Polymers

Research

Jump to: Review

20 pages, 5233 KiB

Open AccessArticle

Creation of Composite Aerogels Consisting of Activated Carbon and Nanocellulose Blended with Cross-Linked Biopolymers: Application as Ethylene Scavengers

by Asadullah, Kittaporn Ngiwngam, Jaejoon Han, Pornchai Rachtanapun, Rafael Auras, Thomas Karbowiak, Duangjai Noiwan, Masubon Thongngam and Wirongrong Tongdeesoontorn

Polymers 2024, 16(21), 3081; https://doi.org/10.3390/polym16213081 - 31 Oct 2024

Viewed by 580

Abstract

This study involved producing aerogels using activated carbon (AC) and nanocellulose (NC). Two distinct structured composites, AC composite aerogel (ACCA) and NC composite aerogel (NCCA), were developed by separately mixing AC and NC with identical proportions of cross-linked biopolymers: hydroxypropyl methylcellulose (HPMC), methylcellulose [...] Read more.

This study involved producing aerogels using activated carbon (AC) and nanocellulose (NC). Two distinct structured composites, AC composite aerogel (ACCA) and NC composite aerogel (NCCA), were developed by separately mixing AC and NC with identical proportions of cross-linked biopolymers: hydroxypropyl methylcellulose (HPMC), methylcellulose (MC), and chitosan (C). These aerogels were evaluated for their capability to adsorb ethylene gas through batch experiments, while the physical and chemical characteristics were thoroughly examined to determine their feasibility of removing ethylene. The resulting ACCA and NCCA aerogels exhibited low densities of 0.094 g cm⁻³ and 0.077 g cm⁻³, respectively, coupled with high porosity ranging between 95 and 96%. During the ethylene adsorption test, NCCA exhibited superior ethylene removal rates (~14.88–16.77 mL kg⁻¹) compared to ACCA (~13.57–14.97 mL kg⁻¹). Specifically, NCCA achieved a removal efficiency of 83.86% compared to 74.64% for ACCA. Kinetic model fitting yielded high R² values ranging from 0.97 to 0.98 with the Lagergren kinetic model. These findings suggest the potential of composite aerogels to be incorporated into food packaging materials for dynamic ethylene capture, independent of environmental conditions, thereby providing promising routes for further development. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Graphical abstract

14 pages, 4764 KiB

Open AccessArticle

Innovative Polymeric Coatings with Dual Antifouling and Light-Activated Bactericidal Functions for Urinary Catheter Applications

by Po-Hsun Chen, Guan-Hua Chen and Wei-Bor Tsai

Polymers 2024, 16(21), 2974; https://doi.org/10.3390/polym16212974 - 24 Oct 2024

Viewed by 1869

Abstract

Catheter-associated urinary tract infections (CAUTIs) present significant health risks in medical settings, necessitating innovative solutions to prevent bacterial colonization on catheter surfaces. This study introduces a novel polymeric coating with dual antifouling and light-activated bactericidal properties to enhance the bactericidal efficacy of urinary [...] Read more.

Catheter-associated urinary tract infections (CAUTIs) present significant health risks in medical settings, necessitating innovative solutions to prevent bacterial colonization on catheter surfaces. This study introduces a novel polymeric coating with dual antifouling and light-activated bactericidal properties to enhance the bactericidal efficacy of urinary catheters. The coatings were synthesized using a one-step process involving pyrogallol chemistry to deposit a copolymer composed of zwitterionic sulfobetaine for antifouling and sodium copper chlorophyllin, a photosensitizer that generates reactive oxygen species under light exposure to effectively kill bacteria. We evaluated the antifouling properties, cytocompatibility, and bactericidal performance of the coatings under various light conditions. The results showed significant reductions in bacterial adhesion, with light activation further endowing the catheter with bactericidal effects. Additionally, light could be delivered through an optical fiber within the catheter lumen to target and kill bacteria. The innovative coating using light-activated bactericidal action offers a promising approach to preventing CAUTIs, representing a potential breakthrough in developing safer and more effective urinary catheters. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

11 pages, 928 KiB

Open AccessArticle

Catalytic Hydrolysis of Paraoxon by Immobilized Copper(II) Complexes of 1,4,7-Triazacyclononane Derivatives

by Michaela Buziková, Hanna Zhukouskaya, Elena Tomšík, Miroslav Vetrík, Jan Kučka, Martin Hrubý and Jan Kotek

Polymers 2024, 16(20), 2911; https://doi.org/10.3390/polym16202911 - 16 Oct 2024

Viewed by 551

Abstract

Organophosphate neuroactive agents represent severe security threats in various scenarios, including military conflicts, terrorist activities and industrial accidents. Addressing these threats necessitates effective protective measures, with a focus on decontamination strategies. Adsorbents such as bentonite have been explored as a preliminary method for [...] Read more.

