1. Enhancing the NaCl/Na2SO4 separation selectivity and chlorine resistance of nanofiltration membranes by incorporating novel designed starch nanoparticles.
- Author
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Chen, Yuhao, Zhang, Tengfang, Chai, Dingdong, Ye, Haixing, Tang, Sihui, Wang, Peijian, Sun, Haixiang, Ge, Baosheng, and Jason Niu, Q.
- Subjects
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NANOFILTRATION , *NANOPARTICLES , *ACYL group , *ACYL chlorides , *CHLORINE , *FILTERS & filtration , *PIPERAZINE , *COMPOSITE membranes (Chemistry) - Abstract
[Display omitted] • Carboxylated starch nanoparticles (CSNPs) were synthesized and embedded in the separation layer of the nanofiltration membrane. • The aggregated or large CSNPs adsorb the aqueous phase to build an aqueous template during the interfacial polymerization transferring the reaction interface. • The compatibility problem of nanoparticles and separation layer was effectively solved. • The S NaCl/Na2SO4 of the modified nanofiltration membrane reached 180 with more than 2 times improvement in flux. The challenge of poor compatibility between nanoparticles and separation layers in thin film nanocomposite (TFN) nanofiltration (NF) membranes has always plagued the researchers. In this work, a carboxylated starch nanoparticles (CSNPs) were introduced into the polyamide (PA) separation layer of NF membrane by the IP reaction between trimesoyl chloride (TMC) and piperazine (PIP). The agglomerated or large size CSNPs could transfer the reaction interface above the particles through the formation of a water template by adsorption of aqueous phase monomers, which shaped the defect-free separation layer. Furthermore, the reduced thickness and increased density of the separation layer greatly enhanced the separation selectivity of the nanofiltration membrane thanks to the introduction of hydrophilic groups of nanoparticles. The modified membrane achieved a nearly 5-fold improvement in separation selectivity for NaCl and Na 2 SO 4 (S NaCl/Na2SO4 = 180) and a 2-fold increase in the water permeance. In addition, the modified NF membrane also possessed better chlorine-resistance property based on the formation of polyarylester between the reaction of hydroxyl groups in CSNPs and acyl chloride groups in TMC. Such novel aqueous-phase additives provide new insights to effectively solve the compatibility problem between the nanoparticles and separation layers, which is favorable for the commercial production of NF membrane. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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