Active-screen plasma surface multi-functionalisation of biopolymers and carbon-based materials – an overview

Biopolymer and carbon-based materials have found widespread applications, spanning across different industries, including the medical, energy storage, wind energy, and aerospace sectors. The increasing popularity of both types of materials in industry has created a driving force for the enhancement of their properties to meet the current and future requirements. Active-screen plasma (ASP) has attracted much attention as a versatile and powerful surface engineering solution to meet these growing demands, owing to its treatment uniformity, remote plasma nature, capability for treating both electrically conductive and insulating materials, ability to functionalise surfaces, and the unique combined function of surface activation and deposition (CFAD). Through the introduction of moieties, modification of chemical bonding, change of morphology, and improvement in wettability on the treated surfaces, recent studies have demonstrated the ability for ASP treatments to enhance the biocompatibility of biopolymers. Moreover, ASP has also been tested (and ‘bespoke’ ASP techniques developed) for advanced carbon-based materials for tailored applications with promising property/performance enhancements, including a) enhanced wettability and interfacial shear strength for carbon fibres in polymer matrix composites, b) improved catalyst layer growth on carbon paper, c) improved electrical conductivity and capacitive performance for carbon nanofibers, and d) enhanced electric and electrochemical properties for graphene oxide.

This review evaluates the recent achievements and findings of ASP treatments performed on biopolymers and carbon-based materials from the Surface Engineering group in the University of Birmingham. The current status of ASP surface multi-functionalisation is communicated, along with the future research focus for materials with poor electrical conductivity and/or vulnerability to degradation.