静电纺丝法制备有序纳米纤维

一维纳米材料由于其独特的光、电、磁等性质,是近年来科学研究的热门．用静电纺丝法对质量分数为12％的聚丙烯腈（PAN）溶液进行纺丝制备电纺纤维,通过采用不同的收集装置,制备出具有一维有序结构的聚丙烯腈纳米纤维;用扫描电镜考察了3种收集装置制备的一维纳米纳米纤维．结果表明：以具有一定间隔对立的铜针尖作为收集装置所制备的纤维有较高的有序度．     

静电纺丝法制备聚丙烯腈／细菌纤维素复合纳米纤维研究

利用静电纺丝方法制备了聚丙烯腈／细菌纤维素复合纳米纤维．研究了溶液浓度、细菌纤维素含量对复合纳米纤维成形及吸水性能的影响．研究结果表明：随着溶液浓度的增加,静电纺丝产物由珠状结构纤维逐渐成为平滑纤维,上工平均纤维直径逐渐增大;随着细菌纤维素含量的增加,共混纺丝溶液的黏度增加,得到的复合纳米纤维直径也增加,同时其吸水性也有较大的提高．     

PEO基聚合物电解质的制备

为采用蒸馏水替代有机溶剂溶解PEO,减轻对空气的污染,改善由于有机溶剂挥发较快使得聚合物膜易裂的缺点,采用溶液浇铸法,首次以蒸馏水为溶剂溶解PEO,以纳米SiO₂为填料,锂盐采用LiClO₄,制备出复合聚氧化乙烯基电解质PEO-LiClO₄-SiO₂,并对纳米SiO₂的作用进行分析．采用SEM、XRD和交流阻抗法等测试方法对PEO基复合电解质的微观形貌、晶体结构和相关电化学性能等进行表征．结果表明:添加纳米填料后,PEO聚合物电解质的结晶度下降,拉伸强度增加．PEO-LiClO₄-SiO₂(6％)聚合物电解质的电化学稳定窗口为4.8 V,离子电导率(25 ℃)为3.95×10-5S·cm-1,离子迁移数为0.29．     

静电纺丝法制备ZnFe_2O_4纳米纤维

采用静电纺丝法制备了PVP/[zn(NO3)2+Fe(NO3)3]复合纳米纤维,研究了反应体系的最佳组成,系统地讨论了静电纺丝工艺的影响,获得了最佳制备条件.将PVP/[Zn(NO3)2+Fe(NO3)3]复合纳米纤维在600℃焙烧5h,获得了晶态的ZnFe2O4纳米纤维.XRD分析表明,ZnFe2O4纳米纤维属于单相尖晶石结构,空间群为Fd3m.SEM分析表明,PVP/[Zn(NO3)2+Fe(NO3)3]复合纳米纤维表面光滑,平均直径约为200nm,ZnFe2O3纳米纤维的直径为175nm.     

静电纺丝法制备PAN/PVDF-HFP超级电容器隔膜及其力学性能分析

静电纺丝技术制备PAN/PVDF-HFP复合纳米纤维膜,对PAN/PVDF-HFP/PAN三层结构复合膜进行热压处理,对其力学性能进行分析评价,最后组装纽扣型超级电容器,并对其电化学性能进行分析测试.结果表明:静电纺PAN纺丝溶液中DMF/丙酮溶剂体系的最佳配比为7∶3;PAN/PVDF-HFP热压复合最佳温度和时间为120℃和60 s,此时复合膜的断裂强度为13.5 MPa;PAN/PVDF-HFP复合膜作为超级电容器隔膜,其等效串联电阻(ESR)为0.57Ω,小于商品膜Celgard2400的0.64Ω;,CV曲线在5 m V/s扫速下仍保持较好的矩形特征,GCD曲线在0.05 A/g电流密度下比容量为79.55 F/g,高于商品膜Celgard2400的62.78 F/g.     

静电纺丝法制备醋酸纤维素纳米纤维

静电纺丝是一种利用聚合物溶液或熔体在强电场作用下形成喷射流进行纺丝加工的工艺,是一项制备纳米级纤维材料简单有效的技术．本文以六氟异丙醇和甲酸为溶剂,对静电纺丝制备醋酸纤维素纳米纤维的影响因素进行探讨,研究溶剂、电压、浓度及接收距离对纳米纤维形貌和直径的影响．研究结果表明：以六氟异丙醇（HFIP）为溶剂,当纺丝液浓度为8％、电压为15—20kV、接收版距离为16cm时,可以静电纺丝制得直径300nm的明胶纳米纤维．在本实验设定的静电纺丝基本参量范围内,醋酸纤维素溶液的浓度越大,纤维直径越大;接收距离越大,纤维直径也越大,而且容易产生纺锤状纤维;电压越大,纤维直径越小．     