Organophosphate neuroactive agents represent severe security threats in various scenarios, including military conflicts, terrorist activities and industrial accidents. Addressing these threats necessitates effective protective measures, with a focus on decontamination strategies. Adsorbents such as bentonite have been explored as a preliminary method for chemical warfare agent immobilization, albeit lacking chemical destruction capabilities. Chemical decontamination, on the other hand, involves converting these agents into non-toxic or less toxic forms. In this study, we investigated the hydrolytic activity of a Cu(II) complex, previously studied for phosphate ester hydrolysis, as a potential agent for chemical warfare decontamination. Specifically, we focused on a ligand featuring a thiophene anchor bound through an aliphatic spacer, which exhibited high hydrolytic activity in its Cu(II) complex form in our previous studies. Paraoxon, an efficient insecticide, was selected as a model substrate for hydrolytic studies due to its structural resemblance to specific chemical warfare agents and due to the presence of a chromogenic 4-nitrophenolate moiety. Our findings clearly show the hydrolytic activity of the studied Cu(II) complexes. Additionally, we demonstrate the immobilization of the studied complex onto a solid substrate of Amberlite XAD4 via copolymerization of its thiophene side group with dithiophene. The hydrolytic activity of the resultant material towards paraoxon was studied, indicating its potential utilization in organophosphate neuroactive agent decontamination under mild conditions and the key importance of surface adsorption of paraoxon on the polymer surface. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

15 pages, 5317 KiB

Open AccessArticle

Preparation of Double-Layer Composite Coffee Filtration Nonwovens

by Lihuan Zhao, Yujie Yang, Yuwen Wang, Ziyan Yan and Rong Zhang

Polymers 2024, 16(16), 2275; https://doi.org/10.3390/polym16162275 - 10 Aug 2024

Viewed by 1048

Abstract

The coffee industry is developing rapidly in the world, and the use of coffee filtration nonwovens (CFNs) is becoming more and more extensive; however, there is a lack of standards and research for its production and trade, and the quality of related products [...] Read more.

The coffee industry is developing rapidly in the world, and the use of coffee filtration nonwovens (CFNs) is becoming more and more extensive; however, there is a lack of standards and research for its production and trade, and the quality of related products on the market is uneven at present. Here, eight double-layer composite coffee filtration nonwovens (D-LCCFNs) were prepared by using 5 g/m² and 10 g/m² polypropylene (PP) melt-blown nonwovens (MNs), 20 g/m² PP spunbonded nonwovens and 20 g/m² viscose/ES fiber chemically bonded nonwovens, and the physical properties, morphology and the filtration effect of coffee and purified water for the prepared samples were tested. It was found that the surface density of the microfiber layer (MNs) in the D-LCCFNs was negatively correlated with the coffee filtration rate; when the microfiber layer in the D-LCCFNs was in direct contact with the coffee, the liquid started to drip later, and the filtration rate of the coffee was slower; the filtration rate of the samples with the viscose/ES chemically bonded nonwovens was very fast. However, the samples without viscose/ES fibers basically did not filter pure water much, but they could filter out the coffee liquid normally, and the samples’ hydrophilicity increased significantly after filtering coffee. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

15 pages, 6254 KiB

Open AccessEditor’s ChoiceArticle

Effects of the Amylose/Amylopectin Ratio of Starch on Borax-Crosslinked Hydrogels

by Kai Lu, Rudy Folkersma, Vincent S. D. Voet and Katja Loos

Polymers 2024, 16(16), 2237; https://doi.org/10.3390/polym16162237 - 6 Aug 2024

Viewed by 2122

Abstract

Herein, we simultaneously prepared borax-crosslinked starch-based hydrogels with enhanced mechanical properties and self-healing ability via a simple one-pot method. The focus of this work is to study the effects of the amylose/amylopectin ratio of starch on the grafting reactions and the performance of [...] Read more.

