明胶/聚乳酸复合纤维膜的制备、表征及作为角膜细胞载体的评价

利用静电纺丝技术制备了明胶与聚乳酸的复合纤维膜, 研究了组分配比对复合膜的表面性能、孔隙结构和力学性能的影响, 并以复合膜为组织工程支架进行兔角膜上皮细胞的体外培养. 采用扫描电子显微镜、免疫荧光染色和噻唑蓝四氮唑溴化物(MTT)比色法综合评价了细胞在支架表面的黏附与增殖能力. 结果表明, 纺丝溶液的组分对纤维的直径分布和表面亲水性有显著影响, 不同组分配比的复合纤维膜均具有高孔隙率的通孔结构; 以明胶为基材可维持复合膜的细胞黏附性; 与聚乳酸复合可以明显提高复合膜的力学性能.     

亚表面引发原子转移自由基聚合构筑温度响应型纳米纤维油水分离膜

亚表面引发聚合是一种用于制备共价嵌入型聚合物刷的新型改性策略.该方法在发展高稳定性聚合物刷功能化表界面材料方面具有显著的优势.本工作利用亚表面引发原子转移自由基聚合(sSI-ATRP)对静电纺丝聚丙烯腈(PAN)基纳米纤维膜进行亚表面改性,通过接枝聚N-异丙基丙烯酰胺(PNIPAM)制备了温度响应型纳米纤维油水分离膜(...     

静电纺丝法制备PLLA/g-HNTs复合纳米纤维膜及其性能研究

以辛酸亚锡为催化剂,利用HNTs表面的羟基引发L-LA开环聚合,合成了表面接枝聚(L-乳酸)(PLLA)链段的埃洛石纳米管(g-HNTs),通过红外、热失重和透射电镜对改性前后HNTs的组成与形貌进行了观察;然后采用静电纺丝技术制备了PLLA纳米纤维膜以及不同组成的PLLA/HNTs和PLLA/g-HNTs复合纳米纤维膜,探讨了纺丝条件对纳米纤维膜形貌的影响,并对复合膜的组成、形貌、力学性能和细胞相容性进行了研究.结果表明,当HNTs与L-LA的摩尔投料比为1∶10时,g-HNTs表面PLLA链段的接枝率为14.22％,HNTs纳米管的形态在接枝后变化不大,易于在无水乙醇中分散.电压强度和进样速率对纤维膜的形貌有一定影响,当电压强度为15 kV、进样速率为1 mL/h时,电纺纤维的直径较为均匀.复合纤维膜中g-HNTs在基体PLLA中的分散性以及与基体的界面相容性要优于相应的HNTs,当g-HNTs含量高达40％时,复合纳米纤维膜中的纤维形态仍然保持较好,可以得到连续、粗细较均匀的纤维;随着HNTs和g-HNTs含量增加,复合纳米纤维膜的拉伸强度和模量先增大后下降,当HNTs和g-HNTs的含量为5％时,两种复合纳米纤维膜的拉伸强度和模量均达到最大值,但PLLA/g-HNTs组复合纳米纤维膜的拉伸强度始终大于相应的PLLA/HNTs组.体外3T3细胞培养结果显示,PLLA/g-HNTs复合纳米纤维膜具有良好的细胞相容性,且优于相应的PLLA和PLLA/HNTs纳米纤维膜.     

基于静电纺丝技术的PET/PVA复合超滤膜制备条件的探索

采用多喷头静电纺丝技术制备了复合超滤膜,该复合超滤膜是以聚对苯二甲酸乙二酯(PET)无纺布为支撑层,PET/PVA复合纳米纤维膜为分离层,再用丙酮和水的混合溶剂处理得到致密分离层.采用扫描电镜法(SEM)、红外光谱法(FTIR)对复合膜表面进行表征,测试了复合超滤膜的抗水解性能.SEM结果表明,复合膜表面的PET纳米纤维的直径为960 nm,PVA纳米纤维的直径为320 nm,用不同比例的混合溶剂对复合超滤膜进行处理会产生不同的表面形貌,最佳的比例是w(丙酮)/w(水)=30/70.抗水解性能实验结果显示比较适宜的交联剂加入量为2 wt%,用该含量对复合膜进行交联,复合膜具有较好的抗水解性能,其中重量损失率为2.12%,溶胀度为3.62%.红外光谱分析表明,交联处理后,复合膜表面的—OH量大大减少,耐水性能提高,交联前后膜表面在—C O和C—O—C处的吸收峰有很大的区别.     