溶液静电纺丝制备聚氨酯纳米纤维的研究进展

因聚氨酯纳米纤维在新材料领域的潜在应用价值,重点论述了溶液静电纺丝法制备聚氨酯纳米纤维时,聚氨酯溶液的性质、纺丝工艺条件和纺丝环境等对制备纳米纤维直径、均匀性和形貌的影响,最后阐述该研究目前存在的不足,并提出展望。     

静电纺 LA-SA/PAN 复合纤维的形貌分析

通过静电纺丝的方法制备以月桂酸和硬脂酸二元低共熔物(LA-SA)为固-液相变材料,聚丙烯腈(PAN)为基体的超细纤维。研究最佳静电纺PAN纤维的纺丝工艺参数,纺丝溶液中不同LA-SA含量对复合纤维的形貌结构影响。确定最佳静电纺PAN纳米纤维的工艺参数(纺丝电压15KV,接收距离20cm,纺丝液流速1ml/h)。SEM观察表明:随LA-SA含量的增加,复合纤维的平均直径逐渐增大;当复合纤维中LA-SA含量较高时,纤维表面变得不光滑,并呈现褶皱的形貌特征。     

电子纺丝制备聚氧化乙烯纳米纤维

通过电子纺丝技术成功制备了分子量为9×105的聚氧化乙烯纳米纤维,并讨论了纺丝液的浓度范围,分析了纺丝条件对制备纳米纤维的影响,探讨了不同剪切粘度的聚氧化乙烯溶液制备的纳米纤维的差异和形成原因。随着聚氧化乙烯溶液零剪切粘度的增加,制备的纳米纤维直径逐渐变细而且表面也较平滑。其中,分子量为9×105的零剪切粘度为30 Pa.s的8 wt%的聚氧化乙烯溶液用电子纺丝技术制备的纳米纤维直径最小,分布在120~160nm,表面平滑。     

LCI-MMT/PEO聚合物电解质的结晶、电化学及力学性能

为了提高聚合物电解质电导率的同时兼具良好的力学性能,采用溶液共混方法在体系中加入了带有磺酸基团的主链液晶离聚物的插层蒙脱土复合材料(LCI-MMT)并制备了PEO基聚合物电解质.利用差示扫描量热仪、电化学工作站、偏光显微镜、电脑伺服材料控制实验机等对电解质的熔融和结晶性能、微观形貌、电化学和力学性能进行了分析.结果表明,当LCI-MMT的质量分数为1%时,PEO的结晶度由48. 8%降低至41. 3%,体系的最大室温电导率为3. 3×10~(-5)S/cm,同时当电解质的最大应变达到800%时仍未断裂,此时电解质的综合性能最佳.     

Effect of catalyst on structure of (PEO)8sLiClO4-SiO2 composite polymer electrolyte films

(PEO)8LiClO4-SiO2 composite polymer electrolytes(CPEs) were prepared by in-situ reaction, in which ethyl-orthosilicate (TEOS) was catalyzed by HC1 and NH3·H2O, respectively. The ionic conductivity, the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra, contact angle method and TEM. The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10-5 and 1.1×10-5 S/cm respectively at 30 ℃. The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2, and influences the surface energy and conductivity of CPE films directly. Meanwhile, the ionic conductivity is related to the surface energy.     

PA6/PVA复合纳米纤维的制备及性能研究

采用静电纺丝法制备了PA6/PVA复合纳米纤维.分析了不同质量比的PA6/PVA共混纺丝溶液的粘度、电导率、表面张力,并探讨其静电纺丝效果.采用扫描电镜、红外光谱、表面张力仪等对纳米纤维膜的形貌结构、成分相容性及亲水性能进行表征.结果表明,在纺丝电压为19kV、纺丝距离为20cm、丝液流量为0.2mL/h的条件下,共混溶液质量比为12%∶4%时的静电纺丝所得纤维具有良好的形貌,复合纳米纤维中PA6与PVA具有良好的相容性,并有效地克服了纯纺PVA纳米纤维在水溶液中出现的过度溶胀问题.     

碳基凝胶聚合物电解质双电层电容器的研究

为了克服液体电解液电容器的漏液和安全问题,以活性炭作电极材料,丙烯腈作聚合物单体,分别以碳酸丙烯酯 碳酸乙烯酯、碳酸二甲酯 碳酸乙烯酯和碳酸甲乙酯 碳酸乙烯酯的混合液作增塑剂,高氯酸锂为支持电解质盐,采用内聚合法制备了PAN基凝胶聚合物电解质双电层电容器(GPE-EDLCs).采用交流阻抗法测量了凝胶聚合物电解质(GPE)的离子电导率.采用交流阻抗、循环伏安、恒流充放电等测试方法研究了GPE-EDLCs的性能,并与有机电解液双电层电容器(LOE-EDLCs)进行了比较.结果表明,PAN基GPE的电导率在室温下为6.51～8.94 mS·cm-1,PAN基GPE-EDLCs的工作电压为2.5 V,电容器的比容量为43.9～47.4F/g(i=0.5 mA/cm2),能量密度为128.8～148.1 J/g,与LOE-EDLCs性质相近.     