Herein, we simultaneously prepared borax-crosslinked starch-based hydrogels with enhanced mechanical properties and self-healing ability via a simple one-pot method. The focus of this work is to study the effects of the amylose/amylopectin ratio of starch on the grafting reactions and the performance of the resulting borax-crosslinked hydrogels. An increase in the amylose/ amylopectin ratio increased the gel fraction and grafting ratio but decreased the swelling ratio and pore diameter. Compared with hydrogels prepared from low-amylose starches, hydrogels prepared from high-amylose starches showed pronouncedly increased network strength, and the maximum storage modulus increased by 8.54 times because unbranched amylose offered more hydroxyl groups to form dynamic borate ester bonds with borate ions and intermolecular hydrogen bonds, leading to an enhanced crosslink density. In addition, all the hydrogels exhibited a uniformly interconnected network structure. Furthermore, owing to the dynamic borate ester bonds and hydrogen bonds, the hydrogel exhibited excellent recovery behavior under continuous step strain, and it also showed thermal responsiveness. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Graphical abstract

17 pages, 1629 KiB

Open AccessArticle

Influence of Different Deep Eutectic Solvents and Plant Extracts on Antioxidant, Mechanical, and Color Properties of Alginate Film

by Jolanta Kowalonek, Malo Hamieau and Aleksandra Szydłowska-Czerniak

Polymers 2024, 16(14), 2084; https://doi.org/10.3390/polym16142084 - 22 Jul 2024

Viewed by 938

Abstract

Eco-friendly functional alginate films with plant extracts (chokeberry pomace (ChP) or lemon balm (LB) herb) were obtained. Moreover, deep eutectic solvents (DESs) based on choline chloride, glucose, and betaine were used to acquire the active substances from plant materials. The films were tested [...] Read more.

Eco-friendly functional alginate films with plant extracts (chokeberry pomace (ChP) or lemon balm (LB) herb) were obtained. Moreover, deep eutectic solvents (DESs) based on choline chloride, glucose, and betaine were used to acquire the active substances from plant materials. The films were tested regarding the antioxidant, mechanical, and color properties. The results revealed that the films’ antioxidant capacities (AC) depended on the extract type and DES used, namely AC values for alginate films with LB were higher than those with ChP. Moreover, the results of the films’ mechanical properties depended only on the DES, which acted as a plasticizer in most cases. Furthermore, the color analysis of the studied films showed a dependence on the type of extract and DES. The lightness (L*) was influenced only by the DES type, while the solvent and extract type affected the a* and b* values. Our results show that the films can be applied as active packaging for food products. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

13 pages, 6431 KiB

Open AccessArticle

Effective Unidirectional Wetting of Liquids on Multi-Gradient, Bio-Inspired Surfaces Fabricated by 3D Printing and Surface Modification

by Che-Ni Hsu, Ngoc Phuong Uyen Mai, Haw-Kai Chang and Po-Yu Chen

Polymers 2024, 16(13), 1874; https://doi.org/10.3390/polym16131874 - 30 Jun 2024

Viewed by 1086

Abstract

The movement of liquid droplets on the energy gradient surface has attracted extensive attention inspired by biological features in nature, such as the periodic spindle-shaped nodes in spider silks and conical-like barbs of cacti, and the structure–property–function relationship of multifunctional gradient surfaces. In [...] Read more.

The movement of liquid droplets on the energy gradient surface has attracted extensive attention inspired by biological features in nature, such as the periodic spindle-shaped nodes in spider silks and conical-like barbs of cacti, and the structure–property–function relationship of multifunctional gradient surfaces. In this study, a series of specific patterns are fabricated with 3D printing technology, followed by modification via the atmospheric pressure plasma treatment and liquid phase chemical deposition, resulting in enhancing the ability of water droplets of 5 μL to travel 18.47 mm on a horizontal plane and 22.75 mm against gravity at up to a 20° tilting angle. Additionally, analysis techniques have been employed, including a contact angle analyzer, ESCA, and a laser confocal microscope to evaluate the sample performance. This work could further be applied to many applications related to microfluidic devices, drug delivery and water/fog collection. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

