Atmospheric-Pressure Plasma-Induced In Situ Polymerization of Liquid Silsesquioxane Monomer for the Synthesis of Polysilsesquioxane Nanocomposite Membranes with Sub- Nanometer Pores for Molecular Separation

Plasma-induced polymerization of liquid silsesquioxane monomer (1,2-bis(triethoxysilyl)ethane, BTESE) at the gas- liquid interface was achieved at room temperature by employing an atmospheric-pressure plasma jet. The polymerization of the liquid monomer under exposure to atmospheric-pressure plasma resulted in the formation of a thin polysilsesquioxane layer at the immediate surface of the porous support. The confined polymerization at the plasma-liquid interface was demonstrated to be beneficial for preparing nanocomposite membranes with a thin selective layer on top of the porous support. The BTESE-derived polysilsesquioxane membrane exhibited high selectivity for gas separation (H2/CH4 = 195) based on the molecular sieving mechanism.

Automated summary

The plasma-induced polymerization of liquid silsesquioxane monomer (BTESE) at the gas-liquid interface was successfully achieved using an atmospheric-pressure plasma jet at room temperature. This resulted in the formation of a thin polysilsesquioxane layer on the surface of a porous support. The confined polymerization at the plasma-liquid interface proved to be advantageous for preparing nanocomposite membranes with a thin selective layer.