添加剂对PSF/ER合金膜结构和性能的影响

介绍了大分子添加荆聚乙烯吡咯烷酮(PVP)和小分子添加荆H2O时聚砜(PSF)／环氧树脂(ER)合金膜结构和渗透、分离及成膜性能的影响。结果表明，添加荆使PSF／ER合金膜的水通量上升，截留率下降；PVP改善了PSF／ER合金膜的成膜性能，当水质量分数大于0．8％时，PSF／ER合金膜的成膜性能下降。     

聚合物浓度对PSF/SPSF合金膜性能的影响

用膜材料液相共混制备了PSF／SPSF高分子分离膜，介绍了聚合物的浓度对不同组成的PSF／SPSF合金膜的渗透，分离性能和成膜性能，机械性能的影响，表明聚合物浓度增加，合金膜铸膜液的粘度增大，合金膜的截留率上升，水通量下降，合金膜的成膜性能和机械性能改善，上述变化规律与单一聚合物分离膜一致，与PSF／SPSF间的相容性无关。     

聚偏氟乙烯共混膜的制备和性能研究

主要讨论了聚偏氟乙烯(PVDF)膜以及聚甲基丙烯酸甲酯(PVDF/PMMA)、PVDF/PMMA/PS(聚砜)共混膜的制备及性能,并研究了不同添加剂对PVDF/PMMA/PS共混膜的结构和性能的影响。实验数据表明:PVDF/PMMA/PS共混膜的通量最大;PVPK 40成膜通量最大;T iO 2成膜截留率最大。     

正交实验法优化氯甲基化聚砜／聚砜共混膜的季铵化条件

将氯甲基化聚砜(CMPSF)/聚砜(PSF)共混膜浸于三甲胺溶液中制得季铵化聚砜(QMPSF)/聚砜(PSF)膜.采用正交实验考察了季铵化反应条件如季铵化温度、季铵化时间、三甲胺浓度等对QMPSF/PSF膜性能的影响,优化了季铵化条件,制得了性能较佳的季铵化QMPSF/PSF膜.研究结果表明,在0.2MPa压力下.制备的季铵化QMPSF/PSF膜的水通量为31.35 L/(m2·h),对相对分子质量为31 000～50 000的聚乙烯醇溶液的截留率为89.6%.     

聚合物膜的研制

以聚丙烯腈(PAN)／聚乙烯醇(PVA)合金为膜材料，用液-固相转化法成膜制备PAN/PVA体系的非对称型合金微滤膜。研究了铸膜液浓度、聚合物共混配比、铸膜液温度溶剂蒸发时间、凝胶浴温度对膜结构和膜性能的影响。结果表明：采用了液-固相转化法成膜，可制成孔径为0．5～5．0μm的非对称性PAN/PVA合金微滤膜。     

聚偏氟乙烯和聚砜共混中空纤维膜的制备和性能研究

考察了聚偏氟乙烯(PVDF)和聚砜(PSF)共混比例、聚合物浓度对制得的中空纤维膜结构和性能的影响。通过扫描电镜观察膜的结构,并用相关设备测试检测中空纤维膜的纯水通量、截留率、孔隙率和断裂强度等膜性能;通过实验数据对比,最终确定一个最佳配比。     

PSF/SPSF相容性对合金膜结构和性能的影响

通过混合焓法预测并用相差显微镜表征了PSF/SPSF合金体系的相容性，表明二者为部分相容体系，合金膜中聚合物的组成和铸膜液中溶剂的性能影响PSF/SPSF间的相容性，进而影响合金膜的结构和性能。随合金体系相容性下降，膜的平均孔径显著增加，水通量增大而相应的截留率下降，研究表明，改变PSF/SPSF间的相容性是调节膜结构，提高膜性能的有效方法。     

CdS-PVDF/PSF光催化膜的制备及其刚果红降解性能研究

光催化-膜分离耦合工艺是目前水处理研究新热点之一。光催化技术和膜分离技术的耦合既能解决光催化技术中光催化剂回收难的问题,又能解决或者缓解制约膜分离工艺发展的膜污染问题。采用相转化法将聚砜(PSF)、聚偏氟乙烯(PVDF)与硫化镉(CdS)纳米球共混制备出光催化膜。以刚果红为模拟污染物,考察Cd S-PVDF/PSF光催化膜的膜通量和其在可见光照射下对刚果红的降解情况。测试发现,负载CdS可提高PVDF/PSF的膜通量并使其通量衰减得到有效缓解;CdS-PVDF/PSF光催化膜在出水口对刚果红的截留率随着时间增加变化不大,在120分钟时截留率仍能达到93.0%,显著大于PVDF/PSF膜的82.7%。CdS-PVDF/PSF光催化膜对储液罐中刚果红的降解率在120min时达到76.2%,也显著大于PVDF/PSF膜的41.5%。实验结果表明,CdS-PVDF/PSF光催化膜在降解有机污染物方面具有较好应用前景。     

