成膜条件对聚醚砜超滤膜性能和结构的影响

以聚醚砜(PES)为膜材,聚乙二醇600(PEG600)为添加剂,N,N-二甲基甲酰胺(DMF)为溶剂,纯水为凝固浴,用相转化法制备聚醚砜超滤膜.详细探讨了PES浓度、添加剂含量、凝固浴温度对膜性能和结构的影响规律,确定了制备高水通量、高截留率聚醚砜超滤膜的最佳工艺条件.     

磺化聚醚酰亚胺/聚醚砜共混型质子交换膜的制备及其性能

以磺化聚醚酰亚胺(SPEI)和聚醚砜(PES)为原料, 采用溶液共混法成功制备出了SPEI/PES共混型质子交换膜,并经热重分析、AFM、SEM等对膜的结构和性能进行了表征. 结果表明, 共混膜较纯SPEI膜具有更高的热稳定性和较低的溶胀性; 在室温环境下, 共混膜在干态和湿态时均具有优异的机械性能; 与纯SPEI膜相比, 共混膜的形态结构更为致密, 这将有利于降低甲醇的渗透性. 采用交流阻抗法和隔膜扩散法分别考察了膜的质子传导性和阻醇性能, 对于共混质量比为50/50的膜来说, 其质子传导率达到了5.5 mS·cm-1的水平, 能满足质子交换膜的需求, 但其甲醇渗透系数明显降低, 仅为市用Nafion 112膜的5%, 这表明该共混膜有望作为一种新型的直接甲醇燃料电池用质子交换膜.     

DMFC用PES/SPEEK共混阻醇质子交换膜

将磺化聚醚醚酮(SPEEK, 磺化度DS为68.3%)和聚醚砜(PES)两种聚合物共混制得PES/SPEEK共混膜. DSC研究表明两种聚合物之间具有较好的相容性, 因而共混膜均匀致密, 未发生大尺度相分离. PES的混入能有效降低膜的溶胀度及甲醇透过系数. 纯SPEEK 膜40 ℃时在1 mol•L−1甲醇水溶液中溶胀度达到160%, 45 ℃时就完全溶解, 而含30%(w)PES的共混膜在80 ℃时的溶胀度仅有15%. 室温下含20%−30%(w)PES的共混膜的甲醇透过系数为1×10−7 cm2•s−1左右, 比Nafion 115膜的透过系数小一个数量级. 尽管80 ℃下30%(w)PES/SPEEK共混膜的电导率与Nafion 115膜相当, 但由于共混膜的厚度比Nafion 115膜小1/3左右, 膜电阻较小, 因而其电池性能比Nafion 115膜的好.     

PES中空纤维复合纳滤膜的制备

采用界面聚合法制备聚醚砜（PES）中空纤维复合纳滤（NF）膜,讨论了制备条件对PES中空纤维复合NF膜性能的影响。实验结果表明,聚合反应时间、均苯三甲酰氯浓度、哌嗪浓度和酸吸收剂三乙胺浓度对复合NF膜性能有显著影响,同时二次反应能够提高复合NF膜的截留率,对2g／L的Na2SO4截留率可达到99．2％。     

聚酰亚胺对高性能树脂共混体系界面的反应增强

研究了以5-降冰片烯-2,3-二羧酸单甲酯为端基的PMR型聚酰亚胺(POI)作为界面介质对部分相容的聚醚砜/聚苯硫醚(PES/PPS)、聚醚醚酮/聚醚砜(PEEK/PES)共混体系的界面性质、形态结构及结晶行为的影响.结果表明,POI可以有效地增强两相间的界面粘结,显著降低PPS/PES共混物中PPS分散区的尺寸,改善两组分间的相容性.在熔融共混过程中,POI从本体向界面扩散并同PPS,PES产生交联和/或接枝,POI同PPS的反应活性远高于PES,但POI与PES发生反应.POI是PPS结晶的有效成核剂.     

