恩诺沙星分子印迹纳米纤维膜的制备及性能

通过沉淀聚合法制备了恩诺沙星（ENRO）分子印迹聚合物（MIPs）微球,将其添加到聚乙烯醇（PVA）溶液中,采用静电纺丝技术制备了恩诺沙星分子印迹纳米纤维膜（MINFMs）. 利用扫描电子显微镜（SEM）研究了纺丝液浓度、纺丝电压及接收距离对MINFMs纤维直径及表面形貌的影响,从溶胀性、孔隙率、吸附容量及吸附选择性等几个方面对印迹膜的性能进行了评价. 结果表明,在环境温度25 ℃、相对湿度 40%~50%、MIPs加入量8%（质量分数）、PVA质量分数7%、纺丝电压15 kV和接收距离25 cm的条件下,得到的MINFMs的纤维形态良好,纤维平均直径为180 nm. MINFMs的溶胀度和孔隙率分别为136.76%和33.42%,均大于非印迹纳米纤维膜（NINFMs）. 动力学吸附性能结果显示,MINFMs在300 min后吸附基本达到平衡,且明显高于NINFMs的吸附量;Scatchard分析结果表明,在所研究的浓度范围内MINFMs对模板ENRO的结合位点是等价的,其离解平衡常数（K_d）与最大表观结合量（Q_max）分别为505.817 mg/L和3.862 mg/g. 与环丙沙星（CIP）和氧氟沙星（OFL）相比,MINFMs对ENRO表现出更强的特异性吸附能力.     

双酚A分子印迹聚醚砜纳米纤维膜的制备和识别性能的研究

采用静电纺丝技术制备双酚A分子印迹聚醚砜纳米纤维膜.利用聚醚砜功能基与模板分子的相互作用形成结合位,其结构在纺丝过程中被固定下来,模板分子去除后聚醚砜纳米纤维膜上就留下能选择性结合目标分子的结合位.研究了模板分子加入量、静电纺丝电压和溶剂等纺丝条件对纳米纤维膜印迹效果的影响.识别实验表明,10％双酚A的聚醚砜印迹纳米纤...     

磁场辅助静电纺有序聚丙烯腈纳米纤维的研究

磁场辅助静电纺丝方法能够制备有序纳米纤维,但是其参数之间的匹配关系很少被研究。本文通过正交实验,对影响磁场辅助静电纺丝制备聚丙烯腈纳米纤维的四个工艺参数(溶液浓度、磁铁间距、纺丝电压和注射速度)在3个水平上进行优化筛选。以纤维直径大小、均匀度和纤维有序度为考察目标,同时考虑溶液浓度、磁铁间距与纺丝电压这三个因素之间的两两交互作用,结合极差分析、方差分析,发现溶液浓度是影响纤维直径和均匀度的高度显著因素,溶液浓度和纺丝电压的交互作用对直径均匀度有显著影响,纺丝电压是影响纤维有序度的显著因素。     

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.     

静电纺丝方法制备a2-K8 P2W17 MnO61纳米纤维

运用高压静电纺丝和程序升温焙烧的方法制备了a2-K8P2W17MnO61纳米纤维．通过红外光谱（FT-IR）和X射线粉末衍射（XRD）对纤维进行了表征．结果表明，制备的纳米纤维为纯杂多酸盐a2—K8P2W17MnO61,扫描电子显微镜（SEM）图形显示焙烧后获得纳米纤维的平均直径大约为140nm。     

静电纺丝法和气流-静电纺丝法制备聚砜纳米纤维

应用电纺法制备了聚砜纳米纤维.设计了一种新型的气流静电纺丝装置,其特点是在喷丝头上添加了喷气组件.电纺过程中所用聚砜的特性粘数为0.97dLg,溶剂为二甲基乙酰胺,载气为氮气.研究了聚砜纳米纤维的平均直径与过程参数之间的关系.研究表明影响聚砜纳米纤维的平均直径的主要因素为电压、纺丝液的流速、喷丝头与收集器之间的距离、操作温度以及纺丝液的性质(如粘度、表面张力和电导率).纳米纤维的平均直径和直径分布用扫描电镜表征.应用这种气流静电纺丝法制备的纳米纤维的直径范围是50～500nm.所得纳米纤维的直径依赖于电压、喷丝头与收集器之间的距离以及喷丝液的浓度.结果表明,采用气流静电纺丝不仅能制备较细而且均匀的纳米纤维,而且产量更高.     

