Research

15 pages, 4290 KiB

Open AccessArticle

Characterization of Ceria Nanoparticles as Abrasives Applied with Defoaming Polymers for CMP (Chemical Mechanical Polishing) Applications

by Sohee Hwang and Woonjung Kim

Polymers 2024, 16(6), 844; https://doi.org/10.3390/polym16060844 - 19 Mar 2024

Viewed by 588

Abstract

Chemical mechanical polishing/planarization (CMP) is an essential manufacturing process in semiconductor technologies. This method combines chemical and mechanical forces to smooth the surfaces of wafers. The effectiveness of CMP relies on a carefully chosen slurry, demanding a sophisticated manufacturing technology. This technology must [...] Read more.

Chemical mechanical polishing/planarization (CMP) is an essential manufacturing process in semiconductor technologies. This method combines chemical and mechanical forces to smooth the surfaces of wafers. The effectiveness of CMP relies on a carefully chosen slurry, demanding a sophisticated manufacturing technology. This technology must seamlessly integrate both chemical composition and mechanical elements, highlighting the intricate synergy required for successful semiconductor fabrication. Particularly in milling processes, if agglomerated particles due to slurry particle corrosion are present during polishing, uneven polishing, numerous fine scratches occur, leading to an increase in roughness and a deterioration in the quality of the finished surface. In this study, to overcome the issue of particle agglomeration and uneven polishing in commonly used ceria nanoparticle slurries during CMP processes, we investigated the ceria nanoparticle behavior based on styrene–maleic acid (SMA) dispersant polymer applied with three types of defoaming polymers. The investigations are expected to open up the possibility of utilizing ceria nanoparticles with applied defoaming polymer as an abrasive for advanced CMP applications. All samples were characterized by DLS (dynamic light scattering), SEM-EDX (scanning electron microscopy–energy dispersive X-ray spectroscopy), pH, conductivity, viscosity, a 10-day stability test at 60 °C, the AF4 test, and the polishing rate efficiency test. Our research demonstrates a significant improvement achieved through the use of SMA dispersant polymer, resulting in a polishing selection ratio exceeding 80 for oxide and nitride films. The G-336 defoaming polymer utilized here is expected to serve as a viable alternative in CMP processes by providing stable uniformity. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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12 pages, 2871 KiB

Open AccessArticle

Electrospinning Silk-Fibroin-Based Fibrous Membranes with AgNPs for Antimicrobial Application

by Qing Li, Hongyu Gong, Xiang Jia, Ran Wang, Zhiwei Liu, Lexin Zhang, Jisheng Li and Tifeng Jiao

Polymers 2024, 16(5), 648; https://doi.org/10.3390/polym16050648 - 28 Feb 2024

Viewed by 550

Abstract

Silk fibroin (SF) has excellent biocompatibility and is one of the most commonly used polymer materials. However, SF fibers have serious drawbacks as antibacterial materials due to their lack of stability and bacterial resistance. Therefore, it is of paramount significance to enhance the [...] Read more.

Silk fibroin (SF) has excellent biocompatibility and is one of the most commonly used polymer materials. However, SF fibers have serious drawbacks as antibacterial materials due to their lack of stability and bacterial resistance. Therefore, it is of paramount significance to enhance the stability and bolster the bacterial resistance of SF fibers. In this study, SF fibers were fabricated and loaded with Ag nanoparticles (AgNPs) to improve the antimicrobial properties of the fibers. The impact of reduction conditions on the size of AgNPs was also investigated. In an antibacterial test, the fibers that were prepared exhibited over 98% bacterial resistance against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli). Therefore, as an efficient antibacterial material, these fibers are expected to become a candidate material in medical and textile fields. This study offers a novel approach for the utilization of SF fibers in the realm of antibacterial applications. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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13 pages, 4918 KiB

Open AccessArticle

A Water-Processed Mesoscale Structure Enables 18.5% Efficient Binary Layer-by-Layer Organic Solar Cells

by Chen Xie, Hui Huang, Zijian Li, Xianghui Zeng, Baoshen Deng, Chengsheng Li, Guangye Zhang and Shunpu Li

Polymers 2024, 16(1), 91; https://doi.org/10.3390/polym16010091 - 28 Dec 2023

Cited by 1 | Viewed by 794

Abstract

The two-step layer-by-layer (LBL) deposition of donor and acceptor films enables desired vertical phase separation and high performance in organic solar cells (OSCs), which becomes a promising technology for large-scale printing devices. However, limitations including the use of toxic solvents and unpredictable infiltration [...] Read more.

