聚醚侧链型聚硅氧烷对含氟聚合物凝胶锂离子电解质膜性能的影响

通过浸没沉淀相转化法制备了具有类似孔结构的聚醚侧链型聚硅氧烷(PDMS-g-(PPO-PEO))改性的聚偏氟乙烯(PVDF)和聚偏氟乙烯-六氟丙烯(PVDF-HFP)多孔骨架,经电解液活化后得到凝胶电解质膜,研究了PDMS-g-(PPO-PEO)对含氟聚合物凝胶电解质膜性能的影响。由改性PVDF和PVDF-HFP骨架被电解液活化制备的聚合物凝胶电解质膜,离子电导率分别达到2.2×10-3和1.7×10-3S/cm,综合分析凝胶电解质膜中电解液稳定性和膜的电化学性能发现,PDMS-g-(PPO-PEO)对PVDF骨架的改性效果明显优于PVDF-HFP骨架,共混改性后PVDF可代替PVDF-HFP作为隔膜作为锂离子电池凝胶电解质膜。     

聚乙烯吡咯烷酮含量对聚偏氟乙烯/聚醚砜共混膜性能和结构的影响

采用二甲基乙酰胺为溶剂,聚乙烯吡咯烷酮(PVP K90)为致孔性添加荆,研究了PVP的浓度对聚偏氟乙烯/聚醚砜(PVDF/PES)共混膜的收缩率、纯水通量、牛血清蛋白(BSA)截留率和膜结构的影响.在PVP含量为5%时,共混膜的收缩率最低,水通量取得极大值,截留率有一极小值.     

静电纺丝法制备PVP/PVDF复合微/纳米纤维

研究了不同条件下聚乙烯吡咯烷酮/聚偏氟乙烯(PVP/PVDF)的N,N-二甲基乙酰胺(DMAc)溶液的静电纺丝.采用扫描电镜(sEM)观察不同条件下制备的PVP/PVDF复合微/纳米纤维的微观形貌,并利用傅立叶变换红外光谱分析(FT-IR)纤维结构特征.结果表明,当PVP:PVDF为6:4时,制得的PVP/PVDF复合微/纳米纤维较好.     

废弃聚偏氟乙烯中空纤维膜再生与回用性能

研究了经膜生物反应器(MBR)系统运行6年的废弃聚偏氟乙烯(PVDF)中空纤维膜再生回用性能。讨论了运行过程中膜污染对PVDF中空纤维膜的影响;采用溶液相转化法制备了再生PVDF平板膜。研究结果表明,经运行6年后,PVDF中空纤维膜中致孔剂(如聚乙二醇(PEG)或聚乙烯吡咯烷酮(PVP))含量减少至零,断裂强度降低,断裂伸长率减小,相对分子质量降低,结晶度升高,膜孔堵塞等现象明显;与常规PVDF膜相比,再生PVDF膜的断裂强度和断裂伸长率较小,成膜过程中致孔难度增大(孔隙率较低),而再生PVDF膜的润湿性、渗透性以及截留率等与常规PVDF膜相近。     

基于电纺技术的纸质文物保护初探

针对纸质文物传统保护方法的不足,本研究利用电纺技术构筑网状多孔纳米纤维薄膜的独特优势,对具有优异的物理化学性能的聚偏氟乙烯(PVDF)开展电纺实验研究。在获得较佳纺丝参数后,对宣纸、报纸、胶版纸和古书纸4种代表性纸张进行纤维膜沉积封护,并对有无纤维膜封护处理的纸张进行了疏水角、抗酸碱及防污测试,同时也对纤维膜的孔隙大小进行了测量。实验结果表明,PVDF纳米纤维膜的封护处理,不仅能大幅度提高纸张的防水性能、耐酸碱性能和抗污染物能力,而且还可以使纸张保持良好的透气性。可以预见,在不久的将来,电纺技术将有望被广泛应用于纸质文物保护。     