15 pages, 5923 KiB

Open AccessArticle

Ultrafast Polymerization of a Self-Adhesive and Strain Sensitive Hydrogel-Based Flexible Sensor for Human Motion Monitoring and Handwriting Recognition

by Bin Du, Mengwei Yin, Kenan Yang, Sainan Wang, Yiting Pei, Rubai Luo, Shisheng Zhou and Huailin Li

Polymers 2024, 16(11), 1595; https://doi.org/10.3390/polym16111595 - 4 Jun 2024

Cited by 1 | Viewed by 1022

Abstract

Hydrogel-based flexible electronic devices have great potential in human motion monitoring, electronic skins, and human-computer interaction applications; hence, the efficient preparation of highly sensitive hydrogel-based flexible sensors is important. In the present work, the ultrafast polymerization of a hydrogel (1–3 min) was achieved [...] Read more.

Hydrogel-based flexible electronic devices have great potential in human motion monitoring, electronic skins, and human-computer interaction applications; hence, the efficient preparation of highly sensitive hydrogel-based flexible sensors is important. In the present work, the ultrafast polymerization of a hydrogel (1–3 min) was achieved by constructing a tannic acid (TA)-Fe³⁺ dynamic redox system, which endowed the hydrogel with good adhesion performance (the adhesion strength in wood was 17.646 kPa). In addition, the uniform dispersal ensured by incorporating polydopamine-decorated polypyrrole (PPy@PDA) into the hydrogel matrix significantly improved the hydrogel’s stretching ability (575.082%). The as-prepared PAM/CS/PPy@PDA/TA hydrogel-based flexible sensor had a high-fidelity low detection limit (strain = 1%), high sensitivity at small strains (GF = 5.311 at strain = 0–8%), and fast response time (0.33 s) and recovery time (0.25 s), and it was reliably applied to accurate human motion monitoring and handwriting recognition. The PAM/CS/PPy@PDA/TA hydrogel opens new horizons for wearable electronic devices, electronic skins, and human-computer interaction applications. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

16 pages, 4872 KiB

Open AccessEditor’s ChoiceArticle

Active Poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) Films Containing Phenolic Compounds with Different Molecular Structures

by Carla Ivonne La Fuente Arias, Chelo González-Martínez and Amparo Chiralt

Polymers 2024, 16(11), 1574; https://doi.org/10.3390/polym16111574 - 2 Jun 2024

Cited by 2 | Viewed by 1182

Abstract

To obtain more sustainable and active food packaging materials, PHBV films containing 5% wt. of phenolic compounds with different molecular structures (ferulic acid, vanillin, and catechin) and proved antioxidant and antimicrobial properties were obtained by melt blending and compression molding. These were characterized [...] Read more.

To obtain more sustainable and active food packaging materials, PHBV films containing 5% wt. of phenolic compounds with different molecular structures (ferulic acid, vanillin, and catechin) and proved antioxidant and antimicrobial properties were obtained by melt blending and compression molding. These were characterized by their structural, mechanical, barrier, and optical properties, as well as the polymer crystallization, thermal stability, and component migration in different food simulants. Phenolic compounds were homogenously integrated within the polymer matrix, affecting the film properties differently. Ferulic acid, and mainly catechin, had an anti-plasticizing effect (increasing the polymer glass transition temperature), decreasing the film extensibility and the resistance to breaking, with slight changes in the elastic modulus. In contrast, vanillin provoked a plasticizing effect, decreasing the elastic modulus without notable changes in the film extensibility while increasing the water vapor permeability. All phenolic compounds, mainly catechin, improved the oxygen barrier capacity of PHBV films and interfered with the polymer crystallization, reducing the melting point and crystallinity degree. The thermal stability of the material was little affected by the incorporation of phenols. The migration of passive components of the different PHBV films was lower than the overall migration limit in every simulant. Phenolic compounds were released to a different extent depending on their thermo-sensitivity, which affected their final content in the film, their bonding forces in the polymer matrix, and the simulant polarity. Their effective release in real foods will determine their active action for food preservation. Catechin was the best preserved, while ferulic acid was the most released. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

19 pages, 5593 KiB

Open AccessArticle

Fabrication of Waterborne Silicone-Modified Polyurethane Nanofibers for Nonfluorine Elastic Waterproof and Breathable Membranes

by Fang Li, Kai Weng, Toshihisa Tanaka, Jianxin He, Haimin Zheng, Daisuke Noda, Shinji Irifune and Hiromasa Sato

Polymers 2024, 16(11), 1505; https://doi.org/10.3390/polym16111505 - 25 May 2024

Cited by 1 | Viewed by 1091

Abstract

Waterproof and breathable membranes have a huge market demand in areas, such as textiles and medical protection. However, existing fluorinated nanofibrous membranes, while possessing good waterproof and breathable properties, pose health and environmental hazards. Consequently, fabricating fluorine-free, eco-friendly waterborne membranes by integrating outstanding [...] Read more.