RGD改性聚醚氨酯及其内皮细胞相容性的研究

利用氢键稳定的溶液互穿技术对聚醚氨酯(PEU)进行改性.用ATR-FTIR对十八烷基-聚氧乙烯-4,4'-二苯甲烷二异氰酸酯-聚氧乙烯-十八烷基(MSPEO)与PEU共混膜表面进行研究,结果表明,MS-PEO中的氨基甲酸酯链段与PEU基材之间发生了氢键缔合的作用.通过水化处理PEO及十八烷基自发地富集在基材表面.根据氢键缔合和表面自迁移原理,设计了两种RGD改性聚醚氨酯的方法:(1)将含RGD端基的聚氧乙烯-4,4'-二苯甲烷二异氰酸酯-聚氧乙烯偶联物(MPEO-RGD)与PEU进行共混改性,利用RGD端基及PEO的自迁移特性获得RGD富集的表面;(2)将含甲磺酸酯端基的聚氧乙烯-4,4'-二苯甲烷二异氰酸酯-聚氧乙烯偶联物(MPEO-mesyl)与PEU共混成膜,并对膜片进行水化处理,使甲磺酸酯端基富集在PEU表面,浸泡于RGD的PBS溶液中,在膜片表面成功地原位接枝了RGD.对两种RGD改性方法获得的表面进行了内皮细胞的培养,结果表明,两种改性方法均大大提高了PEU的细胞相容性,其中方法(1)共混改性的表面细胞相容性略优于方法(2)的接枝改性表面.     

酚酞型聚醚砜（PES—C）超滤膜的制备及性能

以聚乙烯吡咯烷酮（PVP）和乙醇（EtOH）为添加剂,采用相转化法制得了酚酞型聚醚砜（PES-C）超滤膜。结果表明：当以乙醇为添加剂时,随着乙醇含量的增加,膜上表面变为致密结构,下表面呈多孔结构,水通量先上升后减小;当以PVP为添加剂时,随着PVP含量增加,PES—C膜的指状孔得到发展,膜通量和截留率都上升,当PVP的质量含量为10％时,PES—C膜的通量达到134．3L／（m^2·h）,对牛血清蛋白的截留率达85．1％。     

PSF-SPES共混中空纤维超滤膜制备的研究

以聚砜(PSF)、磺化聚醚砜(SPES)和醋酸纤维素(CA)为膜材料,水为内凝胶剂,采用干湿法制备了PSF-SPES共混中空纤维超滤膜,探讨了PSF-SPES铸膜液中SPES离子交换容量(IEC)、SPES浓度、添加剂、外凝胶剂的选择和热处理对膜性能的影响。所得共混超滤膜性能如下:w=0.0 0 1的Na2SO4截留率19.9%,通量62 L/(h.m2.MPa);w=0.001的PEG4000截留率78.2%,通量85 L/(h.m2.MPa)。此外,以PSF-SPES中空纤维为支撑膜,采用醋酸纤维素作为涂层液,研究了CA/PSF-SPES复合超滤膜性能,讨论了CA/PSF-SPES共混中空纤维超滤膜结构。     

聚醚砜/酚酞基聚醚砜共混相容性及凝胶特性研究

采用混合热焓法和稀溶液粘度法预测了聚醚砜/酚酞基聚醚砜体系相容性,并观察了聚醚砜/酚酞基聚醚砜共混制膜液的凝胶值与共混比的关系.聚醚砜/酚酞基聚醚砜为部分相容体系,其相容性与组成有关.共混制膜液的凝胶值受共混组成的影响,并非纯组分制膜液凝胶值的线性加和.     

静电纺丝制备空气过滤用抗分层聚酰胺66/聚丙烯腈/聚醚砜(PA-66/PAN/PES)三明治结构膜（英文）

通过在经处理的不锈钢网(SSM)上逐层电纺制备了简易有效的聚酰胺66/聚丙烯腈/聚醚砜(PA-66/PAN/PES)复合纤维过滤材料.材料中间层采用以N,N-二甲基甲酰胺(DMF)为溶剂的PAN/PES共混聚合物电纺而成.扫描电子显微镜表征和比表面积测试结果表明,在相同纺丝条件下PES量的增加有利于减小纤维直径,增大膜的孔隙率.同时,通过拉伸实验测量了未带有SSM的膜的机械性能(5.857 MPa).利用PES的良好疏水性,过滤膜表面具有相对良好的疏水效果,接触角约为130.58°.在样品厚度尽可能相等的情况下,通过对实际空气环境中0.3~5μm的颗粒进行截流测试发现,PAN/PES-3的过滤效率达到且大于99%.通过机械振动和空气反吹考察了过滤膜的再生性能.此外,还通过使用喷雾喷涂SSM研究了防分层过滤介质的基质.     

