纳米Ag-聚乙烯醇缩丁醛静电纺丝复合纳米纤维的制备及性能

采用静电纺丝技术制备纳米Ag-聚乙烯醇缩丁醛（PVB）复合纳米纤维,获得一类过滤性能和抗菌性能优异的空气过滤材料。采用TEM分析纳米Ag的形貌,采用SEM、FTIR和XRD等表征手段研究纳米Ag-PVB复合纳米纤维的微观形貌、化学结构以及结晶行为,并对其空气过滤性能、透气性能和抗菌性能进行了研究。结果表明：以乙醇为溶剂,当PVB含量为10wt%、纳米Ag含量为0.25wt%时,得到的纤维尺寸均一,平均直径为542.14 nm。性能测试结果表明,纺丝最佳时间为10 min,纳米Ag-PVB复合纳米纤维对PM2.5过滤效率为99.99%,过滤阻力为16 Pa,透气率为155.0 mm/s,并且对大肠杆菌表现出优异的抗菌性能,其抑菌率为95.52%。     

静电纺壳聚糖/聚乙烯醇纳米纤维膜的制备及表征

通过静电纺丝技术首次将溶解在1%(体积分数)超低浓度乙酸溶液中的3%(wt,质量分数,下同)壳聚糖(CS)与溶解在去离子水中的11%聚乙烯醇(PVA)溶液进行混合,在20～22kV高压静电场下制备出直径在70～300nm之间、CS含量高达60%,具有均匀结构的CS/PVA纳米纤维膜。通过旋转流变仪、扫描电镜、X射线衍射仪、红外光谱、热重分析和万能试验机等手段对其混合溶液进行表征。结果表明:CS/PVA纳米纤维膜的形貌与CS和PVA的混合比例有关,当CS含量低于60%时,纤维形貌良好,当CS含量高于60%时,纤维中存在有液滴以及纺锤体。另外,CS与PVA之间存在强有力的氢键作用并具有很好的相容性,PVA可以降低壳聚糖的结晶性利于静电纺过程的进行;并且该CS/PVA纳米纤维膜具有较好的热稳定性和弹性,随着PVA比例的增加其最大拉伸强度可达到9.98MPa。     

壳聚糖/聚乙烯醇复合纳米导电纤维的制备及性能表征

以壳聚糖(CS)、聚乙烯醇(PVA)和纳米石墨粉(G)为原料,利用静电纺丝技术分别制备了壳聚糖/聚乙烯醇共混纳米纤维及壳聚糖/聚乙烯醇/纳米石墨粉复合纳米纤维,采用原位聚合法在纤维表面聚合导电聚合物聚苯胺,得到具有优良导电性能的聚合CS/PVA和聚合CS/PVA/G复合纳米纤维。通过扫描镜、X射线衍射、红外光谱等测试手段对纤维的形貌和结构进行表征。结果表明,聚苯胺均匀包覆在经原位聚合的复合纳米纤维表面,提高了纤维的导电性能,纳米石墨粉与聚苯胺形成插入化合物进一步提高了纤维的导电性能。     

羽毛角蛋白/PVA复合纳米纤维膜的制备及表征

以羽毛角蛋白(FK)和聚乙烯醇(PVA)为原料,水为溶剂,通过静电纺丝技术制备了FK/PVA复合纳米纤维膜.探讨了复合纳米纤维中FK与PVA的相容性,研究了FK的添加对纤维膜微观形貌、结晶度、热稳定性、亲水性等性能的影响.SEM结果表明,在聚合物总质量分数为14％的条件下制备的FK/PVA复合纳米纤维,表面平整光滑,平均直径为250～320 nm,FK含量越大,直径越小.FTIR结果表明,FK与PVA具有良好的相容性,分子间存在氢键作用力.XRD结果表明,FK的加入破坏了PVA分子的规整排列,复合纳米纤维膜的结晶度下降.TG分析与接触角测试结果表明,随着体系中FK配比的增大,复合纳米纤维膜的热稳定性和亲水性均得到提高.     

