed that the primary mechanism of hardening, over the range of applied strains, was the result of the propagation of shear bands throughout the specimens. The intersection of shear bands was found to divide the volume of the specimens into nano and microvolumes with dimensions limited by the width of the microbands. Due to structure renewal processes such as polygonization and dynamic geometric recrystallization, the formed micro and nano volumes were transformed into nano and micrograins with large misorientation angles. In terms of the occurrence of grain microstructure, a sustained uniform level of hardening was found, which was defined as steady-state flow. The research has shown that the steady state of flow is a result of the competitive interaction between the processes of hardening and structure renewal. The higher the metal purity, the higher the intensity of the structure renewal processes was. The formation of new grains and their growth under dynamic and post-dynamic recrystallization was observed in Al99.992 aluminum, in which high purity of the metal and high strain accumulation caused the growth of new grains at room temperature. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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12 pages, 5038 KiB  
Article
Inhibition of Alkali-Carbonate Reaction by Fly Ash and Metakaolin on Dolomitic Limestones
by Huan Cao, Zhongyang Mao, Xiaojun Huang and Min Deng
Materials 2022, 15(10), 3538; https://doi.org/10.3390/ma15103538 - 15 May 2022
Cited by 1 | Viewed by 1430
Abstract
In this paper, the dolomitic limestone determined as alkali–carbonate-reactive by various methods is used as an aggregate. Inhibition experiments were carried out on the basis of the concrete microbar method (RILEM AAR-5 standard), in which 10%, 30%, and 50% fly ash and metakaolin [...] Read more.
In this paper, the dolomitic limestone determined as alkali–carbonate-reactive by various methods is used as an aggregate. Inhibition experiments were carried out on the basis of the concrete microbar method (RILEM AAR-5 standard), in which 10%, 30%, and 50% fly ash and metakaolin were used to replace cement. Thermogravimetric–differential scanning calorimetry (TG-DSC), X-ray diffractometry (XRD), mercury intrusion porosimetry (MIP), and scanning electron microscopy–energy dispersive X-ray spectrometry (SEM-EDS) were used to analyze the inhibition mechanism of fly ash and metakaolin on ACR. The results show that the expansion of samples at the age of 28 days are less than 0.10% when the fly ash contents exceed 30% and the metakaolin contents exceed 10%, which proves that the ACR is inhibited effectively. Meanwhile, the Ca(OH)2 content of the samples was reduced and the pore structure of the samples was optimized after adding fly ash and metakaolin. The dolomite crystals in the samples containing 50% fly ash and metakaolin are relatively complete. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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17 pages, 6585 KiB  
Article
Distribution of Hydrogen and Defects in the Zr/Nb Nanoscale Multilayer Coatings after Proton Irradiation
by Roman Laptev, Ekaterina Stepanova, Natalia Pushilina, Leonid Svyatkin, Dmitriy Krotkevich, Anton Lomygin, Sergei Ognev, Krzysztof Siemek, Aleksandr Doroshkevich and Vladimir Uglov
Materials 2022, 15(9), 3332; https://doi.org/10.3390/ma15093332 - 06 May 2022
Cited by 5 | Viewed by 1899
Abstract
Radiation damage is one of the significant factors limiting the operating time of many structural materials working under extreme conditions. One of the promising directions in the development of materials that are resistant to radiation damage and have improved physical and mechanical properties [...] Read more.
Radiation damage is one of the significant factors limiting the operating time of many structural materials working under extreme conditions. One of the promising directions in the development of materials that are resistant to radiation damage and have improved physical and mechanical properties is the creation of nanoscale multilayer coatings (NMCs). The paper is devoted to the experimental comprehension of changes in the defect structure and mechanical properties of nanoscale multilayer coatings (NMCs) with alternating layers of Zr and Nb under irradiation. Series of Zr/Nb NMCs with different thicknesses of individual layers were fabricated by magnetron sputtering and subjected to H+ irradiation. The evolution of structure and phase states, as well as the defect state under proton irradiation, was studied using the methods of high-resolution transmission electron microscopy (HRTEM), X-ray diffraction analysis (XRD), glow discharge optical emission spectroscopy (GDOES), and positron annihilation spectroscopy (PAS). The layer-by-layer analysis of structural defects was carried out by Doppler broadening spectroscopy (DBS) using a variable-energy positron beam. To estimate the binding energy and the energy paths for the hydrogen diffusion in Zr/Nb NMCs, calculations from the first principles were used. When the thickness of individual layers is less than 25 nm, irradiation causes destruction of the interfaces, but there is no significant increase in the defect level, the S parameter (open volume defects amount) before and after irradiation is practically unchanged. After irradiation of NMC Zr/Nb with a thickness of layers 50 and 100 nm, the initial microstructure is retained, and the S parameter is significantly reduced. The GDOES data reveal the irregular H accumulation at the interface caused by significant differences in H diffusion barriers in the bulk of Zr and Nb multilayers as well as near the interface’s region. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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22 pages, 8327 KiB  
Article
Applying Flax FRP in an Innovative Closed-Shape Stirrup for Concrete Beams
by Cheng Chen, Caiwei Li, Yingwu Zhou, Lili Sui and Xue Li
Materials 2022, 15(8), 2927; https://doi.org/10.3390/ma15082927 - 17 Apr 2022
Cited by 2 | Viewed by 1717
Abstract
Under the background of climate change, the steel industry is considered one of the least eco-friendly industries. Flax fiber-reinforced polymer (FFRP) is an emerging sustainable alternative to steel reinforcement bar; however, its application is much restricted due to its interior material properties. This [...] Read more.
