PVA/Au纳米复合纤维的制备及表征

以聚乙烯醇(PVA)为还原剂和保护剂,采用PVA还原氯金酸(HAuCl4)制备纳米金(Au),一步法制备PVA/Au溶液,通过静电纺丝制备了PVA/Au纳米复合纤维.利用紫外可见光谱仪、透明电镜和扫描电镜对PVA/Au纳米复合纤维进行了表征.结果表明:随着HAuCl4浓度的增加,Au纳米粒子的粒径逐渐增大;HAuCl4...     

电纺丝技术制备无机/有机复合纳米纤维的研究进展

静电纺丝法是一种利用聚合物溶液或熔体在强电场中进行喷射纺丝的加工技术,是获得纳米尺寸长纤维的有效方法之一。目前电纺丝技术逐渐转移到无机/有机纳米复合纤维的制备方面。回顾了近年来电纺丝技术制备无机/有机复合纳米纤维的研究进展,包括:半导体纳米粒子/聚合物复合纳米纤维的制备,无机氧化物纳米粒子/聚合物复合纳米纤维的制备以及贵金属纳米粒子/聚合物复合纳米纤维的制备。     

聚乙烯吡咯烷酮/银纳米复合纤维膜的制备及抗菌性

通过液相原位还原法(用乙醇还原硝酸银)获得了合有银纳米粒子的溶胶,从而制得聚乙烯吡咯烷酮(PVP)/银纳米粒子/乙醇纺丝液;再利用静电纺丝技术,得到了含有银纳米粒子的PVP纳米复合纤维膜.利用紫外光谱仪(UV-vis)对溶胶内银纳米粒子进行了表征,运用扫描电子显微镜(SEM)和透射电子显微镜(TEM)对纤维及其内部的纳米粒子的形貌结构和分布进行了表征,并且测试了该样品对大肠埃希菌的抗菌性能.结果表明:利用静电纺丝方法可制取PVP/银纳米粒子复合纤维膜,该膜具有抗菌性.     

蔗糖水解制备金纳米粒子的研究

文章报道了一种工艺简单、条件温和、环境友好的绿色制备金纳米粒子的方法。以蔗糖为还原剂,在水解条件下还原氯金酸制备金纳米粒子。采用紫外-可见吸收光谱(UV-Vis)、透射电子显微镜(TEM)、能谱仪(EDX)对合成的金纳米粒子进行表征。实验系统的考察了水解时间、氯金酸添加量、反应时间等制备条件对纳米粒子光学性能的影响。实验结果表明最佳水解时间为20 min,金纳米粒子的粒径随着氯金酸溶液添加量及反应时间的增加而增大。     

基于普鲁士蓝/聚多巴胺/纳米金纳米粒子构建的电流型免疫传感器

首先制备普鲁士蓝纳米粒子(PB),通过利用多巴胺(DA)自氧化聚合形成聚多巴胺膜(Dopa)的特性,在PB纳米粒子表面包覆成膜,有效增加PB的稳定性,并在氯金酸溶液中原位还原沉积金纳米粒子,利用纳米金固定化甲胎蛋白抗体(anti-AFP),制得灵敏度高和稳定性好的无标记免疫传感器。采用透射电子显微镜(TEM)对纳米粒子进行表征,采用循环伏安法(CV)和交流阻抗法(EIS)考察修饰电极的电化学特性,实验结果表明,PB-Dopa-Au纳米粒子修饰的电极在实验过程中呈现出良好的氧化还原活性,对甲胎蛋白的检测范围为0.02~80 ng/mL检出限为0.01ng/mL。     

聚乙烯吡咯烷酮及鞣酸对纳米金制备的影响

在经典Frens法制备金纳米粒子过程中引入聚乙烯吡咯烷酮(PVP)及鞣酸作为保护剂,制备出金纳米粒子并考察了保护剂用量、反应温度和搅拌速度对制备出的金纳米粒子的影响;在制备好的金纳米粒子表面,通过化学还原方法沉积生长银层。利用UV-Vis分光光度计,透射电子显微镜(TEM)等手段对得到的样品进行表征。结果表明:两种保护剂的存在可提高粒子的稳定性、单分散性、粒径分布均匀且在7 nm~25 nm内可控,重现性好;Au/Ag核壳结构复合粒子在适当的摩尔比范围内粒径可控且均匀稳定。     

纳米粒子/纤维新型功能纤维的制备

以钛酸四丁酯为原料,将制备锐钛矿TiO2纳米无机粒子工艺与纤维化学改性工艺相结合,利用纳米粒子表面的羟基与纤维的活性基团作用而吸附在纤维表面,从而制备出具有光催化抗菌作用的纤维。该纤维织物在较低温度(70℃)下就可制得,结构不受损害,具有广泛的应用前景。     