CUR-CAP/PLGA纳米静电纺丝纤维膜的制备和活性研究

采用静电纺丝的方法制备了不同质量分数的CUR-CAP/PLGA复合静电纺丝纤维膜,并通过扫描电子显微镜、红外光谱、单晶X射线衍射进行表征,并用四唑盐MTT比色法测定其对成纤维细胞增殖的影响.表征结果表明:所合成的复合静电纺丝纤维膜的直径具有纳米结构,复合薄膜中,3种物质很好的混合在一起,没有发生化学键的结合.细胞实验检测结果显示,CUR-CAP/PLGA复合膜有助于细胞在其表面的生长及增殖,当姜黄素的质量分数为3%、氯霉素的质量分数为1%时效果最佳.     

抗污染PVA/PVDF电纺纳米纤维复合超滤膜的制备及过滤性能

以聚对苯二甲酸二醇酯(PET)无纺布为基底,聚偏氟乙烯(PVDF)纳米纤维为支撑层,聚乙烯醇(PVA)纳米纤维膜为分离层,采用静电纺丝法制备超滤膜,并用水/丙酮混合溶液对复合纳米纤维膜表面进行溶液处理,再加入戊二醛交联改性得到致密分离层.采用扫描电子显微镜(SEM)和红外光谱(FTIR)表征了复合超滤膜的表面,用水接触角(WCA)表征复合超滤膜的亲水性.在0.02 MPa恒压下死端过滤油/水乳液,测试复合超滤膜的过滤性能.结果表明,最优条件下制备的复合超滤膜死端过滤油/水乳液的通量为(42.50±4.78)L/(m~2·h),截留率达到(95.72±0.33)%;循环使用5次后,依然具有较好的过滤性能,常压下死端过滤复合超滤膜的纯水通量为(3469±28)L/(m~2·h).     

静电纺丝纳米纤维膜固定化酶及其应用*

静电纺丝是一种简单有效的制备聚合物纳米纤维的技术,在组织工程、药物控释和传感器等方面具有广泛的应用。采用静电纺丝技术制备得到的纳米纤维膜具有比表面积大、孔隙率高和易于分离回收等优点,可以作为一种优良的酶固定化载体,目前在酶固定化领域受到了广泛的关注。本文综述了近年来静电纺丝纳米纤维膜固定化酶的研究进展,在阐述静电纺丝纳米纤维膜制备技术的基础上,详细介绍了纳米纤维膜表面担载法和包埋法固定化酶的原理和方法,分析了不同固定化方法的优缺点,并讨论了静电纺丝纳米纤维膜固定化酶的应用前景,对静电纺丝纳米纤维膜固定化酶的发展方向进行了展望。     

静电纺丝法制备新型吸附分离材料

随着现代经济、工业的发展,许多环境问题出现在了人类面前,对于新型吸附分离材料的需求也变得十分迫切。静电纺丝法是一种简单有效制备连续纳米长丝的技术,有着十分广阔的应用前景。由于静电纺丝法制备的纤维膜具有较大的比表面积、易于调控的微观结构及化学性质,静电纺丝法能够用于制备新型的吸附分离材料。本文对电纺纤维膜的制备与改性,以及电纺纤维膜在空气过滤、油水分离、重金属离子去除等领域的应用进行了介绍,同时对其未来的发展进行了展望。     

硬脂酸改性β-TCP的分析测定及其PLLA复合纳米纤维膜性能研究

采用硬脂酸对β-磷酸三钙(β-TCP)进行表面改性,并研究了β-TCP与硬脂酸的界面作用,通过透射电子显微镜(TEM)、热重分析仪(TGA)以及X光电子能谱(XPS)对改性前后β-TCP的形貌、热失重和表面基团进行表征;采用静电纺丝法制备不同质量配比的β-TCP/PLLA和改性β-TCP/PLLA复合纳米纤维膜,用扫描电镜(SEM)观察复合膜的形貌,并研究其力学性能。结果表明,硬脂酸包覆在β-TCP表面,改性后的β-TCP具有一定疏水性,硬脂酸的H+可与β-TCP中PO3-4的1个O发生质子化反应形成—OH;硬脂酸改性减轻了β-TCP微粒的团聚,可以得到连续均匀的纤维,改性后的β-TCP/PLLA复合纳米纤维膜的力学性能较改性前有明显提高。     

