Grafting polysiloxane onto ultrafiltration membranes to optimize surface energy and mitigate fouling

Published

May 18, 2020

Author(s)

Thien Tran, Xiaoyi Chen, Sarthak Doshi, Christopher Stafford, Haiqing Lin

Abstract

Conventional approaches to mitigate fouling of membrane surfaces impart hydrophilicity to the membrane surface, which increases the water of hydration and fluidity near the surface. By contrast, we demonstrate here that tuning the membrane surface energy close to that of the dispersive component of water surface tension (21.8 mN/m) can also improve the antifouling properties of the membrane while retaining water permeance. Specifically, ultrafiltration (UF) membranes were first modified using polydopamine (PDA) followed by grafting of amine-terminated polysiloxane (PSi-NH2). For example, with 2 g/L PSi-NH2 coating solution, the obtained coating layer contains 53 mass% PSi-NH2 and exhibits a total surface energy of 21 mN/m, decreasing the adsorption of bovine serum albumin (BSA) by 44 % compared to the unmodified membrane. When challenged with 1 g/L sodium alginate in a constant-flux crossflow system, the PSi-NH2-grafted membrane exhibits 70 % lower fouling rate than the pristine membrane at a water flux of 110 liter/(m2 h) (LMH) and good stability when cleaned with NaOH solutions.

Citation

Soft Matter

Volume

16

Issue

21

Pub Type

Journals

Download Paper

https://doi.org/10.1039/D0SM00551G

Local Download

Keywords

membranes, fouling, surface modification, polydopamine, siloxanes, surface energy, water purification

Citation

Tran, T. , Chen, X. , Doshi, S. , Stafford, C. and Lin, H. (2020), Grafting polysiloxane onto ultrafiltration membranes to optimize surface energy and mitigate fouling, Soft Matter, [online], https://doi.org/10.1039/D0SM00551G, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=930074 (Accessed October 26, 2025)