同轴静电纺丝法在纳米中空TiO2纤维中填充Ag的应用

以聚乙烯吡咯烷酮（PVP）溶胶/钛酸四正丁酯和PVP溶胶/银颗粒为前驱体,以共轴静电纺丝法制备了银填充的TiO2中空纳米纤维.将双组分纤维在200℃下热处理去除乙醇与表面吸附水后,继而在空气气氛中焙烧至600℃,可以得到在内表面上沉积银颗粒的TiO2纳米管,银颗粒的直径为5-40nm,TiO2纳米管的外径150-300nm,管臂厚10-20nm.用红外吸收光谱（IR）、X射线衍射（XRD）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）等测试手段对超细纤维进行了表征.中空纤维的直径和管壁可以通过改变电纺参数来调节.与Ag-TiO2纳米纤维、TiO2纳米中空纤维、TiO2纳米纤维及TiO2纳米粉体相比较,Ag颗粒填充的TiO2纳米中空纤维在光分解亚甲基蓝上表现出了更好的光催化性能.     

静电纺聚丙烯腈纳米纤维晶态结构及取向的形成

采用新型流动水浴收集方式制备出连续单向排列的静电纺聚丙烯腈(PAN)纳米初生纤维,收集静电纺丝不同阶段的静电纺PAN纳米纤维,并在热水中进行后牵伸,使其伸长至原长的2倍、3倍.通过扫描电子显微镜(SEM)、广角X射线衍射(WAXD)等方法对静电纺丝过程不同阶段的PAN纳米纤维的形貌、直径、致密性、晶态结构及取向进行了表征.研究表明,(1)在静电纺丝过程中PAN纺丝液射流受到牵伸作用,静电纺PAN纳米纤维的晶态结构形成并逐渐完善.纳米纤维的直径随着静电纺丝过程逐渐减小(从664 nm减小至353 nm),结晶度从42.55％增加至47.76％,晶区取向由37.48％提高至43.93％.纳米纤维致密性也逐渐提高(密度由1.1917 g/cm3增加至1.1943 g/cm3).(2)静电纺丝过程进入PAN射流溶剂含量较低的阶段后,继续通过静电纺丝过程提高纳米初生纤维晶态结构及取向的效果很有限,而通过热水后牵伸过程可进一步使晶态结构及取向得到有效果的完善.研究同时发现,静电纺初生纤维的晶态结构及取向与其在热水牵伸过程中的进一步完善具有相关性.     

聚丙烯腈纳米纤维的高效制备及结晶取向性能

分别采用传统静电纺丝装置和自行搭建的离心-静电纺丝装置制备出聚丙烯腈(PAN)纳米初生纤维,并在热空气浴中和一定外力作用下进行牵伸,牵伸后使其伸长至原长的1倍到3倍.通过广角X射线衍射(WAXD)、扫描电子显微镜(SEM)等方法对2种纺丝方法制备的PAN纳米初生纤维及经过热空气浴牵伸后的PAN纳米纤维的晶态结构、取向及形貌等进行了表征.研究表明:(1)离心-静电纺丝效率远高于静电纺丝,可达静电纺丝的120倍(离心-静电纺丝纺丝液流速为2 m L/min,静电纺丝纺丝液流速1 m L/h);(2)无论是离心纺丝还是静电纺丝制得的纳米初生纤维结晶度均很低(离心纺丝为25%,静电纺丝为10.1%),但离心纺丝制得的纳米初生纤维有一定的取向(60.5%),而静电纺丝基本没有;(3)经过热空气浴牵伸后,2种纺丝方式制得的纳米纤维结晶度均有所提高(分别为45.8%和36.2%),取向度也有所提高(分别为72.5%和59.8%),随着牵伸温度的提高和牵伸应力的增大,纤维的平均直径不断减小(离心纺丝由675 nm降至510 nm,静电纺丝由460 nm降至355 nm).纳米纤维在制备过程晶态结构及取向的效果有限,但通过热空气浴牵伸可以使晶态结构及取向得到进一步完善.     