Improved protein-adsorption-resistant property of PES/SPC blend membrane by adjustment of coagulation bath composition

To improve surface protein-adsorption-resistant property of polyethersulfone (PES) membranes, soybean phosphatidylcholine (SPC) was added to PES casting solution. The blend membranes were prepared by a phase inversion method in a wet process. The surface of PES/SPC blend membranes was characterized by X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM). XPS data revealed that the phosphorylcholine (PC) groups were concentrated at the surface by changing the composition of coagulation bath. Addition of N,N-dimethylformamide (DMF) in coagulation bath could prolong coagulation time and facilitate the migration of SPC from polymer bulk to membrane surface. The PES/SPC blend membranes dramatically reduced BSA and fibrinogen adsorption compared to PES control membrane due to effective immobilization of PC groups at the surface of PES/SPC blend membranes.     

Characteristics of polyethersulfone/sulfonated polyimide blend membrane for proton exchange membrane fuel cell

Solution-cast membranes from sulfonated polyimide (SPI) and its blend were prepared from polyethersulfone (PES) and SPI. The water uptake and swelling were tested and compared between the SPI membrane and the four kinds of blend membranes. Through comparison of the stability of the membranes, we concluded that the PES could greatly increase the stability of the whole membrane and restrict the swelling. However, the PES did not decrease the water uptake very much. We also compared the fuel cell performance with different membranes. The performance was decreased when the content of the PES in the blend membrane increased. The loss of the fuel cell performance with the blend membranes did not decrease very much before the content of the PES was exceeded 20%. It was prospected that the blend membrane could increase the stability of the SPI and, more importantly, even replace the commercial Nafion membranes.     

Protein-adsorption-resistance and permeation property of polyethersulfone and soybean phosphatidylcholine blend ultrafiltration membranes

Novel ultrafiltration membranes were prepared by simple blending of polyethersulfone (PES) and soybean phosphatidylcholine (SPC). X-ray photoelectron spectroscopy (XPS) and water contact angle measurements indicated SPC enrichment at the membrane surfaces. The immobilization and arrangement of PC groups at surfaces rendered the membranes more hydrophilic. BSA adsorption amount decreased from 56.2 μg/cm² for SPC-free PES membrane to 2.4 μg/cm² for PES/SPC blend membrane. The fouling-resistant property of the blend membranes was improved considerably with an increase of SPC content while the pure water permeation flux decreased remarkably. Using PEG/PVP mixture instead of PEG as pore-forming agent increased pure water flux of PES/SPC blend membrane to some extent.     

Improved protein-adsorption resistance of polyethersulfone membranes via surface segregation of ultrahigh molecular weight poly(styrene-alt-maleic anhydride)

A styrene-maleic anhydride (SMA) alternating copolymer with ultrahigh molecular weight (M_w > 10⁶) synthesized in super critical carbon dioxide (SC CO₂) medium was used as hydrophilic polymeric additive in the preparation of polyethersulfone (PES) membranes. The PES/SMA blend membranes were prepared by immersion precipitation process. X-ray photoelectronic spectroscopy (XPS) measurements confirmed that the hydrolyzed SMA preferentially segregated to membrane–coagulant interface during membrane formation. For the PES/SMA blend membranes, no big change was observed in the cross-sectional structure and the mechanical properties were well maintained after SMA addition except that a thicker top layer was formed. The surface morphology analysis by atomic force microscopy (AFM) showed that the membrane surface roughness increased with the added SMA amount. The results of water contact angle, water absorbance measurements and static protein adsorption experiments revealed that the surface enrichment of SMA endowed PES/SMA blend membranes with significantly improved surface hydrophilicity and protein-adsorption resistance.     

聚醚砜/纤维素晶体共混膜材料及其超滤性能

聚醚砜与纤维素晶体等共混成铸膜液,采用浸没沉淀相转化法制备聚醚砜/纤维素晶体共混膜材料.通过超滤装置检测复合膜的水通量、截留率、平均孔径、孔隙率、抗污染性等超滤性能,从而讨论了纤维素晶体含量对共混膜超滤性能的影响.采用抗张测试机、热重分析仪(TGA)、原子力显微镜(AFM)对共混膜的力学性能、热稳定性能、形貌结构进行表征.结果表明,随着纤维素晶体的含量的增加,共混膜的纯水通量先升高后有所降低,截留率均保持在91%～95%,抗张强度、断裂伸长率先增大后有所下降,抗污染性较纯聚醚砜膜显著提高.当纤维素晶体质量分数为1%时,纯水通量达到最大为813.3L·m-2·h-1,孔隙率为88.8%,平均孔径达为70.9nm,抗张强度为7.25MPa,断裂伸长率为11.6%,平均污染度FR值为22.0%,衰减系数m值为35.8%.共混膜具有由纤维素晶体、聚醚砜热降解分别引起的两个失重阶段.共混膜为典型非对称膜结构,表皮层较为致密,多孔支撑层孔径较大.     

