Controllable preparation of separation membrane with nano-ridge structure surface through Cyclam induced interfacial polymerization

Abstract

The intrinsic microstructure of the polyamide (PA) barrier layer in nanofiltration (NF) membranes (NFMs) has a significant influence on their separation performance. The most promising aspect of this work was that the nanoscale adjustable structure of NFMs with high separation performance and well antibacterial properties. The adjustable structure was engineered precisely via interfacial polymerization (IP) reaction using aqueous Tobramycin (Tob), 1,4,8,11-tetraazacyclotetradecane (Cyclam), and trimesoyl chloride (TMC) in organic solution. The structure and performance of membranes can be conveniently optimized by varying the content of Cyclam. The rejection of Na 2 SO 4 (98%) of the optimal membranes increased approximately 1.6-fold compared to the membranes without Cyclam, while the water flux continued to retain a high level (170 L m −2 h −1 MPa −1 ). Meanwhile, the pure water flux was about 2.2 folds than that of commercial NF1 with comparable solutes rejection. The prepared membrane exhibited good separation performance, antibacterial properties, and long-term stability. • Tob and Cyclam were introduced into the IP process for the first time. • The morphology of membranes was transformed from nodules to ridges through the introduction of Cyclam. • The performance of the membranes could be optimized conveniently by adjusting the content of Cyclam. • The membrane exhibited high rejection towards dyes and ions. • The membranes showed high permselective, long-term stability and antibacterial properties simultaneously.