By intercalating citrate anions into the inter-layer of layered double hydroxides (LDHs), the inter-layer spacing of the resultant CA-Mg-LDH is enlarged from 7.5 to 11.8 Å. With the aid of this newly developed CA-Mg-LDH, novel thin-film nanocomposite (TFN) membranes have been prepared, systematically investigated, and demonstrated for brackish water reverse osmosis (BWRO) desalination. By manipulating the nanofiller concentration, a water permeance of 3.21 LMH bar⁻¹ and a salt rejection of 98.9% are obtained for the TFN membrane at the optimal loading of 0.15 wt%. It achieves a 68% higher water permeance than the pristine TFC membrane but without notably sacrificing the selectivity, owing to the moderate enlargement of the inter-layer spacing of CA-Mg-LDH. In addition, this novel TFN membrane has a boron rejection of 75% when using a 2000 ppm NaCl solution containing 10 ppm boron as the feed at 20 bar. This work is the first attempt to use CA-Mg-LDH as nanofillers in TFN membranes for demonstration of BWRO and boron removal, offering new insights and strategies for the design of next-generation TFN membranes for water treatment.

通过将柠檬酸根阴离子嵌入层状双氢氧化物 (LDH) 的层间，所得 CA-Mg-LDH 的层间距从 7.5 扩大到 11.8 Å。借助这种新开发的 CA-Mg-LDH，制备了新型薄膜纳米复合材料 (TFN) 膜，并对其进行了系统研究，并证明了其可用于微咸水反渗透 (BWRO) 脱盐。通过控制纳米填料浓度，3.21 LMH bar ^{-1的水渗透率}在 0.15 wt% 的最佳负载下，TFN 膜的脱盐率为 98.9%。由于 CA-Mg-LDH 的层间距适度扩大，它的透水性比原始 TFC 膜高 68%，但不会显着牺牲选择性。此外，当在 20 bar 下使用含有 10 ppm 硼的 2000 ppm NaCl 溶液作为进料时，这种新型 TFN 膜的硼截留率为 75%。这项工作是首次尝试使用 CA-Mg-LDH 作为 TFN 膜中的纳米填料来演示 BWRO 和硼去除，为设计用于水处理的下一代 TFN 膜提供新的见解和策略。