Under the background of climate change, the steel industry is considered one of the least eco-friendly industries. Flax fiber-reinforced polymer (FFRP) is an emerging sustainable alternative to steel reinforcement bar; however, its application is much restricted due to its interior material properties. This paper proposed a novel way to form closed-shape stirrups with FFRP, which is suitable for replacing steel stirrups. A multi-disciplinary investigation was conducted concerning the structural and environmental performance of FFRP stirrups in reinforced concrete (RC) beams. Seven specimens were tested under a three-point bending load. The FFRP stirrups substantially increased the shear capacity and ultimate vertical displacement by 77% and 74%, respectively, and shifted brittle failure to ductile failure. The closed-shape stirrups avoided the stress concentration and increased the utilization of FFRP tensile capacity to over 80%. Decreasing the spacing of FFRP stirrups effectively increased the shear capacity and ductility; increasing the width or layer of FFRP stirrups improved ductility only. A life cycle assessment (LCA) was later performed to evaluate and compare the environmental performance of steel, FFRP, and carbon FRP stirrups. As compared to carbon FRP and steel ones, FFRP stirrups substantially decreased the global warming and fossil depletion potential by over 60%. The main contributors to the environmental impacts of FFRP stirrups were the heavy metal released into the water and terrestrial environment during the cultivation process. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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10 pages, 3810 KiB  
Article
Effect of Carbon on Dislocation Loops Formation during Self-Ion Irradiation in Fe-Cr Alloys at High Temperatures
by Tiantian Shi, Wenbo Liu, Zhengxiong Su, Xu Yan, Chenyang Lu and Di Yun
Materials 2022, 15(6), 2211; https://doi.org/10.3390/ma15062211 - 17 Mar 2022
Cited by 2 | Viewed by 1469
Abstract
In this study, two types of ferritic model alloys (Fe-9Cr and Fe-9Cr-C) were simultaneously irradiated with 3.5 MeV Fe13+ ions at 450 °C and 550 °C to a dose of 3dpa at the peak damage region, respectively. Transmission electron microscopy (TEM) was [...] Read more.
In this study, two types of ferritic model alloys (Fe-9Cr and Fe-9Cr-C) were simultaneously irradiated with 3.5 MeV Fe13+ ions at 450 °C and 550 °C to a dose of 3dpa at the peak damage region, respectively. Transmission electron microscopy (TEM) was used to investigate the microstructural evolution of the Fe-Cr alloys after irradiation. The experimental results showed that the size of the dislocation loops formed in the Fe-9Cr-C alloy was larger than that in the Fe-9Cr alloy, but the loop density of the Fe-9Cr-C alloy was lower than that of the Fe-9Cr alloy after irradiation at 450 °C. The reason for this phenomenon was attributed to the fact that loops formed in Fe-9Cr-C alloy have greater capture efficiency for interstitial atoms. Compared to Fe-Cr alloys irradiated at 450 °C, high-density loops were not observed in the Fe-Cr alloys irradiated at 550 °C; the number of dislocation loops in the Fe-Cr alloys irradiated at 550 °C significantly decreased due to the rapid conversion of the dislocation loops into network dislocations. In addition, subgrains were observed in the Fe-Cr alloys after irradiation. The underlying reason behind the formation of subgrains is discussed in detail. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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12 pages, 2111 KiB  
Article
Novel, Inexpensive, and Scalable Amyloid Fibril Formation Method
by Ethan Hessick, Milind Pawar, Reid Souchereau, Emma Schmitz and Pelagia-Irene Gouma
Materials 2022, 15(5), 1766; https://doi.org/10.3390/ma15051766 - 26 Feb 2022
Cited by 5 | Viewed by 2230
Abstract
Wheat flour was used as a source of protein for the in vitro synthesis of Amyloid fibrils to develop a novel and inexpensive fabrication method. Amyloid fibrillation was confirmed by Thioflavin T Fluorescence, using confocal microscopy. A morphological study was carried out by [...] Read more.
Wheat flour was used as a source of protein for the in vitro synthesis of Amyloid fibrils to develop a novel and inexpensive fabrication method. Amyloid fibrillation was confirmed by Thioflavin T Fluorescence, using confocal microscopy. A morphological study was carried out by transmission electron microscopy (TEM), which revealed the high aspect ratio of the amyloid fibrils formed via a novel process. An application of the amyloid fibers produced by the novel method is shown to be melatonin sensing. Tests showed that the amyloid samples had a measurable color variation dependent on the melatonin concentration. This newly derived process could prove to be a cost-effective tool for future nano-biomaterial applications in commercial and research settings. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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10 pages, 3634 KiB  
Article
Intermediate-Temperature Tensile Behavior of a Hot-Rolled Mg-Li-Al-Cd-Zn Alloy
by Lunyong Zhang, Yongjiang Huang, Ming Wu, Chao Xu, Zhiliang Ning, Fuyang Cao and Jianfei Sun
Materials 2022, 15(5), 1686; https://doi.org/10.3390/ma15051686 - 24 Feb 2022
Cited by 2 | Viewed by 1415
Abstract
Developing light structure materials that work stably at elevated temperatures is a long-standing challenge for many application fields, particularly in the development of aerospace equipment. Zn/Cd alloying elements were prospected to improve the stability of the lightest Mg-Li based alloys; however, little is [...] Read more.