An efficient nanofiltration membrane based on blending of polyethersulfone with modified (styrene/maleic anhydride) copolymer

In this study, styrene–maleic anhydride (SMA) copolymer was modified by ring opening reaction of its anhydride groups with diethanolamine (DEA). The modified SMA copolymer was blended in different concentrations (2.5, 4 and 5.5 %) with Polyethersulfone (PES) to improve the hydrophilicity of PES membranes and the corresponding blend membrane was prepared through phase inversion. The influence of SMA copolymer on morphology, mechanical properties, water flux, rejection and anti-fouling properties of blend membrane were investigated. The modified SMA and their composition were confirmed by FT-IR and ¹HNMR techniques. The asymmetric structure of membrane was revealed by SEM. The water flux and contact angle results show that the hydrophilicity of membrane surface was increased by addition of SMA copolymer. The better anti-fouling properties of the PES/modified SMA blend membranes in comparison with the PES membrane also confirmed that the hydrophilicity of blend membrane enhances.     

Amphiphilic graft copolymers based on ultrahigh molecular weight poly(styrene-alt-maleic anhydride) with poly(ethylene glycol) side chains for surface modification of polyethersulfone membranes

Amphiphilic graft copolymers having ultrahigh molecular weight poly(styrene-alt-maleic anhydride) (SMA) backbones and methoxyl poly(ethylene glycol) (MPEG) grafts were synthesized via the esterification between anhydride groups with hydroxyl groups. The synthesized graft copolymers, SMA-g-MPEGs, were used as additives in the preparation of polyethersulfone (PES) membranes via phase inversion process. X-ray photoelectron spectroscopy (XPS) analysis showed the comb-like graft copolymers spontaneously segregated to membrane surface during membrane formation. Water contact angle measurements and water absorbance experiments indicated the PES/SMA-g-MPEG blend membranes were much more hydrophilic than pure PES membrane. The blend membranes had stronger protein adsorption resistance than pure PES membrane did. After washed using de-ionized water for 25 days, the blend membranes exhibited higher hydrophilicity and stronger protein adsorption resistance. This phenomenon was attributed to the further accumulation of SMA-g-MPEG additives on membrane surface in aqueous conditions. SMA-g-MPEGs can be well preserved in membrane near-surface and not lost during membrane washing due to their high molecular weight and comb-like architecture.     

Tailoring polyethersulfone/quaternary ammonium polysulfone ultrafiltration membrane with positive charge for dye and salt selective separation

Polyethersulfone (PES)/quaternary ammonium polysulfone (QAPSf) blend ultrafiltration (UF) membranes with positive charge were fabricated by nonsolvent induced phase separation (NIPS) for use in dye and salt selective separation. QAPSf was synthesized by nucleophilic substitution with chloromethylated polysulfone (CMPSf). The effect of the PES/QAPSf mass ratio on the morphology and performance of blend UF membranes were studied. The membranes' zeta potentials gradually changed from negative to positive with decreases in the PES/QAPSf mass ratio. At PES/QAPSf mass ratios of 30:70 and 10:90, the zeta potentials of the membranes reached +1.8 mV and + 5.9 mV, respectively. Additionally, the contact angles of the membranes decreased from 74° to 52° as the QAPSf content increased from 0 wt% to 90 wt%. Furthermore, the membrane with a PES/QAPSf mass ratio of 30:70 showed a high water permeance (181.4 LMH bar⁻¹) and excellent dye and salt selective separation performance. The rejection ratios reached 99.1%, 87.8%, 99.6%, and 92.4% for dyes Congo red, methyl blue, Alixin blue 8GX, and basic blue 24, respectively, while those for salts Na₂SO₄, MgSO₄, MgCl₂, and NaCl were ≤ 10%. In addition, the PES/QAPSf membranes showed excellent antifouling performance and good operating stability with dye-salt mixtures of various pHs and salt concentrations.