溶剂的性质对聚砜／磺化聚砜合金膜性能的影响

介绍了溶剂的性质对聚砜 /磺化聚砜 (PSF/SPSF)合金分离膜膜性能的影响     

制取聚苯胺-聚乙烯醇导电共混膜的条件研究

用共混浇铸法制备PAN-PVA共混膜,探讨了制膜液中PAN与PVA的质量比、成膜干燥温度和制膜液浓度对共混膜性能的影响,测定了膜的拉伸断裂强度和断裂伸长率。结果表明,制取电导率高、力学性能较好的适合作电磁屏蔽材料的PAN-PVA共混膜的条件为:制膜液内PVA的质量百分数为40%,成膜干燥温度为80℃,制膜液浓度为17.0 mg/mL。     

用于油水分离的非化学计量掺杂Ce纳米SiO_2聚砜复合膜的研究

为提高膜分离法对油水分离的效果,减小油质对膜的污染,采用非化学计量掺杂Ce纳米SiO2聚砜(PSF)复合膜对油田回注水进行处理.通过对复合膜的拉伸强度、亲水性和ESEM性能测试并将其应用于油水分离试验可知,纳米SiO2复合粒子添加量为PSF质量的10%时,复合膜的机械强度最大,接触角为最小值41.7°.以此含量制得的复合膜的渗透通量最大,且随着操作时间的进行该复合膜的渗透通量下降的最慢,表明复合膜的耐污染能力得到增强;同时此复合膜对油的截留率高于98%,处理后的水样符合国家水质排放标准.     

Selective swelling of polysulfone/poly(ethylene glycol) block copolymer towards fouling-resistant ultrafiltration membranes

Fouling resistance of ultrafiltration (UF) membranes is critical for their long-term usages in terms of stable performance, so convenient approaches to prepare fouling-resistant membranes are always anticipated. Herein, we demonstrate the facile fabrication of antifouling polysulfone-block-poly(ethylene glycol) (PSF-b-PEG, SFEG) composite membranes. SFEG layer was coated onto macroporous supports and cavitated by immerging them in acetone/n-propanol following the mechanism of selective swelling induced pore generation. Thus-produced SFEG membranes possessed high permeance and excellent mechanical strength. Meanwhile, the structures and separation performances of the SFEG layers can be continuously tuned through simply changing swelling durations. More importantly, the hydrophilic PEG chains were spontaneously enriched onto the pore walls through swelling treatment, endowing intrinsic antifouling property to the SFEG membranes. Bovine serum albumin (BSA)/humic acid (HA) fouling tests proved the prominent fouling resistance of SFEG membranes, and the fouling resistance is expected to be long-standing because of the firm connection between PEG chains and PSF matrix by covalent bonding.     

Preparation of Nonstoichiometric Silica with Multi-Active Groups and Effect of Its Doping on Polysulfone Membrane Capabilities

Nonstoichiometric silica with multi-active groups particles (NS-MAG particles) were first synthesized, and then added to the porous matrix of PSF to prepare a NS-MAG/PSF composite membrane through a phase inversion process. The optimum preparation conditions of NS-MAG particles were researched and determined. Then the permeation fluxes of NS-MAG/PSF membranes with different doping amount of NS-MAG particles were tested. NS-MAG/PSF membrane, SiO₂/PSF membrane, and PSF membrane were prepared respectively. These membranes were characterized by testing the tensile strength and the permeation flux. The results show that doping NS-MAG particles can better enhance the tensile strength and permeation flux of PSF membrane.     

共混改性法对有机分离膜影响进展

有机聚合物如聚砜类、聚偏氟乙烯类、醋酸纤维素类、聚烯烃类等具有优良特性,是重要的膜材料。然而,膜污染问题限制了膜的应用。共混改性法操作简单,改性和成膜同时进行,效果稳定,通过共混改性法对有机聚合物膜进行膜改性可以有效降低膜污染。一方面通过共混亲水性聚合物、两亲性聚合物、两性离子聚合物对有机聚合物膜进行膜改性,制备改性膜的防污性和渗透性等性能均有不同程度的提升;另一方面,共混如TiO₂、SiO₂、碳纳米管（CNTs）、Al₂O₃、氧化石墨烯（GO）和ZrO₂等无机纳米粒子也可以制备高性能分离膜。本文从以上两方面综述了共混改性法的研究进展和存在的问题,并指出了通过共混改性提升膜的抗污染等性能是今后主要的发展趋势。     

