Fabrication and characterization of novel polyester thin‐film nanocomposite membranes achieved by functionalized SiO2 nanoparticles for gas separation

Abstract

In this article, a new type of soluble polyester/silica (PE/SiO2) hybrid was prepared by the ultrasonic irradiation process. Surface modification of SiO2 was conducted using coupling agent γ‐glycidyloxypropyltrimethoxysilane (GOTMS) under ultrasonic irradiation. The structures of the modified hybrid nanocomposites were identified with a Fourier‐transform infrared spectroscopy (FT‐IR), whereas the size of the SiO2 in PE was characterized with a scanning electron microscope (SEM). SEM results indicated the formation and dispersion of nanometer scale size of inorganic domains inside the PE matrix due to the introduction of modified SiO2 and the interactions between organic and inorganic phases. The size of SiO2 particles in the modified system was about 25 nm. The transmission electron microscope (TEM) analysis showing the well‐dispersed nanosized titania nanoparticles (NPs). The densities and solubilities of the PE/SiO2 hybrids were also measured. Furthermore, thermal stability, residual solvent in the membrane film, and structural ruination of membranes were analyzed by thermal gravimetric analysis (TGA). Moreover, their mechanical properties were also characterized. It can be observed that the Young's moduli (E) of the hybrid films increase linearly with the silica content. The results obtained from gas permeation experiments showed that adding SiO2 to the PE membrane structure increased the permeability of the membranes. POLYM. ENG. SCI., 59:E237–E247, 2019. © 2018 Society of Plastics Engineers