Glycerol-assisted uniform dispersion of TpHz nanoparticles in the poly(vinyl alcohol) membrane matrix to construct water permeation channels

Abstract

Achieving uniform dispersion of nanoparticles within the polymer membrane matrix while simultaneously constructing continuous selective permeation channels has always been key to preparing high-performance mixed matrix membranes. In this study, we employ glycerol (Gol) molecules as “bridges” to harness the hydrogen bonding interactions between Gol, TpHz, and poly(vinyl alcohol) (PVA) molecules. This approach facilitates the nanoscale dispersion of TpHz nanoparticles within the PVA membrane, establishing continuous channels that selectively permit the permeation of water molecules. By incorporating just 0.3 wt % of TpHz nanoparticles, the resultant PVA/Gol/TpHz membrane demonstrates a mechanism that favors the selective adsorption, dissolution, and rapid diffusion of water molecules from the feed, thereby reducing the activation energy required for their permeation through the membrane. The prepared PVA/Gol/TpHz membrane with pure water contact angle of only 19.6° has total flux and separation factor of 134 L m⁻² h⁻¹ and 705, which were 3.4 and 3.5 times higher than those of the pure PVA membrane, respectively. It broke the “trade-off” effect of traditional PVA membrane. Moreover, the tensile strength and thermal decomposition temperature of the PVA/Gol/TpHz membrane were increased from 130.31 MPa to 120.90 °C to 442.05 MPa and 246.8 °C, respectively. The membrane structure and separation performances remained stable during the 80-h pervaporation test, which suggests potential for industrial applications.