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[Display omitted] • pDE nanocoating imparts anti-microbial, non-cytotoxic properties to the filter without filtration performance loss. • pDE-coated nanofiber filter provides superior long-term anti-bacterial and anti-viral efficacy. • pDE-coated nanofiber filter exhibits enhanced durability in highly humid conditions. We fabricated a multi-use face mask with anti-bacterial and anti-viral, but non-cytotoxic properties by adding a functional nanocoating on an electrospun nanofiber filter. The nanocoating consists of a copolymer synthesized from dimethyaminomethyl styrene (DMAMS) monomer containing anti-microbial tertiary amine moiety, and a biocompatible crosslinker, ethylene glycol dimethylacrylate (EGDMA). Initiated chemical vapor deposition process is utilized to deposit the nanocoating in order to impart desired functionalities conformally onto the nanofiber filter without deforming its highly porous structure. The synthesized non-cytotoxic copolymer of p(DMAMS-co-EGDMA), or pDE film showed excellent biocidal efficacy of > 99.995% and > 99.985% against Escherichia coli O157: H7 (E. coli O157: H7) and Staphylococcus aureus , respectively. The pDE-coated nanofiber filter shows a filtration efficiency of 91% with extremely low air resistance of ∼ 50 Pa. In highly humid conditions, the pDE-coated nanofiber filter shows long-term anti-microbial efficacy of 99.89% for E. coli O157: H7 up to 168 h, 99.21%, and 99.23% for human influenza virus (H1N1) strain A/Puerto Rico/8/1934 and human beta-coronavirus strain OC43 up to 100 h, without sacrificing breathability, and filtration performance. Furthermore, the surface-modified filter can easily eliminate dead pathogens with a simple water rinse, which enabled the full retention of the filtration efficiency even in six washing cycles, proving excellent reusability. We envision the highly breathable, antimicrobial, multi-use face mask will serve as an environmentally free platform for personal protective equipment against future viral threats. [ABSTRACT FROM AUTHOR]

• The morph-genetic method was innovatively used to fabricate the ABH actuator. • The ABH actuator exhibits promising comprehensive performance. • The assembled biomimetic actuators show excellent synergistic performance. • The biomimetic actuator shows potential for a variety of applications. Stimuli-responsive hydrogels are most promising for the fabrication of autonomous bio-mimetic soft actuators. However, their weak actuation forces and isotropic volume change hinder their practical utilization as versatile actuators, owing to their fragility. Herein, we used the morph-genetic method to fabricate anisotropic bamboo/poly(N-isopropylacrylamide) hydrogel (ABH) complex for use as soft actuator. First of all, the bamboo fiber structure provides an anisotropic framework for the ABH actuator to achieve precise deformational programmability. Secondly, benefiting from the ultra-high directional strength (110 MPa) of bamboo, ABH actuator exhibits sufficiently robust mechanical property, which generates a powerful actuating force. Lastly, owing to the regulation of bamboo sheet and PNIPAM hydrogel, the ABH actuator not only achieves ultra-fast response speed (825°/s of the bending speed), but also has excellent synergetic performance. We demonstrate several bio-mimetic actuating devices based on ABH actuator, inspired by the intricate motions of natural organisms, to highlight how the specific materials properties and their synergy can be systematically exploited for the rational design of soft actuators. Henceforth, it is anticipated that the development of hydrogel actuators could continue to benefit from the use of various naturally-anisotropic materials, such as shape-memory polymers or liquid crystals, for the preparation of further advanced hydrogel actuators by the morph-genetic method. [ABSTRACT FROM AUTHOR]

[Display omitted] • 2D-MOF is connected to 3D-MOF with coordination bond to form Ni-HHTP@UiO-66NH 2. • 2D-MOF@3D-MOF affords porosity, conductivity, and active interface for sensing. • Ni-HHTP@UiO-66NH 2 shows superior sensitivity and low detection limit toward H 2 S. • A plausible mechanism is proposed from the joint experimental/computational data. Research to develop ideal sensing devices for toxic gases is on the rise, and amongst various materials, metal–organic frameworks (MOFs) have opened up promising vistas as chemiresistive sensors due to their high structural and functional tunability. Here, we report the composites of dimensionally (2D and 3D) and functionally (conductive and porous) different two MOFs in the form of a well-integrated core–shell structure. The hierarchically assembled 2D-MOF@3D-MOF exhibits new interfacial properties that are responsible for synergetically enhanced sensing performances toward toxic H 2 S gas with the lowest recorded limit of detection (1.4 ppb), superior sensitivity (ΔR/R 0 = 3.37), and outstanding selectivity at room temperature in air. The sensing mechanisms are proposed by combinational studies of experiments and calculation, which indicates that multiple changes (e.g., local structural change of the shell MOF, secondary binding sites generation from the core MOF, and free radicals formation) play a critical role in achieving synergetic chemiresistive sensing. [ABSTRACT FROM AUTHOR]

Antiviral and antibacterial violacein embedded porous nanofiber that can sterilize itself is proposed as an effective solution to prevent aerosol and post-contact transmission of pathogens viruses for safer personal protective equipments. [Display omitted] • Self-sterilizable nanofiber filter with naturally occurring violacein is developed. • Remarkable biocidal activities against infectious viruses and bacteria are achieved. • Viricidal efficacy for influenza and human coronavirus is studied by TCID 50 analysis. • Porous nanofiber matrix immobile pathogens and prevents aerosol transmission. • Violacein endows nanofibers with UV shielding property to help protect skin. Most respiratory masks are made of fabrics, which only capture the infectious virus carriers into the matrix. However, these contagious viruses stay active for a long duration (∼7 days) within the fabric matrix possibly inducing post-contact transmissions. Moreover, conventional masks are vulnerable to bacterial growth with prolonged exposure to exhaled breaths. Herein, we combined violacein, a naturally-occurring antimicrobial agent, with porous nanofiber membranes to develop a series of functional filters that autonomously sterilizes viruses and bacteria. The violacein-embedded membrane inactivates viruses within 4 h (99.532 % reduction for influenza and 99.999 % for human coronavirus) and bacteria within 2 h (75.5 % reduction). Besides, its nanofiber structure physically filters out the nanoscale (<0.8 μm) and micron-scale (0.8 μm − 3 μm) particulates, providing high filtration efficiencies (99.7 % and 100 % for PM 1.0 and PM 10, respectively) with long-term stability (for 25 days). In addition, violacein provides additional UV-resistant property, which protects the skin from sunlight. The violacein-embedded membrane not only proved the sterile efficacy of microbe extracted pigments for biomedical products but also provided insights to advance the personal protective equipment (PPE) to fight against contagious pathogens. [ABSTRACT FROM AUTHOR]