Computational analysis of atomic binding energy for organosilicon-low-density polyethylene-coated silica embedded in polyvinylidene fluoride composite membrane for membrane gas absorption

Abstract

In an effort to enhance the wetting resistance and chemical stability of membrane contactors, silica nanoparticles (SiNP) have been incorporated into polyvinylidene fluoride (PVDF) membrane. These SiNP have been hydrophobically functionalized with three separate organosilicons (hexamethyldisilane, dimethyldichlorosilane, and polydimethylsiloxane) to produce TS-530, TS-610, and TS-720 SiNP. Then, they were coated with low-density polyethylene (LDPE) before adding them to the membrane casting dope. Using HyperChem, the molecular interaction between SiNP, organosilicons, and LDPE, as well as their aggregation tendency, was predicted using a semi-empirical computational approach (PM3). Both theoretical predictions and experimental results show that TS-610 and TS-720 SiNP have a high propensity to agglomerate, leading to the formation of composite membranes with large macrovoids. The HyperChem analysis, however, also indicates that LDPE/f-SiNP can resist chemical corrosion, and all composite membranes show positive binding energy interactions with amines. This enables the LDPE/f-SiNP membranes to perform better than the neat PVDF membrane with an adequate amine solution, and it remains hydrophobic after prolonged exposure.