PVDF电纺纤维接枝马来酸酐及其负载PbS的光催化性能研究

聚偏氟乙烯(PVDF)电纺纤维经NaOH/无水乙醇溶液处理,在其表面接枝马来酸酐(MAH),得到聚偏氟乙烯纤维接枝马来酸酐(PVDF-g-MAH)。FT-IR结果表明,MAH成功接枝到PVDF纤维上。以PVDF-g-MAH纤维为载体,经水热法在PVDF-g-MAH纤维表面制备PbS纳米粒子光催化剂。SEM、XRD分析显示PbS在纤维表面分布均匀,结晶状态良好。以氙灯模拟太阳光,研究了PbS/PVDF-g-MAH纤维复合材料对亚甲基蓝水溶液的降解效果,6h对亚甲基蓝的降解率达到90%。     

PVDF/PES/CA平板式共混超滤膜的研究

研究了致孔剂种类和用量对聚偏氟乙烯(PVDF)/聚醚砜(PES)/二醋酸纤维素(CA)共混平板膜结构和性能的影响,表征了共混超滤膜的水通量、截留率、孔隙率、收缩率和膜的断面形态等。结果表明,添加PES可以提高PVDF膜的尺寸稳定性,而添加1%CA可以提高PVDF/PES共混膜的亲水性,水通量显著增加。当PVDF/PES配比为9.5/0.5,致孔剂采用PEG20000、用量为60%时,其综合性能最优。     

聚偏氟乙烯/聚二甲基硅氧烷复合纳米纤维膜的渗透汽化脱盐性能研究

以静电纺丝聚偏氟乙烯(PVDF)纳米纤维膜为多孔支撑层,在其上涂覆聚二甲基硅氧烷(PDMS)为致密分离层,制备了PVDF/PDMS复合纳米纤维膜,并对复合膜的渗透汽化脱盐性能进行了研究。在涂覆操作前,使用堵孔剂聚乙二醇处理PVDF纳米纤维膜,以降低涂覆过程的孔渗问题,有效提高了复合膜对盐离子的截留能力。通过扫描电子显微镜、热重分析仪和红外光谱仪等手段表征了复合膜的微观形貌、热稳定性和表面官能团形式。结果表明:聚乙二醇浓度为12%(wt,质量分数,下同)为最佳处理条件。操作温度为25℃时,渗透汽化脱盐通量可达6.46L/(m~2·h),NaCl截留率为98.8%;升温至75℃,通量可达19.3L/(m2·h),NaCl截留率为95.6%。     

热致相分离法制备纳米碳酸钙/聚偏氟乙烯共混膜

以邻苯二甲酸二丁酯(DBP)为主要稀释剂,添加无机粒子CaCO3,采用热致相分离法(TIPS法)制备了聚偏氟乙烯/碳酸钙(PVDF/CaCO3)共混膜。考察了不同冷却条件对共混膜的影响以及CaCO3含量对聚偏氟乙烯结晶温度、结晶度的影响;研究了酸处理对共混膜微观结构、力学性能的影响。实验表明,通过改变冷却条件可以控制球晶的大小以及膜表面皮层的厚度;随着CaCO3含量的增加,PVDF共混膜的水通量先增加后减少,拉伸强度不断增加。经酸处理之后,共混膜水通量显著提高,拉伸强度有所下降。     

聚合物共混对聚偏氟乙烯超滤膜结构与性能的影响

根据聚合物共混焓变、绝对黏度及凝胶点值,考察了4种聚合物(聚乙烯醇(PVA)、聚乙二醇(PEG)、聚乙烯吡咯烷酮(PVP)、聚甲基丙烯酸甲酯(PMMA))与聚偏氟乙烯(PVDF)/N,N-二甲基乙酰胺(DMAc)铸膜液体系的共混相容性。利用凝胶相转化动力学及原子力显微镜(AFM)、扫描电镜(SEM)、亲水接触角和泡点压力等检测手段,分析了水凝胶浴中4种添加剂对PVDF超滤膜成膜过程及膜结构与性能的影响。结果显示,4种添加剂与PVDF/DMAc的共混相容性顺序为PEG>PVP>PVA>PMMA。共混体系均以液液分相为主;其中PEG、PVP共混PVDF体系以瞬时分相为主,膜内部有大孔,表皮层及支撑层较为致密。PMMA和PVA共混PVDF体系有延时分相和液固分相行为,膜表面多孔、内部有大孔且亚层疏松。共混优化了PVDF超滤膜结构。PVA能有效提高膜亲水性能。     

