Influence of cellulose microfiber reinforcement for polyvinyl alcohol on the layer growth of plasma-deposited a-C:H

Abstract Pure polyvinyl alcohol (PVA) and PVA reinforced with cellulose microfibers (PVA/CMF) composite films were coated with amorphous carbon layers (a-C:H, 50 and 100 nm thick) using radio frequency plasma enhanced chemical vapour deposition (RF-PECVD). The effects of cellulose microfibers on the polymer coatability were investigated. The reinforcement of PVA with CMF fibres leads only to a small variation for the resulting coatings. The measurements for the 50 nm samples differ chemically due to the different interlayer phase through the different base materials. Increasing of the layer thickness leads to an equalization of the layer for both materials. Deposited carbon layers were characterized surface morphologically by ex-situ atomic force microscopy (AFM), surface wettability by contact angle (CA) measurements. The chemical composition was analysed by surface sensitive synchrotron X-ray based techniques (near edge X-ray absorption fine structure (NEXAFS) and X-ray photoelectron spectroscopy (XPS)) and diffuse reflectance infrared Fourier transform spectroscopy (DRIFT). Novelty-statement Amorphous carbon layers (a-C:H) were successfully deposited on polyvinyl alcohol (PVA) and cellulose microfiber (CMF) reinforced PVA. Differences in the chemical composition of deposited carbon layers (sp2/sp3) were detected with synchrotron based techniques in combination with changes in their morphology and wettability showing clear substrate effects when used with microfiber reinforcement.