羽毛角蛋白/PVA复合纳米纤维膜的制备及表征

以羽毛角蛋白(FK)和聚乙烯醇(PVA)为原料,水为溶剂,通过静电纺丝技术制备了FK/PVA复合纳米纤维膜。探讨了复合纳米纤维中FK与PVA的相容性,研究了FK的添加对纤维膜微观形貌、结晶度、热稳定性、亲水性等性能的影响。SEM结果表明,在聚合物总质量分数为14%的条件下制备的FK/PVA复合纳米纤维,表面平整光滑,平均直径为250~320nm,FK含量越大,直径越小。FTIR结果表明,FK与PVA具有良好的相容性,分子间存在氢键作用力。XRD结果表明,FK的加入破坏了PVA分子的规整排列,复合纳米纤维膜的结晶度下降。TG分析与接触角测试结果表明,随着体系中FK配比的增大,复合纳米纤维膜的热稳定性和亲水性均得到提高。     

静电纺定向纳米纤维素-碳纳米管/聚乙烯醇复合纤维导电膜及性能

利用纤维素纳米晶须（CNCs）搭载碳纳米管（CNTs）在水相中形成均一稳定的纳米CNCs-CNTs导电复合物,并将其均匀分散于聚乙烯醇（PVA）基体中制得纺丝液,采用静电纺丝技术制备纤维定向排列的CNCs-CNTs/PVA复合导电膜。结果表明：CNCs-CNTs增强了纤维膜热力学性能,并赋予其导电功能;纤维的定向排列显著提高了膜的力学性能;随CNTs含量增加,纺丝液电导率和黏度提高,纤维直径减小;当CNCs和CNTs与PVA的质量比分别为8.0%和1.0%时,CNCs-CNTs/PVA的纤维直径、拉伸强度和电导率分别可达182 nm±35 nm、15.99 MPa±1.25 MPa和0.12 S/m±0.01 S/m;当电流密度为0.2 A/g时,其比电容可达127.1 F/g,且经过1 500次充放电循环后电容量仍保持在83.14%。基于导电膜优良的力学性能、热稳定性和导电性,CNCs-CNTs/PVA导电膜有望应用于可折叠超级电容器、柔性传感器和柔性电极材料等领域。     

利用静电纺丝技术制备纳米黏土/聚乳酸复合纳米纤维与其表征

利用静电纺丝技术制备了纳米黏土/聚乳酸(PLA)复合纳米纤维,并将该复合纳米纤维收集成无纺布薄膜,采用SEM和TEM观察了复合纳米纤维的微观形貌和结构,分别利用XRD和TGA测试了复合纳米纤维的结晶行为及热学行为,并分析了复合纳米纤维薄膜的拉伸力学性能随纳米黏土含量的变化关系。结果表明:当PLA含量为10wt%、纳米黏土含量为1wt%、CHCl3与DMF体积比为3∶1溶剂条件下,所制备的纳米黏土/PLA复合纳米纤维的细度和均匀性均得到改善;XRD测试结果表明,纳米黏土成功附着在PLA中。TGA和力学测试结果表明,纳米黏土/PLA复合纳米纤维的热稳定性和力学性能相对于纯PLA纤维有较大幅度提高,当纳米黏土含量为1wt%时,其初始分解温度提高了60℃,拉伸强度、断裂伸长率和弹性模量分别提高了111.3%、74.9%和20.0%。     

静电纺丝制备聚乙烯醇/再生柞蚕丝素蛋白复合纳米纤维

将聚乙烯醇(PVA)与再生柞蚕丝素蛋白(RWSF)共混,通过静电纺丝技术制备了PVA/RWSF复合纳米纤维,在保持材料降解性能和力学强度不变的前提下,获得了具有生物活性的表面。应用正交法优选出PVA/RWSF复合纳米纤维的最佳制备工艺参数。扫描电镜观察到,各组电纺膜中纤维的形貌较好,不同参数条件下纤维的直径和均匀程度有较大差别;方差分析表明,静电纺丝过程中纺丝液浓度、PVA/RWSF质量比和纺丝电压对纤维均匀性的影响显著;结合后期验证性实验确定PVA/RWSF复合纳米纤维最佳电纺参数为电纺液浓度0.09 g/mL、PVA/RWSF质量比90/10、纺丝电压18kV、推进速度1.5mL/h、接收距离14cm,此时制备的纤维均一、纤细,重复性好。     

