Bioaerosol Inactivation by a Cold Plasma Ionizer Coupled with an Electrostatic Precipitator.

Despite best efforts in air purification, airborne infectious diseases will continue to spread due to the continuous emission of bioaerosols by the host/infected person. Hence, a shift in focus from air purification to bioaerosol inactivation is urgently needed. To explore the potential of the cold plasma technology for preventing rapid spread of airborne infectious diseases, we studied a cold plasma ionizer (CPI) device and an electrostatic precipitator (ESP)-coupled CPI (CPI-ESP) device for the inactivation and cleaning of surface-spread microorganisms and bioaerosols, using porcine respiratory coronavirus (PRCV), Escherichia coli (E. coli), and aerosolized E. coli as representatives. We firstly demonstrated that CPI coupled with ESP is an effective technology for inactivating virus and bacteria spread on surfaces in an in-house test chamber. We then demonstrated the efficacy of CPI-coupled ESP for the inactivation of aerosolized E. coli in the same chamber. Furthermore, we have demonstrated the efficiency of a CPI-ESP coupled device for the inactivation of naturally occurring airborne microbials in a few indoor settings (i.e., a living room, a discussion room, a schoolroom, and an office) to determine the treatment duration- and human activity-dependent efficacy. To understand the disinfection mechanism, we conducted a fluorescence microscopy study to reveal different degrees of E. coli bacteria cell membrane damage under CPI treatment.

Superhydrophobic and slippery liquid-infused porous surfaces formed by the self-assembly of a hybrid ABC triblock copolymer and their antifouling performance.

An ABC triblock copolymer based on poly(dimethylsiloxane)-poly(tert-butyl acrylate)-poly(methacrylolsobutyl POSS) is synthesized via combination of SET-LRP and ATRP from a PDMS macroinitiator. The resulting polymer can readily self-assemble into hierarchical structures through a stepwise "bottom-up" strategy, i.e. self-assembly followed by the nonsolvent vapor-induced phase separation. When a mixture of dichloromethane/dimethylformamide (DCM/DMF) is used as the casting solvent, the resulting surface (SHS) exhibits superhydrophobicity with a high water contact angle (156.7 ± 0.5°) and a low roll-off angle (<9°), and it also displays good self-cleaning property. Moreover, under the dichloromethane/methanol (DCM/MeOH) condition, a porous structure with intertwined networks of nano globules could be formed. Further infusion of the PDMS lubricant leads to the formation of a transparent slippery coating (SLIPS) with excellent water repellency, manifested by a low water contact angle hysteresis (∼3°) and a small sliding angle (∼6°). The SLIPS show excellent antifouling properties that effectively inhibit the attachment of P. aeruginosa ATCC 15692 as compared to that of the structured hydrophobic surfaces and cured PDMS surfaces.

Advancing the frontiers of silk fibroin protein-based materials for futuristic electronics and clinical wound-healing (Invited review).

The present review will introduce the basic concepts of silk-based electronics/optoelectronics including the latest technological advances on the use of silk fibroin in combination with other functional components, with an emphasis on improving the performance of next-generation silk-based materials. It also highlights the patterning of silk fibroin to produce micro/nano-scale features, as well as the functionalization of silk fibroin to impart antimicrobial (i.e. antibacterial) properties. Silk-based bioelectronics have great potential for advanced or futuristic bio-applications including e-skins, e-bandages, biosensors, wearable displays, implantable devices, artificial muscles, etc. Notably, silk-based organic field-effect transistors have highly promising applications in e-skins and biosensors; silk-based electrodes/antennas are used for in vivo bioanalysis or sensing purpose (e.g., measurement of neurotransmitter such as dopamine) in addition to their use as food sensors; silk-based diodes can be applied as light sources for wound healing or tissue engineering, e.g., in cutaneous wound closure or induction of photothrombosis of corneal neovascularization; silk-based actuators have promising applications as artificial muscles; whereas silk-based memristors have exciting applications as logic or synaptic network for realizing e-skins or bionic brains.