Increasing the surface hydrophobicity of silicone rubber by electron beam irradiation in the presence of a glycerol layer

Abstract

A cost-effective and scalable silicone rubber (SR) modification technology for increasing its surface hydrophobicity is urgently needed to enhance the stability of global power systems. In this work, an easily accessible method was developed to increase the surface hydrophobicity of silicone rubber, which was established by high-energy electron beam irradiation in the presence of a layer of glycerol. Although glycerol is a highly hydrophilic alcohol, the contact angle of silicone rubber can be surprisingly increased by 19.9% with the irradiation treatment of glycerol. Despite a high hydroxyl content being observed, a network structure formed on the silicone rubber surface is responsible for the increase in hydrophobicity. Control experiments and molecular dynamics (MD) simulations were also conducted to shed light on the underlying mechanism. This method has some intrinsic advantages, such as cost-effectiveness, easy operation and nontoxicity of glycerol; thus, it is expected to be applicable in large-scale industrial production and modification of silicone rubber.