Perrotta Maria Luisa, Macedonio Francesca, Giorno Lidietta, Jin Wanqin, Drioli Enrico, Gugliuzza Annarosa, Tocci Elena
National Research Council-Institute on Membrane Technology, ITM-CNR, Via P. Bucci Cubo 17/C, 87036 Rende (CS), Italy.
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 211816, China.
Phys Chem Chem Phys. 2020 Apr 15;22(15):7817-7827. doi: 10.1039/d0cp00928h.
Membrane-assisted crystallization is an emerging technology where microporous hydrophobic membranes are used not as selective barriers but to promote the water vapor transfer between phases inducing supersaturation in solution. This has been successfully tested in the crystallization of ionic salts, low molecular weight organic acids and proteins. In this work, molecular dynamics simulations were used to study the crystal nucleation and growth of sodium chloride in contact with hydrophobic polymer surfaces at a supersaturated concentration of salt. A pristine polyvinylidene fluoride (PVDF) surface and PVDF containing different concentrations of graphene platelets were studied. Membrane crystallization tests were performed in parallel, in order to compare the experimental results with the computational ones. Here, with an integrated experimental-computational approach, we demonstrate that graphene-containing membranes assisted the crystal growth of NaCl, speeding up crystal nucleation in comparison with the pristine PVDF membranes. The computational results agreed with the experimental data, allowing the possibility of exploring the behavior of nanomaterials in membrane processes at a microscopic level.
膜辅助结晶是一项新兴技术，其中微孔疏水膜并非用作选择性屏障，而是用于促进相之间的水蒸气传递，从而在溶液中诱导过饱和。这已在离子盐、低分子量有机酸和蛋白质的结晶中得到成功测试。在这项工作中，利用分子动力学模拟研究了在盐的过饱和浓度下与疏水聚合物表面接触的氯化钠的晶体成核和生长。研究了原始聚偏氟乙烯（PVDF）表面以及含有不同浓度石墨烯片的PVDF。同时进行了膜结晶测试，以便将实验结果与计算结果进行比较。在此，通过综合实验 - 计算方法，我们证明含石墨烯的膜促进了NaCl的晶体生长，与原始PVDF膜相比加快了晶体成核。计算结果与实验数据一致，使得在微观层面探索纳米材料在膜过程中的行为成为可能。
