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Background: Demand for alcohol-based products, including gel- and aqueous-type hand sanitizers, room sprays, and mouthwashes, has rapidly increased during the ongoing COVID-19 pandemic because of their microbicidal properties. However, toxic methanol can be found from the intentional addition of methanol by manufacturers and invariable production during the manufacturing of alcohol (ethanol). Although the FDA has recommended that such products should contain less than 630 ppm of methanol, it is only a temporary measure established specifically to regulate such products during the current COVID-19 pandemic and hence is not strictly regulated. Objective: This study aims to detect and quantify the level of methanol in alcohol-based products. However, some manufacturers unethically add methanol to their products and promote them as methanol-free. Besides, they do not provide proficiency and toxicity test results. Therefore, these kinds of products need to be analyzed to determine if they are acceptable to use. Method: This study qualitatively and quantitatively investigates the amount of methanol in commercial alcohol-based products using a newly developed headspace gas chromatography/mass spectrometry method. Moreover, alcoholic beverages which contain methanol are analyzed to be compared with the levels of methanol in alcohol-based products and determine if their methanol levels are acceptable. Results: Methanol concentrations in gel-type hand sanitizers (517 ppm) and mouthwashes (202 ppm) were similar to those in white wine (429 ppm) and beer (256 ppm), respectively, while that of aqueous-type hand sanitizers (1139 ppm) was 1.5 times more than that of red wine (751 ppm). Conclusion: Methanol levels in most of the alcohol-based products did not exceed the FDArecommended limit.

Controlled-release fertilizers (CRFs) are a next-generation type of fertilizers, with several advantages over conventional fertilizer. However, using non-degradable and petroleum-based materials in the fabrication of CRFs possess considerable threat to agricultural soils and the environment. Therefore, this study aimed to develop a highly biodegradable, nontoxic, and biocompatible CRFs based on calcium alginate (CaAlg) beads. The results showed that the sphericity of the beads increased with decreasing CaCl2 concentration and increasing gelation time. Additionally, there was a significant decrease in the viscosity of sodium alginate (NaAlg) suspension with increasing concentration of urea. Moreover, there was an increase in the urea loading (UL) efficiency and a decrease in the urea release rate of the beads with increasing concentration of CaCl2. Furthermore, carrots grown in the control soil and soil containing urea were larger compared with those grown in soils containing CRF, indicating the controlled release of nitrogen by the CRF. Adding humic acid (HA), poly vinyl acid (PVA), and citric acid to the suspension increased the stability and improved the urea release profile of the CRF. Overall, the fabrication process is easy and could be applied for the mass production of CRFs.

Among plastic items, single-use straws are particularly detrimental to marine ecosystems because such straws, including those made of poly(lactic acid) (PLA), are sharp and extremely slowly degradable in the ocean. While paper straws are promising alternatives, they exhibit hydration-induced swelling even when coated with a non-degradable plastic coating and promote effervescence (fizzing) in soft drinks owing to their surface heterogeneities. In this study, upgraded paper straw is coated with poly(butylene succinate) cellulose nanocrystal (PBS/CNC) composites. CNC increases adhesion to paper owing to their similar chemical structures, optimizes crystalline PBS spherulites through effective nucleation, and reinforces the matrix through its anisotropic and rigid features. The straws are not only anti-fizzing when used with soft drinks owing to their homogeneous and seamless surface coatings, but also highly water-resistant and tough owing to their watertight surfaces. All degradable components effectively decompose under aerobic composting and in the marine environment. This technology contributes to United Nations Sustainable Development Goal 14 (Life Below Water).

