静电纺丝法制备超细聚苯乙烯纳米纤维

采用静电纺丝方法制备了超细聚苯乙烯纤维, 通过向溶液中添加有机胺盐并降低溶液浓度将纤维的平均直径降至100 nm, 并研究了盐的添加量对纤维直径的影响.     

聚丙烯腈纳米纤维的再细化

通过电纺丝法研究了溶剂种类、溶液浓度、纺丝倾斜角、聚合物分子量对纳米纤维形态和直径的影响,寻找到最佳工艺条件,并得到了平均直径为20nm的超细纤维.     

基于荧光素的荧光纳米纤维的制备与表征

以电纺聚丙烯腈(PAN)纳米纤维为起始物,经乙二胺改性后,再利用Mannich反应将荧光素共价连接于PAN纳米纤维薄膜表面.用荧光光谱、扫描电镜和红外光谱进行了结构表征.结果表明,利用荧光素对静电纺丝薄膜表面进行修饰,获得了很强的荧光信号,证明了方法的可行性.     

静电纺丝法制备NiO纳米纤维及其表征

纳米级NiO因具有优良的催化和热敏等性能而被广泛用于催化剂^[1]、电池电极^[2,3]、光电转化材料^[4～6]、电化学电容器^[7～8]等诸多方面.迄今,已成功地制备出N iO的纳米颗粒^[9]、纳米线^[10]及纳米薄膜^[11],但是对于具有准一维结构的NiO纳米纤维的制备及性能研究尚未见报道.     

静电纺丝法制备抑菌性聚酰亚胺纳米纤维

采用静电纺丝技术,以联苯四甲酸二酐(BPDA)和4,4'-二氨基二苯醚(ODA)为单体,硝酸银为银源,通过两步法制备含银聚酰亚胺(PI/Ag)纳米纤维.通过X射线衍射(XRD)、透射电子显微镜(TEM)及扫描电子显微镜(SEM)表征了PI/Ag纳米纤维的结构和微观形貌;通过浸渍培养法研究了聚酰亚胺(PI)及PI/Ag纳米纤维的抑菌性能.结果表明,聚酰亚胺基体中存在单质银的立方晶体结构,银粒子在聚酰亚胺基体表面均匀分散,平均粒径为10 nm;PI/Ag纳米纤维对大肠杆菌(E.coli)、金黄色葡萄球菌(S.aureus)和枯草芽孢杆菌(B.subtilis)表现出良好的抑菌效果,最大抑菌率可达99.1%,为聚酰亚胺在耐高温抑菌生物医用材料等领域的应用提供了新的方向.     

聚丙烯腈/氧化石墨烯复合纳米纤维的制备与性能研究

以氧化石墨烯为添加物,采用静电纺丝的方法制备不同质量分数的聚丙烯腈/氧化石墨烯(PAN/GO)复合纳米纤维。使用扫描电镜(SEM)、透射电镜(TEM)对复合纳米纤维的微观结构进行观察;采用差示扫描量热仪(DSC)和热重分析仪(TGA)研究复合纳米纤维的热学性能随着氧化石墨烯添加量增加的变化;采用微机控制电子万能试验机对复合纳米纤维的力学性能进行研究。结果表明,加入氧化石墨烯后,纺制的PAN/GO纳米复合纤维会变细,但随着GO添加量的增多出现珠节现象,降低了纤维的粗细均匀度,同时加入GO后对PAN的氧化具有一定的抑制作用,而且GO的加入也使PAN的力学性能增加,当加入量为0.1%时断裂强力增加了一倍,但添加量为1%时,断裂强力又会降低,综合实验结果显示当加入氧化石墨烯的质量分数为0.1%时最适宜。     

High strength electrospun polymer nanofibers made from BPDA-PDA polyimide

A series of high molecular weight PI precursors, poly(p-phenylene biphenyltetracarboxamide acid), were synthesized from 3,4,3′,4′-biphenyltetracarboxylic dianhydride (BPDA) and p-phenylenediamine (PDA) by using intense mechanical stirring at −15 to 0 °C for 48-72 h. The as-synthesized PI precursor solution was used to make BPDA/PDA polyimide thin films and electrospun nanofibers. IR, Ostward Viscometer, CMT-8102 Electromechanical Universal Testing Machine and scanning electron microscope (SEM) were used for the characterizations of the as-synthesized PI precursor, PI films and nanofiber sheets. The high molecular weight BPDA/PDA PI thin films and electrospun nanofiber sheets possess excellent mechanical properties of up to 900 MPa tensile strength with up to 18.0 GPa E-modulus and up to 210 MPa tensile strength with up to 2.5 GPa E-modulus, respectively.     

