添加剂对聚砜膜结构和性能的影响

通过浸没沉淀相转化法制备聚砜超滤膜,分别以高分子聚乙烯基吡咯烷酮（PVP-K30,PVP-K90）、聚乙二醇（PEG-6000,PEG-20000）和小分子氯化锌（ZnCl2）、丙酸（AS）6种物质作为制备聚砜超滤膜的添加剂,含量均为10%。并对聚砜超滤膜的断面结构、纯水通量、牛血清蛋白（BSA）截留率、孔隙率及平衡水含量等5项性能进行了测试及表征。由断面结构可以看出,PVP-K90作为添加剂时,制得膜的断面完全为海绵状结构,其它添加剂制得膜断面中均有指状孔结构;PVP-K30作为添加剂时制得膜的纯水通量最大;丙酸作为添加剂制得膜的BSA截留率最高;聚乙烯基吡咯烷酮（PVP）和聚乙二醇（PEG）制得膜的平衡水含量及总孔隙率均较高,但闭孔也较多。     

添加剂对聚醚砜酮超滤膜结构和性能的影响

在杂萘联苯聚醚砜酮(PPESK)铸膜液中,分别添加磺化聚醚砜酮(SPPESK)、聚乙二醇(PEG)、有机小分子和无机盐添加剂,采用相转化法制备了聚醚砜酮超滤膜,并通过扫描电镜和超滤性能测试考察了不同添加剂对超滤膜结构和性能的影响。结果表明,SPPESK的加入提高了膜的亲水性和孔隙率,使膜的渗透性显著提高。有机高分子添加剂PEG的加入,使膜亚层指状孔结构向海绵状孔结构转变。改善了孔道的连通性,提高了膜的亲水性和孔隙率,使膜的纯水通量增加而截留率略有下降。含有羟基的醇类和酸类小分子添加剂有助于纯水通量的提高。无机盐添加剂起到成孔和增溶聚合物的作用。在保持截留率相对较高的条件下,LiCl和ZnCl2可以提高膜的纯水通量。FeCl2在成膜过程中发生水解氧化,部分铁均匀分布在膜三维空间中,与聚合物相互作用,改善膜的结构和性能。     

新型纳米纤维素/聚醚砜复合膜的性能研究

通过超声均匀分散纳米纤维素与聚醚砜共混,形成纳米纤维素/聚醚砜共混铸膜液。采用浸入沉淀相转化法制备纳米纤维素/聚醚砜复合膜。利用黏度法与荧光显微镜方法研究了共混铸膜液的性能;探讨了纳米纤维素和聚醚砜添加量对复合膜超滤性能的影响;利用扫描电镜观察了复合膜的截面孔结构。结果表明,共混铸膜液的黏度随纳米纤维素含量的增加,呈非线性增长;其相结构是以纳米纤维素为主的分散相分散在以聚醚砜为主的连续相中的"海岛结构";纳米纤维素的加入使复合膜的水通量显著增加;随着聚醚砜含量的增加,复合膜水通量下降。复合膜为典型的非对称膜孔结构。     

新型聚醚砜-磺化聚醚砜共混膜的性能研究

以浓硫酸为聚醚砜(PES)的溶剂和磺化剂,制备磺化聚醚砜(SPES)。选取磺化度(DS)为14%的SPES溶液,制备PES-SPES共混膜,考察了共混膜的脱盐效果和抗污染性能。结果表明,共混膜的基质材料中,随SPES、PES的质量比的增加,共混膜表面膜孔径增大,断面结构由指状孔向海绵状孔转化,共混膜水通量增加,截留率降低,当SPES的DS为14%、SPES、PES的质量比0.75时,制得共混膜水通量为253.7 L/(m~2·h),对PEG6000、PEG10000和PEG20000的截留率分别为56.8%、74.5%和90.6%;共混膜在相同测试条件下对Na_2SO_4截留效果大于NaCl,经亲水改性的PES-SPES共混膜亲水性提高,抗污染性能明显增强。     

纳米TiO_2/聚醚砜复合膜的制备及其性能研究

通过共混和相转化法制备了纳米TiO_2/聚醚砜复合膜,并考察了纳米TiO_2对膜结构及性能的影响。结果表明,添加纳米TiO_2后,膜断面结构中微孔增多,指状孔长度增长,且有效改善了膜的亲水性和抗污染性。当纳米TiO_2含量为0.3%时,膜综合性能最佳,此时,复合膜的表面接触角为75.9°,纯水通量为50.23 L/(m2·h),对Na2SO4溶液的截留率为40.89%,对牛血清蛋白溶液(BSA)的通量恢复率为91.67%。     

