The successful processing of bilayer protective coatings on plastics using a combined spray and atmospheric plasma deposition method is shown. The base layer is a spray deposited coating with high adhesion using (3‐glycidyloxypropyl) trimethoxysilane and tetrapropyl zirconate (TPOZ) precursors. The top dense layer is deposited by atmospheric plasma deposition with a tetraethyl orthosilicate precursor. The coating deposition rate, chemical composition, elastic modulus, hardness, and adhesion to poly(methyl methacrylate) (PMMA) substrates are investigated. The adhesion to the polymer substrate is found to decrease with increasing TPOZ content in the precursor solution, while the elastic modulus and hardness of the base layer increase. A silane surface pretreatment of the PMMA substrate is shown to significantly increase the coating adhesion. The adhesion of the optimized coating is so high that it forces the debond interface change from adhesive failure at the coating/PMMA interface to cohesive failure within the PMMA substrate. The combined bilayer structure exhibits a >90% transparency in the visible wavelengths, eightfold increase in adhesion energy and fourfold increase in Young's modulus compared to commercial sol–gel polysiloxane coatings. The approach provides a strategy for an unprecedented combination of adhesion and mechanical properties.
Microbial bioelectronic devices integrate naturally occurring or synthetically engineered electroactive microbes with microelectronics. These devices have a broad range of potential applications, but engineering the biotic–abiotic interface for biocompatibility, adhesion, electron transfer, and maximum surface area remains a challenge. Prior approaches to interface modification lack simple processability, the ability to pattern the materials, and/or a significant enhancement in currents. Here, a novel conductive polymer coating that significantly enhances current densities relative to unmodified electrodes in microbial bioelectronics is reported. The coating is based on a blend of poly(3,4‐ethylenedioxythiophene)‐poly(styrenesulfonate) (PEDOT:PSS) crosslinked with poly(2‐hydroxyethylacrylate) (PHEA) along with a thin polydopamine (PDA) layer for adhesion to an underlying indium tin oxide (ITO) electrode. When used as an interface layer with the current‐producing bacterium
- NSF-PAR ID:
- 10446103
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Materials
- Volume:
- 34
- Issue:
- 13
- ISSN:
- 0935-9648
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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