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摘要
在界面聚合过程中,通过添加改进水热方法制备的球形介孔SiO2纳米材料,制备了改性的聚酰胺反渗透复合膜。使用扫描电镜、X射线衍射和氮气吸附-脱附等手段对制备的介孔SiO2纳米材料进行表征;采用反渗透膜评价装置、原子力显微镜、扫描电镜(SEM)和静态接触角仪器等手段对复合膜的性能和结构进行测试和表征;并对比了相同粒径大小的实心SiO2和介孔SiO2对膜渗透性能的影响。结果证明:成功合成了一种具有孔径分布均匀、粒径均一、比表面积较大、分散性较好的介孔SiO2纳米球形颗粒;SEM表征结果证实纳米材料在膜表面分布均匀,膜表面亲水性能提高,粗糙度变大;膜性能测试结果证实了介孔SiO2的添加使得膜在维持较高截留率的前提下,具有更高的水通量;同时,通过对比相同尺寸的实心SiO2作为添加材料,证实了介孔SiO2的孔道结构更有利于水分子的传输。当介孔SiO2添加质量为0.06%时,水通量由23L/(m2·h)提高至39L/(m2·h),对氯化钠的截留仍然维持在98%以上。
Abstract
A modified polyamide reverse osmosis composite membrane was prepared by doping spherical mesoporous silica nanoparticles which were synthesized by modified hydrothermal method.The silica nanoparticles were characterized by SEM,XRD and N2-adsorption and desorption.The properties and structures of the membranes were tested and characterized by reverse osmosis membrane evaluation device,AFM,SEM and static contact angle instrument.Effects of porous and nonporous silica nanoparticles with same particle size on the membrane permeability and selectivity were also compared.The results demonstrated the successful synthesis of the mesoporous silica nanoparticles with uniformed pore size distribution,uniformed particle size,large specific surface area,good dispersion and sphere structure.The SEM photographs confirmed that the nano-materials were uniformly distributed on the surface of the membrane and the membrane hydrophilicity was improved with larger surface roughness.Furthermore,the membrane with mesoporous silica had higher water flux than the one with solid silica of the same size,which implied that the mesoporous silica with pore structure was more conducive to the transport of water molecules.When the content of mesoporous silica was 0.06wt%,the water flux increased from 23L/(m2·h) to 39L/(m2·h),while the rejection of sodium chloride remained above 98%.
关键词
介孔孔道
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反渗透复合膜
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SiO2
Key words
mesoporous pore structure
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reverse osmosis composite membrane
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SiO2
介孔SiO2孔道结构对聚酰胺反渗透复合膜性能的影响[J].
化工新型材料, 2020, 48(3): 41-45 DOI:
[1] 高从堦,周勇,刘立芬.反渗透海水淡化技术现状和展望[J].海洋技术学报,2016,35(1):1-14.
[2] 宋跃飞,高学理,苏保卫,等.高回收率反渗透海水淡化工艺的应用研究进展[J].水处理技术,2013,39(3):6-12.
[3] Otitoju T A,Saari R A,Ahmad A L.Progress in the modification of reverse osmosis (RO) membranes for enhanced performance[J].Journal of Industrial and Engineering Chemistry,2018.
[4] Yang Z,Ma X H,Tang C Y.Recent development of novel membranes for desalination[J].Desalination,2018,434,37-59.
[5] Tan Z,Chen S,Peng X,et al.Polyamide membranes with nanoscale Turing structures for water purification[J].Science,2018,360(6388):518-521.
[6] Jeong B H,Hoek E M V,Yan Y,et al.Interfacial polymerization of thin film nanocomposites:a new concept for reverse osmosis membranes[J].Journal of Membrane Science,2007,294(1-2):1-7.
[7] Kresge C T,Leonowicz M E,Roth W J,et al.Ordered mesoporous molecular sieves synthesized by a liquid-crystal template mechanism[J].Nature,1992,359(6397):710-712.
[8] Song X,Wang L,Tang C Y,et al.Fabrication of carbon nanotubes incorporated double-skinned thin film nanocomposite membranes for enhanced separation performance and antifouling capability in forward osmosis process[J].Desalination,2015,369:1-9.
[9] Beck J S,Vartuli J C,Schmitt K D,et al.A new family of mesosporous molecular sieves prepared wtih liquid crystal templates[J].J Am Chem Soc,1992,114(27):10834-10843.
[10] Vrijenhoek E M,Hong S,Elimelech M.Influence of membrane surface properties on initial rate of colloidal fouling of reverse osmosis and nanofiltration membranes[J].Journal of Membrane Science,2001,188(1):115-128.
[11] Wang S,Wang S,Yi Z,et al.Aggregation suppressed thin film nanocomposite (TFN) membranes prepared with an in situ generation of TiO2 nanoadditives[J].RSC Advances,2017,7(42):26136-26144.