Morphology and conductivity of in-situ PEO-LiClO4-TiO2 composite polymer electrolyte

PEO-LiClO4-TiO2 composite polymer electrolyte films were prepared. TiO2 was formed directly in matrix by hydrolysis and condensation reaction of tetrabutyl titanate. The crystallinity, morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry, scanning electron microscopy, atom force microscopy and alternating current impedance spectroscopy, respectively. The glass transition temperature and the crystallinity of composite polymer electrolytes are decreased compared with those of PEO-LiClO4 polymer electrolyte film. The results show that TiO2 particles are uniformly dispersed in PEO-LiClO4-5%TiO2 composite polymer electrolyte film. The maximal conductivity of 5.5×10^-5 S/cm at 20℃ of PEO-LiClO4-TiO2 film is obtained at 5% mass fraction of TiO2.     

Effect of catalyst on structure of （PEO）8LiClO4-SiO2 composite polymer electrolyte films

（PEO）8LiClO4-SiO2 composite polymer electrolytes（CPEs） were prepared by in-situ reaction, in which ethyl-orthosilicate （TEOS） was catalyzed by HCl and NH3·H2O, respectively. The ionic conductivity, the contact angle and the morphology of inorganic particles in the CPEs were investigated by AC impedance spectra, contact angle method and TEM. The conductivities of acid-catalyzed CPE and alkali-catalyzed CPE are 2.2×10^-5 and 1.1×10^-5 S/cm respectively at 30 ℃. The results imply that the catalyst plays an important role in the structure of in-situ preparation of SiO2, and influences the surface energy and conductivity of CPE films directly. Meanwhile, the ionic conductivity is related to the surface energy.     

静电场中PVA/PA6复合纳米纤维的成型性研究

为制备一种在包装和过滤领域有着良好应用前景的先进复合材料,采用静电纺丝的方法制备出PVA/PA6复合纳米纤维,对其在静电场中的成型性进行了系统的分析与研究.研究结果表明,随着溶液质量分数的增加,纤维的形貌变好,直径变粗;随着纺丝电压与喷丝流量的增加,纤维的平均直径变细,珠状物逐渐减少;随着接收距离的增加,纤维的平均直径变粗,珠状物增多.     

Preparation and properties of PEO/LiClO4/KH560-SiO2 composite polymer electrolyte by sol-gel composite-in-situ method

Composite polymer electrolytes based on polyethylene oxide（PEO） were prepared by using LiClO4 as doping salt and silane-modified SiO2 as filler. SiO2 was formed in-situ in （PEO）8LiClO4 matrix by the hydrolysis and condensation reaction of Si（OC4H9）4. The crystallinity,morphology and ionic conductivity of composite polymer electrolyte films were examined by differential scanning calorimetry,scanning electron microscopy,atom force microscopy and alternating current impedance spectroscopy,respectively. Compared with the crystallinity of the unmodified SiO2 as inert filler,that of composite polymer electrolytes is decreased. The results show that silane-modified SiO2 particles are uniformly dispersed in （PEO）8LiClO4 composite polymer electrolyte film and the addition of silane-modified SiO2 increases the ionic conductivity of the （PEO）8LiClO4 more noticeably. When the mass fraction of SiO2 is about 10%,the conductivity of （PEO）8LiClO4-modified SiO2 attains a maximum value of 4.8×10^-5 S·cm^-1.     

Filtration of fine particles in atmospheric aerosol with electrospinning nanofibers and its size distribution

In this study,the size distribution of atmospheric aerosol in Beijing was monitored by the scanning mobility particle sizer spectrometer and the optical particle sizer.The size of particles in atmospheric aerosol was primarily distributed in the range of less than 1 m.It showed different changes with the mass concentrations of particulate matters with an aerodynamic diameter of 2.5 m(PM2.5)for different sizes of fine particles.The amount of ultrafine particles(less than about 60 nm)decreased while the larger ones(60 nm)increased along with the mass concentration of PM2.5 in atmospheric aerosol.This was because of the formation of the secondary atmospheric aerosol.The polylactic acid(PLA)nanofibers were prepared for filtering the aerosol by electrospinning.PLA nanofiber mats were used as the middle layer to design the composite filter membranes.Atmospheric aerosol was used as dust source in the filtration test.The results showed that the filtration efficiency of the composite filter media increased along with the thickness of nanofiber mats,which was controlled by the collection time during electrospinning.Filtration efficiency can be improved obviously by compositing with a thin layer of nanofibers.