【作者】 王雪；

【导师】 高从堦；

【作者基本信息】 中国海洋大学 ， 分析化学， 2012， 硕士

【摘要】 聚砜（PSF）是一类机械强度、化学性质和耐热性能优良的聚合物膜材料，同时也是疏水性材料，这种疏水性膜材料制成的超滤膜应用于水体中易造成膜污染，缩短膜使用寿命。目前，为提高膜的抗（有机）污染性能，国内外学者针对PSF膜亲水改性做了大量研究工作。将超滤膜应用于实际水体处理中，如海水淡化工艺，不仅要求超滤膜表面亲水性高、抗（有机）污染性强，还要具有抑制微生物和藻类附着污染的能力。针对上述要求，本文从含辣素衍生结构的功能单体出发，研制出既具有亲水性又具有良好抑菌性的新型聚砜超滤膜。本文首先将含辣素衍生结构的功能单体N-（4-羟基-3-甲氧基—苄基）丙烯酰胺（HMBA）和甲基丙烯酸甲酯(MMA)通过自由基引发聚合，制备出抑菌型二元共聚物，简写为P(H-co-M)；为进一步增强聚合物的亲水性，添加丙烯酸(AAc)单体，合成出三元共聚物，简写为P(H-M-A)。并采用红外光谱分析和热重分析对共聚物进行了表征，验证了共聚物的结构。将二元共聚物P(H-co-M)添加到PSF铸膜液中，通过沉淀相转化法制备出新型抑菌PSF/P(H-co-M)改性超滤膜，简称为二元共聚物改性超滤膜，系统考察了P(H-co-M)添加量、凝胶浴温度和热处理等因素对膜表面性质、分离性能和抑菌性能的影响。结果表明，当加入一定量P(H-co-M)后，亲水性能有所改善。当P(H-co-M)添加量为0.5wt%，凝胶浴温度为20℃时，膜分离性能较佳，对5mg/L腐殖酸（HA）溶液的稳定膜通量和截留率分别为122.2L/m~2.h和84.4%，比原PSF超滤膜分别提高了19.2%和9.2%。当P(H-co-M)添加量为1.0wt%时，膜抑菌性能较好，抑菌率高达80.7%。热处理对二元共聚物改性超滤膜膜通量和截留率的影响较小。同法，将三元共聚物P(H-M-A)添加到PSF铸膜液中，通过沉淀相转化法制备出新型抑菌PSF/P(H-M-A)改性超滤膜，简称为三元共聚物改性超滤膜，主要探索了P(H-M-A)添加量和凝胶浴组成（不同浓度乙醇、冰醋酸）对膜表面性质、分离性能和抑菌性能的影响。结果表明，加入一定量P(H-M-A)后，膜亲水性能大大提高，当P(H-M-A)添加量为0.5wt%时，膜表面接触角比原PSF超滤膜的减小30.0%，比二元共聚物改性超滤膜的减小15.1%。当P(H-M-A)添加量为0.5wt%，以25%乙醇为凝胶浴时，改性膜分离性能较好，对5mg/L HA溶液的稳定膜通量和截留率分别为155.9L/m~2.h和80.3%，与原PSF超滤膜相比，分别提高了36.7%和4.5%。三元共聚物改性超滤膜对大肠杆菌具有明显抑菌性，当P(H-M-A)添加量为3.0wt%时，抑菌率达89.2%。为了考察所研制的抑菌型超滤膜的抗有机污染性能，进行了长达8h的过滤实验，并通过通量恢复率来评价抗污染能力。所用膜样品分别为原PSF膜、上述最佳实验条件制备的二元共聚物改性超滤膜和三元共聚物改性超滤膜，实验考察了对5mg/L HA溶液及实际胶州湾海水的分离性能及化学清洗效果。对过滤5mg/L HA溶液的膜过滤实验结果表明，过滤8h后，二元共聚物改性超滤膜和三元共聚物改性超滤膜的稳定膜通量分别为86.4L/m~2.h和95.9L/m~2.h，截留率分别为84.3%和80.8%，均高于原PSF超滤膜（67.0L/m~2.h、76.1%）；用NaOH清洗后，二元共聚物改性超滤膜和三元共聚物改性超滤膜通量恢复率分别为96.7%和98.4%；对实际胶州湾海水的膜过滤实验结果表明，过滤8h后，二元共聚物改性超滤膜和三元共聚物改性超滤膜的稳定膜通量分别为142.3L/m~2.h和145.7L/m~2.h，比原PSF超滤膜高约15.3%；其截留率分别为41.6%和36.6%，与原PSF膜相比分别提高了40.4%和32.2%；用NaOH清洗后，二元、三元共聚物改性超滤膜通量恢复率分别为53.9%和59.0%。可见，从化学清洗的角度，三元共聚物改性超滤膜的抗污染性能最佳。更多还原