Waterproof and breathable membranes have a huge market demand in areas, such as textiles and medical protection. However, existing fluorinated nanofibrous membranes, while possessing good waterproof and breathable properties, pose health and environmental hazards. Consequently, fabricating fluorine-free, eco-friendly waterborne membranes by integrating outstanding waterproofing, breathability, and robust mechanical performance remains a significant challenge. Herein, we successfully prepared waterborne silicone-modified polyurethane nanofibrous membranes with excellent elasticity, waterproofing, and breathability properties through waterborne electrospinning, using a small quantity of poly(ethylene oxide) as a template polymer and in situ doping of the poly(carbodiimide) crosslinking agent, followed by a simple hot-pressing treatment. The silicone imparted the nanofibrous membrane with high hydrophobicity, and the crosslinking agent enabled its stable porous structure. The hot-pressing treatment (120 °C) further reduced the pore size and improved the water resistance. This environmentally friendly nanofibrous membrane showed a high elongation at break of 428%, an ultra-high elasticity of 67.5% (160 cycles under 400% tensile strain), an air transmission of 13.2 mm s⁻¹, a water vapor transmission rate of 5476 g m⁻² d⁻¹, a hydrostatic pressure of 51.5 kPa, and a static water contact angle of 137.9°. The successful fabrication of these environmentally friendly, highly elastic membranes provides an important reference for applications in healthcare, protective textiles, and water purification. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

15 pages, 6052 KiB

Open AccessArticle

DIW-Printed Thermal Management PDMS Composites with 3D Structural Thermal Conductive Network of h-BN Platelets and Al₂O₃ Nanoparticles

by Hongyi Zhu, Shunxia Wu, Rui Tang, Yang Li, Gang Chen, Bingxue Huang and Biyou Peng

Polymers 2024, 16(11), 1491; https://doi.org/10.3390/polym16111491 - 24 May 2024

Viewed by 1051

Abstract

Electronic devices play an increasingly vital role in modern society, and heat accumulation is a major concern during device development, which causes strong market demand for thermal conductivity materials and components. In this paper, a novel thermal conductive material consisting of polydimethylsiloxane (PDMS) [...] Read more.

Electronic devices play an increasingly vital role in modern society, and heat accumulation is a major concern during device development, which causes strong market demand for thermal conductivity materials and components. In this paper, a novel thermal conductive material consisting of polydimethylsiloxane (PDMS) and a binary filler system of h-BN platelets and Al₂O₃ nanoparticles was successfully fabricated using direct ink writing (DIW) 3D printing technology. The addictive manufacturing process not only endows the DIW-printed composites with various geometries but also promotes the construction of a 3D structural thermal conductive network through the shearing force during the printing process. Moreover, the integrity of the thermal conductive network can be optimized by filling the gaps between the BN platelets with Al₂O₃ particles. Resultingly, the configuration of the binary fillers is arranged by the shearing force during the DIW process, fabricating the thermal conductive network of oriented fillers. The DIW-printed BN/Al₂O₃/PDMS with 45 wt% thermal conductive binary filler can reach a thermal conductivity of 0.98 W/(m·K), higher than the 0.62 W/(m·K) of the control sample. In this study, a novel strategy for the thermal conductive performance improvement of composites based on DIW technology is successfully verified, paving a new way for thermal management. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

19 pages, 5235 KiB

Open AccessArticle

Inherited Structure Properties of Larch Arabinogalactan Affected via the TEMPO/NaBr/NaOCl Oxidative System

by Vladislav A. Ionin, Yuriy N. Malyar, Valentina S. Borovkova, Dmitriy V. Zimonin, Roksana M. Gulieva and Olga Yu. Fetisova

Polymers 2024, 16(11), 1458; https://doi.org/10.3390/polym16111458 - 22 May 2024

Viewed by 983

Abstract

Arabinogalactan (AG), extracted from larch wood, is a β-1,3-galactan backbone and β-1,6-galactan side chains with attached α-1-arabinofuranosyl and β-1-arabinopyranosyl residues. Although the structural characteristics of arabinogalactan II type have already been studied, its functionalization using 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) oxidation remains a promising avenue. In [...] Read more.