空气过滤用电纺聚偏氟乙烯-聚丙烯腈/熔喷聚丙烯无纺布复合材料的制备及过滤性能

为开发高效低阻的空气过滤材料,采用静电纺丝技术制备了聚偏氟乙烯（PVDF）-聚丙烯腈（PAN）复合纳米纤维,并与聚丙烯熔喷非织造布复合制得高效复合过滤材料,研究了PVDF与PAN的质量比对溶液性质、表面形貌、比表面积、透气性和过滤性能的影响。结果表明,当PVDF与PAN质量比为3:5时,其溶液可纺性最好,所得纤维直径均匀,约为0.59 μm;利用BET比表面积分析仪测试可得其比表面积约为PVDF与PAN质量比为2:1时的两倍;利用滤料测试仪对PVDF-PAN/熔喷聚丙烯（PP）无纺布复合滤材的过滤性能进行测试,结果表明,静电纺PVDF-PAN纳米纤维层可显著提高聚丙烯熔喷非织造布的过滤性能,PVDF-PAN/熔喷PP无纺布过滤效率可达99.95%,明显高于熔喷无纺布的过滤效率（65%）,过滤阻力为77 mmH₂O（1 mmH₂O=9.8 Pa）,过滤品质因子达0.0987,远高于熔喷无纺布的过滤品质因子0.0168,过滤效果得到显著提升。      

Electrospun PCL/PLA/HA based nanofibers as scaffold for osteoblast-like cells

Polycaprolactone (PCL), poly (lactic acid) (PLA) and hydroxyapatite (HA) are frequently used as materials for tissue engineering. In this study, PCL/PLA/HA nanofiber mats with different weight ratio were prepared using electrospinning. Their structure and morphology were studied by FTIR and FESEM. FTIR results demonstrated that the HA particles were successfully incorporated into the PCL/PLA nanofibers. The FESEM images showed that the surface of fibers became coarser with the introduction of HA nanoparticles into PCL/PLA system. Furthermore, the addition of HA led to the decreasing of fiber diameter. The average diameters of PCL/PLA/HA nanofiber were in the range of 300-600 nm, while that of PCL/PLA was 776 +/- 15.4 nm. The effect of nanofiber composition on the osteoblast-like MC3T3-E1 cell adhesion and proliferation were investigated as the preliminary biological evaluation of the scaffold. The MC3T3-E1 cell could be attached actively on all the scaffolds. The MTT assay revealed that PCL/PLA/HA scaffold shows significantly higher cell proliferation than PCL/PLA scaffolds. After 15 days of culture, mineral particles on the surface of the cells was appeared on PCL/PLA/HA nanofibers while normal cell spreading morphology on PCL/PLA nanofibers. These results manifested that electrospun PCL/PLA/HA scaffolds could enhance bone regeneration, showing their marvelous prospect as scaffolds for bone tissue engineering.     

Preparation and characterization of chitosan/poly(vinyl alcohol)/poly(vinyl pyrrolidone) electrospun fibers

Ultrafine fibers of chitosan/poly(vinyl alcohol)/poly(vinyl pyrrolidone) (CS/PVA/PVP) were prepared via electrospinning. The structure and morphology of CS/PVA/PVP ultrafine fibers was characterized by the Fourier transform infrared (FT-IR) spectroscope and scanning electron microscope (SEM). Furthermore, the effects of the concentration of PVA, PVP and the electrospinning voltage on the morphology of ultrafine fibers were investigated the the SEM. When the concentration of PVA was at the range of 30wt%–40wt%, ultrafine fibers could be obtained. The diameter distributions of ultrafine fibers decreased when the electrospinning voltage increased from 20 to 30 kV. The rough surface fibers could be obtained after etching with CHCl₃.     

Fabrication and evaluation of polyamide 6 composites with electrospun polyimide nanofibers as skeletal framework

In this study, two types of polyimide (PI) nanofiber mats, including (1) the mats consisting of (almost) randomly overlaid PI nanofibers and (2) the mats consisting of highly aligned PI nanofibers, were prepared by the materials-processing technique of electrospinning. The nanofiber mats were subsequently used to develop composites with polyamide 6 (PA6) via the composites – fabrication method of polymer melt infiltration lamination (PMIL). Owing to superior mechanical properties (i.e., the tensile strength and modulus were 1.7 GPa and 37.0 GPa, respectively) and large specific surface area of electrospun PI nanofibers, the PI/PA6 composites with PI nanofiber mats as skeletal framework demonstrated excellent mechanical properties. In particular, the PI/PA6 composite containing 50 wt.% of aligned PI nanofibers had the tensile strength and modulus of 447 MPa and 3.0 GPa along the longitudinal direction, representing ～700% and ～500% improvements as compared to neat PA6.     