Poly(vinylidene fluoride) hollow‐fiber membranes containing silver/graphene oxide dope with excellent filtration performance

In this study, an antifouling poly(vinylidene fluoride) (PVDF) hollow‐fiber membrane was fabricated by blending with silver‐loaded graphene oxide via phase inversion through a dry‐jet, wet‐spinning technique. The presence of graphene oxide endowed the blended membrane with a high antifouling ability for organic fouling. The permeation fluxes of the blended membrane was 3.3 and 2.9 times higher than those of a pristine PVDF membrane for filtering feed water containing protein and normal organic matter, respectively. On the other hand, the presence of silver improved the antibiofouling capability of the blended membrane. For the treatment of Escherichia coli suspension, the permeation flux of the blended membranes was 8.2 times as high as that of the pristine PVDF membrane. Additionally, the presented blended membrane improved the hydrophilicity and mechanical strength compared to those of the pristine PVDF membrane, with the water contact angle decreasing from 86.1 to 62.5° and the tensile strength increasing from 1.94 to 2.13 MPa. This study opens an avenue for the fabrication of membranes with high permeabilities and antifouling abilities through the blending of graphene‐based materials for water treatment. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44713.     

Synthesis and characterization of cellulose acetate-polysulfone blend microfiltration membrane for separation of microbial cells from lactic acid fermentation broth

This work is focused on synthesis and characterization of a polymer blend microfiltration membrane for separation of microbial cells from lactic acid fermentation broth in a continuous process. The membranes were prepared by blending hydrophilic cellulose diacetate (CA) polymer with hydrophobic polysulfone (PSF) polymer in wet phase inversion method. Polymers were blended in N-methyl-2-pyrrolidone (NMP) solvent (70 wt.%) where polyethylene glycol was added as a pore former. The membranes were characterized in terms of morphology, porosity, flux and microbial separation capability. The best prepared membrane with PSF/CA weight ratio of 25/75 yielded a pure water flux of 1830 LMH (liter/m² h) and a fermentation broth flux of 1430 LMH at around 1.5 bar TMP (trans-membrane pressure). The membrane was successful in complete retention of microbial cells from the broth in a continuous crossflow membrane module integrated with the fermentor.     

Hydrophilic modification of poly(aryl sulfone) membrane materials toward highly-efficient environmental remediation

Poly(aryl sulfone) as a typical membrane material has been widely used due to excellent mechanical, chemical and thermal stability. However, the inherent hydrophobicity of poly(aryl sulfone) based membranes bears with the fouling issue during applications, which makes the membrane tending to adsorb contaminants on the surface so as to result in decreased separation performance and lifetime. In this critical review, we give a comprehensive overview on characterizations of hydrophilic membrane and diverse hydrophilic modification approaches of poly(aryl sulfone) membranes, predominantly including bulky, blending and surface modification technology. The discussions on the different modification methods have been provided in-depth. Besides, focusing on modification methods and performance of modified membranes, the related mechanisms for the performance enhancement are discussed too. At last, the perspectives are provided to guide the future directions to develop novel technology to manipulate the hydrophilicity of poly(aryl sulfone) membranes toward diverse practical and multi-functional applications.     

Morphological and separation performance study of polysulfone/titanium dioxide (PSF/TiO2) ultrafiltration membranes for humic acid removal

In this study, polysulfone (PSF) hollow fiber membranes with enhanced performance for humic acid removal were prepared from a dope solution containing PSF/DMAc/PVP/TiO₂. The main reason for adding titanium oxide during dope solution preparation was to enhance the antifouling properties of membranes prepared. In the spinning process, air gap distance was varied in order to produce different properties of the hollow fiber membranes. Characterizations were conducted to determine membrane properties such as pure water flux, molecular weight cut off (MWCO), humic acid (HA) rejection and resistance to fouling tendency. The results indicated that the pure water flux and MWCO of membranes increased with an increase in air gap distance while HA retention decreased significantly with increasing air gap. Due to this, it is found that the PSF/TiO₂ membrane spun at zero air gap was the best amongst the membranes produced and demonstrated > 90% HA rejection. Analytical results from FESEM and AFM also provided supporting evidence to the experimental results obtained. Based on the anti-fouling performance investigation, it was found that membranes with the addition of TiO₂ were excellent in mitigating fouling particularly in reducing the fouling resistances due to concentration polarization, cake layer formation and absorption.