The two-step layer-by-layer (LBL) deposition of donor and acceptor films enables desired vertical phase separation and high performance in organic solar cells (OSCs), which becomes a promising technology for large-scale printing devices. However, limitations including the use of toxic solvents and unpredictable infiltration between donor and acceptor still hinder the commercial production of LBL OSCs. Herein, we developed a water-based nanoparticle (NP) ink containing donor polymer to construct a mesoscale structure that could be infiltrated with an acceptor solution. Using non-halogen o-xylene for acceptor deposition, the LBL strategy with a mesoscale structure delivered outstanding efficiencies of 18.5% for binary PM6:L8-BObased LBL OSCs. Enhanced charge carrier mobility and restricted trap states were observed in the meso-LBL devices with optimized vertical morphology. It is believed that the findings in this work will bring about more research interest and effort on eco-friendly processing in preparation for the industrial production of OSCs. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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26 pages, 5748 KiB

Open AccessArticle

Preparation and Effect of Methyl-Oleate-Based Polyol on the Properties of Rigid Polyurethane Foams as Potential Thermal Insulation Material

by Norsuhaili Kamairudin, Luqman Chuah Abdullah, Seng Soi Hoong, Dayang Radiah Awang Biak and Hidayah Ariffin

Polymers 2023, 15(14), 3028; https://doi.org/10.3390/polym15143028 - 13 Jul 2023

Cited by 1 | Viewed by 1263

Abstract

Recently, most of the commercial polyols used in the production of rigid polyurethane foams (RPUFs) have been derived from petrochemicals. Therefore, the introduction of modified palm oil derivatives-based polyol as a renewable material into the formulation of RPUFs is the focus of this [...] Read more.

Recently, most of the commercial polyols used in the production of rigid polyurethane foams (RPUFs) have been derived from petrochemicals. Therefore, the introduction of modified palm oil derivatives-based polyol as a renewable material into the formulation of RPUFs is the focus of this study. A palm oil derivative—namely, methyl oleate (MO)—was successfully modified through three steps of reactions: epoxidation reaction, ring-opened with glycerol, followed by amidation reaction to produce a bio-based polyol named alkanolamide polyol. Physicochemical properties of the alkanolamide polyol were analyzed. The hydroxyl value of alkanolamide polyol was 313 mg KOH/g, which is suitable for producing RPUFs. Therefore, RPUFs were produced by replacing petrochemical polyol with alkanolamide polyol. The effects of alkanolamide polyol on the physical, mechanical and thermal properties were evaluated. The results showed that the apparent density and compressive strength increased, and cell size decreased, upon introducing alkanolamide polyol. All the RPUFs exhibited low water absorption and excellent dimensional stability. The RPUFs made with increased amounts of alkanolamide polyol showed higher thermal conductivity. Nevertheless, the thermal conductivities of RPUFs made with alkanolamide polyol are still within the range for thermal insulating materials (<0.1 W/m.K). The thermal stability of RPUFs was improved with the addition of alkanolamide polyol into the system. Thus, the RPUFs made from alkanolamide polyol are potential candidates to be used as insulation for refrigerators or freezers. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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15 pages, 4670 KiB

Open AccessArticle

Synergistic Effect of Zinc-Chitosan Nanoparticles and Hydroxychloroquine to Inhibit Buffalo Coronavirus

by Anju Manuja, Balvinder Kumar, Dharvi Chhabra, Basanti Brar, Riyesh Thachamvally, Yash Pal and Minakshi Prasad

Polymers 2023, 15(13), 2949; https://doi.org/10.3390/polym15132949 - 05 Jul 2023

Cited by 1 | Viewed by 1391

Abstract

Zinc ions can hinder the synthesis of proteins required for accomplishing several stages of the viral life cycle. The intracellular zinc concentration can be increased by using zinc ionophores which transport zinc ions into the cells and hinder viral replication. (Hydroxy)chloroquine is an [...] Read more.

