摘要聚醚砜（PES）超滤膜本身的疏水特性和不具备抗菌性导致其与水中有机污染物及微生物等组分有较强的亲和作用，由此引发的膜污染是 PES 超滤膜在水处理领域大规模工程应用面临的重大技术挑战。本文提出将聚多巴胺（PDA）/Ag复合纳米粒子引入到聚醚砜超滤膜铸膜液体系，利用 PDA 的亲水性和 Ag 纳米粒子的杀菌性能获得兼具亲水性和抗生物污染的复合超滤膜，同时利用 PDA 对 Ag 纳米粒子的螯合作用控制纳米银的流失问题，并开展改性 PES 膜结构表征和性能评价研究。首先利用多巴胺的自聚行为制备PDA纳米粒子，利用 PDA固有的还原性和对 Ag粒子的粘附性在其表面原位负载银纳米粒子，并以共混方式将复合纳米粒子掺杂于PES 铸膜液中，通过相转化法制备改性 PES 超滤膜。采用扫描电镜、透射电镜表征纳米粒子和杂化膜形貌，利用接触角仪对膜表面亲水性进行表征分析，XPS、FTIR 对膜材料组成成分进行分析。研究不同 PDA/Ag 纳米粒子添加量对膜亲水性、纯水通量和BSA截留率的影响，优化最佳投加量，详细研究复合膜的抗有机污染和抗生物污染性能。研究结果表明：经 PDA/Ag 纳米粒子修饰后的 PES 膜的亲水性得到明显改善，随着PDA/Ag纳米粒子量的增加，纯水通量出现先增加后减小，BSA截留率保持在较高的水平（大于 83%），PDA/Ag 添加量为 0.1%时，膜的纯水通量为最大，BSA 截留率为 87.5%。对负载 Ag 纳米粒子膜的 Ag 流失速率进行了一定的探索，13.5cm2的膜片经过滤1L纯水后，Ag+几乎未流失，结果表明 PDA对纳米 Ag粒子有很好的缓释作用，能够使得膜具有长期抗菌效果。以大肠杆菌作为微生物代表，考察了负载Ag 纳米粒子膜的抗生物污染性能，结果证实了负载 Ag的膜表面未形成生物膜，具有显著的抗生物污染性能。  42426
毕业论文关键词：Ag纳米粒子；PES 膜；聚多巴胺；亲水性；抗菌性.   
 Title  The investigation of  polydopamine/Ag composite  nanoparticles  on the modification of the PES membrane structure and performance 
Abstract Owing to the superhydrophobic properties and non-antibacterial properties of polyether sulfone (PES) membrane,  PES membrane  has strong affinity with the role of  organic pollutants, microorganisms and other components  in water. Membrane fouling is triggered in PES ultrafiltration membrane’ large-scale water treatment major technological. And  it’s the major challenges that we face in engineering applications. In  this  paper, polydopamine (PDA)/ Ag composite nanoparticles was introduced into the casting solution of polyethersulfone ultrafiltration membrane. The composite membrane is obtained by  using the properties of PDA and Ag,  hydrophilic and anti-biological contamination. At the same time,  it can solve the problem of nano  silver’s loss by using PDA’s chelation to  Ag nanoparticles. And  then we conduct the structure characterization and performance evaluation of modified PES membrane. Specifically,  the preparation of nanoparticles PDA is  by  using  of dopamine’s  self- polymerization, also by taking advantage of its inherent reductibility and the adhesion for the Ag particles. As the result, it can load silver nanoparticles on the surface of PDA. And the composite nanoparticles  are doped PES casting solution. The modified PES ultrafiltration membranes is prepared by phase inversion.  The morphology of modification membranes and nanoparticles were characterized by scanning electron microscope，transmission electron microscopy .The composition of membrane was characterized by FTIR spectrometer,  XPS.  The effect of different PDA/Ag nanoparticles additive amount on the membrane hydrophily,    pure water fluxes  and BSA  rejections  were examined.  The optimize  dosing quantity  and  the  performance of anti -organic pollution and anti-biological pollution of the composite  membrane were detailed studied. The results indicated that the hydrophilic property has been significantly improved  for PDA/Ag nanoparticles modified PES membrane. With the increase of PDA/Ag nanoparticles’ amount,  the pure water fluxes of the membranes increase firstly and then decrease, whereas BSA rejections remain at high level (greater than 83%), when PDA/Ag nanoparticles’ amount is 0.1%, the pure water fluxes of the membrane is a maximum, BSA rejections is 87.5%. The silver leaching from the membrane loaded Ag nanoparticles was explored. After  filtration 1L water for the13.5cm2 membrane, Ag almost no loss. The results demonstrated that PDA could reduce the release of AgNPs and the antimicrobial effect of AgNPs on the membrane could exist  a long time. The anti-biofouling performance of membrane loaded AgNPs was investigated  using Escherichia coli  as the representative of microorganism. The results showed that the PES membrane with loading AgNPs restrained the growth of microorganism，indicating significant anti -biofouling performance．  聚多巴胺Ag复合纳米粒子改性聚醚砜（PES）超滤膜结构及性能研究:http://www.751com.cn/huaxue/lunwen_42857.html