弹性纳米粒子/纳米TiO2/聚丙烯复合材料的研究

采用专利技术制备了弹性纳米粒子(ENP)／纳米二氧化钛(TiO2)复合材料，并使用这种复合材料改性聚丙烯(PP)，制备了具有较高韧性和较好灭菌性能的PP纳米复合材料。当丁苯ENP的用量为2％，平均粒径为50nm的金红石型TiO2用量为1％时，所研制的PP纳米复合材料的冲击强度可提高30％以上，灭菌率可达60％。     

超声法金纳米粒子的制备及结构表征

文章采用超声膜扩散法以氯金酸为原料,用柠檬酸三钠(TSC)在有保护剂PVP保护的条件下还原制备了金纳米粒子。制得的金纳米粒子溶胶采用X射线衍射(XRD)及透射电子显微镜(TEM)等对得金纳米粒子进行表征。结果表明,在本实验条件下制得的金纳米粒子纯度较高,分散性好,基本呈球形,粒径平均尺寸为20nm。     

Au-Cu复合纳米粒子的制备及其电催化性质

在PEG6000/Vc/HAuCl4体系中,利用Vc还原HAuCl4制备了金纳米粒子,以制备的金纳米粒子为晶种,用水合肼还原硫酸铜制备了Au-Cu复合纳米粒子,并用紫外-可见光谱(Uv-vis)、透射电子显微镜(TEM)、X射线粉末衍射(XRD)、选区电子衍射(SAED)对其进行表征。用循环伏安法研究Au-Cu复合纳米粒子修饰的玻碳电极对H2O2电化学氧化的催化作用,实验结果表明,Au-Cu复合纳米粒子对H2O2电化学氧化具有一定的催化活性。     

Fabrication of Au/PVP nanofiber composites by electrospinning

Gold nanoparticles prepared by trisodium citrate reduction of HAuCl₄ in poly(vinylpyrrolidone) (PVP) ethanol solution were dispersed into PVP nanofibers by electrospinning. The optical property of Au nanoparticles before and after electrospinning was measured by UV‐Vis. The morphology and distribution of gold nanoparticles in PVP nanofibers were observed by transmission electron microscopy (TEM). The influence of the amount of Au added to and the concentration of PVP in electrospinning solution over the morphology of Au/PVP nanofibers were studied. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007     

Fabrication of Chitosan/Silk Fibroin Composite Nanofibers for Wound-dressing Applications

Chitosan, a naturally occurring polysaccharide with abundant resources, has been extensively exploited for various biomedical applications, typically as wound dressings owing to its unique biocompatibility, good biodegradability and excellent antibacterial properties. In this work, composite nanofibrous membranes of chitosan (CS) and silk fibroin (SF) were successfully fabricated by electrospinning. The morphology of electrospun blend nanofibers was observed by scanning electron microscopy (SEM) and the fiber diameters decreased with the increasing percentage of chitosan. Further, the mechanical test illustrated that the addition of silk fibroin enhanced the mechanical properties of CS/SF nanofibers. The antibacterial activities against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) were evaluated by the turbidity measurement method; and results suggest that the antibacterial effect of composite nanofibers varied on the type of bacteria. Furthermore, the biocompatibility of murine fibroblast on as-prepared nanofibrous membranes was investigated by hematoxylin and eosin (H&E) staining and MTT assays in vitro, and the membranes were found to promote the cell attachment and proliferation. These results suggest that as-prepared chitosan/silk fibroin (CS/SF) composite nanofibrous membranes could be a promising candidate for wound healing applications.     

聚乙烯吡咯烷酮/银纳米粒子/β-环糊精复合纳米纤维的制备

采用液相原位还原法,在聚乙烯吡咯烷酮(PVP)/乙醇溶液中加入硝酸银,制得PVP/银纳米粒子/乙醇溶液,然后加入一定量的PVP/氨水溶液,再加入β-环糊精获得复合溶液。通过静电纺复合溶液得到含有银纳米粒子的三组分复合纳米纤维。利用紫外光谱法对溶胶内的银纳米粒子进行了表征,运用扫描电子显微镜对纤维的形貌和结构进行了表征,并以大肠杆菌为细菌模型,测试了样品的抗菌性能。     

Electrospinning of chitosan/poly(vinyl alcohol)/acrylic acid aqueous solutions

Chitosan bicomponent fibers were prepared via the electrospinning of chitosan/poly(vinyl alcohol)/acrylic acid aqueous solutions with different concentrations. With a 4% acrylic acid aqueous solution, when the chitosan/poly(vinyl alcohol) mass ratios were lower than 80/20, electrospinning nanofibers could be obtained. With a 90% acrylic acid aqueous solution, when the chitosan/poly(vinyl alcohol) mass ratios were less than 95/5, good nanofibers could be electrospun. The average diameter of the nanofibers gradually decreased, and its distribution became narrower as the poly(vinyl alcohol) concentration increased. Chitosan/poly(vinyl alcohol)/acrylic acid aqueous solutions could be electrospun at various concentrations by the adjustment of the chitosan and poly(vinyl alcohol) concentrations. The effects of the viscosity and conductivity of the blend solution on the morphologies of the fiber mats were also investigated. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 5692–5697, 2006     