Developing light structure materials that work stably at elevated temperatures is a long-standing challenge for many application fields, particularly in the development of aerospace equipment. Zn/Cd alloying elements were prospected to improve the stability of the lightest Mg-Li based alloys; however, little is known about the intermediate-temperature mechanical properties of such alloys. The present work investigated the tensile behaviors of a cold-rolled Mg-Li-Al-Cd-Zn alloy in a temperature range of 30–150 °C. The results indicate that the alloy can host a tensile strength σUTS of 108~121 MPa, a yield strength σYP of 97~109 MPa and elongation εB of 14–15 % at 150 °C, dependent on the tensile direction. The mechanical properties intensively are modulated by temperature through the competition between work hardening and softening. Work hardening due to dislocation blocking by the precipitated MgLi2X phase dominated the deformation at low temperatures, while softening that resulted from dynamic recrystallization was the main effect at high temperatures. Correspondingly, a quasi-cleavage mechanism dominated the fracture at temperatures near room temperature, and microvoid coalescence worked at high temperatures above 100 °C. Our results offer a new experimental understanding of the elevated-temperature mechanical behaviors of Mg-Li alloys and will advance the development of new light magnesium alloys with high stability. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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10 pages, 2029 KiB  
Article
On Structural Rearrangements during the Vitrification of Molten Copper
by Michael I. Ojovan and Dmitri V. Louzguine-Luzgin
Materials 2022, 15(4), 1313; https://doi.org/10.3390/ma15041313 - 10 Feb 2022
Cited by 13 | Viewed by 1492
Abstract
We utilise displacement analysis of Cu-atoms between the chemical bond-centred Voronoi polyhedrons to reveal structural changes at the glass transition. We confirm that the disordered congruent bond lattice of Cu loses its rigidity above the glass transition temperature (Tg) in [...] Read more.
We utilise displacement analysis of Cu-atoms between the chemical bond-centred Voronoi polyhedrons to reveal structural changes at the glass transition. We confirm that the disordered congruent bond lattice of Cu loses its rigidity above the glass transition temperature (Tg) in line with Kantor–Webman theorem due to percolation via configurons (broken Cu-Cu chemical bonds). We reveal that the amorphous Cu has the Tg = 794 ± 10 K at the cooling rate q = 1 × 1013 K/s and that the determination of Tg based on analysis of first sharp diffraction minimum (FDSM) is sharper compared with classical Wendt–Abraham empirical criterion. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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23 pages, 12587 KiB  
Article
Mechanical and Tribological Characterization of WC-Co and WC-AISI 304 Composites by a Newly Developed Equipment
by Luís Vilhena, Bruno Domingues, Cristina Fernandes, Ana Senos and Amílcar Ramalho
Materials 2022, 15(3), 1187; https://doi.org/10.3390/ma15031187 - 04 Feb 2022
Cited by 6 | Viewed by 1946
Abstract
Tungsten carbide-based composites are, in many cases, the materials of choice in applications requiring high wear resistance. In the present research work, the mechanical characterization of the WC-Co and WC-AISI 304 composites was carried out, with evaluation of the hardness and fracture toughness [...] Read more.
Tungsten carbide-based composites are, in many cases, the materials of choice in applications requiring high wear resistance. In the present research work, the mechanical characterization of the WC-Co and WC-AISI 304 composites was carried out, with evaluation of the hardness and fracture toughness and tribological characterization of the composites that included the study of friction and wear rate coefficient through unlubricated sliding tests according to the Pin-on-Disc test method. It was possible to correlate the effect of the different binding phases on the mechanical and tribological properties of WC-based composites, and it can be concluded that the system composed by the tribological pair WC-AISI304/100Cr6 was the one that showed the lowest coefficient of friction while the tribological pair WC-Co/Al2O3 was the one that showed the lowest wear rate coefficient. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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13 pages, 4478 KiB  
Article
Investigation of Weld Root Defects in High-Power Full-Penetration Laser Welding of High-Strength Steel
by Hengquan Zhang, Meng Jiang, Xi Chen, Lianfeng Wei, Shizhong Wang, Yumo Jiang, Nan Jiang, Zhiyuan Wang, Zhenglong Lei and Yanbin Chen
Materials 2022, 15(3), 1095; https://doi.org/10.3390/ma15031095 - 30 Jan 2022
Cited by 8 | Viewed by 3263
Abstract
The currently available high-power laser shows promising opportunities for the welding of thick plates in a single pass. However, weld-root defect frequently occurs when a high-power laser is used to join thick plates in a full-penetration mode, which has a significantly adverse effect [...] Read more.
The currently available high-power laser shows promising opportunities for the welding of thick plates in a single pass. However, weld-root defect frequently occurs when a high-power laser is used to join thick plates in a full-penetration mode, which has a significantly adverse effect on the serviceability of the weld joint. The purpose of this work is to understand the defect formation mechanism and reduce these defects through controlling welding parameters. In this study, the characteristics of weld root defects were investigated using a 10 kW fiber laser using a program of experiment and theoretical analysis. The corresponding defect formation mechanisms were discussed based on the bottom molten pool behaviors observed by the high-speed camera. The results showed that there were four types of weld-root appearances as follows with an increase of linear heat input from 300 J/mm to 1000 J/mm: weld-root humping (30 mm/s), sound weld (25 mm/s), weld sagging (20 mm/s) and excessive weld sagging. The remedies for reducing weld-root defects were also presented to obtain sound weld bead by optimizing welding parameters. Weld-root humping was formed due to the quasi-full-penetration keyhole. Weld sagging resulted from the imbalance of the hydrostatic pressure and surface tension in the condition of a through keyhole. It was also found that the sound weld was formed when a through keyhole and a proper molten pool size were obtained. Thus, the state of the keyhole and molten pool geometry were the major factors that affect weld-root defects. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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14 pages, 3178 KiB  
Article
K2O-Metakaolin-Based Geopolymer Foams: Production, Porosity Characterization and Permeability Test
by Elettra Papa, Elena Landi, Francesco Miccio and Valentina Medri
Materials 2022, 15(3), 1008; https://doi.org/10.3390/ma15031008 - 27 Jan 2022
Cited by 13 | Viewed by 2339
Abstract
In this paper, four near-net shaped foams were produced via direct foaming, starting from a benchmark metakaolin-based geopolymer formulation. Hydrogen peroxide and metallic silicon were used in different amounts as blowing agents to change the porosity from meso- to ultra-macro-porosity. Foams were characterized [...] Read more.