SPES/SiO_2杂化纳米纤维复合质子交换膜的制备与性能

提出了一种利用杂化纳米纤维来制备高性能质子交换膜的方法,首先采用溶液喷射纺丝技术纺制了SPES/Si O2杂化纳米纤维,再通过溶液浸渍法制备了SPES/Si O2/Nafion复合质子交换膜,并研究了其热稳定性、吸水性能、溶胀性能、质子传导性能以及甲醇渗透性能等.结果表明,杂化纳米纤维的引入明显改善了Nafion膜的热性能、尺寸稳定性,并大大提高了其质子传导性能.TG数据表明复合膜的热稳定性相比于Nafion膜得到了极大改善.复合膜溶胀率均比Nafion膜的小,SPES/Si O2/Nafion-5,SPES/Si O2/Nafion-15和SPES/Si O2/Nafion-25在80℃溶胀率仅为14.9%,15.84%和17.2%,但是复合膜的溶胀率随着Si O2含量的增加而增大.复合膜电导率随Si O2含量的增加呈先增大后减小的规律,Si O2含量为15%的复合膜在80℃、100%湿度条件下,质子导电率可达到0.154 S/cm.其阻醇性能也得到了极大改善,Si O2含量为25%的复合膜相比于Nafion膜其甲醇渗透率降低了55.3%.因此SPES/Si O2杂化纳米纤维复合质子交换膜可以作为一种新型质子交换膜应用于燃料电池中.     

反渗透膜微结构的调控及海水脱硼性能的提升

通过引入聚乙烯亚胺(PEI)链与对叠氮苯甲酸(ABA)分子对薄层芳香聚酰胺复合反渗透膜(TFC)进行接枝改性, 采用傅里叶衰减全反射红外光谱(ATR-FTIR)和X射线光电子能谱(XPS)分析了反渗透膜活性分离层的化学组成和结构, 用静态水接触角仪与Zeta电位仪测试了反渗透膜表面的亲疏水性和电荷性质, 并利用扫描电子显微镜(SEM)及原子力显微镜(AFM)观察其表面形貌, 测试了反渗透膜在苦咸水与海水条件下的分离性能. 实验结果表明, 使用PEI与ABA对反渗透膜改性后, 提升了其分离层的致密度, 使硼渗透通过反渗透膜时的传质阻力变大, 从而将改性反渗透膜(TFC-PEI-ABA)对硼的截留率提升至90.45%, 达到了世界卫生组织对水质的要求.     

添加共试剂改善聚酰胺复合反渗透膜的性能

将N,N′-二甲基乙酰胺(DMAc)作为共试剂添加在间苯二胺水溶液中参与界面聚合反应, 以改善聚酰胺复合反渗透膜(PA-RO-x, x代表添加DMAc的质量分数)的性能. X射线光电子能谱(XPS)和衰减全反射傅里叶红外光谱(ATR-FTIR)分析表明, 随着DMAc含量的增加, 复合膜结构中交联聚酰胺含量相对于线性羧基部分有所增加; 场发射扫描电子显微镜(FE-SEM)和原子力显微镜(AFM)表征结果显示, 随着DMAc含量的增加, 膜表面的粗糙程度逐渐增大; 静态水接触角测试结果表明, 添加DMAc后, 膜的亲水性增强. 结合上述测试结果发现, 添加DMAc可以有效降低水油两相的不相溶性, 提高水相中间苯二胺向正己烷中扩散的速率, 这有助于加快间苯二胺与均苯三甲酰氯反应; 同时, 聚酰胺结构中交联酰胺含量的增加可以提供更多的氢键位点, 有助于水分子快速渗透通过复合膜而不损失截盐率; 膜表面的粗糙程度变大, 有助于提高水通量. 在2 g/L的氯化钠溶液和1.6 MPa测试压力条件下, PA-RO-5.2(DMAc添加质量分数为5.2%)的渗透通量和截盐率分别为66.1 L/(m²·h)和98.7%, 与未添加DMAc的聚酰胺复合反渗透膜相比, 通量增加115%, 截盐率仅下降0.9%.     