Effect of TiO2 on photocatalytic activity of polyvinylpyrrolidone fabricated via electrospinning

Polyvinylpyrrolidone (PVP) is a promising material for electrospinning, and it has many desirable properties, including solubility in various solvents, physiological compatibility, chemical inertness, and excellent film-forming ability. Polymer–matrix composites of PVP–carbon fibers containing TiO₂ were prepared via electrospinning. Degradation of environmental pollutants by the electrospun webs was evaluated based on methylene blue degradation. The optimum photocatalytic activity was achieved with webs containing 7 wt% TiO₂. The results show that the proposed method is effective for improving the photocatalytic properties of TiO₂-doped nanofibers; the doping process also increased the nanofiber surface area.     

聚酯纤维的附生结晶法改善纤维的表面浸润性

将聚对苯二甲酸乙二醇酯(PET)纤维置入过冷态的聚乙二醇(PEG)和聚己二酸丁二酯(PBA)熔体,制备了PET纤维/PEG基体和PET纤维/PBA基体复合体系。使用偏光显微镜和原子力显微镜研究了这两种异质复合体系的界面结晶形态,利用接触角测量仪测量了附生结晶法改性前后PET纤维织物的接触角。结果表明,纤维置入温度和结晶等条件决定附生体系的横穿晶体形态结构,选取合适的树脂并采用附生结晶的方法可明显改善PET纤维织物的表面浸润性,并有望改善PET纤维增强复合材料内部的界面结构。     

左旋聚乳酸/多壁碳纳米管/羟基磷灰石电纺丝纳米纤维的形态及生物降解性能

采用静电纺丝法制备了左旋聚乳酸/多壁碳纳米管/羟基磷灰石(PLLA/MW NT s/HA)杂化纳米纤维无纺毡,分析了MW NT s的加入对杂化纤维形态结构的影响,以及不同工艺条件下纤维的直径分布,并研究了纤维无纺毡在磷酸盐缓冲溶液(pH 7.4,37℃)中的体外降解过程。结果表明:MW NT s的加入使PLLA/HA纤维直径略有减小;PLLA/MW NT s/HA杂化纤维体系降解液的pH值下降到一定程度后,在降解后期呈缓慢上升趋势;碱性MW NT s/HA的加入抑制了PLLA降解过程中的自催化作用,减缓了PLLA的降解速度。     

Poly(vinyl alcohol)-perfluorinated sulfonic acid nanofiber mats prepared via electrospinning as catalyst

Well-formed poly (vinyl alcohol) (PVA)-perfluorinated sulfonic acid (PFSA) nanofiber mats were fabricated via electrospinning process. Homogenous PFSA-PVA solutions were prepared by mixing PFSA-N, N-dimethylacetamide (DMAc) solution with PVA aqueous solution at different weight ratio. Increasing the weight ratio of PFSA in solution greatly increased the viscosity of the solution and slightly decreased the conductivity, which increased the diameter of the resulting PVA-PFSA nanofiber. The operating parameters such as tip to collector distance (TCD) and flow rate have a limited effect on the morphology of nanofibers, but high flow rate can improve the productivity. Ethyl acetate synthesis catalyzed by PVA-PFSA nanofiber mats was investigated, the results showed that all nanofibers have significantly catalytic activity, but the catalytic efficiency is related to the specific surface of PVA-PFSA nanofibers.     

PASS溶液性质对静电纺丝可纺性及纤维形貌的影响

选取苯酚和四氯乙烷的混合物作溶剂,采用不同分子量的聚芳硫醚砜(PASS)树脂配制不同浓度的溶液,考察了溶液动态流变性能、表面张力、导电率对静电纺丝可纺性以及纤维形貌的影响。结果发现溶液的可纺性有实数黏度依赖性,纤维直径受溶液黏度的影响最大。