聚乙二醇600和草酸对中空纤维超滤膜结构和性能的影响

通过考察添加剂PEG600和草酸对杂萘联苯聚醚砜酮（PPESK）中空纤维超滤膜结构和分离性能的影响，发现：PEG600的加入不会改变膜的内部结构，均为指状结构，随着PEG600浓度的增加，膜致密层厚度逐渐增加。膜的水通量和截留率随有机添加剩PEG600的浓度变化规律性不强。随小分子添加剂草酸浓度的提高，膜结构逐渐由指状结构转变成海绵状结构，PPESK中空纤维超滤膜的纯水通量逐渐上升，截留率呈波浪形变化。比较不同凝胶浴温度下的膜分离性能可以看到，凝胶浴温度提高可以显著提升膜的纯水通量。     

磺化聚醚砜(SPES)/聚醚砜(PES)合金超滤膜的研究

本文研究了磺化聚醚砜 (SPES) /聚醚砜 (PES)合金组份变化对膜性能的影响 ,通过选择适当的合金比例研制得到超滤膜 ,在 0 .2Mpa操作压力下 ,对聚乙二醇分子量为 1万的截留率大于 90 % ,水通量为 80L/m2 ·h ,对阴离子脱盐率PO3 -4 >SO2 -4 >CL-。通过扫描电镜观察膜的断面结构 ,结果表明 :PES膜断面形态属于典型的非对称指状孔结构 ,SPES/PES膜断面形态是致密的海绵状结构 ,致密层部分比SPES薄 ,SPES膜断面形态是较厚的海绵状结构 ,致密层部分多     

PES/fMWNT共混超滤膜的制备及其抗污染研究

采用非溶剂致相分离法(NIPS)制备聚醚砜/羧基化碳纳米管共混膜,以N,N-二甲基乙酰胺(DMAc)和N-甲基吡咯烷酮(NMP)为溶剂,聚乙二醇(PEG4000)为致孔剂。研究了碳纳米管添加量和管径对膜结构和膜性能的影响。结果表明,共混膜的拉伸强度、杨氏模量随着碳纳米管含量的增加先增大后减小,但随着碳纳米管的管径增加而减小。当碳纳米管含量为1. 0%,管径为20～30 nm时,聚醚砜/碳纳米管共混膜的接触角从纯聚醚砜膜的78. 16°降到64. 30°,纯水通量达到50. 39 L/(m~2·h),是纯聚醚砜通量的4倍,对牛血清蛋白(BSA)截留率保持在95%以上,通量恢复率从54. 29%增加到84. 59%,抗污染性能较纯聚醚砜膜明显提高。     

PVPK30和Tween80对中空纤维超滤膜结构和性能的影响

通过考察添加剂-聚乙烯吡咯烷酮（PVPK30）和Tween80对杂萘联苯聚醚砜酮（PPESK）中空纤维超滤膜结构和分离性能的影响，发现：随高分子添加剂聚乙烯吡咯烷酮K30浓度的升高，膜水通量减小，截留率基本无变化，膜结构逐渐由指状结构转变成海绵状结构。有机大分子添加剂Tween80可以提高膜的水通量，但膜结构不随添加剂浓度而改变，均为指状结构。当Tween80浓度小于5wt％时，随Tween80浓度的增加，膜水通量升高，截留率下降。比较不同凝胶浴温度下的膜分离性能可以看到，凝胶浴温度提高可以显著提升膜的纯水通量。     

聚间苯二甲酰间苯二胺平板膜的制备及其性能研究

以聚间苯二甲酰间苯二胺（PMIA）为制膜原料,氯化锂（LiCl）、聚乙二醇（PEG-400）和聚乙烯吡咯烷酮（PVP）为添加剂,通过非溶剂诱导相转化法制备了PMIA平板膜,系统考察了聚合物浓度、添加剂种类和含量对PMIA膜结构和性能的影响。结果表明,聚合物浓度和LiCl含量增加,铸膜液黏度增大,导致膜孔径减小,纯水通量降低。而PEG含量的增加,使得聚合物链呈现舒展状态,膜孔径增大,纯水通量升高,亲水性增强。随着PVP含量的增加,膜的纯水通量先升高后降低,膜的亲水性变差。当PMIA的质量分数为9%,LiCl的质量分数为2.8%,PVP的质量分数为1.2%时,膜的纯水通量高达1421.55 L·m^-2·h^-1·bar^-1,对牛血清蛋白（BSA）的截留率为80%,展现出较高的渗透性,为制备高性能膜材料提供了新的思路。     