A nanofibrous composite membrane of PLGA-chitosan/PVA prepared by electrospinning

Tissue engineering scaffolds produced by electrospinning feature a structural similarity to the natural extracellular matrix. In this study, poly(lactide-co-glycolide) (PLGA) and chitosan/poly(vinyl alcohol) (PVA) were simultaneously electrospun from two different syringes and mixed on the rotating drum to prepare the nanofibrous composite membrane. The composite membrane was crosslinked by glutaraldehyde vapor to maintain its mechanical properties and fiber morphology in wet stage. Morphology, shrinkage, absorption in phosphate buffered solution (PBS) and mechanical properties of the electrospun membranes were characterized. Fibroblast viability on electrospun membranes was discussed by MTT [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide] assay and cell morphology after 7 days of culture. Results indicated that the PBS absorption of the composite membranes, no matter crosslinked or not, was higher than the electrospun PLGA membrane due to the introduction of hydrophilic components, chitosan and PVA. After crosslinking, the composite membrane had a little shrinkage after incubating in PBS. The crosslinked composite membrane also showed moderate tensile properties. Cell culture suggested that electrospun PLGA-chitosan/PVA membrane tended to promote fibroblast attachment and proliferation. It was assumed that the nanofibrous composite membrane of electrospun PLGA-chitosan/PVA could be potentially used for skin reconstruction.     

TFC polyamide membranes modified by grafting of hydrophilic polymers: an FT-IR/AFM/TEM study

Surface modification using grafting of a hydrophilic polymer onto the membrane surface is a possible route to improving the fouling properties of polyamide thin-film composite membranes. The structure of nanofiltration (NF) and reverse osmosis (RO) membranes modified using graft polymerization of acrylic (AA) monomers was visualized and analyzed using attenuated total reflection–Fourier transform infrared spectroscopy, atomic force microscopy and transmission electron microscopy. The results show that a layer of AA polymer is indeed formed on the polyamide surface, which could be accompanied by a change of the surface morphology. It was observed that for the NF membranes studied polymerization could also take place inside the pores of the support as a result of penetration of the monomer through the active layer, particularly for high degrees of grafting. It suggests that the modification procedures should be optimized so that the latter effect is minimized.     

The analysis of electric properties of thin film composite reverse osmosis membrane with wet impedance method

A study on the electric properties of reverse osmosis composite membrane was conducted by wet impedance method. The thin film of composite membrane was prepared by interfacial polycondensation with 1,3-phenylene diamine and 1,3,5-benzene tricarbonyl chloride. The electric resistance and capacitance of polyamide skin layer of composite membrane was analyzed by alternating current. The dielectric constant of membrane was also analyzed and compared with theoretical value. Concentration and dipping time of aqueous phase play major role in electrical properties of membrane. The effect of acid treatment on membrane properties was also investigated.     

聚乳酸/壳聚糖纳米纤维结构形成的影响条件及其生物矿化活性

以二氧六环/冰醋酸为溶剂体系,采用相分离法制备了聚乳酸(PLA)/壳聚糖(CS)复合纳米纤维结构的组织工程支架,探讨了不同CS含量、不同凝胶温度及不同分子量对PLA/CS复合支架纳米纤维结构的影响以及支架的生物活性。结果表明,凝胶温度对PLA/CS复合材料的纳米纤维结构影响较大,且随着温度的降低,结构的微观尺寸也逐渐增大,从纳米级上升到普通的尺寸结构;CS含量对PLA/CS复合支架的基体结构影响不大;实验范围内PLA分子量对PLA/CS复合支架的纳米纤维结构有重要影响:分子量大的样品,较易得到PLA/CS复合纳米纤维结构的材料,而分子量小的样品则不能得到纳米纤维结构。另外,生物矿化实验表明CS的添加有利于PLA/CS复合材料生物活性的提高。     

Influence of membrane surface properties on initial rate of colloidal fouling of reverse osmosis and nanofiltration membranes

Recent studies have shown that membrane surface morphology and structure influence permeability, rejection, and colloidal fouling behavior of reverse osmosis (RO) and nanofiltration (NF) membranes. This investigation attempts to identify the most influential membrane properties governing colloidal fouling rate of RO/NF membranes. Four aromatic polyamide thin-film composite membranes were characterized for physical surface morphology, surface chemical properties, surface zeta potential, and specific surface chemical structure. Membrane fouling data obtained in a laboratory-scale crossflow filtration unit were correlated to the measured membrane surface properties. Results show that colloidal fouling of RO and NF membranes is nearly perfectly correlated with membrane surface roughness, regardless of physical and chemical operating conditions. It is further demonstrated that atomic force microscope (AFM) images of fouled membranes yield valuable insights into the mechanisms governing colloidal fouling. At the initial stages of fouling, AFM images clearly show that more particles are deposited on rough membranes than on smooth membranes. Particles preferentially accumulate in the “valleys” of rough membranes, resulting in “valley clogging” which causes more severe flux decline than in smooth membranes.     

