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.

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.

Despite the best efforts in air-purification, airborne infectious diseases do and will continue to spread due to continuous emission of bioaerosols by the host/infected person. To tackle the rapid spread of airborne infectious diseases, a shift in focus from air-purification to bioaerosol disinfection/ decontamination is urgently needed. In this work, we studied a cold plasma ionizer (CPI) and electrostatic precipitator (ESP)-coupled CPI (CPI-ESP) for disinfection and cleaning of bioaerosols. Using porcine respiratory coronavirus (PRCV) and E. coli in a testing chamber, we demonstrated that CPI coupled with ESP is an effective technology for inactivating aerosolized microorganisms and microorganisms spread on surfaces. In addition, we have demonstrated the efficiency of a CPI-ESP coupled device for disinfection of naturally occurring airborne microbials in a few indoor settings (i.e., an 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 conduced fluorescence microscopy study to reveal different degree of bacteria cell membrane damage under CPI treatment.