静电纺PVDF/SiO_2原位复合隔膜的研究

采用原位复合溶胶-凝胶法配制复合纺丝液,通过高压静电纺丝制备出PVDF/SiO2复合纳米纤维膜。通过SEM表征了PVDF/SiO2复合纳米纤维的纺丝效果,同时对比了使用两种方法添加6%SiO2制得的PVDF静电纺复合纳米纤维的表面形貌及力学性能。研究了原位纳米SiO2的加入对膜的孔径变化以及力学性能的影响。结果表明,原位硅的加入,增加了纤维的表面粗糙度;降低了复合膜内的微孔直径,并使得微孔直径分布更加集中;改善了膜的力学性能,添加6%原位硅时效果最佳。在SiO2含量为6%时,与直接添加相比,原位复合法制得的复合膜力学性能更佳。     

新型PVA/PEI/MWCNTs纳米纤维制备及其释药研究

采用高压静电纺丝技术制备聚乙烯醇(PVA)/聚乙烯亚胺(PEI)/多壁碳纳米管(MWCNTs)复合纳米纤维并对其进行表征及释药研究。扫描电子显微镜观察结果表明,按不同质量比的PVA/PEI电纺纤维,当其质量比为75∶25时,纤维形貌最佳;随着MWCNTs的增加,纤维直径呈下降趋势,当MWCNTs含量达到3.0wt%时,纤维中出现串珠,透射电镜结果表明PVA/PEI对MWCNTs具有良好的包裹作用,纳米纤维直径在100nm左右,以酮洛芬为模型药物,制备载药纤维膜并在模拟肠液中考察其体外释放行为。     

Electrospun single-walled carbon nanotube/polyvinyl alcohol composite nanofibers: structure-property relationships

Polyvinyl alcohol (PVA) nanofibers and single-walled carbon nanotube (SWNT)/PVA composite nanofibers have been produced by electrospinning. An apparent increase in the PVA crystallinity with a concomitant change in its main crystalline phase and a reduction in the crystalline domain size were observed in the SWNT/PVA composite nanofibers, indicating the occurrence of a SWNT-induced nucleation crystallization of the PVA phase. Both the pure PVA and SWNT/PVA composite nanofibers were subjected to the following post-electrospinning treatments: (i) soaking in methanol to increase the PVA crystallinity, and (ii) cross-linking with glutaric dialdehyde to control the PVA morphology. Effects of the PVA morphology on the tensile properties of the resultant electrospun nanofibers were examined. Dynamic mechanical thermal analyses of both pure PVA and SWNT/PVA composite electrospun nanofibers indicated that SWNT-polymer interaction facilitated the formation of crystalline domains, which can be further enhanced by soaking the nanofiber in methanol and/or cross-linking the polymer with glutaric dialdehyde.     

LaOCl nanofibers derived from electrospun PVA/Lanthanum chloride composite fibers

Electrospun nanofibers of poly (vinyl alcohol) (PVA)/Lanthanum (Ш) chloride (LaCl₃) composite were employed to prepare the LaOCl nanofibers by calcination. TG-DSC was used to investigate the thermal property of precursor, while FT-IR, XRD, FESEM and TPD were employed to characterize the derived LaOCl nanofibers. Results indicate that the addition of LaCl₃ leads to the formation of fork segments in the structure of electrospun PVA/LaCl₃ composite nanofibers, therefore, changing the decomposition behavior of the fibers. Pure LaOCl fibers with a diameter range of 90-220 nm can be obtained by calcination of electrospun PVA/LaCl₃ composite nanofibers at 700 °C for 7 h. The resultant LaOCl nanofibers show a good sensing behavior for CO₂ gas.     