Gluing dynamic, wet biological tissue is important in injury treatment yet difficult to achieve. Polymeric adhesives are inconvenient to handle due to rapid cross-linking and can raise biocompatibility concerns. Inorganic nanoparticles adhere weakly to wet surfaces. Herein, an aqueous suspension of guanidinium-functionalized chitin nanoparticles as a biomedical adhesive with biocompatible, hemostatic, and antibacterial properties is developed. It glues porcine skin up to 3000-fold more strongly (30 kPa) than inorganic nanoparticles at the same concentration and adheres at neutral pH, which is unachievable with mussel-inspired adhesives alone. The glue exhibits an instant adhesion (2 min) to fully wet surfaces, and the glued assembly endures one-week underwater immersion. The suspension is lowly viscous and stable, hence sprayable and convenient to store. A nanomechanic study reveals that guanidinium moieties are chaotropic, creating strong, multifaceted noncovalent bonds with proteins: salt bridges comprising ionic attraction and bidentate hydrogen bonding with acidic moieties, cation−π interactions with aromatic moieties, and hydrophobic interactions. The adhesion mechanism provides a blueprint for advanced tissue adhesives.

Chemo‐biological upcycling of poly(ethylene terephthalate) (PET) developed in this study includes the following key steps: chemo‐enzymatic PET depolymerization, biotransformation of terephthalic acid (TPA) into catechol, and its application as a coating agent. Monomeric units were first produced through PET glycolysis into bis(2‐hydroxyethyl) terephthalate (BHET), mono(2‐hydroxyethyl) terephthalate (MHET), and PET oligomers, and enzymatic hydrolysis of these glycolyzed products using Bacillus subtilis esterase (Bs2Est). Bs2Est efficiently hydrolyzed glycolyzed products into TPA as a key enzyme for chemo‐enzymatic depolymerization. Furthermore, catechol solution produced from TPA via a whole‐cell biotransformation (Escherichia coli) could be directly used for functional coating on various substrates after simple cell removal from the culture medium without further purification and water‐evaporation. This work demonstrates a proof‐of‐concept of a PET upcycling strategy via a combination of chemo‐biological conversion of PET waste into multifunctional coating materials., PETit four: A proof‐of‐concept upcycling strategy to convert poly(ethylene terephthalate) (PET) into multifunctional catechol coating materials is presented: (1) PET glycolysis without purification; (2) one‐step enzymatic hydrolysis of glycolyzed products into terephthalic acid (TPA); (3) whole‐cell biotransformation of TPA into catechol using an engineered Escherichia coli; (4) application of crude catechol solution as a multifunctional coating material without purification.

Intrinsic self-healing hydrogel materials have been studied by many researchers owing to their excellent durability and high applicability in the biomedical field. Herein, we report a self-healing hydrogel containing dynamic boronate ester bonds. First, low-molecular-weight hyperbranched polyglycerol (LMPG), containing cis-1,2- or 1,3-diols, was synthesized by cationic ring-opening polymerization of glycidol initiated from citric acid. Second, 4-vinylphenyl boronic acid and acrylamide were co-polymerized in the LMPG-containing alkaline solution used for preparing the hydrogel. The composition of vinyl monomers, LMPG, and chemical cross-linker affects the gel-formation and self-healing properties of the hydrogel. Interestingly, the prepared hydrogel with specific composition exhibits excellent extensibility, resulting in 416-fold (41,600%) elongation. The formation of a reversible boronate ester bond by a diol of LMPG and boronic acid of vinyl polymer enables flexible fiber spinning process by reducing the drawing stress. After fiber fabrication is completed, the reversible bonds act as permanent multi-cross-point under absence of water, thereby giving a high tensile strength (128 MPa) to the hydrogel-based fiber.

Designing efficient plastic-digesting microorganisms is necessary to accelerate the decomposition of biodegradable plastics leaking into outer environments. However, screening of microorganisms for hydrophobic plastics is labor-intensive and time-consuming. Herein, a high-throughput, straightforward micro-spray-based screening system is presented; the whole process only takes 1–5 days using a minimal amount of polymers. Bioplastic microparticles sprayed on an agar plate share a large interface with microorganisms, and therefore their discovery is readily recognizable. This method inspires finding new microorganisms that digest conventional plastics known as non-degradable plastics.

Intrinsic self-healing polymeric materials are substances that relieve external stress and restore their original mechanical properties after extreme damage via dynamic covalent bonding in the polymeric structure or the reversible association of supramolecular motifs. Boronic ester-based dynamic covalent bonds formed between boronic acids and diols impart excellent self-healing properties to the hydrogels, organic gels, elastomers, and plastics depending on the characteristics of the corresponding polymer. In addition, these bonds induce internal reorganization in the chemical/physical structure in response to changes in the biological signals and biomaterials, such as hydrophilicity, pH, and the presence of glucose. This multi-responsiveness to stimuli as well as the self-healing, injectability, and biocompatibility of boronic ester-based polymers have led to several technological achievements with applicability in biomedical fields, including drug delivery, medical adhesion, bioimplants, and healthcare monitoring. This review provides an overview of various self-healing polymeric materials based on reversible B–O bonds, with a focus on boronic/boronate esters, borax, and benzoxaborole and their properties, responses to external stimuli, and applications.

Plastic packaging effectively protects food from mechanical, microbial, and chemical damage; however, oxygen and moisture permeate these plastics and spoil the food. Thus, the gas barrier function is usually imparted through metallic or halogenated polymeric coatings. However, the former blocks visible light, while the latter causes environmental concerns. Moreover, plastic packaging contaminated with food scraps and stains requires a washing process for recycling. To satisfy the key requirements for food packaging, we fabricated a (1) sustainable, (2) self-cleaning, (3) transparent, and (4) oxygen/moisture barrier coating on poly(ethylene terephthalate) (PET) film. A spray-assisted layer-by-layer assembly of negatively charged cellulose nanofibers and positively charged chitosan nanowhiskers was coated on one side of the PET film. Salt bridge-mediated synergistic interplay between these highly crystalline nanomaterials imparted a low oxygen transmission rate of less than 0.1 mL m−2 day−1. The other side of the PET film was formed with a porous surface by spray-coating of silica nanoparticles and chitosan nanowhiskers. Thereafter, the porous surface was impregnated with bio-based sunflower oil. This side repelled the contaminants and exhibited a low water vapor transmission rate of 1.4 g m−2 day−1. The gas barrier performance meets the packaging requirements for most food products. This coating has high potential for sustainable packaging applications.

Self-repairable materials strive to emulate curable and resilient biological tissue; however, their performance is currently insufficient for commercialization purposes because mending and toughening are mutually exclusive. Herein, we report a carbonate-type thermoplastic polyurethane elastomer that self-heals at 35 °C and exhibits a tensile strength of 43 MPa; this elastomer is as strong as the soles used in footwear. Distinctively, it has abundant carbonyl groups in soft-segments and is fully amorphous with negligible phase separation due to poor hard-segment stacking. It operates in dual mechano-responsive mode through a reversible disorder-to-order transition of its hydrogen-bonding array; it heals when static and toughens when dynamic. In static mode, non-crystalline hard segments promote the dynamic exchange of disordered carbonyl hydrogen-bonds for self-healing. The amorphous phase forms stiff crystals when stretched through a transition that orders inter-chain hydrogen bonding. The phase and strain fully return to the pre-stressed state after release to repeat the healing process., Self-healing materials strive to emulate curable and resilient biological tissue but their performance is often insufficient for commercial applications because self-healing and toughening are mutually exclusive properties. Here, the authors report a tough and strong carbonate-type thermoplastic polyurethane elastomer that self-heals at ambient temperature.

Current sustainable bioplastics need dramatic improvement to become competitive. Herein, we prepared poly(butylene succinate-co-carbonate) nanocomposites with citric acid and cellulose nanocrystals (CNCs). The dimethyl carbonate co-monomer lowers crystallinity and increases elongation; citric acid increases the strength, and the CNCs maximize mechanical performance. Accelerated biodegradation is also favorable for sustainable tough bags.

The performance limits of conventional super engineering plastics with inorganic nanofillers are surpassed by all-organic nanocomposites prepared via in situ S

Inspired by the human skin, a wholly self-healing electronic-skin (e-skin) is designed by the monolithic combination of a dermis-like hydrogel for conductivity and an epidermis-like thermoplastic p...

The performance limits of conventional super engineering plastics with inorganic nanofillers are surpassed by all-organic nanocomposites prepared via in situ SNAr polymerization of polysulfone (PSU...

Biodegradable polyesters, such as poly(butylene adipate-co-terephthalate) (PBAT), can trigger the hydrolysis of esters in a natural environment. However, biodegradability does not guarantee its eco-friendliness due to the concerns associated with terephthalic acid. Substitution by biomass-based counterparts no longer ensures “truly” eco-friendly biodegradable polyesters. In this study, we have used poly(butylene adipate-co-furanoate) (PBAF), which utilizes a biomass-derived substituent, furan-2,5-dicarboxylic acid (FDCA), and have proven that this is superior from the perspective of both mechanical performance and enzymatic degradation. Compared to its terephthalate counterpart, PBAF exhibits remarkable elasticity upon stretching: when released beyond 800% extension, PBAT almost malfunctioned, whereas PBAF exhibited instant elastic recovery. This results in PBAT and PBAF having a similar tensile strength in the range of 50–70 MPa at the ring fraction of 50 to 80 mol%. During the enzymatic degradation using lipase from Thermomyces lanuginosus, PBAF with a ring fraction of 50 mol% solely undergoes hydrolysis due to enzyme specificity. Ex situ spectroscopic analysis confirms that the participation of FDCA ester groups in the early stages of degradation triggered the successive hydrolytic reaction. Thus, understanding the structural characteristics of FDCA would open new opportunities in the field of sustainable plastic industries.

As plastic consumption has increased, environmental problems associated with the accumulation of plastic wastes have started to emerge. These include the non-degradability of plastic and its disintegration into sub-micron particles. Although some biodegradable plastic products have been developed to relieve the landfill and leakage burden, a significant portion of discarded plastics are inevitably still incinerated. The concern here is that incinerating plastics may result in the emission of toxic volatile organic compounds (VOCs). Moreover, lack of policy and the limited market share contributes to the indiscriminate discarding of biodegradable plastics, whereby it is mixed and subsequently incinerated with non-degradable plastics. The aim of this study was therefore to qualitatively and quantitatively analyze the VOCs emitted from both non-degradable and biodegradable plastics during combustion employing gas chromatography mass spectrometry. Here, non-degradable poly(vinyl chloride) and poly(ethylene terephthalate) emitted 10-115 and 6-22 ppmv of VOCs, respectively. These emission levels were more than 100 times higher than the VOC concentrations of 0.1-0.5 and 0.1-1.8 ppmv obtained for biodegradable polyhydroxyalkanoate and polylactic acid, respectively. Notably, due to the presence of a repeating butylene group in both non-degradable and biodegradable plastics, 1,3-butadiene accounted for the highest concentration among the VOCs identified, with concentrations of 6-116 ppmv and 0.5-558 ppmv obtained, respectively. During the evaluation of gas barrier films employed for food packaging purposes, non-degradable aluminum-coated multilayered films emitted 9-515 ppmv of VOCs, compared to the 2-41 ppmv VOCs emitted by biodegradable nanocellulose/nanochitin-coated films. Despite the significantly lower levels of VOCs emitted during the incineration of biodegradable plastics, this does not represent suitable waste treatment solution because VOCs are still emitted during incomplete combustion. This study aims to encourage further research into diverse combustion conditions for plastics and stimulate discussions on the fate of discarded plastics.

Composite materials have been extensively studied to optimize properties such as lightness and strength, which are the advantages of plastics. We prepared a highly concentrated (30 wt %) nylon/chitosan nanowhisker (CSW) masterbatch by blending nylon 6,10 and CSW by solvent casting to achieve high dispersion efficiency while considering an industrial setting. Subsequently, 0.3 wt % nylon/CSW nanocomposites were prepared with a large quantity of nylon 6,10 via melt blending. During preparation, the materials were stirred in the presence of formic acid at different times to investigate the effect of stirring time on the structure of the CSW and the physical properties of the composite. The formation of nanocomposites by the interactions between nylon and CSW was confirmed by observing the change in hydrogen bonding using FT-IR spectroscopy and the rise in melting temperature and melting enthalpy through differential scanning calorimetry. The results demonstrated increases in complex viscosity and shear thinning. The rheological properties of the composites changed due to interactions between CSW and nylon, as indicated by the loss factor. The mechanical properties produced by the nanocomposite stirred for 1.5 h were superior, suggesting that formic acid caused minimal structural damage, thus verifying the suitability of the stirring condition.

Polyhydroxybutyrate (PHB) is a natural polyester synthesized by several microorganisms. Moreover, it has excellent biodegradability and is an eco-friendly material because it converts water and carbon dioxide as final decomposition products. However, the applications of PHB are limited because of its stiffness and brittleness. Because cellulose nanocrystals (CNCs) have excellent intrinsic mechanical properties such as high specific strength and modulus, they may compensate for the insufficient physical properties of PHB by producing their nanocomposites. In this study, natural polyesters were extracted from Cupriavidus necator fermentation with CNCs, which were well-dispersed in nitrogen-limited liquid culture media. Fourier-transform infrared spectroscopy results revealed that the additional O–H peak originating from cellulose at 3500–3200 cm−1 was observed for PHB along with the C=O and –COO bands at 1720 cm−1. This suggests that PHB–CNC nanocomposites could be readily obtained using C. necator fermented in well-dispersed CNC-supplemented culture media.

Conductive self-healing polymer hydrogel and related soft sensor devices are receiving considerable attention from academia to industry because of their impacts on the lifetime and ergonomic design of soft robotics, prosthesis, and health monitoring systems. However, the development of such a material has thus far been limited considering performances and accessibility. Herein, robustness, self-healing, and conductivity for soft electronic skin are realized by an interpenetrating polymer network (IPN) system based on chemical/ionic cross-linked poly(acrylic acid) containing ferric ions, intercalated with physically cross-linked poly(vinyl alcohol). This IPN hydrogel successfully satisfies all three aforementioned capabilities; elongation at break greater than 1400%; recovery to original mechanical properties greater than 80% after 24 h; and 0.14 S m−1 of ionic conductivity, which is electrically healable. Such ionic conductivity of hydrogels enables multimodal sensing capabilities, i.e., for strain, pressure, and temperature. Particularly, a uniquely designed dual sensor attached to a finger simultaneously detects mechanical folding and pressure changes independently and can undergo large deformation 1000 times repeated and heating up to 90 °C.

Environmental and health concerns force the search for sustainable super engineering plastics (SEPs) that utilise bio-derived cyclic monomers, e.g. isosorbide instead of restricted petrochemicals. However, previously reported bio-derived thermosets or thermoplastics rarely offer thermal/mechanical properties, scalability, or recycling that match those of petrochemical SEPs. Here we use a phase transfer catalyst to synthesise an isosorbide-based polymer with a high molecular weight >100 kg mol−1, which is reproducible at a 1-kg-scale production. It is transparent and solvent/melt-processible for recycling, with a glass transition temperature of 212 °C, a tensile strength of 78 MPa, and a thermal expansion coefficient of 23.8 ppm K−1. Such a performance combination has not been reported before for bio-based thermoplastics, petrochemical SEPs, or thermosets. Interestingly, quantum chemical simulations show the alicyclic bicyclic ring structure of isosorbide imposes stronger geometric restraint to polymer chain than the aromatic group of bisphenol-A., Super engineering plastics that utilise bio-derived cyclic monomers rarely offer the same thermal/mechanical properties, scalability and recyclability as petrochemical derived plastics. Here the authors use a phase transfer catalyst to synthesise a transparent, recyclable and tough isosorbide-based polymer with a high molecular weight.