Zinc ions can hinder the synthesis of proteins required for accomplishing several stages of the viral life cycle. The intracellular zinc concentration can be increased by using zinc ionophores which transport zinc ions into the cells and hinder viral replication. (Hydroxy)chloroquine is an example of a zinc ionophore, but both zinc and (hydroxy)chloroquine can be toxic to the host organism. The nanocarriers may serve as camouflage to evade the adverse effects of drugs, chemicals, and nanoparticles on the host. We formulated ZnO nanoparticles with flower-like morphology (ZnONFs). It was further decorated with chitosan along with hydroxychloroquine (as a zinc ionophore) (CHCZnO NPs). We have chosen the cationic polymer chitosan since it is biocompatible, biodegradable and binds easily with the cells, and enhances the transport of drugs across cell membranes. The formulation was investigated for size, shape, surface charge, and interaction of chemicals used. We evaluated the formulations for cytotoxicity, and biocompatibility in embryonated chicks and their efficacy against bovine coronavirus (BCoV) isolated from a buffalo calf, and pneumo-enteric coronaviruses isolated from a buffalo calf with promising results in comparison to ZnONFs/hydroxychloroquine alone. Furthermore, we elucidate the mechanism underlying the lysosomotropic effect of various formulations on Vero cells infected with the buffalo coronavirus. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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11 pages, 2926 KiB

Open AccessArticle

Reinforced Bioremediation of Excessive Nitrate in Atrazine-Contaminated Soil by Biodegradable Composite Carbon Source

by Zhongchen Yang, Yanhong Lou, Hong Pan, Hui Wang, Quangang Yang, Yajie Sun and Yuping Zhuge

Polymers 2023, 15(13), 2765; https://doi.org/10.3390/polym15132765 - 21 Jun 2023

Cited by 1 | Viewed by 857

Abstract

Bioremediation is a good alternative to dispose of the excessive nitrate (NO₃⁻) in soil and alleviate the secondary salinization of soil, but the presence of atrazine in soil interferes with the bioremediation process. In the present study, the biodegradable composite [...] Read more.

Bioremediation is a good alternative to dispose of the excessive nitrate (NO₃⁻) in soil and alleviate the secondary salinization of soil, but the presence of atrazine in soil interferes with the bioremediation process. In the present study, the biodegradable composite carbon source with different dosages was added to the atrazine-contaminated soil to intensify the bioremediation of excessive NO₃⁻. The atrazine-contaminated soil with a 25 g/kg composite carbon source achieved the optimal NO₃⁻ removal performance (92.10%), which was slightly higher than that with a 5 g/kg composite carbon source (86.15%) (p > 0.05). Unfortunately, the negative effects of the former were observed, such as the distinctly higher emissions of N₂O, CO₂ and a more powerful global warming potential (GWP). Microbial community analysis showed that the usage of the composite carbon source clearly decreased the richness and diversity of the microbial community, and greatly stimulated nitrogen metabolism and atrazine degradation (p < 0.05). To sum up, the application of a 5 g/kg composite carbon source contributed to guaranteeing bioremediation performance and reducing adverse environmental impacts at the same time. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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12 pages, 3828 KiB

Open AccessArticle

Performance Enhancement of PLA-Based Blend Microneedle Arrays through Shish-Kebab Structuring Strategy in Microinjection Molding

by Lifan Zhang, Yinghong Chen, Jiayu Tan, Shuo Feng, Yeping Xie and Li Li

Polymers 2023, 15(10), 2234; https://doi.org/10.3390/polym15102234 - 09 May 2023

Cited by 2 | Viewed by 1571

Abstract

Poly(lactic acid) (PLA) microneedles have been explored extensively, but the current regular fabrication strategy, such as thermoforming, is inefficient and poorly conformable. In addition, PLA needs to be modified as the application of microneedle arrays made of pure PLA is limited because of [...] Read more.

Poly(lactic acid) (PLA) microneedles have been explored extensively, but the current regular fabrication strategy, such as thermoforming, is inefficient and poorly conformable. In addition, PLA needs to be modified as the application of microneedle arrays made of pure PLA is limited because of their easy tip fracture and poor skin adhesion. For this purpose, in this article, we reported a facile and scalable strategy to fabricate the microneedle arrays of the blend of PLA matrix and poly(p-dioxanone) (PPDO) dispersed phase with complementary mechanical properties through microinjection molding technology. The results showed that the PPDO dispersed phase could be in situ fibrillated under the effect of the strong shear stress field generated in micro-injection molding. These in situ fibrillated PPDO dispersed phases could hence induce the formation of the shish-kebab structures in the PLA matrix. Particularly for PLA/PPDO (90/10) blend, there are the densest and most perfect shish-kebab structures formed. The above microscopic structure evolution could be also advantageous to the enhancement in the mechanical properties of microparts of PLA/PPDO blend (tensile microparts and microneedle arrays), e.g., the elongation at break of the blend is almost double that of pure PLA while still maintaining the high stiffness (Young’s modulus of 2.7 GPa) and the high strength (tensile strength of 68.3 MPa) in the tensile test, and relative to pure PLA, there is 100% or more increase in the load and displacement of microneedle in the compression test. This could open up new spaces for expanding the industrial application of the fabricated microneedle arrays. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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11 pages, 2628 KiB

