Synthesis, characterization and desalination study of polyvinyl chloride-co-vinyl acetate/cellulose acetate membranes integrated with surface modified zeolites

• Published in: Microporous and mesoporous materials 2020-12, Vol.309, p.110579, Article 110579
• Main Authors: Jamshaid, Fahd, Dilshad, Muhammad Rizwan, Islam, Atif, Khan, Rafi Ullah, Ahmad, Adnan, Adrees, Muhammad, Haider, Bilal
• Format: Article
• Language: English
• Subjects: (3-Aminopropyl) triethoxysilane; Cellulose acetate; Desalination; NaY zeolite; Polyvinyl chloride-co-vinyl acetate
• ISSN: 1387-1811; 1873-3093
• DOI: 10.1016/j.micromeso.2020.110579

Novel mixed matrix membranes of polyvinyl chloride-co-vinyl acetate/cellulose acetate (PVCA/CA) infused with nano-particles of both pristine zeolite (p-zeolite) and 3-aminopropyl triethoxysilane (APTS) functionalized zeolite (f-zeolite) were synthesized by dissolution casting method for desalination application. MMMs were then characterized using FTIR, SEM, contact angle and DMA analysis. FTIR and TGA analysis were also carried out for zeolite particles to confirm the surface functionalization. The loading effect of zeolite (1, 3 and 5 wt. %) and the impact of APTS functionalization on dispersion, morphological structure, thermo-mechanical properties and hydrophilicity were also analyzed. Desalination performance of the membranes was evaluated using 2000 ppm NaCl solution at 6 bar pressure. SEM analysis demonstrated that APTS functionalization improved the uniformity of the zeolite nano-particles in the membrane and a noticeable reduction in undesirable microscopic voids. Higher hydrophilicity was attained with the inclusion of f-zeolite nanoparticles, as confirmed by contact angle measurement analysis. It was found that the membrane infused with 5 wt. % of f-zeolite exhibited substantial improvements in storage modulus, glass transition temperature and cross-link density. Membranes infused with f-zeolite demonstrated enhanced transport mechanism without showing trade-off between water flux and salt rejection. In particular, inclusion of 5 wt. % f-zeolite, resulted in achieving the highest salt rejection of 99.56% with water flux increment of ~24% in comparison to the neat PVCA/CA membrane. Finally, the membranes were tested for anti-fouling properties using flux recovery ratio test. Thus, the newly developed PVCA/CA membranes embedded with APTS f-zeolite can be exploited for high performance desalination applications. [Display omitted] •Zeolite infused CA/PVCA blend is a promising material for reverse osmosis membranes.•f-zeolite infused membranes exhibit better properties compared to p-zeoilte membranes.•APTS f-zeolite greatly improves the dispersion quality leading to a densified membrane microstructure.•5 wt % APTS f-zeolite infused membrane greatly enhances the desalination capacity.•Storage modulus, Tg and crosslink density also improve with APTS-f-zeolite infusion.