In this paper, four near-net shaped foams were produced via direct foaming, starting from a benchmark metakaolin-based geopolymer formulation. Hydrogen peroxide and metallic silicon were used in different amounts as blowing agents to change the porosity from meso- to ultra-macro-porosity. Foams were characterized by bulk densities ranging from 0.34 to 0.66 g cm−3, total porosity from 70% to 84%, accessible porosity from 41% to 52% and specific surface area from 47 to 94 m2 g−1. Gas permeability tests were performed, showing a correlation between the pore features and the processing methods applied. The permeability coefficients k1 (Darcian) and k2 (non-Darcian), calculated applying Forchheimer’s equation, were higher by a few orders of magnitude for the foams made using H2O2 than those made with metallic silicon, highlighting the differing flow resistance according to the interconnected porosity. The gas permeability data indicated that the different geopolymer foams, obtained via direct foaming, performed similarly to other porous materials such as granular beds, fibrous filters and gel-cast foams, indicating the possibility of their use in a broad spectrum of applications. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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12 pages, 5404 KiB  
Article
Experimental Investigation on the Structural Performance of Single Span Hollow Core Slab under Successive Impact Loading
by Kamal Amin Chebo, Yehya Temsah, Zaher Abou Saleh, Mohamad Darwich and Ziad Hamdan
Materials 2022, 15(2), 599; https://doi.org/10.3390/ma15020599 - 13 Jan 2022
Cited by 3 | Viewed by 1548
Abstract
In Lebanon and many other countries where structures are vulnerable to impact loads caused by accidental rock falls due to landslides, specifically bridges with hollow core slab, it is mandatory to develop safe and efficient design procedures to design such types of structures [...] Read more.
In Lebanon and many other countries where structures are vulnerable to impact loads caused by accidental rock falls due to landslides, specifically bridges with hollow core slab, it is mandatory to develop safe and efficient design procedures to design such types of structures to withstand extreme cases of loading. The structural response of concrete members subjected to low velocity high falling weight raised the interest of researchers in the previous years. The effect of impact due to landslide falling rocks on reinforced concrete (RC) slabs has been investigated by many researchers, while very few studied the effect of impact loading on pre-stressed structures, noting that a recent study was conducted at Beirut Arab University which compared the dynamic behavior of reinforced concrete and post-tensioned slabs under impact loading from a 605 kg impactor freely dropped from a height of 20 m. Hollow core slabs are widely used in bridges and precast structures. Thus, studying their behavior due to such hazards becomes inevitable. This study focuses on these types of slabs. For a better understanding of the behavior, a full scale experimental program consists of testing a single span hollow core slab. The specimen has 6000 mm × 1200 mm × 200 mm dimensions with a 100 mm cast in a place topping slab. Successive free fall drops cases from 14 m height will be investigated on the prescribed slab having a span of 6000 m. This series of impacts will be held by hitting the single span hollow core slab at three different locations: center, edge, and near the support. The data from the testing program were used to assess the structural response in terms of experimental observations, maximum impact and inertia forces, structural damage/failure: type and pattern, acceleration response, and structural design recommendations. This research showed that the hollow core slab has a different dynamic behavior compared to the post tensioned and reinforced concrete slabs mentioned in the literature review section. Full article
(This article belongs to the Special Issue Feature Paper Collection of Topical Advisory Members)
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13 pages, 2798 KiB  
Article
Compositional Effects on Indentation Mechanical Properties of Chemically Strengthened TiO2-Doped Soda Lime Silicate Glasses
by Stefan Karlsson
Materials 2022, 15(2), 577; https://doi.org/10.3390/ma15020577 - 13 Jan 2022
Cited by 4 | Viewed by 2008
Abstract
TiO2 is an important oxide for property modifications in the conventional soda lime silicate glass family. It offers interesting optical and mechanical properties, for instance, by substituting heavy metals such as lead in consumer glasses. The compositional effects on the hardness, reduced [...] Read more.
TiO2 is an important oxide for property modifications in the conventional soda lime silicate glass family. It offers interesting optical and mechanical properties, for instance, by substituting heavy metals such as lead in consumer glasses. The compositional effects on the hardness, reduced elastic modulus and crack resistance as determined by indentation of chemically strengthened (CS) TiO2-doped soda lime silicate glass was studied in the current paper. The CS, which was performed by a K+ for Na+ ion exchange in a molten KNO3 salt bath at 450 °C for 15 h, yielded significant changes in the indentation mechanical properties. The hardness of the glass samples increased, and this was notably dependent on the SiO2, CaO and TiO2 content. The reduced elastic modulus was less affected by the CS but showed decrease for most samples. The crack resistance, an important property in many applications where glasses are subjected to contact damage, showed very different behaviors among the series. Only one of the series did significantly improve the crack resistance where low CaO content, high TiO2 content, high molar volume and increased elastic deformation favored an increased crack resistance. Full article
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17 pages, 3215 KiB  
Article
Structure Prediction and Mechanical Properties of Silicon Hexaboride on Ab Initio Level
by Tamara Škundrić, Branko Matović, Aleksandra Zarubica, Jelena Zagorac, Peter Tatarko and Dejan Zagorac
Materials 2021, 14(24), 7887; https://doi.org/10.3390/ma14247887 - 20 Dec 2021
Cited by 6 | Viewed by 1825
Abstract
Silicon borides represent very appealing industrial materials for research owing to their remarkable features, and, together with other boride and carbide-based materials, have very wide applications. Various Si–B phases have been investigated in the past, however a limited number of studies have been [...] Read more.