Open AccessArticle

The Role of the Interface of PLA with Thermoplastic Starch in the Nonisothermal Crystallization Behavior of PLA in PLA/Thermoplastic Starch/SiO₂ Composites

by Deling Li, Congcong Luo, Jun Zhou, Liming Dong, Ying Chen, Guangtian Liu and Shuyun Qiao

Polymers 2023, 15(6), 1579; https://doi.org/10.3390/polym15061579 - 22 Mar 2023

Cited by 4 | Viewed by 1475

Abstract

Corn starch was plasticized by glycerol suspension in a twin-screw extruder, in which the glycerol suspension was the pre-dispersion mixture of glycerol with nano-SiO₂. Polylactide (PLA)/thermoplastic starch/SiO₂ composites were obtained through melt-blending of PLA with thermoplastic starch/SiO₂ in a [...] Read more.

Corn starch was plasticized by glycerol suspension in a twin-screw extruder, in which the glycerol suspension was the pre-dispersion mixture of glycerol with nano-SiO₂. Polylactide (PLA)/thermoplastic starch/SiO₂ composites were obtained through melt-blending of PLA with thermoplastic starch/SiO₂ in a twin-screw extruder. The nonisothermal crystallization behavior of PLA in the composites was investigated by differential scanning calorimetry. An interface of PLA with thermoplastic starch was proven to exist in the composites, and its interfacial bonding characteristics were analyzed. The interfacial binding energy stemming from PLA with thermoplastic starch exerts a significant influence on the segmental mobility of PLA at the interface. The segmental mobility of PLA is gradually improved by increasing interfacial binding energy, and consequently, the relative crystallinity on the interface exhibits progressive promotion. The Jeziorny model could well describe the primary crystallization of PLA in the composites. The extracted Avrami exponents based on the Jeziorny model indicate that the primary crystallization of PLA follows heterogeneous nucleation and three-dimensional growth. This study has revealed the intrinsic effect of the interfacial segmental mobility on the nonisothermal crystallization behavior of PLA in composites, which is of technological significance for its blow molding. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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23 pages, 760 KiB

Open AccessArticle

Identifying the Most Efficient Natural Fibre for Common Commercial Building Insulation Materials with an Integrated PSI, MEREC, LOPCOW and MCRAT Model

by Alptekin Ulutaş, Figen Balo and Ayşe Topal

Polymers 2023, 15(6), 1500; https://doi.org/10.3390/polym15061500 - 17 Mar 2023

Cited by 18 | Viewed by 2939

Abstract

Building insulation is the most respected among the compatible and effective energy conservation technologies available today, as it also reduces yearly energy costs and negative environmental effects. A building envelope is made up of various insulation materials that are important in determining a [...] Read more.

Building insulation is the most respected among the compatible and effective energy conservation technologies available today, as it also reduces yearly energy costs and negative environmental effects. A building envelope is made up of various insulation materials that are important in determining a building’s thermal performance. Proper insulation material selection concludes in less energy requisition for operation. The purpose of this research is to supply information about natural fibre insulating materials used in construction insulation to maintain energy efficiency, as well as to recommend the most efficient natural fibre insulation material. As in most decision-making problems, several criteria and alternatives are involved in insulation material selection, too. Therefore, we used a novel integrated multi criteria decision making (MCDM) model including the preference selection index (PSI), method based on the removal effects of criteria (MEREC), logarithmic percentage change-driven objective weighting (LOPCOW), and multiple criteria ranking by alternative trace (MCRAT) methods to deal with the complexity of numerous criteria and alternatives. The contribution of this study is that a new hybrid MCDM method is developed. Additionally, the number of studies using the MCRAT method is very limited in the literature; therefore, this study will provide more insights into and results of this method to the literature. Full article

(This article belongs to the Special Issue Eco-Friendly Polymers: Synthesis, Characterization and Applications II)

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