Li0.5-0.5xZnxFe2.5-0.5xO4纳米纤维的电纺制备及其结构和磁性能

以聚乙烯吡咯烷酮、硝酸锂、硝酸锌和硝酸铁为主要原料,通过静电纺丝技术结合后期的热处理制备了直径在50～100 nm的单相Li0.5-0.5xZnxFe2.5-0.5xO4（x=0.0,0.2,0.3,0.4,0.5,0.8）纳米纤维.利用热重-差热分析、X射线衍射、场发射扫描电子显微镜、透射电子显微镜和振动样品磁强计研...     

Voltage effect on color,optical, and surface properties of fibers of PS/PES blends

Fibers of polystyrene (PS)/polyethersulfone (PES) blend were prepared with different concentrations under variant voltages. By increasing the voltage, a decrease in the fiber diameter and a gradual disappearance of the beads were determined by optical microscopy and scan electron microscopy whereas the roughness was increased as proved by atomic force microscopy. This study succeeded in detecting colored fiber of PS and PS/PES blend, under white light illumination, with different angles of incidence without utilizing any colorants whereas, PES had no color. Blending PES with PS as well as increasing the applied voltage has increased the fiber hydrophobicity.     

Characterization of gelatin nanofibers electrospun using ethanol/formic acid/water as a solvent

Gelatin nanofibers were prepared via electrospinning using aqueous solutions of formic acid and ethanol as the solvent instead of cytotoxic solvents. The resulting mat was further crosslinked with glutaraldehyde (GTA). The influence of the storing time on the viscosity and gel point of the solution was investigated. The gelatin nanofibers were examined using a field emission scanning electron microscope (FESEM) for the fiber size and morphology. The lowest diameter of gelatin fiber (85 nm, without beads) was achieved when the gelatin concentration was 20 wt% and electrospinning was conducted with a voltage of 20 kV over a distance of 10 cm at ambient temperature. The results from differential scanning calorimetry (DSC) showed that the softening temperature of gelatin nanofibers crosslinked with GTA was elevated. In addition, GTA‐crosslinked gelatin nanofibers exhibited cell compatibility for mouse mesangial cells (CRL 1927). Copyright © 2008 John Wiley & Sons, Ltd.     

静电纺丝法制备LaFeO3微纳米纤维

采用静电纺丝技术并结合溶胶-凝胶方法制备了LaFeO3微纳米纤维. 用差热-热重分析(TG-DTA)、X射线衍射(XRD)、红外光谱(FTIR)、X射线光电子能谱和场发射扫描电镜(FE-SEM)对样品进行了表征. 实验结果表明, 390 ℃时钙钛矿结构的LaFeO3晶体开始形成, 同时伴有少量微弱的La2O2CO3和Fe2O3杂相存在, 600 ℃煅烧获得正交钙钛矿结构的LaFeO3微纳米纤维, 其纤维直径分布在300~600 nm之间, 其平均直径约为420 nm, 平均晶粒尺寸为28 nm.     

Surface-guided self-assembly of silver nanoparticles on edges of heterogeneous surfaces

A general method for the generation of two-dimensional (2D) ordered silver nanoparticles (av 45 nm) ring array has been demonstrated via controllable self-assembly. The selective self-assembly is conducted on the edges of a gold coated polyelectrolyte film. This film is fabricated using the monolayer polystyrene (PS) spheres (av 600 nm) on a substrate as template, followed by depositing a positively charged polyelectrolyte and gold colloids (av 17 nm) via the layer-by-layer (LbL) self-assembly technique, and finally by eliminating the PS monolayer. This gold coated polyelectrolyte film has a regular pattern of sharp edges, and those edges are composed of abundant polyelectrolyte. This heterogeneous surface is easily prepared and universal for site-selective absorption of nanoparticles (silver nanoparticles in this paper, av 45 nm). This surface-guided self-assembly is powerful for fabricating micro/nanostructures on the edges of prepatterns. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the products.     

