Surface modification of polymer surfaces: atmospheric plasma versus vacuum plasma treatments

Abstract

An atmospheric pressure non-equilibrium plasma (APNEP) has been developed in the UK by EA Technology Ltd and is currently being investigated in collaboration with the University of Surrey. The main focus is the use of atmospheric pressure plasmas to modify the surfaces of commercially important polymers including polyolefins, poly(ethylene terephthalate) and poly(methyl methacrylate). These surface modifications include surface cleaning and degreasing, oxidation, reduction, grafting, cross-linking (carbonization), etching and deposition. When trying to achieve targeted surface engineering, it is vital to gain an understanding of the mechanisms that cause these effects, for example, surface functionalization, adhesion promotion or multi-layer deposition. Hence comparisons between vacuum plasma treated surfaces have also been sought with a view to using the extensive vacuum plasma literature to gain further insight. In this paper, we will introduce the APNEP and compare the key characteristics of the plasma with those of traditional vacuum plasma systems before highlighting some of the surface modifications that can be achieved by using atmospheric plasma. Data from the analysis of treated polymers (by spectroscopy, microscopy and surface energy studies) and from direct measurements of the plasma and afterglow will be presented. Finally, our current understanding of the processes involved will be given, particularly those that are important in downstream surface treatments which take place remote from the plasma source.

Atmospheric pressure plasma treatment of amorphous polyethylene terephthalate for enhanced heatsealing properties

“…It was found that the roughness as measured using peak to valley (R p-v ), root mean squared (R q ) and average roughness (R a ) approximately doubles for the plasma treated APET samples. The roughened surface morphology is due to energetic species within the plasma impacting on the polymer surface [29][30][31]. …”

Towards green carbon fibre manufacturing from waste cotton: a microstructural and physical property investigation

“…Surface modification of the CFs also alters their properties. Vacuum plasma treatment was adopted due to intriguing benefits such as effective surface modification, easy to operate, low cost and controlled treatment as compared to other surface modification techniques [20,21]. The surface modification and temperature dependent behaviour of waste cotton based CFs were studied by comparing the structural properties, wettability and response to nanoscale deformation.…”

Time resolved optical emission spectroscopy in power modulated atmospheric pressure plasma jet

“…), plasma enhanced chemical vapour deposition (PECVD) of thin films, plasma decontamination of toxic compounds, and recently in biomedical application and plasma medicine [1][2][3][4][5][6]. The dielectric barrier discharges (DBD) [1,2] and atmospheric pressure plasma jets (APPJ) [7] belong to the most successful designs.…”