【作者】 于媛；

【导师】 李东亮；

【作者基本信息】 西安建筑科技大学 ， 应用化学， 2009， 硕士

【摘要】 超滤是以压力为推动力的筛孔分离过程,它介于纳滤和微滤之间。超滤膜特殊的纳米级孔径范围决定了其特殊的应用,目前可广泛应用于溶液净化、浓缩、饮用水制备和物料回收等领域。本论文的主要研究目标是:将无机纳米Al₂O₃粒子与高分子聚合物PSU共混,制备出改性后的有机/无机共混超滤膜,以改善膜的分离性能和理化特性,提高其亲水性,从而增强膜的抗污染性能,延长使用寿命。研究中以聚砜（PSU）为超滤膜材料,通过考察溶剂种类、聚砜质量分数、添加剂种类及质量分数、铸膜液温度、凝固浴种类及温度、铸膜液挥发时间等因素对PSU膜结构和性能的影响,确定最佳工艺条件,制备了具有一定分离性能的PSU超滤膜。为进一步提高超滤膜的性能,我们再以PSU为聚合物膜材料,添加无机材料纳米Al₂O₃制备共混超滤膜。通过考察聚砜质量分数、纳米Al₂O₃质量分数、添加剂种类及质量分数和凝固浴温度等因素对共混膜结构和性能的影响,确定最佳工艺条件,制备了具有良好分离性能的PSU/纳米Al₂O₃共混超滤膜。对比研究了PSU超滤膜和PSU/纳米Al₂O₃共混超滤膜的结构和各项性能,主要包括:利用扫描电子显微镜（SEM）观察膜的表面形貌;测定孔隙率说明膜的孔分布情况;着重结合两种超滤膜的亲水性和抗污染性的研究,比较其分离性能的变化;通过测试膜的机械性能、热稳定性能及化学稳定性能,研究两种超滤膜的物理化学特性等。实验结果表明,最佳制膜方案下得到的PSU超滤膜的纯水通量和PEG800溶液通量分别为66.9 L·m^-2·h^-1和59.1 L·m^-2·h^-1,截留率为65.6%;PSU/纳米Al₂O₃共混超滤膜的纯水通量和PEG800溶液通量分别为181.8 L·m^-2·h^-1和171.0L·m^-2·h^-1,截留率达到了69.2%。可以看到,将纳米Al₂O₃粒子引入PSU膜进行共混改性后,在一定程度上提高了超滤膜的通量和截留性能。此外,PSU/纳米Al₂O₃共混超滤膜比PSU超滤膜,在亲水性能、抗污染性能以及其他物理化学特性方面均得到了较好改善,制备出了性能优越的共混超滤膜。更多还原

【Abstract】 Ultrafiltration is the sieve pole separation process using pressure as the driving force,which is between the range of nanofiltration and microfiltration.The special nano-aperture range determines that the ultrafiltration membrane has the especial application in the field of solution purification,concentration,preparation of drinking water and material recovery currently.The main research target of the paper is to prepare the organic-inorganic blend ultrafiltration membrane using the blends of inorganic nano-Al₂O₃ particles and the polymer（PSU）after modification in order to improve the separatory properties,properties of physical and chemical,hydrophicity and anti-fouling of the membrane then extend its’ service life.Using polysulfone（PSU）as the materials of ultrafiltration membrane,determined the optimal process conditions and prepared the PSU ultrafiltration membrane according to investigate the various single factors on the effects of structure and performance of PSU ultrafiltration membrane in process.The factors include solvent species,concentration of PSU,additive species and content,temperature and evaporation time of casting solution,species and temperature of coagulation bath and so on.Further more,PSU and the inorganic materials of nano-Al₂O₃ were used to prepare blend ultrafiltration membrane in order to improve the performance of ultrafiltration membrane.Studied the factors such as concentration of PSU,content of nano-Al₂O₃,additive species and content and temperature of coagulation bath on the effects of structure and performance of blend films,ascertained the optimum conditions and prepared PSU/nano-Al₂O₃ blend ultrafiltration membrane,which has the favorable separatory properties.Investigated the structure and properties of PSU ultrafiltration membrane and PSU/nano-Al₂O₃ blend ultrafiltration membrane comparatively.Observed the surface morphology of films by SEM,determined the porosity to illuminate the distribution of pore,characterized the chemical composition of the membrane by FT-IR,emphatically studied the hydrophilicity,pollution resistibility and compared PSU ultrafiltration membrane with PSU/nano-Al₂O₃ blend ultrafiltration membrane in the change of separatory properties,and researched the physical and chemical properties of two types of ultrafiltration membranes by testing the mechanical properties,thermal stability and chemical stability.According to the results,it can be seen that the water flux of PSU ultrafiltration membrane prepared under the optimum condition and the PEG800 flux were 66.9 L·m^-2·h^-1 and 59.1 L·m^-2·h^-1 respectively,and the retention rate was 65.6%.And the flux for water and PEG800 of PSU/nano-Al₂O₃ blend ultrafiltration membrane were 181.8 L·m^-2·h^-1 and 171.0 L·m^-2·h^-1.Then,the retention rate was reached up to 69.2%. It was indicated that the flux and retention of ultrafiltration membrane were improved to some extent when adding the nano-Al₂O₃ particles into PSU membrane and blending modification.The blend ultrafiltration membrane of superior performances was prepared.更多还原