Stabilization of electrospun poly(vinyl alcohol) nanofibrous mats in aqueous solutions

<正>The stability ofpoly(vinyl alcohol)(PVA) nanofibrous mats in water media was improved by post-electrospinning treatments.Bifunctional glutaraldehyde(GA) in methanol was used as a crosslinking agent to stabilize PVA nanofiber,but fiber twinning was observed frequently,and the highly porous structure of PVA nanofibrous mats was destroyed when the crosslinked fiber was soaked in water.To overcome this shortcoming,chitosan(CS) was introduced into the PVA spinning solution to prepare PVA/CS composite nanofibers.Their treatment in GA/methanol solution could retain the fiber morphology of PVA/CS nanofibers and porous structure of PVA/CS nanofibrous mats even if they were soaked in aqueous solutions for 1 month.Scanning electron microscopy(SEM),X-ray diffraction(XRD),thermal gravimetric analysis(TGA) and differential scanning calorimetry(DSC) were applied to characterize the physicochemical structure and thermal properties of PVA nanofibers.It was found that the water resistance of PVA nanofibrous mats was enhanced because of the improvement of the degree of crosslinking and crystallinity in the electrospun PVA fibers after soaking in GA/methanol solution.     

静电纺丝——从无规纳米纤维膜到取向连续长纱

静电纺丝是通过对聚合物溶液或熔体施加外电场制造纳米纤维的有效方法.电纺过程中,在静电力作用下聚合物射流快速鞭动,形成的纳米纤维无规堆砌,得到无纺布状的无规纳米纤维膜.这种纳米纤维膜具有极大的比表面积,已用于超高效过滤,在刨伤修复、组织工程、水处理等领域有广泛的应用前景.为了进一步拓展纳米纤维在纤维工业、纺织品、微制造等领域的应用,电纺纳米纤维的取向和连续长纱的制备研究受到科学家的重视,文献报道了多种纳米纤维取向方法.本文分析了纳米纤维膜无规堆砌结构的形成机理,总结了纳米纤维取向研究和连续长纱制备研究进展,特别介绍了基于静电作用分析提出的共轭电纺方法,讨论了取向纳米纤维的应用以及纳米纤维未来的研究方向.     

Performance of electrospun nanofibers for SPE of drugs from aqueous solutions

A novel extraction technique was reported. The solid phase material, nanofiber, was prepared by electrospinning using polystyrene. Twenty different drugs (10 microg/L in water) were extracted using 1 mg of nanofibers within 5 min. The analytes can be desorpted from the fibers with 50 microL of the methanol and then monitored by LC coupled to a UV detector. Packed-fiber SPE (PFSPE) provide high recoveries (>50%) for some relatively non-polar drugs (log P >1.5) (n-octanol-to-water partition ratio), and relatively low recoveries (9.9-39.8%) for the drugs within the log P window below 1. Experimental optimization of the technique has been carried out using seven representative drugs, edaravone, cinchonine, quinine, voriconazole, chlordiazepoxide, verapamil, and rutonding. Except for edaravone, the maximum yields of seven drugs (0.2 microg/L) from water samples were approximately 100%, and were 33.7-88.2% from human plasma. The advantageous aspect of the technique encompasses high throughput, high sensitivity, simplicity, low cost, and green chemistry.     

Preparation and characterization of crosslinked chitosan-based nanofibers

Crosslinked chitosan-based nanofibers were successfully prepared via electrospinning technique with heat mediated chemical crosslinking followed.The structure,morphology and mechanical property of nanofibers were characterized by attenuated total reflection-Fourier transform infrared spectroscopy(ATR-FTIR),scanning electron microscopy(SEM),Instron machine,respec- tively.The results showed that,nanofibers exhibited a smooth surface and regular morphology,and tensile strength of nanofibers improved with increasing of triethylene glycol dimethacrylate(TEGDMA)content.     

Transferring CdTe Nanoparticles from Liquid Phase to Polyvinylpyrrolidone Nanofibers by Electrospinning and Detecting Its Photoluminescence Property

The major aim of this work was to synthesize thio-stabilized CdTe nanoparticles(NPs) in an aqueous solution,which was then enwrapped with cetyltrimethylammonium bromide(CTAB),and finally transferred to the polyvinylpyrrolidone(PVP) matrix by electrospinning,The PVP nanofibers containing CdTe NPs were characterized by scanning electron microscopy(SEM) and transmission electron microscopy(TEM),to observe the morphology of the nanofibers and the distribution of CdTe NPs,The selective area electronic diffraction(SAED) pattern verified that CdTe NPs were cubic lattice,The photoluminescence(PL) spectrum indicated that CdTe NPs existed in an optical style in PVP nanofibers,Moreover,X-ray photoelectron spectra(XPS) revealed that thiol-stabilized CdTe NPs were enwrapped by CTAB,and PVP acted as a dispersant in the process of electrospinning.     

