(3-Aminopropyl) Triethoxysilane-Modified ZIF-90 Nanoparticle/Polydimethylsiloxane Mixed Matrix Membranes for Ethanol Recovery via Pervaporation
Zhentong Han, Yaxin Zhao, Haoji Jiang, Ao Sheng, Hao Li, Jia Hao, Zhiyuan Yun, Zhong Wei, Heyun Wang
Abstract
The present study eliminated nonselective defects by amending the MOF-based mixed matrix membrane (MMM) interface with (3-aminopropyl) triethoxysilane (APTES) via Schiff’s base reaction. This modification on the ZIF-90 nanoparticle surfaces enhanced the polydimethylsiloxane (PDMS) matrix interaction in the MMMs. Interfacial defects were then minimized through APTES-ZIF-90 nanoparticle surface alkoxy and PDMS chain hydroxyl group cross-linking. Enhanced chemical interactions between the nanoparticles and the polymeric matrix in the APTES-ZIF-90/PDMS MMMs resulted in higher interface compatibility and separation performance than the ZIF-90 nanoparticle MMMs, which ultimately improved its ethanol affinity and hydrophobicity. When the load of APTES-ZIF-90 nanoparticles was 15% and the temperature was 40 °C, the pervaporation performance of APTES-ZIF-90/PDMS MMMs was optimal, the separation factor was 16.8, and the permeation flux was 223 g/(m2·h). Compared with pure PDMS, the separation factor and permeation flux increased by 91 and 67%, respectively. In addition, stable APTES-ZIF-90/PDMS MMM pervaporation performance was observed after an optimal operation time of 120 h. Overall, the present work presented methods to optimize MOF-based MMMs for enhanced interface morphology and separation performance for ethanol recovery.