Silicon borides represent very appealing industrial materials for research owing to their remarkable features, and, together with other boride and carbide-based materials, have very wide applications. Various Si–B phases have been investigated in the past, however a limited number of studies have been done on the pristine SiB6 compound. Structure prediction using a data mining ab initio approach has been performed in pure silicon hexaboride. Several novel structures, for which there are no previous experimental or theoretical data, have been discovered. Each of the structure candidates were locally optimized on the DFT level, employing the LDA-PZ and the GGA-PBE functional. Mechanical and elastic properties for each of the predicted and experimentally observed modifications have been investigated in great detail. In particular, the ductility/brittleness relationship, the character of the bonding, Young’s modulus E, bulk modulus B, and shear modulus K, including anisotropy, have been calculated and analyzed. Full article
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14 pages, 6171 KiB  
Article
Investigation of Micromechanical Properties and Tribological Behavior of WE43 Magnesium Alloy after Deep Cryogenic Treatment Combined with Precipitation Hardening
by Adrian Barylski, Krzysztof Aniołek, Grzegorz Dercz, Piotr Kowalewski, Sławomir Kaptacz, Jan Rak and Marian Kupka
Materials 2021, 14(23), 7343; https://doi.org/10.3390/ma14237343 - 30 Nov 2021
Cited by 7 | Viewed by 1396
Abstract
This study investigated the micromechanical and tribological properties of WE43 alloy (Mg-Y-Nd-Zr) alloy subjected to cryogenic treatment and precipitation hardening. Microindentation tests were carried out in the range of load from 100 to 1000 mN. The introduction of deep cryogenic treatment (DCT) was [...] Read more.
This study investigated the micromechanical and tribological properties of WE43 alloy (Mg-Y-Nd-Zr) alloy subjected to cryogenic treatment and precipitation hardening. Microindentation tests were carried out in the range of load from 100 to 1000 mN. The introduction of deep cryogenic treatment (DCT) was shown to increase hardness and Young’s modulus, and reduce the total indentation work. As the load set during the tests increased, a gradual decrease in the measured values was observed, indicating a significant relationship between the indent size and the value of the measured parameters. Cryogenic treatment used in conjunction with precipitation hardening (after solutioning and after aging) reduces the tribological wear of the alloy. Tests have shown an almost twofold reduction in the area of the wear trace and in the volumetric wear of the alloy, as well as a more than twofold reduction in linear wear, with relatively small fluctuations in the coefficient of friction. Abrasion was the main mechanism of wear. Areas where microcutting, adhesion and plastic deformation occurred were also observed. The results indicate the significant effectiveness of the applied heat treatment in improving the service life of the WE43 alloy containing rare earth metals. Full article
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13 pages, 6222 KiB  
Article
Entrapment of a Cytotoxic Drug into the Crystal Structure of Calcite for Targeted Drug Delivery
by Amina Vazda, Michael Pujari-Palmer, Wei Xia and Håkan Engqvist
Materials 2021, 14(22), 6735; https://doi.org/10.3390/ma14226735 - 09 Nov 2021
Viewed by 1539
Abstract
Controlled drug release and targeted drug delivery can reduce systemic toxicity of chemotherapeutics by restricting drugs to the target organ and increasing the local concentration. As tumors and inflamed tissue are often surrounded by an acidic microenvironment, pH-responsive calcium carbonates (CaCO3) [...] Read more.
Controlled drug release and targeted drug delivery can reduce systemic toxicity of chemotherapeutics by restricting drugs to the target organ and increasing the local concentration. As tumors and inflamed tissue are often surrounded by an acidic microenvironment, pH-responsive calcium carbonates (CaCO3) are promising vehicles for controlled drug delivery applications. The aim of this study was to evaluate the loading efficacy and release of a chemotherapeutic drug, Hydroxyurea (HU), into the crystal structure of calcite. Incorporation of HU did not alter the crystallinity, crystal size, or morphology of precipitated calcite crystals, as assessed by XRD and SEM. The amount of HU was quantified by High-Pressure Liquid Chromatography (HPLC) and showed that 6.7 ± 0.7 µg of HU could be for each milligram of calcite (0.016 mol% ± 0.002). In cell media, the optimal pH for controlled release was 5 (0.1 mg/mL released after 1 h). However, in vitro, pH below 6.5 was cytotoxic to human breast cancer cells (MCF-7). Direct contact studies, where particles were incubated with MCF-7 cells, showed that the amount of HU release from calcite was not high enough to kill the cell or arrest growth at pH 6.5. Pre-dissolved release studies, where the particles were pre-dissolved in acidic media to simulate complete drug release in vivo, pH neutralized, and exposed to the cells, showed that the amount of loaded HU reduced the survival/proliferation of MCF7. In conclusion, it is possible to integrate HU into the crystal structure of a calcite crystal and release the drug in vitro at concentrations that can slow the growth of cancer cells, without affecting calcite morphology and crystallinity. Further research is needed to investigate the in vivo behavior of the particles and whether the actual tumor pH is low enough to achieve complete drug release in vivo. Full article
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14 pages, 5601 KiB  
Article
Source for In Situ Positron Annihilation Spectroscopy of Thermal—And Hydrogen-Induced Defects Based on the Cu-64 Isotope
by Iurii Bordulev, Roman Laptev, Denis Kabanov, Ivan Ushakov, Viktor Kudiiarov and Andrey Lider
Materials 2021, 14(21), 6693; https://doi.org/10.3390/ma14216693 - 06 Nov 2021
Cited by 4 | Viewed by 1741
Abstract
This work aims to investigate the 64Cu isotope applicability for positron annihilation experiments in in situ mode. We determined appropriate characteristics of this isotope for defect studies and implemented them under aggressive conditions (i.e., elevated temperature, hydrogen environment) in situ to determine [...] Read more.
