Lv Zhiwei, Hu Jiahui, Zhang Xuan, Wang Lianjun
Key Laboratory of Jiangsu Province for Chemical Pollution Control and Resources Reuse, Nanjing University of Science & Technology, Nanjing 210094, China.
Phys Chem Chem Phys. 2015 Oct 7;17(37):24201-9. doi: 10.1039/c5cp04105h. Epub 2015 Sep 1.
In the current study, thin-film composite (TFC) nanofiltration membranes desirable for water softening were successfully developed through interfacial polymerization using N-(2-hydroxyethyl)ethylenediamine (HEDA) as the amine monomer in the aqueous phase. The hydrophilicity of the membrane surface was greatly enhanced with the introduction of the residual hydroxyl groups during the fabrication process. The TFC membranes possessed a permeate flux of 15.8 L m(-2) h(-1) under 0.6 MPa, with a rejection of 85.9%, 73.8%, and 99.8% for Na2SO4, MgSO4 and Congo red, respectively. The interplays of the solvent, solute and polymer matrix on the separation performance were investigated by means of the solubility parameter study. Moreover, density functional theory was employed to calculate the Fukui function by the Hirshfeld charge, which gave the global and local softness values to predict the reactivity of the atomic sites in the HEDA molecule. The findings of this study support the possible forming mechanism of the barrier layer for the first time. The TFC membrane was found to be stable and displayed good separation ability over a week-long filtration process. The combined results of this work suggest that these HEDA/TMC TFC nanofiltration membranes are promising candidates for various applications, such as desalination and dye removal from wastewater.
在当前研究中，通过界面聚合成功开发出了适用于水软化的薄膜复合（TFC）纳滤膜，该过程使用N-(2-羟乙基)乙二胺（HEDA）作为水相中的胺单体。在制备过程中，随着残留羟基的引入，膜表面的亲水性大大增强。TFC膜在0.6 MPa压力下的渗透通量为15.8 L m(-2) h(-1)，对Na2SO4、MgSO4和刚果红的截留率分别为85.9%、73.8%和99.8%。通过溶解度参数研究考察了溶剂、溶质和聚合物基体对分离性能的相互作用。此外，采用密度泛函理论通过Hirshfeld电荷计算福井函数，得到全局和局部软度值，以预测HEDA分子中原子位点的反应活性。本研究结果首次支持了阻挡层可能的形成机制。在长达一周的过滤过程中，发现TFC膜稳定且具有良好的分离能力。这项工作的综合结果表明，这些HEDA/TMC TFC纳滤膜有望用于各种应用，如海水淡化和从废水中去除染料。
