LARGE-AREA ROLL-TO-ROLL ATMOSPHERIC PLASMA TREATMENT OF NANOCELLULOSE TRANSPARENT PAPER

Cellulose, as the most abundant polymer in the world, and recently nanocellulose, have emerged as sustainable, biodegradable and recyclable substrates for flexible and printed electronics in applications that require rapid roll-to-roll manufacturing. However, the wetting and printability of any material surface are linked to its surface energy. These may be modified by cleaning and activation of the surface, i.e. removal, formation or alteration of the adventitious or functional chemical groups on it. Recently, novel surface treatment techniques compatible with roll-to-roll manufacturing have attracted considerable attention on the part of researchers. In this contribution, we present atmospheric-pressure plasma generated by diffuse coplanar surface barrier discharge (DCSBD) for the surface treatment of nanocellulose transparent paper. The effect of ambient-air, low-temperature plasma on the surface of nanocellulose was investigated. Water contact angle measurements revealed increased hydrophilicity of the surface after short plasma treatment. X-ray photoelectron spectroscopy was utilized for chemical analysis of the surface of the nanocellulose. Plasma treatment led to a decrease in carbon concentration and a corresponding increase in oxygen concentration. Analysis of carbon peaks in the spectra revealed decreased C-C bonds and the formation of oxygen polar groups. The formation of polar groups was directly related to the increased hydrophilicity. Scanning electron microscopy was used to observe the morphological effects of plasma treatment on the nanocellulose surface. No damage to the nanocellulose fibres was observed after plasma treatment, which confirms that lowtemperature plasma is suitable for large-area roll-to-roll treatment of nanocellulose.