【作者】 晋明会；

【导师】 潘见；

【作者基本信息】 合肥工业大学 ， 农产品加工及贮藏工程， 2009， 硕士

【摘要】 以截留分子量为30000的聚砜商品膜为基膜,采用原位生成法制备出Fe₃O₄/PSF磁性复合超滤膜,随后对所制膜的表面形貌、内部结构和分离性能进行了表征,并考察了FeCl₂浓度、NaOH浓度、反应温度和反应时间对所制膜平均孔径的影响。稳定性实验结果表明,在实验室条件下原位生成法具有较好的稳定性。扫描电镜结果表明,粒子主要沉积在聚砜基膜孔道中;XRD和XPS分析表明,聚砜基膜中沉积的主要成分是Fe₃O₄纳米粒子,根据XRD图谱结果计算出粒子的平均粒径为6.99nm;XPS结果显示,所制磁性复合超滤膜中很有可能形成了Fe-O-S键;液液界面法测得,磁性复合超滤膜的平均孔径从无磁场下的9.36nm减小到0.8T磁场下的8.54nm。在外加磁场下,磁性复合超滤膜对不带电的溶菌酶截留率增大,对带电的溶菌酶截留率减小。经过分析认为,磁性复合超滤膜在磁场下的超滤机理,主要是磁场诱导效应和磁致伸缩效应。单因素试验得到的最佳制备条件为:FeCl₂乙醇溶液浓度为0.2mol/L、NaOH水溶液浓度为2mol/L、反应温度为60℃和反应时间为45min;正交试验结果表明,影响磁性复合超滤膜孔径的因素按影响程度从大到小依次为:FeCl₂浓度＞反应温度＞NaOH浓度＞反应时间。更多还原

【Abstract】 With polysulfone commercial membrane as substrate material,Fe₃O₄/PSF magnetic composite ultrafiltration membrane was prepared.Then the properties of the membrane prepared,such as surface morphology,internal structure and separation performance,were characterized.Effects of iron dichloride concentration,sodium hydroxide concentration,reactive temperature and reactive time on average pore diameter of the membrane prepared were investigated.The result of stability experiment showed that the stability of in situ synthesis method was good in experimental conditions;The result of SEM showed that most particles deposited in the pore of the polysulfone membrane; XRD and XPS analysis indicated that particles deposited in the pore were mainly Fe₃O₄,and the average particle size of the particles calculated from XRD result was about 6.99nm;The result of XPS indicated that Fe-O-S bond was very likely formed in the magnetic composite ultrafiltration membrane prepared;Liquid-liquid displacement method measured that the average pore size declined from 9.36nm without magnetic field to 8.54nm in magnetic field with the intensity of 0.8T.The rejection to uncharged lysozyme of magnetic composite ultrafiltration membrane rose in magnetic field,while the rejection to charged lysozyme declined in magnetic field.After analysis,we realized that the rejection mechanisms of magnetic composite ultrafiltration membrane in magnetic field consisted of the magnetoinductive effect and magnetostrictive effect.Based on the result of single factor test,the optimum preparing conditions were as follows:iron dichloride concentration 0.2mol/L,sodium hydroxide concentration 2mol/L,reactive temperature 60℃,reactive time 45min.The result of orthogonal test indicated that the effectiveness of factors on the average pore diameter of the magnetic composite ultrafiltration membrane were in this order:iron dichloride concentration＞reactive temperature＞sodium hydroxide concentration＞reactive time.更多还原