This work aims to investigate the 64Cu isotope applicability for positron annihilation experiments in in situ mode. We determined appropriate characteristics of this isotope for defect studies and implemented them under aggressive conditions (i.e., elevated temperature, hydrogen environment) in situ to determine the sensitivity of this approach to thermal vacancies and hydrogen-induced defects investigation. Titanium samples were used as test materials. The source was obtained by the activation of copper foil in the thermal neutron flux of a research nuclear reactor. Main spectrometric characteristics (e.g., the total number of counts, fraction of good signals, peak-to-noise ratio) of this source, as well as line-shaped parameters of the Doppler broadening spectrum (DBS), were studied experimentally. These characteristics for 64Cu (in contrast to positron sources with longer half-life) were shown to vary strongly with time, owing to the rapidly changing activity. These changes are predictable and should be considered in the analysis of experimental data to reveal information about the defect structure. The investigation of samples with a controlled density of defects revealed the suitability of 64Cu positron source with an activity of 2–40 MBq for defects studies by DBS. However, greater isotope activity could also be applied. The results of testing this source at high temperatures and in hydrogen atmosphere showed its suitability to thermal vacancies and hydrogen-induced defects studies in situ. The greatest changes in the defect structure of titanium alloy during high-temperature hydrogen saturation occurred at the cooling stage, when the formation of hydrides began, and were associated with an increase in the dislocation density. Full article
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9 pages, 2894 KiB  
Article
Syntheses, Structures and Properties of Alkali and Alkaline Earth Metal Diamond-Like Compounds Li2MgMSe4 (M = Ge, Sn)
by Hongbo Gao, Kewang Zhang, Ailijiang Abudurusuli, Chen Bai, Zhihua Yang, Kangrong Lai, Junjie Li and Shilie Pan
Materials 2021, 14(20), 6166; https://doi.org/10.3390/ma14206166 - 18 Oct 2021
Cited by 6 | Viewed by 1657
Abstract
Two new diamond-like (DL) chalcogenides, Li2MgGeSe4 and Li2MgSnSe4, have been successfully synthesized using a conventional high-temperature solid-state method. The two compounds crystallize in the non-centrosymmetric space group Pmn21 with a = 8.402 (14) Å, [...] Read more.
Two new diamond-like (DL) chalcogenides, Li2MgGeSe4 and Li2MgSnSe4, have been successfully synthesized using a conventional high-temperature solid-state method. The two compounds crystallize in the non-centrosymmetric space group Pmn21 with a = 8.402 (14) Å, b = 7.181 (12) Å, c = 6.728 (11) Å, Z = 2 for Li2MgSnSe4, and a = 8.2961 (7) Å, b = 7.0069 (5) Å, c = 6.6116 (6) Å, Z = 2 for Li2MgGeSe4. The calculated results show that the second harmonic generation (SHG) coefficients of Li2MgSnSe4 (d33 = 12.19 pm/v) and Li2MgGeSe4 (d33 = −14.77 pm/v), mainly deriving from the [MSe4] (M = Ge, Sn) tetrahedral units, are close to the one in the benchmark AgGaS2 (d14 = 13.7 pm/V). The calculated band gaps for Li2MgSnSe4 and Li2MgGeSe4 are 2.42 and 2.44 eV, respectively. Moreover, the two compounds are the first series of alkali and alkaline-earth metal DL compounds in the I2-II-IV-VI4 family, enriching the structural diversity of DL compounds. Full article
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11 pages, 2650 KiB  
Article
Annealing-Induced Off-Stoichiometric and Structural Alterations in Ca2+- and Y3+-Stabilized Zirconia Ceramics
by Wenliang Zhu, Shizuka Nakashima, Elia Marin, Hui Gu and Giuseppe Pezzotti
Materials 2021, 14(19), 5555; https://doi.org/10.3390/ma14195555 - 24 Sep 2021
Cited by 3 | Viewed by 1497
Abstract
In the current study, high-temperature stability was investigated in two types of zirconia ceramics stabilized with two different additives, namely, calcia and yttria. The evolutions of structure and oxygen-vacancy-related defects upon annealing in air were investigated as a function of temperature by combining [...] Read more.
In the current study, high-temperature stability was investigated in two types of zirconia ceramics stabilized with two different additives, namely, calcia and yttria. The evolutions of structure and oxygen-vacancy-related defects upon annealing in air were investigated as a function of temperature by combining X-ray diffractometry with Raman, X-ray photoelectron and cathodoluminescence spectroscopies. We systematically characterized variations in the concentration of oxygen vacancies and hydroxyl groups during thermal treatments and linked them to structural alterations and polymorphic transformation. With this approach, we clarified how the combined effects of different dopants and temperature impacted on structural development and on the thermal stability of the oxygen-vacancy-related defect complex. Full article
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17 pages, 2014 KiB  
Article
The Multipole Structure and Symmetry Classification of Even-Type Deviators Decomposed from the Material Tensor
by Changxin Tang, Wei Wan, Lei Zhang and Wennan Zou
Materials 2021, 14(18), 5388; https://doi.org/10.3390/ma14185388 - 17 Sep 2021
Viewed by 1454
Abstract
The number of distinct components of a high-order material/physical tensor might be remarkably reduced if it has certain symmetry types due to the crystal structure of materials. An nth-order tensor could be decomposed into a direct sum of deviators where the order [...] Read more.