Preparation,structure characteristics and separation properties of thin-film composite polyamide-urethane seawater reverse osmosis membrane

A novel thin-film composite (TFC) seawater reverse osmosis membrane was developed by the interfacial polymerization of 5-chloroformyloxyisophthaloyl chloride (CFIC) and metaphenylenediamine (MPD) on the polysulphone supporting membrane. The performance of the TFC membrane was optimized by studying the preparation parameters, which included the reaction time, pH of the aqueous-MPD solution, monomer CFIC concentration, additive isopropyl alcohol content in aqueous solution, curing temperature and time. The reverse osmosis performance of the resulting membrane was evaluated through permeation experiment with synthetic seawater, and the structure of the novel membrane was characterized by using SEM, AFM and XPS. Furthermore, the separation properties of the TFC membrane were tested by examining the reverse osmosis performances of various conditions, the boron rejection performance and the long-term stability. The results show that the desired TFC seawater reverse osmosis membrane has a typical salt rejection of 99.4% and a flux of about 35 L/m² h for a feed aqueous solution containing 3.5 wt.% NaCl at 5.5 MPa, and an attractive boron rejection of more than 92% at natural pH of 7–8; that the novel seawater reverse osmosis membrane appears to comprise a thicker, smoother and less cross-linking film structure. Additionally, the TFC membrane exhibits good long-term stability.     

木质素磺酸钠改性聚砜膜的制备及其在正渗透膜中的应用

采用木质素磺酸钠作为亲水添加剂,通过浸没沉淀相转化法制备了木质素磺酸钠共混改性聚砜膜,以改善聚砜膜的亲水性,并用作正渗透膜的支撑层,以降低内浓差极化效应.利用扫描电子显微镜、衰减全反射傅里叶变换红外光谱仪、水接触角仪等研究了不同木质素磺酸钠添加量对聚砜膜的结构和表面性质的影响.结果表明,添加木质素磺酸钠后,聚砜膜的指状孔变得规整且狭长.水接触角实验证实添加木质素磺酸钠能改善聚砜膜的亲水性,当木质素磺酸钠含量为0.4 wt%时,聚砜膜的表面水接触角可降低至65°.正/反渗透测试装置分别用于表征正渗透膜的传质性质和结构参数.结果表明,以0.4 wt%木质素磺酸钠改性聚砜膜为支撑层的正渗透膜的水渗透性能(A=3.12×10~(-5) LMH×Pa~(-1))优于纯聚砜基底正渗透膜(0.76×10~(-5)LMH×Pa~(-1)),而且前者的结构参数(S=2010mm)远小于后者(3450mm),说明木质素磺酸钠改性聚砜膜有效弱化了正渗透膜的内浓差极化效应.     

Influence of the polyacyl chloride structure on the reverse osmosis performance,surface properties and chlorine stability of the thin-film composite polyamide membranes

This paper aims to study the structure–property relationship and make several reasonable suggestions for tailoring special separation performance and surface properties of thin-film composite polyamide membranes. In the experiments, composite membranes of different thin films with small structural differences were prepared through interfacial polymerization of trimesoyl chloride (TMC), 5-isocyanato-isophthaloyl chloride (ICIC), and 5-chloroformyloxy-isophthaloyl chloride (CFIC) with m-phenylenediamine (MPD) separately, after which their reverse osmosis performances were evaluated by permeation experiment with salt aqueous solution, and film properties were characterized by AFM, SEM, XPS, ATR-IR, contact angle and streaming potential measurements. Chlorine stability was also studied through the evaluation of membrane performance before and after hypochlorite exposure. The results show that the polyacyl chloride structure strongly influences the reverse osmosis performance, surface properties and chlorine stability of the composite membranes; that the introduction of isocyanato group into polyacyl chloride improves the hydrophilicity, water permeability and surface smoothness of the thin-film composite membrane, and increases the absolute value of zeta potential at both low and high pH, but reduces the chlorine stability; and that the introduction of chloroformyloxy group increases the salt rejection rate and the surface roughness of the composite membrane, but lowers the water permeability.