【Abstract】 Polysulfone(PSF) is a kind of polymer membrane materials with excellentmechanical strength, chemical properties and heat resistance. But PSF membranes areeasily to suffer membrane fouling due to the hydrophobicity of the PSF material,which often shortens the membrane service lifie. At present, in order to improve themembrane anti-fouling property, a number of research on the hydrophilic modificationof membrane surface has been carried out. When the membarens are used into a realwater treatment, such as seawater desalination, not only hydrophilicity andanti-organic-fouling of the membarne are required, also the ability to bear thepollution of microbial and algae. For this, a kind of new antibacterial ultrafilration(UF) membranes with good hydrophilicity and excellent bacteriostasis were prepared.First, the antibacterial dipolymer P(H-co-M) was synthesized through a freeradical initiated pomerization from capsaicin derivative structure HMBA and methylmethacrylate (MMA). In order to enhance the hydrophilicity of the polymer, acid(AAc) was added as one nomoner, and, terpolymer P(H-M-A) was synthesized as thesame method above. Stuctures of these polymers were confirmed using the infraredabsorption spectrum (FT-IR) and thermo gravimetric analysis.A given amount of dipolymer P(H-co-M) was added into the PSF castingsolution, and a kind of new antibacterial PSF/P(H-co-M) UF membrane namedmodified dipolymer UF membrane was prepared through the immersion precipitationphase inversion. The effects of P(H-co-M) contentbath temperature and heatingtreatment on the membrane structure, separation performanece and antibacterialproperty were investigated. The results showed that, the hydrophilicity of membranesurface were improved; When the content of P(H-co-M) was0.5wt%and the gel bathtemperature was20℃, the separation performance of the modified membrane wasimproved with the the steady flux of122.2L/m~2.h and rejection of84.4%for5mg/L humic acid (HA) solution, which increased by19.2%and9.2%compared to theunmodified PSF UF membrane, respectively. When the content of P(H-co-M) was1.0wt%, the modified membrane had an excellent antibacterial property and theantibacterial rate was up to80.7%. Heat treatment played little influence in flux andrejection of the modified dipolymer UF membrane.As the same method above, A given amount of P(H-M-A) was added into thecasting solution, and PSF/P(H-M-A) UF membrane named modifief terpolymer UFmembrane was prepared. The effects of P(H-M-A) content and bath type (differentconcentration of ethanol and acetic acid) on the membrane structure, separationperformanece and antibacterial property were evaluated. The results were as follows.When P(H-M-A) was added, the membrane surface hydrophilicity was dramaticallyimproved, when the content of P(H-M-A) was0.5wt%, the contact angle reduced by30.0%and15.1%compared to the unmodified membrane and modified dipolymer UFmembrane, respectively. When the content of P(H-M-A) was0.5wt%and A25%ethanol solution was used as gel bath, the membrane separation performance wasenhanced with the steady flux of55.9L/m~2.h and rejection of80.3%for5mg/L HAsolution. Moreover, the modified terpolymer UF membrane had an excellentantibacterial property and the antibacterial rate was up to89.2%, which is better thanthe modified dipolymer UF membrane.In order to investigate the anti-organic-fouling propertis of these two UFmembranes, filtration experiments for a relatively long operating period (8h) werecariied out. The flux recovery rate was used as a parameter for evaluating theanti-organic-fouling property.5mg/L HA solution and raw seawater were used as thefeed, respectively. The sepeartion perfomamnces and anti-organic-fouling propertiesof various membarens, including PSF/P(H-M-A) membrane, PSF/P(H-co-M)membrane and PSF membrane, were systematically investigated. The results showthat, after filtering8hours with5mg/L HA solution, the steady fluxes of the modifieddipolymer and terpolymer UF membrane were86.4L/m~2.h and95.9L/m~2.h, and therejections were84.3%and80.8%, respectively, which were all higher than theunmodified UF membrane (67.0L/m~2.h and76.1%). After cleaning with NaOH solution, the flux recovery rates of the modified dipolymer and terpolymer UFmembrane were96.7%and98.4%, respectively. After filtering8hours with rawseawater, the steady fluxes of the two kinds modified UF membranes were142.3L/m~2.h and145.7L/m~2.h, which were higher than the unmodified PSF membrane;rejections were41.6%and36.6%, which increased by40.4%and32.2%compared tothe unmodified membrane, respectively. After cleaning with NaOH solution, the fluxrecovery rates of the modified dipolymer and terpolymer UF membrane were53.9%and59.0%, respectively. Therefore, the modified terpolymer UF membrane was thebest in antifouling property among all other testing membranes.更多还原