Arabinogalactan (AG), extracted from larch wood, is a β-1,3-galactan backbone and β-1,6-galactan side chains with attached α-1-arabinofuranosyl and β-1-arabinopyranosyl residues. Although the structural characteristics of arabinogalactan II type have already been studied, its functionalization using 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) oxidation remains a promising avenue. In this study, the oxidation of AG, a neutral polysaccharide, was carried out using the TEMPO/NaBr/NaOCl system, resulting in polyuronides with improved functional properties. The oxidation of AG was controlled by analyzing portions of the reaction mixture using spectrophotometric and titration methods. To determine the effect of the TEMPO/NaBr/NaOCl system, air-dried samples of native and oxidized AG were studied by Fourier-transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopy, as well as by gel permeation chromatography. Compounds that model free (1,1-diphenyl-2-picrylhydrazyl (DPPH)) and hydroxyl radicals (iron(II) sulfate, hydrogen peroxide, and salicylic acid) were used to study the antioxidant properties. It was found that, in oxidized forms of AG, the content of carboxyl groups increases by 0.61 mmol compared to native AG. The transformation of oxidized AG into the H⁺ form using a strong acid cation exchanger leads to an increase in the number of active carboxyl groups to 0.76 mmol. Using FTIR spectroscopy, characteristic absorption bands (1742, 1639, and 1403 cm⁻¹) were established, indicating the occurrence of oxidative processes with a subsequent reduction in the carboxyl group. The functionality of AG was also confirmed by gel permeation chromatography (GPC), which is reflected in an increase in molecular weights (up to 15,700 g/mol). A study of the antioxidant properties of the oxidized and protonated forms of AG show that the obtained antioxidant activity (AOA) values are generally characteristic of polyuronic acids. Therefore, the TEMPO oxidation of AG and other neutral polysaccharides can be considered a promising approach for obtaining compounds with the necessary controlled characteristics. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

16 pages, 9463 KiB

Open AccessArticle

An Eco-Friendly Manner to Prepare Superwetting Melamine Sponges with Switchable Wettability for the Separation of Oil/Water Mixtures and Emulsions

by Guyita Berako Belachew, Chien-Chieh Hu, Yan-Yu Chang, Chih-Feng Wang, Wei-Song Hung, Jem-Kun Chen and Juin-Yih Lai

Polymers 2024, 16(5), 693; https://doi.org/10.3390/polym16050693 - 3 Mar 2024

Viewed by 1520

Abstract

Oil/water separation processes have garnered significant global attention due to the quick growth in industrial development, recurring chemical leakages, and oil spills. Hence, there is a significant demand for the development of inexpensive superwetting materials in an eco-friendly manner to separate oil/water mixtures [...] Read more.

Oil/water separation processes have garnered significant global attention due to the quick growth in industrial development, recurring chemical leakages, and oil spills. Hence, there is a significant demand for the development of inexpensive superwetting materials in an eco-friendly manner to separate oil/water mixtures and emulsions. In this study, a superwetting melamine sponge (SMS) with switchable wettabilities was prepared by modifying melamine sponge (MS) with sodium dodecanoate. The as-prepared SMS exhibited superhydrophobicity, superoleophilicity, underwater superoleophobicity, and underoil superhydrophobicity. The SMS can be utilized in treating both light and heavy oil/water mixtures through the prewetting process. It demonstrated fast permeation fluxes (reaching 108,600 L m⁻² h⁻¹ for a light oil/water mixture and 147,700 L m⁻² h⁻¹ for a heavy oil/water mixture) and exhibited good separation efficiency (exceeding 99.56%). The compressed SMS was employed in separating surfactant-stabilized water-in-oil emulsions (SWOEs), as well as surfactant-stabilized oil-in-water emulsions (SOWEs), giving high permeation fluxes (reaching 7210 and 5054 L m⁻² h⁻¹, respectively). The oil purity for SWOEs’ filtrates surpassed 99.98 wt% and the separation efficiencies of SOWEs exceeded 98.84%. Owing to their remarkable capability for separating oil/water mixtures and emulsions, eco-friendly fabrication method, and feasibility for large-scale production, our SMS has a promising potential for practical applications. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Graphical abstract