动态线性电极静电纺PVA纳米纤维的可纺性

为了解决传统针式静电纺针头易堵塞不易产业化的问题,采用铜丝动态线性电极静电纺丝技术对PVA纳米纤维的可纺性进行研究。利用扫描电子显微镜研究了PVA溶液浓度、电压和纺丝距离对PVA纤维形貌及直径分布的影响。结果表明:随PVA溶液浓度降低,溶液粘度和电导率减小,纤维直径及其分布变小。且随纺丝距离增大,纤维直径变细,纤维形貌变好。当PVA浓度为10%(质量分数),电压80 kV,距离30 cm时,可制备出形貌良好的纳米纤维,其直径为433 nm,产量高达 6.8 g/h ;当PVA浓度为5%(质量分数),电压80 kV,距离30 cm, 可纺最细纤维直径为96 nm。本研究可为未来PVA静电纺纳米纤维膜的规模化制备提供参考。     

壳聚糖/聚氧乙烯复合纺丝液性能对静电纺丝的影响

为了研究壳聚糖/聚氧乙烯复合纺丝液性能对静电纺丝的影响,利用质量分数为3％的壳聚糖(CS)与聚氧乙烯(PEO)以不同的质量比溶解在浓度为50％的冰乙酸水溶液中制备了CS/PEO复合纺丝液,采用静电纺丝技术制备了CS/PEO复合纳米纤维.用扫描电子显微镜(SEM)对制备出的CS/PEO复合纳米纤维进行表征,并测试了CS/PEO复合纺丝液的溶液性能.从复合纺丝液性能对静电纺纤维成型的影响机理角度对实验结果进行了分析.分析结果表明,在其他静电纺丝参数一定时,纺丝液黏度影响射流的稳定性,从而影响纤维的形貌和直径.只要纺丝液电导率在合适的范围内,对静电纺的影响不大.从泰勒的临界公式中得出了纺丝液临界电压与纺丝液表面张力最佳值的一一对应关系,并与本实验中的实验数据相吻合.     

Structure and properties of novel electrospun tussah silk fibroin/poly(lactic acid) composite nanofibers

The tussah silk fibroin (TSF)/poly(lactic acid) (PLA) composite nanofibers with different composition ratios were prepared by electrospinning with 1,1,1,3,3,3-Hexafluoro-2-propanol as the solvent. The morphology and secondary structure of the fibers were characterized by Scanning electronic microscope, Fourier transform infrared (FTIR), and X-ray diffraction (XRD). The thermal and mechanical tests were also performed. The spinnability of TSF solution was improved significantly through adding 10% PLA, and the average diameter of the fibers decreased from 583 nm to 178 nm with an obvious improvement in fiber diameter uniformity. In addition, the mechanical properties of electrospun nanofibers increased evidently after blending 10% PLA, whereas the thermal properties kept stable. FTIR and XRD analysis indicated the addition of 5% PLA could induce a conformation transformation of TSF from random coil and α-helix to β-sheet, however, when PLA content was more than 10%, the β-sheet structure of TSF in composite nanofibers decreased, and the phase separation of two compositions occurred. Therefore, when PLA content exceeded 15%, the average diameters of TSF/PLA composite nanofibers increased and appeared to be polarized, moreover, the mechanical properties of the fibers decreased with the increase of PLA content, and the fibers displayed the mechanical behavior of PLA component more.     

Electrospun polyvinyl alcohol/chitosan composite nanofibers involving Au nanoparticles and their in vitro release properties

Au nanoparticles (Au NPs) containing polyvinyl alcohol (PVA)/chitosan (CS) composite nanofibers were successfully prepared by a simple and effective method called electrospinning. Au NPs were firstly synthesized under a mild condition with CS as the reducing agent and stabilizer, followed by being mixed with PVA solution and then the resulting fibers were fabricated. The research indicated that Au NPs were indeed doped into the as-prepared fibers and the composite fibers well preserved Au NPs' unique optical characteristics. Additionally, with the adjustment of the weight ratios between PVA and CS, the diameter distribution and the morphology of the nanofibers were largely changed. In vitro drug release experiments demonstrated that the drug release rate can be conveniently controlled by changing the crosslink time.     

