Yang Jie, Xu Zhijun, Yang Xiaoning
State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical Engineering, Nanjing Tech University, Nanjing 210009, China.
Phys Chem Chem Phys. 2017 Aug 16;19(32):21481-21489. doi: 10.1039/c7cp04236a.
Graphyne has been proposed as a distinctive molecular sieving membrane due to its intrinsic nanoscale pores and single-atom thickness. However, this novel application requires a precise quantification and understanding of the molecular interaction at graphyne interfaces, which can modulate molecular transport across graphyne. Herein, interfacial adsorption and permeation of ethanol-water mixtures on graphynes are studied by a multiscale simulation strategy, in which dispersion-corrected density functional theory (DFT-D) and classical molecular dynamics (MD) are combined. Our results show that graphyne possesses differential surface affinities with ethanol and water, provoking a preferential adsorption layer of ethanol. The adsorption on the graphyne surface is dominated by attractive dispersion force, even for polar water molecules. As a joint function of ethanol-rich segregation adsorption on graphyne and preferred pore occupation of ethanol, polyporous graphyne with a suitable pore size is envisioned to act as an alcohol-permselective membrane. Our simulation results present new insights into interfacial interaction and have an impact on the promising application of two-dimensional graphyne membranes.
由于其固有的纳米级孔隙和单原子厚度，石墨炔被认为是一种独特的分子筛膜。然而，这种新应用需要对石墨炔界面处的分子相互作用进行精确量化和理解，这种相互作用可以调节分子在石墨炔上的传输。在此，采用多尺度模拟策略研究了乙醇-水混合物在石墨炔上的界面吸附和渗透，该策略将色散校正密度泛函理论（DFT-D）和经典分子动力学（MD）相结合。我们的结果表明，石墨炔对乙醇和水具有不同的表面亲和力，从而形成了乙醇的优先吸附层。即使对于极性水分子，在石墨炔表面的吸附也主要由吸引性色散力主导。作为乙醇在石墨炔上的富偏析吸附和乙醇优先占据孔隙的共同作用，具有合适孔径的多孔石墨炔有望用作醇类渗透选择性膜。我们的模拟结果为界面相互作用提供了新的见解，并对二维石墨炔膜的前景应用产生影响。