聚间苯二甲酰间苯二胺平板膜的制备及其性能研究

以聚间苯二甲酰间苯二胺（PMIA）为制膜原料,氯化锂（LiCl）、聚乙二醇（PEG-400）和聚乙烯吡咯烷酮（PVP）为添加剂,通过非溶剂诱导相转化法制备了PMIA平板膜,系统考察了聚合物浓度、添加剂种类和含量对PMIA膜结构和性能的影响。结果表明,聚合物浓度和LiCl含量增加,铸膜液黏度增大,导致膜孔径减小,纯水通量降低。而PEG含量的增加,使得聚合物链呈现舒展状态,膜孔径增大,纯水通量升高,亲水性增强。随着PVP含量的增加,膜的纯水通量先升高后降低,膜的亲水性变差。当PMIA的质量分数为9%,LiCl的质量分数为2.8%,PVP的质量分数为1.2%时,膜的纯水通量高达1421.55 L·m^-2·h^-1·bar^-1,对牛血清蛋白（BSA）的截留率为80%,展现出较高的渗透性,为制备高性能膜材料提供了新的思路。     

Effects of coagulation bath temperature and polyvinylpyrrolidone content on flat sheet asymmetric polyethersulfone membranes

In this study, effects of coagulation bath temperature (CBT) and polyvinylpyrrolidone (PVP K15) concentration as a pore former hydrophilic additive on morphology and performance of asymmetric polyethersulfone (PES) membranes were investigated. The membranes were prepared from a PES/ethanol/NMP system via phase inversion induced by immersion precipitation in a water coagulation bath. The morphology of prepared membranes was studied by scanning electron microscopy (SEM), contact angle measurements, and mechanical property measurements. Permeation performance of the prepared membranes was studied by separation experiments using pure water and bovine serum albumin (BSA) solution as feed. The obtained results indicate that addition of PVP in the casting solution enhances pure water permeation flux and BSA solution permeation flux while reducing protein rejection. Increasing CBT results in macrovoid formation in the membrane structure and increases the membrane permeability and decreases the protein rejection. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers     

聚醚砜质量分数对聚偏氟乙烯/聚醚砜共混膜性能和结构的影响

用与聚醚砜共混的方法来改善聚偏氟乙烯膜的抗收缩性能,以二甲基乙酰胺作溶剂,聚乙烯吡咯烷酮为添加剂,研究了聚醚砜(PES)质量分数对聚偏氟乙烯/聚醚砜共混膜的收缩率、水通量、截留率及形态结构的影响。聚醚砜的加入可以有效地降低共混膜的收缩率,在w(PES)=1.5%时,共混膜的水通量取得极大值,截留率取得极小值。     

Fabrication of novel polyethersulfone based nanofiltration membrane by embedding polyaniline-co-graphene oxide nanoplates

Mixed matrix polyethersulfone (PES) based nanofiltration membrane was prepared through phase inversion method by using of polyvinylpyrrolidone (PVP) as pore former and N, N dimethylacetamide (DMAc) as solvent. Polyaniline-co-graphene oxide nanoplates (PANI/GO) were utilized as additive in membrane fabrication. The PANI/GO nanoplates were prepared by polymerization of aniline in the presence of graphene oxide nanoplates. FTIR analysis, scanning electron microscopy (SEM), scanning optical microscopy (SOM), 3D images surface analysis, water contact angle, water content tests, tensile strength tests, porosity tests, salt rejection and flux tests were used in membrane characterization. FT-IR results verified formation of PANI on graphene oxide nanoplates. SOM images showed uniform particles distribution for the mixed matrix membranes. SEM images also showed formation of wide pores for the modified membranes. Water flux showed constant trend nearly by use of PANI/GO in the casting solution. Opposite trend was found for the membrane surface hydrophilicity. Salt rejection was enhanced sharply by utilizing of PANI/GO. The membrane’s tensile strength was improved by increase of PANI/GO concentration. The water content was increased initially by use of PANI/GO nanoplates up to 0.05%wt into the casting solution and then decreased. Membrane porosity was also enhanced by using of PANI/GO nanoplates. Modified membrane containing 0.5%wt PANI/GO nanoplates showed more appropriate antifouling characteristic compared to others.     