18 pages, 1257 KiB

Open AccessArticle

A Facile Surface Modification Scheme for Medical-Grade Titanium and Polypropylene Using a Novel Mussel-Inspired Biomimetic Polymer with Cationic Quaternary Ammonium Functionalities for Antibacterial Application

by Chi-Hui Cheng, Xiang-Zhen Zeng, Wen-Yuan Chiu and Jui-Che Lin

Polymers 2024, 16(4), 503; https://doi.org/10.3390/polym16040503 - 12 Feb 2024

Viewed by 1388

Abstract

Medical device-associated infection remains a critical problem in the healthcare setting. Different clinical- or device-related methods have been attempted to reduce the infection rate. Among these approaches, creating a surface with bactericidal cationic functionality has been proposed. To do so, a sophisticated multi-step [...] Read more.

Medical device-associated infection remains a critical problem in the healthcare setting. Different clinical- or device-related methods have been attempted to reduce the infection rate. Among these approaches, creating a surface with bactericidal cationic functionality has been proposed. To do so, a sophisticated multi-step chemical procedure would be needed. Instead, a simple immersion approach was utilized in this investigation to render the titanium and polypropylene surface with the quaternary ammonium functionality by using a mussel-inspired novel lab-synthesized biomimetic catechol-terminated polymer, PQA-C8. The chemical oxidants, CuSO₄/H₂O₂, as well as dopamine, were added into the novel PQA-C8 polymer immersion solution for one-step surface modification. Additionally, a two-step immersion scheme, in which the polypropylene substrate was first immersed in the dopamine solution and then in the PQA-C8 solution, was also attempted. Surface analysis results indicated the surface characteristics of the modified substrates were affected by the immersion solution formulation as well as the procedure utilized. The antibacterial assay has shown the titanium substrates modified by the one-step dopamine + PQA-C8 mixtures with the oxidants added and the polypropylene modified by the two-step scheme exhibited bacterial reduction percentages greater than 90% against both Gram-positive S. aureus and Gram-negative E. coli and these antibacterial substrates were non-cytotoxic. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

17 pages, 11402 KiB

Open AccessArticle

Single-Component Hydrophilic Terpolymer Thin Film Systems for Imparting Surface Chemical Versatility on Various Substrates

by Yun Hee Ko, Hai Ha Tran Nguyen, Christopher R. Branstetter, Soeun Park, Jin-Kyun Lee, Jaesung Yang, Jangwook P. Jung and Myungwoong Kim

Polymers 2024, 16(1), 44; https://doi.org/10.3390/polym16010044 - 21 Dec 2023

Viewed by 1451

Abstract

We demonstrate a single-component hydrophilic photocrosslinkable copolymer system that incorporates all critical functionalities into one chain. This design allows for the creation of uniform functional organic coatings on a variety of substrates. The copolymers were composed of a poly(ethylene oxide)-containing monomer, a monomer [...] Read more.

We demonstrate a single-component hydrophilic photocrosslinkable copolymer system that incorporates all critical functionalities into one chain. This design allows for the creation of uniform functional organic coatings on a variety of substrates. The copolymers were composed of a poly(ethylene oxide)-containing monomer, a monomer that can release a primary amine upon UV light, and a monomer with reactive epoxide or cyclic dithiocarbonate with a primary amine. These copolymers are easily incorporated into the solution-casting process using polar solvents. Furthermore, the resulting coating can be readily stabilized through UV light-induced crosslinking, providing an advantage for controlling the surface properties of various substrates. The photocrosslinking capability further enables us to photolithographically define stable polymer domains in a desirable region. The resulting copolymer coatings were chemically versatile in immobilizing complex molecules by (i) post-crosslinking functionalization with the reactive groups on the surface and (ii) the formation of a composite coating by mixing varying amounts of a protein of interest, i.e., fish skin gelatin, which can form a uniform dual crosslinked network. The number of functionalization sites in a thin film could be controlled by tuning the composition of the copolymers. In photocrosslinking and subsequent functionalizations, we assessed the reactivity of the epoxide and cyclic dithiocarbonate with the generated primary amine. Moreover, the orthogonality of the possible reactions of the presented reactive functionalities in the crosslinked thin films with complex molecules is assessed. The resulting copolymer coatings were further utilized to define a hydrophobic surface or an active surface for the adhesion of biological objects. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

