Effects of different porous fillers on interfacial properties of poly (vinyl alcohol) hybrid films

Abstract

Poly(vinyl alcohol) (PVA)‐based hybrids have demonstrated broad liquid separation applications but separation performances are constrained by the compatibility between fillers and polymer, and thus it is essential to study the interfacial properties of these hybrids. In this work, PVA hybrids with four different porous fillers have been fabricated and characterized with Fourier transform infrared, X‐ray diffraction, Scanning electron microscope, swelling and contact angle tests. Swelling results show that PVA has a degree of swelling (DS) of 79% in water but the swelling is compressed after adding fillers and the DS for PVA hybrids has decreased by 19%, 17%, 15%, and 9% for 30 wt% loading of ZIF‐8, UiO‐66, Hβ and ZSM‐5, respectively. For methanol and its 10 wt% aqueous solution, similar swelling results are obtained due to mutual interactions among the filler, polymer and test liquids. Based on water and glycerol contact angle results, the surface energy of PVA is estimated to be 40.56 Nm−1 and it drops to 27.39 Nm−1 after adding less hydrophilic ZIF‐8 or rise to 48.56 Nm−1 after introducing more hydrophilic ZSM‐5. The high‐film hydrophilicity and then large surface energy have rendered methanol/water sorption selectivity of PVA hybrids decrease to some extent or vice versa.

Pervaporative poly(vinyl alcohol)/H‐β zeolite mixed matrix membranes for dewatering C2–C3 alcohols

“…The δ d , δ p , δ h , and δ parameters for alcohols and PVA are referred from the well-known book 38 while those for H-β zeolite are not experimentally available but collected from the estimation reported elsewhere. 40 These HSP data are presented in Table 4 and the Δδ 1,2 values estimated according to Equation (10) are given in Table 4. Generally, the lower the Δδ 1,2 value, the stronger affinity between a liquid and a membrane involved and subsequently the stronger swelling.…”

Swelling-Resistant, Crosslinked Polyvinyl Alcohol Membranes with High ZIF-8 Nanofiller Loadings as Effective Solid Electrolytes for Alkaline Fuel Cells

“…Increasing the ZIF-8 loads to 40.5–45.4% exhibited negligible volume swelling changes (<1.4%) and confirmed the dimensional stability. Much literature used dried ZIF nanofiller powders (1–10 wt.%) into polymeric matrices and obtained moderate to high swelling ratios (22–320%) [ 49 , 50 , 51 , 52 ]. Such highly swollen composites may suffer from dimensional changes and weakened mechanical strength.…”