芳香族聚酰胺反渗透膜结构的分子动力学模拟研究
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- 英文论文题名：Molecular Dynamics Simulation of the Structure of Aromatic Polyamide Reverse-Osmosis Membranes
- 论文作者：崔凤超 ; 李云琦
- 英文论文作者：Fengchao Cui ; Yunqi Li ; Key Laboratory of Synthetic Rubber ; Changchun Institute of Applied Chemistry ; Chinese Academy of Sciences
- 年：2016
- 作者机构：中国科学院长春应用化学研究所;
- 论文关键词：微观结构 ; 聚酰胺 ; 反渗透膜 ; 分子动力学 ; 交联度
- 会议召开时间：2016-08-25
- 会议录名称：中国化学会2016年软物质理论计算与模拟会议论文摘要集
- 语种：中文
- 分类号：TQ051.893
- 学会代码：ZGHY
- 会议名称：中国化学会2016年软物质理论计算与模拟会议
- 会议地点：中国天津
- 主办单位：中国化学会
- 学会名称：中国化学会
- 页数：2
- 文件大小：170k
- 原文格式：D
- 会议级别：全国
摘要
反渗透膜(RO)其具有低能耗、高效、所产水品质好等优点,在海水淡化、工业废水净化等领域的学术和商用价值日益凸显1。芳香族聚酰胺是最佳的构造反渗透膜的材料,其聚合可形成稳定的微观结构。膜的核心性能包括水通量、脱盐率和抗污染能力强烈依赖于膜的微观结构和物理化学性质,如膜中水通道尺寸分布、孔表面亲疏水性,膜表面极性基团分布和粗糙度等。为了定量揭示芳香族聚酰胺反渗透膜的结构性能关系,我们利用第一性原理结合分子动力学模拟,研究了间苯二胺(MPD)和均苯三甲酰氯(TMC)界面原位聚合反应形成的反渗透膜的微观结构特征。研究发现膜的交联度,密度和膜中水通道尺寸分布与组成、反应条件等密切相关。进一步通过Voronoi图解分析2膜中水通道尺寸发现该反渗透膜有三种特征孔洞,与广角X-ray衍射结果定性一致。
Reverse osmosis(RO) membranes have increasingly academic and commercial values in the desalination and the purification of seawater and brackish water,owe to their merits in low energy cost and high quality of water products.Aromatic polyamide is the best material to fabricate RO membranes,because they can steadily assemble into appreciated microstructure with superior stability.The water permeation,salt rejection and anti-fouling of RO membranes are the three critical performance characteristics which are determined by the microstructure and the associated physicochemical properties.They are the size and the distribution of pores,the polarity of the membrane surface and the wall of pore,the distribution of functional groups and the roughness of the membrane surface.In order to provide quantitatively description of the structure-performance relationship,we carried out molecular dynamics simulation on the membranes fabricated through the interfacial polymerization of m-phenylenediamine(MPD) and trimesoyl chloride(TMC).Parameters engaged in the simulation are explicitly computed from atomic structures based on the first principle,different reaction energy barriers and compositions are investigated.We found that the degrees of polymer cross-linking(DPC),densities,the size and the distribution of pores can be well tuned by composition and reaction conditions.Three types of pores are found inner the RO membrane through Voronoi decomposition,their sizes are in qualitative agreement with the wide-angle X-ray scattering(WAXS) characterization on the membranes fabricated under the same conditions.
Reverse osmosis(RO) membranes have increasingly academic and commercial values in the desalination and the purification of seawater and brackish water,owe to their merits in low energy cost and high quality of water products.Aromatic polyamide is the best material to fabricate RO membranes,because they can steadily assemble into appreciated microstructure with superior stability.The water permeation,salt rejection and anti-fouling of RO membranes are the three critical performance characteristics which are determined by the microstructure and the associated physicochemical properties.They are the size and the distribution of pores,the polarity of the membrane surface and the wall of pore,the distribution of functional groups and the roughness of the membrane surface.In order to provide quantitatively description of the structure-performance relationship,we carried out molecular dynamics simulation on the membranes fabricated through the interfacial polymerization of m-phenylenediamine(MPD) and trimesoyl chloride(TMC).Parameters engaged in the simulation are explicitly computed from atomic structures based on the first principle,different reaction energy barriers and compositions are investigated.We found that the degrees of polymer cross-linking(DPC),densities,the size and the distribution of pores can be well tuned by composition and reaction conditions.Three types of pores are found inner the RO membrane through Voronoi decomposition,their sizes are in qualitative agreement with the wide-angle X-ray scattering(WAXS) characterization on the membranes fabricated under the same conditions.
引文
[1]Shenvi,S.S;Isloor,A.M.;Ismail,A.F.Desalination 2015,368:10.
[2]Jimenez-Solomon,M.F.;Song,Q.L.;Jelfs,K.E.;Munoz-Ibanez,M.;Livingston,A.G.Nat.Mat.2016,doi:10.1038/nmat4638.
[2]Jimenez-Solomon,M.F.;Song,Q.L.;Jelfs,K.E.;Munoz-Ibanez,M.;Livingston,A.G.Nat.Mat.2016,doi:10.1038/nmat4638.