| Nanofiltration (NF) gains a lot of attention because its advantages such as relatively low operating pressures, high fluxes, low operating and maintenance costs. However, many polymeric membranes applied in aqueous system generally fail to maintain their physical integrity in organic solvents. A challenge still in this field is to broaden the application range of NF membranes from aqueous to organic feeds. Thus, organic solvent resistant nanofiltration (SRNF) becomes an emerging technology. Interfacial polymerization (IP) is a useful technique for fabrication of thin film composite (TFC) membranes. TFC membranes have many advantages, such as high-flux, low operating, and the materials used are usually inexpensive. The TFC membrane has increased in popularity recently.In order to develop higher performance of solvent resistant nanofiltration (SRNF) membranes, thin film composite (TFC) is prepared here by interfacial polymerization (IP) with various acyl chloride and poly (ethyleneimine)(PEI) on the substrate of thermal stable polypropylene UF membrane. In this work, microporous polypropylene (PP) flat film was used as a support to fabricate TFC nanofiltration membranes by the IP technique. The monomeric system chosen for IP was poly (ethyleneimine) and a broad range of binary chlorides have been used to prepare PA-based TFC membranes. Among six employed binary acyl chlorides, including three alkyl and three aryl acyl chlorides, isophthaloyl chloride (IPC) exhibits the best effect for the fabricated polyamide TFC membrane, which keep a stable performance both on solvent flux and on solute rejection even after21days pre-treating with ethanol, acetone, ethyl acetate and n-hexane, respectively. Moreover, it can resist high temperature treatment more than80℃. The TFC membranes were characterized by FCF (MW808.9) dyes in ethanol. Rejection values of93%, at a trans-membrane pressure of80psi.However, the fabrication TFC membranes have poor fluxes and confronting a serious problem of membrane fouling, For the purpose of overcoming these drawbacks, we report here the effects of aromatic phenols in the water phase on the membrane performance to improve the solvent flux and auto-fouling was investigated.Aromatic phenols were added into poly (ethyleneimine)(PEI) solution to react with isophthaloyl chloride (IPC) during the interfacial polymerization between PEI and IPC. Aromatic phenols were as additives compared with other additives the resulted showed that resorcinol was in dramatically improved solvent fluxes and anti-fouling without a significant lose of rejection. Worth to note, based on the understanding of the polymeric structures on molecular scale, we optimize a resorcinol from aromatic phenols as additive in water phase to further improve the anti-fouling property of the PEI-IPC TFC membrane, whilst a dramatically enhanced solvent flux is found without compromising solute rejection. Thus, a novel high-performance SRNF membrane is obtained and it shows a great potential for industry application. In this study, Fast Green FCF (MW=808.9) dye was utilized to evaluate the SRNF membranes. |
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