PEG/PVA相变复合纳米纤维的制备及其性能研究

在室温下制得了PEG/PVA相变复合纳米纤维。探讨了PVA/PEG和PEG2000/PEG4000各自不同质量分数、外加电压、接收距离、外加盐离子等参数对纤维直径和纤维网形态的影响。结果表明PEG/PVA为60/40,电压为15kV,接受距离为10cm时,成纤较好。运用DSC测试复合纳米纤维的可逆相转变特性,Tm和TC值与PEG2000/PEG4000的比例有关。     

Synthesis and characterization of nanofiber webs of chitosan/poly(vinyl alcohol) blends incorporated with silver nanoparticles

Nanofiber webs of chitosan (CS)/poly(vinyl alcohol) (PVA) blends incorporated with silver nanoparticles (AgNs) were fabricated by two different methods: a refluxing method and an annealing method. We found that the characterization and antibacterial activity of AgNs depended on not only the fabrication methods but also the weight ratio of CS and PVA in the CS/PVA blend. The change in the size and number of AgNs due to the interaction between AgNs and CS, in turn, affected the antibacterial property of the non-woven webs. Non-woven webs of CS/PVA nanofibers containing AgNs that were fabricated by the refluxing method showed higher antibacterial ability against Escherichia coli than did the other types of non-woven webs. The morphology of the electrospun non-woven webs was observed by field emission scanning electron microscopy. The characterization of AgN formation on the surface of electrospun fibers was examined by transmission electron microscopy, attenuated total reflectance-Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy.     

Hyaluronic Acid‐Functionalized Electrospun Polyvinyl Alcohol/Polyethyleneimine Nanofibers for Cancer Cell Capture Applications

Capturing circulating tumor cells (CTCs) with sufficient sensitivity and specificity in vitro is of paramount importance for early cancer diagnosis. Here a facile approach to immobilizing hyaluronic acid (HA) onto electrospun polyvinyl alcohol/polyethyleneimine (PVA/PEI) nanofibers for capturing cancer cells overexpressing CD44 receptors is reported. In this study, electrospun PVA/PEI nanofibers were crosslinked using glutaraldehyde vapor, covalently conjugated with HA via N‐(3‐dimethy‐laminopropyl)‐N′‐ethylcarbodiimide/N‐hydroxysuccinimide coupling reaction, followed by neutralization of the remaining fiber surface PEI amines via acetylation. The formed nanofibers were characterized using different techniques. It is shown that the HA‐modified PVA/PEI nanofibers with a mean diameter of 459.7 nm possess a smooth and uniform fibrous morphology, similar to the PVA/PEI nanofibers without HA modification. The HA‐modified PVA/PEI nanofibers display good cytocompatibility and hemocompatibility as confirmed by cell viability, hemolysis, and anticoagulant assays. Importantly, with the modified HA, the nanofibers exhibit superior capability to capture CD44 receptor‐overexpressing cancer cells. The developed HA‐modified PVA/PEI nanofibers may hold a great promise to be applied for capturing CTCs for cancer diagnosis applications.     

Bacterial cellulose nanocrystals-embedded silk nanofibers

Nanofibrous Bacterial cellulose nanocrystals (BCNs)-embedded silk fibroin were successfully fabricated using electrospinning. The morphology, structure and mechanical properties of the silk fibroin nanofibers were investigated at various BCNs concentrations from 0 to 7 wt%. SEM, TEM and XRD analyses were conducted to confirm the incorporation of the BCNs in the electrospun silk fibroin nanofibers. The average diameter of the silk fibroin/BCNs nanofibers increased from 230 to 430 nm according to the increasing of the BCNs ratio due to the rising solute content. The FT-IR spectra confirmed the conformational transition of the silk fibroin, from a random coil to a beta-sheet structure, which shows the enhanced mechanical properties of silk fibroin based nanofibers even with small amounts of the BCNs. Moreover, it was observed that the Young's modulus of the silk fibroin/BCNs nanofibers unexpectedly increased with the formation of BCNs with a percolation structure at a concentration between 3 and 5 wt%.