Concentration of gelatin solution with polyethersulfone ultrafiltration membranes

In this work, polyethersulfone (PES) flat sheet ultrafiltration (UF) membranes were prepared by immersion precipitation phase inversion process with polyvinylpyrrolidone (PVP 30K) and acetone as additives. The best preparation condition for PES membranes with high water flux and rejection (to BSA) was decided. It was found that the optimal composition of the polymer casting solution was: 16 wt% (PES), 2 wt% (PVP 30K), and 1 wt% (acetone). Pure water flux of the membrane prepared at this condition reached to 373 L/m² h at 0.1 MPa, and the rejection to BSA was 91%. Compared with other reports, the rejection was slightly low but the flux of the PES membrane was high. When the membrane was used to concentrate gelatin solutions, the rejection value was over 75%. It was found that increasing the feed temperature and transmembrane pressure enhanced the permeation flux, but the rejection decreased slightly. However, increasing the cross-flow velocity of the feed solution simultaneously increased both the permeation flux and the rejection.     

Effect of silver loaded sodium zirconium phosphate (nanoAgZ) nanoparticles incorporation on PES membrane performance

Polyethersulfone (PES) based ultrafiltration membranes were fabricated via phase inversion by adding silver-loaded sodium zirconium phosphate nanoparticles (nanoAgZ) in PES casting solutions. The effect of nanoAgZ concentration on the membrane performance, i.e., morphology, hydrophilicity, thermal stability, permeation and antifouling properties was investigated. The results of thermal gravitational analysis (TGA) showed that the thermal stability of the hybrid membrane had been improved by the addition of nanoAgZ particles. Contact angle results indicated that the hydrophilicity of the modified membranes was enhanced. The contact angle of the membrane decreased from 71.5° to 52.6° with the increase of the nanoparticle content in the casting solution. Permeation experiment results showed that the modified PES membranes demonstrate better separation performance over the pure PES membrane. The pure water flux of PES membrane increased from 82.1 L/m² h to 100.6 L/m² h with the addition of the nanoparticles. Most importantly, the incorporation of the nanoAgZ particles enhanced the BSA fouling resistance and also the anti-biofouling performance of the membrane.     

Construction of membrane formation system with low critical solution temperature for preparing hydrophilic polysulfone membrane via modified reverse thermally induced phase separation process

This paper presents a novel method to construct a membrane formation system featuring a low critical solution temperature (LCST) by incorporating hydroxy terminated hyperbranched polyester (HBPE) into polysulfone (PSF) casting solution. PSF membranes were developed by modified reverse thermally induced phase separation (m-RTIPS) process while the introduction of HBPE improved the hydrophilicity of the membrane. The critical properties of the flat-sheet PSF membranes were discussed in detail. The cloud point decreased as the HBPE concentration was increased. When membranes were prepared via m-RTIPS, the region of bicontinuous finger-like pores in the sublayer gradually broadened. The membranes showed better permeation properties, larger pore size, and better mechanical properties than those of the membranes prepared via non-solvent-induced phase separation (NIPS) process. Furthermore, no matter the enhanced hydrophilicity of membrane or m-RTIPS membrane-forming mechanism was beneficial to the anti-fouling properties. In general, the membrane MPSF-8-b had relatively high flux, good hydrophilicity and excellent mechanical properties at 0.8 wt.% HBPE content, and the pure water flux recovery of the membrane was increased to 55.2%.     

二氧化硅填充聚醚砜超滤膜

本文通过在聚醚砜中引入活性炭粉和无定型二氧化硅粒子，以N，N-二甲基甲酰胺为溶剂，以水为凝固浴，利用相转化湿法成膜机理，制得了一系列不同粒子含量的聚醚砜超滤平板膜。通过扫描电子显微镜对膜结构进行了观察和对比研究，并对膜的纯水通量和鸡蛋卵清蛋白的截留进行了测试，结果发现：二氧化硅的加入，改变了铸膜液的浊点组成；产生了大量的界面空隙，即界面孔：增加了膜孔的贯通性；提高了膜的亲水性；使膜的通量大大提高，并且保持了很好的截留率。而活性炭粉填充聚醚砜超滤膜的综合性能远远差于二氧化硅填充聚醚砜超滤膜。     

Preparation of modified polyethersulfone membranes using variation in coagulation bath temperature and addition of hydrophilic surfactant

In this study, novel asymmetric polyethersulfone membranes were prepared from PES/PEG/Tween-20/NMP system via immersion precipitation. Pure water was used as gelation media. Simultaneous effects of variation in coagulation bath temperature (CBT) and addition of Tween-20 on morphology, wettabiliy, pure water permeation flux (PWF) and bovine serum albumin (BSA) rejection of the prepared membranes were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), contact angle measuring instrument and experimental set up. The obtained results indicate that the small addition of surfactants in the casting solution along with using the lowest level of CBT increases hydrophilicity of the PES membranes. Also it was found out that addition of Tween-20 in the casting solution along with increasing the CBT incites the formation of the bigger pores on the top surface and results in the formation of membranes with higher porosity in the sublayer.