A facile approach to preparing palladium nanoparticles-embedded polyvinylpyrrolidone (PVP) heterogeneous hybrid nanofibers mats by electrospinning

Well-dispersed palladium nanoparticles (Pd NPs) were prepared under the condition that trisodium citrate was the reduction agent and polyvinylpyrrolidone (PVP) was the stabilizing agent via sol-gel process. By making good use of the advanced electrospinning technology we obtained Pd NPs/PVP composite nanofibers films. Optical properties were examined by UV-visible absorbance spectra (UV-vis) and Fourier transform infrared spectroscopy (FTIR). The morphology and distribution of Pd NPs in/on PVP matrix were characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). The results showed that Pd NPs presented as spherical spots and distributed in/on PVP nanofibers uniformly; their diameter was 4–10 nm and decreased with the increase of PVP. The as-prepared Pd NPs/PVP hybrid mats possess catalytic activity, stability and reusability, as verified by performance in Heck reaction.     

Electrospinning silica/polyvinylpyrrolidone composite nanofibers

Small diameter nanofibers of silica and silica/polymer are produced by electrospinning silica/polyvinylpyrrolidone (SiO₂/PVP) mixtures composed of silica nanoparticles dispersed in polyvinylpyrrolidone solutions. By controlling various parameters, 380 ± 100 nm diameter composite nanofibers were obtained with a high silica concentration (57.14%). When the polymer concentration was low, “beads‐on‐a‐string” morphology resulted. Nanofiber morphology was affected by applied voltage and relative humidity. Tip‐to‐collector distance did not affect the nanofiber diameter or morphology, but it did affect the area and thickness of the mat. Heat treatment of the composite nanofibers at 200°C crosslinked the polymer yielding solvent‐resistant composite nanofibers, while heating at 465°C calcined and selectively removed the polymer from the composite. Crosslinking did not change the nanofiber diameter, while calcined nanofibers decreased in diameter (300 ± 90 nm) and increased in surface area to volume ratio. Nanofibers were characterized by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40966.     

Synthesis and characterization of highly dispersed multi‐walled carbon nanotubes/polyvinylpyrrolidone composite nanofibers for EMI shielding application

Multi‐walled carbon nanotubes (MWCNTs)/polyvinylpyrrolidone (PVP) composite nanofibers having varying amounts of MWCNTs were fabricated with an aim to investigate the potential of such nanofibers as an effective light weight electromagnetic interference (EMI) shielding material in the frequency range of 8.2–12.4 GHz (X‐band). The state of dispersion of MWCNTs in PVP matrix was studied by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The TEM and SEM analyses confirmed the presence of individual dispersion MWCNTs encapsulated within the electrospun nanofibers and showed MWCNTs/PVP composite nanofiber morphologies with diameters of 150–600 nm. Moreover, the MWCNTs/PVP composite nanofibers were characterized by X‐ray diffraction and Raman spectrophotometer. The thermal stability of composite nanofibers studied from thermogravimetric analysis was increased after addition of MWCNTs to PVP matrix. The EMI shielding efficiency of MWCNTs/PVP composite nanofibers increased up to 42 dB. The MWCNTs/PVP composite nanofibers developed in this study have benefits in being light weight and having effective EMI shielding performance and can be best candidates for a broad range of electronic applications. POLYM. COMPOS., 38:2026–2034, 2017. © 2016 Society of Plastics Engineers     

静电纺丝法制备BaO微/纳米纤维及其表征

以聚乙烯吡咯烷酮(PVP)为络合剂,与醋酸钡[Ba(CH3COO)2]反应制得前驱体溶液;以36%乙酸为钡盐的相容剂,和乙醇组成了混合溶剂体系,用静电纺丝法制备了PVP/Ba(CH3COO)2纤维,经煅烧得到BaO微/纳米纤维。对所制备纳米纤维的结晶度、纯度和表面形貌,分别采用差热-热重分析、红外光谱、X-射线衍射、扫描电镜等进行了表征。结果表明:煅烧前后,纤维的结晶度和形貌有很大变化。     

Antibacterial electrospun chitosan/poly(vinyl alcohol) nanofibers containing silver nitrate and titanium dioxide

Chitosan/poly(vinyl alcohol) (PVA) nanofibers with antibacterial activity were prepared by the electrospinning of a chitosan/PVA solution with a small amount of silver nitrate (AgNO₃) and titanium dioxide (TiO₂). Nanofibers with diameters of 270–360 nm were obtained. The yield of low‐viscosity chitosan (LCS)/PVA nanofibers was higher than that of high‐viscosity chitosan (HCS)/PVA, and the water content of the HCS/PVA nanofibers and the LCS/PVA nanofibers were 430 and 390%, respectively. The nanofibers developed in this study exhibited antibacterial activities of 99 and 98% against Staphylococcus aureus and Escherichia coli, respectively. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009