The number of distinct components of a high-order material/physical tensor might be remarkably reduced if it has certain symmetry types due to the crystal structure of materials. An nth-order tensor could be decomposed into a direct sum of deviators where the order is not higher than n, then the symmetry classification of even-type deviators is the basis of the symmetry problem for arbitrary even-order physical tensors. Clearly, an nth-order deviator can be expressed as the traceless symmetric part of tensor product of n unit vectors multiplied by a positive scalar from Maxwell’s multipole representation. The set of these unit vectors shows the multipole structure of the deviator. Based on two steps of exclusion, the symmetry classifications of all even-type deviators are obtained by analyzing the geometric symmetry of the unit vector sets, and the general results are provided. Moreover, corresponding to each symmetry type of the even-type deviators up to sixth-order, the specific multipole structure of the unit vector set is given. This could help to identify the symmetry types of an unknown physical tensor and possible back-calculation of the involved physical coefficients. Full article
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11 pages, 17095 KiB  
Article
Effects of TiB2 Particles on the Microstructure Evolution and Mechanical Properties of B4C/TiB2 Ceramic Composite
by Haiyan Niu, Yu Zhu, Ning You, Yangwei Wang, Huanwu Cheng, Dujun Luo, Mengying Tang and Jiamin Zhang
Materials 2021, 14(18), 5227; https://doi.org/10.3390/ma14185227 - 11 Sep 2021
Cited by 7 | Viewed by 1837
Abstract
B4C/TiB2 ceramic composites reinforced with three size scales (average particle size: 7 μm, 500 nm, and 50 nm) of TiB2 were prepared by using a pressureless sintering furnace at 2100 °C under Ar atmosphere for 60 min. The results [...] Read more.
B4C/TiB2 ceramic composites reinforced with three size scales (average particle size: 7 μm, 500 nm, and 50 nm) of TiB2 were prepared by using a pressureless sintering furnace at 2100 °C under Ar atmosphere for 60 min. The results demonstrated that during the sintering process, TiB2 located on the boundaries between different B4C grains could inhibit the grain growth which improved the mass transport mechanism and sintering driving force. A semi-coherent interface between B4C and SiC was found, which is supposed to help to reduce the interface energy and obtain good mechanical properties of the B4C/TiB2 ceramic composite. On sample cooling from sintering temperature to room temperature, the residual tensile stress fields formed at the TiB2 interfaces owning to the thermo-elastico properties mismatched, which might have contributed to increase the ability of the sample to resist crack propagation. The results showed that the relative density, Vickers hardness, and fracture toughness of the composite with 20 wt.% submicron and 10 wt.% nano-TiB2 were significantly improved, which were 98.6%, 30.2 GPa, and 5.47 MPa·m1/2, respectively. Full article
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13 pages, 3830 KiB  
Article
Tailoring the Structural and Electronic Properties of Graphene through Ion Implantation
by Fei Ren, Mengli Yao, Min Li and Hui Wang
Materials 2021, 14(17), 5080; https://doi.org/10.3390/ma14175080 - 05 Sep 2021
Cited by 3 | Viewed by 2446
Abstract
Ion implantation is a superior post-synthesis doping technique to tailor the structural properties of materials. Via density functional theory (DFT) calculation and ab-initio molecular dynamics simulations (AIMD) based on stochastic boundary conditions, we systematically investigate the implantation of low energy elements Ga/Ge/As into [...] Read more.
Ion implantation is a superior post-synthesis doping technique to tailor the structural properties of materials. Via density functional theory (DFT) calculation and ab-initio molecular dynamics simulations (AIMD) based on stochastic boundary conditions, we systematically investigate the implantation of low energy elements Ga/Ge/As into graphene as well as the electronic, optoelectronic and transport properties. It is found that a single incident Ga, Ge or As atom can substitute a carbon atom of graphene lattice due to the head-on collision as their initial kinetic energies lie in the ranges of 25–26 eV/atom, 22–33 eV/atom and 19–42 eV/atom, respectively. Owing to the different chemical interactions between incident atom and graphene lattice, Ge and As atoms have a wide kinetic energy window for implantation, while Ga is not. Moreover, implantation of Ga/Ge/As into graphene opens up a concentration-dependent bandgap from ~0.1 to ~0.6 eV, enhancing the green and blue light adsorption through optical analysis. Furthermore, the carrier mobility of ion-implanted graphene is lower than pristine graphene; however, it is still almost one order of magnitude higher than silicon semiconductors. These results provide useful guidance for the fabrication of electronic and optoelectronic devices of single-atom-thick two-dimensional materials through the ion implantation technique. Full article
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12 pages, 3398 KiB  
Article
Surface Modification of Nanocrystalline LiMn2O4 Using Graphene Oxide Flakes
by Monika Michalska, Dominika A. Buchberger, Jacek B. Jasiński, Arjun K. Thapa and Amrita Jain
Materials 2021, 14(15), 4134; https://doi.org/10.3390/ma14154134 - 24 Jul 2021
Cited by 11 | Viewed by 2154
Abstract
In this work, a facile, wet chemical synthesis was utilized to achieve a series of lithium manganese oxide (LiMn2O4, (LMO) with 1–5%wt. graphene oxide (GO) composites. The average crystallite sizes estimated by the Rietveld method of LMO/GO nanocomposites were [...] Read more.