Synthesis of polystyrene/poly[2-(dimethylamino)ethyl methacrylate-stat-ethylene glycol dimethacrylate] core-shell latex particles by seeded emulsion polymerization and their application as stimulus-responsive particulate emulsifiers for oil-in-water emulsions

Surfactant-stabilized polystyrene (PS) latex particles with a mean hydrodynamic diameter of 155 nm were prepared by aqueous emulsion polymerization using 2,2'-azobis(2-amidinopropane) hydrochloride as a cationic radical initiator. Seeded aqueous emulsion copolymerizations of 2-(dimethylamino)ethyl methacrylate (DMA) and ethylene glycol dimethacrylate (EGDMA) were conducted in the presence of these PS particles to produce two batches of colloidally stable core-shell latex particles, in which the shell comprised a cross-linked P(DMA-stat-EGDMA) overlayer. Both the PS and PS/P(DMA-stat-EGDMA) latexes were characterized in terms of their particle size, morphology, and composition using dynamic light scattering, electron microscopy, and FT-IR spectroscopy, respectively. Using the PS/P(DMA-stat-EGDMA) latex particles as a pH-responsive particulate ('Pickering'-type) emulsifier, polydisperse n-dodecane-in-water emulsions were prepared at pH 8 that could be partially broken (demulsified) on lowering the solution pH to 3. These emulsions were characterized in terms of their emulsion type, mean droplet diameter, and morphology using electrical conductivity and Mastersizer measurements, optical microscopy, and scanning electron microscopy (using critical point drying for sample preparation).     

Using collagen fiber as a template to synthesize hierarchical mesoporous alumina fiber

Hierarchical mesoporous alumina fiber was synthesized by using collagen fiber as the template, and characterized by means of scanning electron microscopy, transmission electron microscopy, N2 adsorption techniques, X-ray photoelectron spectroscopy, and X-ray diffraction. The alumina fiber obtained is approximately 1-4 microm in outer diameter and 0.5-1 mm in length. The pore size distribution of the alumina fiber is narrow (2-20 nm), and its pore size is controllable by varying preparation methods. This study indicates that collagen fiber, which has hierarchical supermolecular structure, could be used as an ideal template to prepare well-defined porous metal oxide fibers.     

Crosslinked Polymeric Nanocapsules Via Surface-initiated Atom Transfer Radical Polymerization from SiO2 Nano-templates

The aim of the present work was to develop the crosslinked polymeric nanocapsules for drug delivery from the SiO₂ nano-templates via surface-initiated atom transfer radical polymerization (SI-ATRP) technique. The crosslinked polymeric nanocapsules were fabricated via the SI-ATRP of 2-hydroxyethyl acrylate (HEA) from initiator modified silica nano-templates. After the hydroxyl side-groups of the polymer grafted silica nanoparticles (SN@PHEA) were crosslinked with hexamethylene diisocyanate (HDI), the silica templates encapsulated in the crosslinked polymer shells were removed by being etched with HF to produce the crosslinked polymeric nanocapsules. The diameter of the polymeric nanocapsules is in the range of 20–40 nm, characterized by transmission electron microscopy (TEM).     

Gold 3D Brush Nanoelectrode Ensembles with Enlarged Active Area for the Direct Voltammetry of Daunorubicin

3D gold brush nanoelectrode ensembles (BNEEs) consisted of gold nanowires 100 nm in diameter and 300 nm in length were fabricated by combining the technologies of template synthesis and controlled chemical etching of the membrane. The structure and morphology of the BNEEs was imaged by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The real active areas of BNEEs were found to be different when characterized by different redox species. The direct redox of daunorubicin (DNR) at the gold BNEEs exhibited absorption‐controlled characteristics and high current activity. BNEEs are reliable and effective in DNR detection.     

Facile Route Using Highly Arrayed PMMA Spheres as Hard Template for the Fabrication of 3D Ordered Nanoporous MgO

"Using magnesium nitrate as Mg source and regularly packed polymethyl methacrylate (PMMA) spheres were synthesized via a combined strategy of emulsifier-free emulsion polymerization and water floating technique as hard template, we fabricated ordered nanoporous magnesium oxide. The synthesized PMMA and MgO samples were characterized by N2 adsorption-desorption, X-ray diffraction, high-resolution scanning electron microscopy, transmission electron microscopy, and selected area electron diffraction. It was observed that the synthesized PMMA spheres possessed a uniform diameter of approximately 284 nm and were in a highly ordered array, and the MgO generated by using the PMMA-templating method exhibited polycrystallinity with three-dimensionally ordered pores. BET surface area of the synthesized MgO sample is 100.7 m2/g, pore volume is 0.46 cm3/g, wall thickness is 4-24 nm, and pore sizes are in the range of 10-120 nm. Such a 3D high-surface-area nanoporous strongly basic MgO is useful in the applications of catalyst supports and acidic gas adsorbents."