Fabrication and characterization of a novel nanofiltration membrane by the interfacial polymerization of 1,4-diaminocyclohexane (DCH) and trimesoyl chloride (TMC)

Abstract

A novel thin-film composite polyamide membrane for nanofiltration is prepared, and the addition of sodium N-cyclohexylsulfamate is found to have a significant influence on its performance.

Preparation and characterization of a composite nanofiltration membrane interfacially polymerized from cis,cis‐1,3,5‐triaminocyclohexane and trimesoyl chloride

“…When the membrane was treated at ambient temperature, the rejection of Na 2 SO 4 was 95%, whereas when the temperature exceeded 60 °C, the crosslinking reaction was obviously enhanced, and the rejection was improved to nearly 98%, but WP dropped a little because it had already reached a high crosslinking level given that TAC was also a crosslinking point. It is known that a excessively high temperature is harmful to the membrane, and some membranes treated at 100 °C gave a worse separation performance . Although it did not happen in our experiments, it seems that 80 °C should be the appropriate choice according to the results.…”

“…A further concentration increase did not bring any obvious change to the rejection and WP values. So 0.2 wt % of TAC was good enough to form a dense selective layer, and this concentration is lower than the reported values of diamines as TAC was trifunctional and could provide enough amine groups even at a relatively low concentration.…”

“…The influence of reaction time on the performance of the membrane was exhibited in Figure . It was surprising that the rejection could reach 98% within only 5 s, which was much shorter than the time the other reported amines needed . Further increasing the reaction time, the rejection stayed almost constant, and the WP dropped from 1.73 L m −2 h −1 bar −1 to 1.56 L m −2 h −1 bar −1 , indicating that the active layer formed at 5 s was already dense enough.…”

A thin film composite membrane supported by a hydrophilic poly(vinyl alcohol‐co‐ethylene) nanofiber membrane: Preparation, characterization, and application in nanofiltration

“…It is constructed of three layers, including an ultrathin and very dense selective barrier layer, a microporous intermediate layer, and a nonwoven fabric supporting layer . Interfacial polymerization (IP) is the most popular method to fabricate the ultrathin and dense selective barrier layer and refers to the polymerization of aqueous monomers and oil‐phase monomers at their mutually incompatible interface . Hence, it is necessary to optimize the IP reaction factors, including the reaction time, temperature, monomer type and concentration, amd catalyst type and concentration, to enhance the performance of the TFC membrane …”

High‐performance composite nanofiltration membranes fabricated via ternary mixture: Complementary preponderance of the fluorine‐containing monomer 2,2′‐bis(1‐hydroxyl‐1‐trifluoromethyl‐2,2,2‐triflutoethyl)‐4,4′‐methylene dianiline and the rigid monomer bisphenol F

“…However, the function of one single monomer is limited. To further enhance the NF membrane performance, a lot of researchers have focused on the synergistic effects of two or more monomers mixed in the aqueous or organic phase …”