17 pages, 2469 KiB

Open AccessArticle

Interpenetration Networked Polyimide–Epoxy Copolymer under Kinetic and Thermodynamic Control for Anticorrosion Coating

by Dong-Sen Chen, Chun-Hua Chen, Wha-Tzong Whang and Chun-Wei Su

Polymers 2023, 15(1), 243; https://doi.org/10.3390/polym15010243 - 3 Jan 2023

Cited by 6 | Viewed by 2224

Abstract

Epoxy (EP) was copolymerized with polyamic acid (PAA, precursor of polyimide (PI)) with termanil monomers of (1) 4,4′-Oxydianiline (ODA) and (2) pyromellitic dianhydride (PMDA) individually to form (PI-O-EP) and (PI-P-EP) copolymers. The FTIR spectrum of PI-O-EP copolymerization intermediates shows that some amide-EP linkages [...] Read more.

Epoxy (EP) was copolymerized with polyamic acid (PAA, precursor of polyimide (PI)) with termanil monomers of (1) 4,4′-Oxydianiline (ODA) and (2) pyromellitic dianhydride (PMDA) individually to form (PI-O-EP) and (PI-P-EP) copolymers. The FTIR spectrum of PI-O-EP copolymerization intermediates shows that some amide-EP linkages were formed at low temperature and were broken at higher temperature; in additoin, the released amide was available for subsequent imidization to form PI. The curing and imidization of the amide groups on PAA were determined by reaction temperature (kinetic vs. thermodynamic control). In PI-P-EP, the released amide group was very short-lived (fast imidization) and was not observed on FTIR spectra. Formation and breakage of the amide-EP linkages is the key step for EP homopolymerization and formation of the interpenetration network. PI contributed in improving thermal durability and mechanical strength without compromising EP’s adhesion strength. Microphase separations were minimal at PI content less than 10 wt%. The copolymerization reaction in this study followed the “kinetic vs. thermodynamic control” principle. The copolymer has high potential for application in the field of higher-temperature anticorrosion. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

Review

Jump to: Research

15 pages, 847 KiB

Open AccessReview

Cryogenic Insulation—Towards Environmentally Friendly Polyurethane Foams

by Laima Vevere, Vladimir Yakushin, Beatrise Sture-Skela, Janis Andersons and Ugis Cabulis

Polymers 2024, 16(17), 2406; https://doi.org/10.3390/polym16172406 - 24 Aug 2024

Viewed by 1200

Abstract

Cryogenics is the science and technology of very low temperatures, typically below 120 K. The most common applications are liquified natural gas carriers, ground-based tanks, and propellant tanks for space launchers. A crucial aspect of cryogenic technology is effective insulation to minimise boil-off [...] Read more.

Cryogenics is the science and technology of very low temperatures, typically below 120 K. The most common applications are liquified natural gas carriers, ground-based tanks, and propellant tanks for space launchers. A crucial aspect of cryogenic technology is effective insulation to minimise boil-off from storage tanks and prevent frost build-up. Rigid closed-cell foams are prominent in various applications, including cryogenic insulation, due to their balance between thermal and mechanical properties. Polyurethane (PU) foam is widely used for internal insulation in cryogenic tanks, providing durability under thermal shocks and operational loads. External insulation, used in liquified natural gas carriers and ground-based tanks, generally demands less compressive strength and can utilise lower-density foams. The evolution of cryogenic insulation materials has seen the incorporation of environmentally friendly blowing agents and bio-based polyols to enhance sustainability. Fourth-generation physical blowing agents, such as HFO-1233zd(E) and HFO-1336mzz(Z), offer low global warming potential and improved thermal conductivity. Additionally, bio-based polyols from renewable resources like different natural oils and recycled polyethylene terephthalate (PET) are being integrated into rigid PU foams, showing promising properties for cryogenic applications. Research continues to optimise these materials for better mechanical performance and environmental impact. Full article

(This article belongs to the Special Issue Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Functional Polymers: Interaction, Surface, Processing and Applications: 2nd Edition

Share This Special Issue

Special Issue Editor

Special Issue Information

Keywords

Benefits of Publishing in a Special Issue

Published Papers (17 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI