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Nonwoven media used as electret air filters are often embedded with charges to improve particle capture efficiency. These charged filters are invariably exposed to low surface tension fluids such as oils and alcohols leading to charge loss. In this study, filtration media are endowed with charge protection through increased surface repellency using melt additives that can migrate to the surface during processing. Nonwovens containing fluorochemical melt additives are produced, and examined to determine the relationship between surface chemistry, isopropyl alcohol (IPA) repellency, resultant charge retention, and filtration characteristics. Surface fluorine/carbon (F/C) ratios of ≈0.2 are sufficient to protect filtration performance from vapor discharging methods. Samples with bulk additive loadings of 1.2% or higher are found to achieve the necessary repellency to resist discharging independent of the migration state of the sample, while samples loaded at the 0.6% level required sufficient migration to achieve the requisite F/C ratio of 0.2 in order to be protected. Samples that achieved the necessary surface chemistry to provide significant IPA repellency retained > 80% of electret charge and corresponding filtration performance. These results have special significance in the design of filtration media relevant in global healthcare and other industrial settings.

This study presents a set of strategies for producing potent antibacterial fabrics by functionalizing nonwoven fabrics (NWFs) with antimicrobial peptides and polymers (AMPs). The incorporation of AMPs is initially optimized on 2D substrates by evaluating conjugation on a poly(maleic anhydride) copolymer coating versus adsorption on polycationic/anionic films and microgels. The evaluation of the resulting surfaces againstS. aureusandE. colihighlights the superior antibacterial activity of poly‐ionic films loaded with daptomycin and polymyxin B as well as microgels featuring controlled release of bacitracin and polymyxin B. These formulations are translated onto spun‐bond polypropylene and poly(ethylene terephthalate) NWFs. The poly‐ionic coatings are either covalently anchored or physically adsorbed onto the surface of the fibers, while the microgels and antibacterial polymers are adsorbed and photo‐crosslinked thereon using a ultraviolet (UV)‐crosslinkable benzophenone‐based polymer. Selected formulations loaded with bacitracin and polymyxin B afford a 10⁵‐fold reduction ofStaphylococcus aureus (S. aureus)andEscherichia coli (E. coli)in artificial sweat, respectively, on par with commercial antibacterial NWFs. The proposed antibacterial fabric, however, outperforms its commercial counterparts in terms of biocompatibility, showing virtually no adverse effect on human epidermal keratinocytes. Collectively, these results demonstrate affordable and scalable routes for developing antimicrobial NWFs that efficiently eliminate resilient pathogenic bacteria.

Fabrication of aqueous particulate dispersions of biodegradable cellulose esters (CEs) as efficient carriers of agrochemical active‐ingredients (AIs) for foliar applications, is reported. The use of different ester substituent groups on CE permits modulation of particle morphology and size, from irregular shapes (<350 nm) to spheres (≈1.1 µm diameter), while maintaining stability as supported by minimal change in zeta potential and particle size over one year. Rainfastness is tested by simulating >50 mm h⁻¹ rainfall on coated banana and tomato leaves and silicon. Surface coverage loss as low as 9%, based on the nature of leaf and formulation, confirms the rainfastness of the formulations. Variation in the release kinetics of a model AI fluopyram from different CEs can be attributed to the particle morphology and the nature of binding between fluopyram and various CEs. Thermodynamic analysis demonstrates spontaneous binding between fluopyram and multiple sites of CEs, justifying its two‐step release from CE particles. System functionalities are corroborated via in‐vitro fungal inhibition assays demonstrating a 100% inhibition of the fungal growth. This “lab‐to‐leaf” approach of materials development involving fundamental insights and functional performance reveals CE dispersions are promising green agricultural formulations with the potential to impact a myriad of crops around the globe.

This study presents a comprehensive survey of microgel‐coated materials and their functional behavior, describing the complex interplay between the physicochemical and mechanical properties of the microgels and the chemical and morphological features of substrates. The cited literature is articulated in four main sections: i) properties of 2D and 3D substrates, ii) synthesis, modification, and characterization of the microgels, iii) deposition techniques and surface patterning, and iv) application of microgel‐coated surfaces focusing on separations, sensing, and biomedical applications. Each section discusses – by way of principles and examples – how the various design parameters work in concert to deliver functionality to the composite systems. The case studies presented herein are viewed through a multi‐scale lens. At the molecular level, the surface chemistry and the monomer make‐up of the microgels endow responsiveness to environmental and artificial physical and chemical cues. At the micro‐scale, the response effects shifts in size, mechanical, and optical properties, and affinity towards species in the surrounding liquid medium, ranging from small molecules to cells. These phenomena culminate at the macro‐scale in measurable, reversible, and reproducible effects, aiming in a myriad of directions, from lab‐scale to industrial applications.

Aerogels are considered ideal candidates for various applications, because of their low bulk density, highly porous nature, and functional performance. However, the time intensive nature of the complex fabrication process limits their potential application in various fields. Recently, incorporation of a fibrous network has resulted in production of aerogels with improved properties and functionalities. A facile approach is presented to fabricate hybrid sol–gel electrospun silica‐cellulose diacetate (CDA)‐based nanofibers to generate thermally and mechanically stable nanofiber aerogels. Thermal treatment results in gluing the silica‐CDA network strongly together thereby enhancing aerogel mechanical stability and hydrophobicity without compromising their highly porous nature (>98%) and low bulk density (≈10 mg cm⁻³). X‐ray photoelectron spectroscopy and in situ Fourier‐transform infrared studies demonstrate the development of strong bonds between silica and the CDA network, which result in the fabrication of cross‐linked structure responsible for their mechanical and thermal robustness and enhanced affinity for oils. Superhydrophobic nature and high oleophilicity of the hybrid aerogels enable them to be ideal candidates for oil spill cleaning, while their flame retardancy and low thermal conductivity can be explored in various applications requiring stability at high temperatures.