Polycarbonate (PC) is a transparent polymeric material which can replace shattering glass, but bisphenol-A, used for improving its properties, has controversial hazards. An alternative biomass-derived isosorbide (ISB)-based PC can be used owing to its complementary properties. To satisfy the two factors of sustainability and performance simultaneously, this paper proposes the in situ polymerization of ISB pre-dispersed with cellulose nanocrystals (CNCs), which directly produces PC nanocomposites, as a facile method for achieving record-high mechanical strength among all types of PCs and their nanocomposites. The proposed nanocomposite is more transparent, exhibits an ultimate tensile strength of 93 MPa and a 4.3-fold increased toughness of 40 MJ m−3, compared to a homo-polymer, and is better than post-blended nanocomposites due to the excellent dispersibility of 0.3 wt% nanofiller. Formidable improvements in in situ PC/CNC nanocomposites originate from the simultaneous contributions of covalent and physical interactions through polymeric grafting on the CNC surface and hydrogen bonding with a polar ISB moiety of PC, in advance, from the monomer dispersion, respectively, enhancing the interfacial interaction with the polymer matrix. This in situ approach opens new possibilities in the field of sustainable plastic industries.

Nanochitin and nanochitosan (with random-copolymer-based multiscale architectures of glucosamine and N-acetylglucosamine units) have recently attracted immense attention for the development of green, sustainable, and advanced functional materials. Nanochitin and nanochitosan are multiscale materials from small oligomers, rod-shaped nanocrystals, longer nanofibers, to hierarchical assemblies of nanofibers. Various physical properties of chitin and chitosan depend on their molecular- and nanostructures; translational research has utilized them for a wide range of applications (biomedical, industrial, environmental, and so on). Instead of reviewing the entire extensive literature on chitin and chitosan, here, recent developments in multiscale-dependent material properties and their applications are highlighted; immune, medical, reinforcing, adhesive, green electrochemical materials, biological scaffolds, and sustainable food packaging are discussed considering the size, shape, and assembly of chitin nanostructures. In summary, new perspectives for the development of sustainable advanced functional materials based on nanochitin and nanochitosan by understanding and engineering their multiscale properties are described.

Polyhydroxybutyrate (PHB) is a natural polyester synthesized by several microorganisms. Moreover, it has excellent biodegradability and is an eco-friendly material because it converts water and carbon dioxide as final decomposition products. However, the applications of PHB are limited because of its stiffness and brittleness. Because cellulose nanocrystals (CNCs) have excellent intrinsic mechanical properties such as high specific strength and modulus, they may compensate for the insufficient physical properties of PHB by producing their nanocomposites. In this study, natural polyesters were extracted from Cupriavidus necator fermentation with CNCs, which were well-dispersed in nitrogen-limited liquid culture media. Fourier-transform infrared spectroscopy results revealed that the additional O–H peak originating from cellulose at 3500–3200 cm−1 was observed for PHB along with the C=O and –COO bands at 1720 cm−1. This suggests that PHB–CNC nanocomposites could be readily obtained using C. necator fermented in well-dispersed CNC-supplemented culture media.

As human beings have been consistently exposed to bisphenol A (BPA) and bisphenol S (BPS) derived from various products, the intake of BPS/BPA to humans has been extensively studied. However, using conventional biological matrices such as urine, blood, or dissected skin to detect BPS/BPA in the human body system requires longer exposure time to them, hardly defines the pollutant source of the accumulated BPS/BPA, and is often invasive. Herein, our new approach i.e. fingerprint analysis quantitatively confirms the transfer of BPS/BPA from receipts (specific pollution source) to human skin only within receipt-handling of “20 s”. When receipts (fingertip region size; ~1 cm2) containing 100–300 μg of BPS or BPA are handled, 20–40 μg fingerprint-1 of BPS or BPA is transferred to human skin (fingertip). This transferred amount of BPS/BPA can still be toxic according to the toxicity test using water fleas. As a visual evidence, a fingerprint map that matches the distribution of the absorbed BPS/BPA is developed using a mass spectrometry imaging tool. This is the first study to analyze fingerprints to determine the incorporation mechanism of emerging pollutants. This study provides an efficient and non-invasive environmental forensic tool to analyze amounts and sources of hazardous substances.

