Synthesis, modification and optimization of titanate nanotubes-polyamide thin film nanocomposite (TFN) membrane for forward osmosis (FO) application

Abstract

In the present study, the self-synthesized thin film nanocomposite (TFN) membrane incorporated with hydrophilic functionalized titanate nanotubes (TNTs) has been fabricated and tested for forward osmosis (FO) desalination. The ATR-FTIR results showed that NH2-TNTS were successfully modified by AATPS and while TEM and XRD revealed the tubular morphology and crystal structure of NH2-TNTs nanotubes, respectively. The presence of the chemical bondings between NH2-TNTs and polyamide (PA) selective top layer of TFN is corroborated with the FTIR results. The existence of NH2-TNTs in PA top layer was further confirmed by XPS analysis on the control and TFN membranes. The effect of NH2-TNTs on the PA layer was investigated and discussed in terms of surface morphology and separation performance. The morphology of the PA layer was investigated through FESEM and AFM micrographs and the outgrowth of the "leaf-like" structure was observed following the increase in NH2-TNTs content. Compared to the thin film composite (TFC) control membrane, the TFN membrane embedded with 0.05wt% NH2-TNTs (designated as TFN0.05) exhibited two times improvement in water flux without sacrificing salt rejection.