Transferring CdTe Nanoparticles from Liquid Phase to Polyvinylpyrrolidone Nanofibers by Electrospinning and Detecting Its Photoluminesccnce Property

The major aim of this work was to synthesize thio-stabilized CdTe nanoparticles（NPs） in an aqueous solution, which was then enwrapped with cetyltrimethylammonium bromide（CTAB）, and finally transferred to the polyvinylpyrrolidone（PVP） matrix by electrospinning. The PVP nanofibers containing CdTe NPs were characterized by scanning electron microscopy（SEM） and transmission electron microscopy（TEM）, to observe the morphology of the nanofibers and the distribution of CdTe NPs. The selective area electronic diffraction（SAED） pattern verified that CdTe NPs were cubic lattice. The photoluminescence（PL） spectrum indicated that CdTe NPs existed in an optical style in PVP nanofibers. Moreover, X-ray photoelectron spectra（XPS） revealed that thiol-stabilized CdTe NPs were enwrapped by CTAB, and PVP acted as a dispersant in the process of electrospinning.     

A Synergistic Strategy for Nanoparticle/Nanofiber Composites Towards p-Nitrophenol Catalytic Hydrogenation

Nanoparticle(NP)/nanofiber(NF) composites based on Ag/hydrostable-polyvinyl alcohol were fabricated by a green synergistic strategy via electrospinning. The electrospun NFs served as an in situ reducing agent for the metal salt precursors and a protecting agent for the resulting NPs. Additionallly, during the fomation of the NPs, the water-soluble NFs were in situ oxidized and catalyzed by the metal ions to achieve chemical crosslinking. This two-in-one process achieves polymer curing and metal nanoparticles reducing/protecting synergistically. It eliminates the usage of organic electrospinning solvents, conventional chemical reducing agents and stabilizers, as well as harmful chemical crosslinking agents during the whole process. By the absolutely green synergistic electrospinning, nanoparticle/nanofiber composites with super-hydrophilicity, good hydrostability, as well as uniform and thin particle sizes were obtained. They exhibited enhanced activities when used for catalytic hydrogenation of p-nitrophenol in water.     

PVA/GA/β-CD纳米纤维的制备及染料吸附性能

利用静电纺丝技术,以六氟异丙醇(HFIP)和水为溶剂,制备了环糊精(β-CD)含量为70%(质量分数)的聚乙烯醇(PVA)/β-CD纳米纤维,并经戊二醛(GA)交联处理得到了可用于染料吸附的PVA/GA/β-CD纳米纤维.通过红外光谱和扫描电子显微镜研究了交联反应前后纳米纤维组成和形貌的变化;考察了PVA/GA/β-CD纳米纤维对7种水溶性染料的吸附性能.结果表明,PVA/GA/β-CD纳米纤维对孔雀石绿、甲基紫和刚果红的吸附效果较好,最大吸附量分别为124.71,121.14和127.39 mg/g,4次吸附-解吸附循环后,染料去除率仍保持80%左右,在染料废水处理中具有良好的应用前景.     

Organic semiconductors-coated polyacrylonitrile(PAN) electrospun nanofibrous mats for highly sensitive chemosensors via evanescent-wave guiding effect

We report the first use of organic semiconductors（OSCs）-coated PAN nanofibrous mats as highly responsive fluorescence quenching-based chemosensors for 2,4,6-trinitrotoluene（TNT） and H₂O2 detection in vapor phase.Conjugated polymers,poly（triphenylaminealt-biphenylene vinylene）（TPA- PBPV）,and small organic molecules,1 -boronic-ester pyrene and 1,6-bisboron-ester pyrene,were coated onto the nanofibers fabricated by electrospinning.By introducing the nanofibers structure,a 9-fold fluorescence intensity enhancement and a 14-fold sensitivity enhancement were achieved,which could be attributed to its high area-to-volume ratio,excellent gas permeability,and more importantly,the evanescent-wave effect occurred once the diameters of the fibers were small enough.Since the organic semiconductors coated onto the nanofibrous mats could be replaced by other functional materials,the nanofibers-enhanced detection strategies could be extended to more general domains including chemical and environmental detection.