In article number 2003155, Jeyoung Park, Dongyeop X. Oh, Sung Yeon Hwang, and co‐workers report a biodegradable, moisture‐resistant, highly efficient, and breathable face mask filter based on easy‐to obtain poly(butylene succinate) coated with chitosan nanowhiskers. Integrated microfiber/nanofiber mats present a particulate matter removal efficiency as high as the commercial N95 filter due to a combination of physical sieving and electrostatic adsorption. [Image: see text]

Aluminum-coated polypropylene films are commonly used in food packaging because aluminum is a great gas barrier. However, recycling these films is not economically feasible. In addition, their end-of-life incineration generates harmful alumina-based particulate matter. In this study, coating layers with excellent gas-barrier properties are assembled on polypropylene films through layer-by-layer (LbL) deposition of biorenewable nanocellulose and nanochitin. The coating layers significantly reduce the transmission of oxygen and water vapors, two unfavorable gases for food packaging, through polypropylene films. The oxygen transmission rate of a 60 μm-thick, 20 LbL-coated polypropylene film decreases by approximately a hundredfold, from 1118 to 13.10 cc m−2 day−1 owing to the high crystallinity of nanocellulose and nanochitin. Its water vapor transmission rate slightly reduces from 2.43 to 2.13 g m−2 day−1. Furthermore, the coated film is highly transparent, unfavorable to bacterial adhesion and thermally recyclable, thus promising for advanced food packaging applications.

The demand for face masks is increasing exponentially due to the coronavirus pandemic and issues associated with airborne particulate matter (PM). However, both conventional electrostatic‐ and nanosieve‐based mask filters are single‐use and are not degradable or recyclable, which creates serious waste problems. In addition, the former loses function under humid conditions, while the latter operates with a significant air‐pressure drop and suffers from relatively fast pore blockage. Herein, a biodegradable, moisture‐resistant, highly breathable, and high‐performance fibrous mask filter is developed. Briefly, two biodegradable microfiber and nanofiber mats are integrated into a Janus membrane filter and then coated by cationically charged chitosan nanowhiskers. This filter is as efficient as the commercial N95 filter and removes 98.3% of 2.5 µm PM. The nanofiber physically sieves fine PM and the microfiber provides a low pressure differential of 59 Pa, which is comfortable for human breathing. In contrast to the dramatic performance decline of the commercial N95 filter when exposed to moisture, this filter exhibits negligible performance loss and is therefore multi‐usable because the permanent dipoles of the chitosan adsorb ultrafine PM (e.g., nitrogen and sulfur oxides). Importantly, this filter completely decomposes within 4 weeks in composting soil., An eco‐friendly face mask filter with high‐level functionality is developed. Made only of biodegradable materials, it completely decomposes in the soil, thereby providing a fundamental waste problem solution. Moreover, the filter is a practical alternative to conventional disposable filters by integrating the physical sieving role of a poly(butylene succinate) fiber mat and the permanent electrostatic adsorption roles of chitosan nanowhiskers.

To address environmental concerns related to the large volume of plastics currently used, high-performance, sustainable, and satisfactorily performing bioplastics can be a solution. Isosorbide (ISB)-based amorphous poly(arylene ether sulfone)s (PAESs) derived from biomass feedstocks instead of harmful aromatic petrochemicals, such as bisphenol-A (BPA), are promising novel materials. To expand the range of eco-friendly products, ISB-PAES microfibers (ISU) along with BPA-PAES-based microfibers (PSU) have been fabricated through dry-jet wet spinning. ISU is mechanically 2.3 times stronger (247 MPa) than PSU (106 MPa), which may be ascribed to the compact and homogeneous structure of ISU compared to the porous structure of PSU. This structural superiority is due to the polar ISB moiety, which improves the phase stability of the ISU spinning dope in water (a role of the coagulant). For potential wig applications, the diameter, strength, and moduli of ISU are well matched to those of human hair. In addition, ISU is easily colored and endures high temperatures better than current wig filaments. It survives at high temperatures without breaking down during hair iron treatment (200 °C).