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In this study, vapor phase deposition of quaternary ammonium polymers on different substrates was reported. Thin films of the poly(diethylaminoethyl methacrylate) (PDEAEMA) homopolymer and the poly(diethyl aminoethyl methacrylate-co-vinylbenzyl chloride) [P(DEAEMA-VBC)] copolymer were deposited by an initiated chemical vapor deposition (iCVD) technique using tert-butyl peroxide as an initiator. The variation of monomer feed ratios allowed control over the film structure. In the film structure, the tertiary amine group of DEAEMA is a key functionality behind the antibacterial activity, as verified after Fourier transform infrared spectroscopy and x-ray photoelectron spectroscopy analyses. The PDEAEMA homopolymer could be quaternized in a dry manner using an oxygen plasma treatment. The P(DEAEMA-VBC) copolymer, however, did not need an extra quaternization step because the tertiary amine group of the polymer could be readily quaternized by the chlorine moiety of the VBC unit. Both the homo- and copolymers exhibited high antibacterial activity on three different substrates, namely, glass, a polyethylene terephthalate sheet, and fabric. The antibacterial activity depended on the intensity of the quaternized nitrogen atoms in the as-deposited polymer. The adhesion and durability of the copolymer films were superior to that of the homopolymer film, verified using an adhesive tape peel-off test. The most durable copolymer film exhibited very high log-reduction values (>3) against gram-negative and gram-positive bacteria. Based on e cell viability analysis, the antibacterial films deposited by iCVD in this study were found to be nontoxic.

In this study, the successful transfer of chemical vapor deposition (CVD)‐grown graphene on an ordinary printing paper surface is demonstrated. Pristine paper is not a suitable substrate for graphene transfer because of its fragile and hydrophilic nature against the chemicals used during the transfer process. Two different fluoroalkyl polymers, namely poly(hexafluorobutyl acrylate) (PHFBA) and poly(perfluorodecyl acrylate) (PPFDA) are coated on paper surfaces by an initiated CVD (iCVD) technique to make the paper surfaces hydrophobic. Hydrophobicity is found to be an important factor in order for the graphene to be transferred onto the paper substrate. Although surfaces coated with PPFDA possess better hydrophobicity owing to their longer perfluoroalkyl group and higher roughness, the graphene transfer is found to be more successful on a PHFBA‐coated surface. A thin film of PHFBA on the paper surface acts as a prime layer for effective and defect‐free transfer of graphene and makes the paper surface ideal and robust during the graphene transfer process. The as‐transferred graphene layer on the PHFBA‐coated paper surface shows high conductivity values, even after repeated folding and flattening cycles.

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Purpose This study aims to find out friction and wear characteristics of graphene and graphene coating deposited by the Chemical Vapor Deposition (CVD) process on Honda GX270 engine (nodular cast iron) piston rings experimentally investigated under boundary lubricated conditions. Design/methodology/approach This study consists of two stages: tribotest and engine tests. First test was conducted through a reciprocating tribotest machine and second test was conducted through an engine bench with a duration of 75h. Engine piston ring was coated with graphene by two different methods: transfer method and direct CVD method. Findings Graphene has been demonstrated to be a potential and promising candidate for wear- and scratch-resistant coating because it is the thinnest, lightest and strongest known nanomaterial. In this case, the ability of a mono-layer graphene film to withstand high pressure differences (6 atm) indicates its mechanical robustness. It can effectively prevent or reduce mechanical failure by strengthening and toughening the loaded surface as well as by transferring the stress throughout the structure. The positive tribological outcomes of the graphene reinforced material under various dynamic loads revealed the potential of graphene-based coatings in macro - and micro-tribology. Originality/value This study fulfils an identified need to study for automotive industry a coating which is wear and scratch resistant.