Effect of VUV Radiation on Surface Modification of Polystyrene Exposed to Atmospheric Pressure Plasma Jet.

Rok Zaplotnik,Alenka Vesel

doi:10.3390/polym12051136

Abstract

Precise tailoring of surface properties by gaseous plasma treatments remains a key scientific challenge, especially when adequate surface wettability should be laterally distributed, and sharp interfaces between hydrophobic and hydrophilic areas are desirable. The evolution of surface wettability and functional groups on polystyrene (PS) upon treatment with argon plasma jet was monitored by water contact angles and X-ray photoelectron spectroscopy (XPS). An array of water droplets was deposited on PS samples treated either directly by the plasma jet or only VUV radiation arising from the plasma. Rather sharp interfaces between the activated and not-affected regions were observed in both cases. The functionalization with highly-oxidized carbon functional groups, as determined by high-resolution C1s XPS spectra, was by far more efficient using the VUV radiation only. In contrast, the optimal wettability was achieved using direct plasma treatment. The results were explained by different mechanisms involved in the interaction of radiation and reactive plasma species with the polymer surface.

Highlights

Polystyrene (PS) is among the most commonly used aromatic polymers
PS surface surface versus we show the evolution of surface wettability, as well treatment time by treatment either with an atmospheric pressure plasma jets (APPJs) sustained in Ar or with VUV radiation arising from such plasma
The diameter of the activated spot remains practically the same, but the water contact angles at the center of the sample are much smaller

Summary

Introduction

Polystyrene (PS) is among the most commonly used aromatic polymers. It is widely used in different industrial branches, and one of its important applications is in biology for multi-well plates.Because PS is a pure hydrocarbon material, it is often used as a model polymer in studying surface functionalization. Polystyrene (PS) is among the most commonly used aromatic polymers. It is widely used in different industrial branches, and one of its important applications is in biology for multi-well plates. Functionalization is desirable in cases where the original wettability is not sufficient. It is often important to assure for uniform functionalization of a polymer sample over a large surface area. In such cases, low-pressure oxygen plasma has been proved to cause sufficient wettability on large samples. An investigation of the interaction between low-pressure oxygen plasma and PS foils revealed some interesting results [1]

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Results

Conclusion