In this work, a facile, wet chemical synthesis was utilized to achieve a series of lithium manganese oxide (LiMn2O4, (LMO) with 1–5%wt. graphene oxide (GO) composites. The average crystallite sizes estimated by the Rietveld method of LMO/GO nanocomposites were in the range of 18–27 nm. The electrochemical performance was studied using CR2013 coin-type cell batteries prepared from pristine LMO material and LMO modified with 5%wt. GO. Synthesized materials were tested as positive electrodes for Li-ion batteries in the voltage range between 3.0 and 4.3 V at room temperature. The specific discharge capacity after 100 cycles for LMO and LMO/5%wt. GO were 84 and 83 mAh g−1, respectively. The LMO material modified with 5%wt. of graphene oxide flakes retained more than 91% of its initial specific capacity, as compared with the 86% of pristine LMO material. Full article
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13 pages, 5241 KiB  
Article
Size Effects in Internal Friction of Nanocrystalline Aluminum Films
by Nhat Minh Dang, Zhao-Ying Wang, Yun-Chia Chou, Tra Anh Khoa Nguyen, Thien Ngon Dang and Ming-Tzer Lin
Materials 2021, 14(12), 3401; https://doi.org/10.3390/ma14123401 - 19 Jun 2021
Cited by 2 | Viewed by 1441
Abstract
Al thin film is extensively used in micro-electromechanical systems (MEMS) and electronic interconnections; however, most previous research has concentrated on their quasi-static properties and applied their designs on larger scales. The present study designed a paddle-like cantilever specimen with metal films deposited on [...] Read more.
Al thin film is extensively used in micro-electromechanical systems (MEMS) and electronic interconnections; however, most previous research has concentrated on their quasi-static properties and applied their designs on larger scales. The present study designed a paddle-like cantilever specimen with metal films deposited on the upper surface to investigate the quasi-static properties of Al thin film at room temperature under high vacuum conditions at microscopic scales. Energy loss was determined using a decay technique in the oscillation amplitude of a vibrating structure following resonant excitation. Grain size and film thickness size were strictly controlled considering the quasi-static properties of the films. This study found that the internal friction of ultra-thin and thin Al films was more dependent on the grain boundaries than film thickness. Full article
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20 pages, 7260 KiB  
Article
Development of Resistance Spot Welding Processes of Metal–Plastic Composites
by Paweł Kustroń, Marcin Korzeniowski, Tomasz Piwowarczyk and Paweł Sokołowski
Materials 2021, 14(12), 3233; https://doi.org/10.3390/ma14123233 - 11 Jun 2021
Cited by 14 | Viewed by 3114
Abstract
Metal–plastic composites (MPCs) are gaining importance mainly due to high strength to weight ratio. They consist of three layers, two outer metallic cover sheets, and a plastic core. The presence of that inner plastic layer makes them rather unsuitable for joining by means [...] Read more.
Metal–plastic composites (MPCs) are gaining importance mainly due to high strength to weight ratio. They consist of three layers, two outer metallic cover sheets, and a plastic core. The presence of that inner plastic layer makes them rather unsuitable for joining by means of any conventional welding processes, which significantly reduces the application range of MPC. In this work, three various resistance spot welding (RSW)-based concepts were developed to overcome that limitation and join Litecor to DP600 steel. In all cases, a dedicated initial stage was implemented to RSW, which was aimed at removing the non-conductive polymer layer from the welding zone and creating the proper electrical contact for the resistance welding. These were, namely: (i) shunt current-assisted RSW; (ii) induction heating-assisted RSW; and (iii) ultrasonic-assisted RSW. The development of each concept was supported by finite element modeling, which was focused on setting the proper process parameters for polymer layer removal. Finally, the macro- and microstructure of exemplary RSW joints are shown and the most common spot weld features as well as the further development possibilities are discussed. Full article
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Review

Jump to: Research

26 pages, 2935 KiB  
Review
The Reuse of Biomass and Industrial Waste in Biocomposite Construction Materials for Decreasing Natural Resource Use and Mitigating the Environmental Impact of the Construction Industry: A Review
by Iwona Ryłko-Polak, Wojciech Komala and Andrzej Białowiec
Materials 2022, 15(12), 4078; https://doi.org/10.3390/ma15124078 - 08 Jun 2022
Cited by 15 | Viewed by 3364
Abstract
The construction industry is the world’s largest emitter of greenhouse gases. The CO2 emission levels in the atmosphere are already reaching a tipping point and could cause severe climate change. An important element is the introduction of a technology that allows for [...] Read more.
The construction industry is the world’s largest emitter of greenhouse gases. The CO2 emission levels in the atmosphere are already reaching a tipping point and could cause severe climate change. An important element is the introduction of a technology that allows for the capture and sequencing of carbon dioxide levels, reducing both emissions and the carbon footprint from the production of Portland cement and cement-based building materials. The European Union has started work on the European Climate Law, establishing the European Green Deal program, which introduces the achievement of climate neutrality in the European Union countries. This includes a new policy of sustainable construction, the aim of which is to develop products with a closed life cycle through proper waste management. All efforts are being made to create generated waste and thus to support their production and/or use as substitutes for raw materials to produce biocomposites. This article reviews environmental issues and characterizes selected waste materials from the agri-food, mineral, and industrial sectors with specific properties that can be used as valuable secondary raw materials to produce traditional cements and biocomposite materials, while maintaining or improving their mechanical properties and applications. Full article
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