Synthesis and Electrical Properties of TiO_2 Nanoparticles Embedded in Polyamide-6 Nanofibers Via Electrospinning

We report on the synthesis and characterizations of TiO2 nanoparticles embedded in polyamide-6composite nanofibers by using electrospinning technique. The influence of substrate on the electrical characteristics of polyamide-6/TiO2 composite nanofibers was investigated. The resultant nanofibers exhibit good incorporation of TiO2 nanoparticles. The doping of TiO2 nanoparticles into the polyamide-6 nanofibers were confirmed by high resolution transmission electron microscopy and energy dispersive X-ray spectroscopy. Photoluminescence（PL） and cathodoluminescence（CL） spectroscopy were also used to characterize the samples.The PL and CL spectra reveal that the as-spun polyamide-6/TiO2 composite nanofibers consisted of overlapping of two broad emission bands due to the contribution of polyamide-6（centered at about 475 nm）, which might originate from organic functional groups of polyamide-6 and TiO2 nanoparticles（centered around 550 nm）. The electrical conductivity of the polyamide-6/TiO2 composite nanofibers on different substrates was carried out.It was found that the electrical conductivity of the polyamide-6/TiO2 composite nanofibers on silicon substrate was in the range of 13 μA, and about 1 to 20 p A for the paper and glass substrates.

Fabrication and catalytic behavior of hierarchically-structured nylon 6 nanofiber membrane decorated with silver nanoparticles

A hierarchically‐structured nylon 6 (PA6) nanofiber membrane decorated with silver nanoparticles (Ag NPs) was fabricated by electrospinning and impregnation methods. The as‐fabricated hierarchically‐structured Ag/PA6 nanofiber membrane (HS‐Ag/PA6 NM) exhibits a morphology in which Ag NPs are deposited on the surfaces of both thick fibers and thin fibers. The content and size of theAg NPs can be controlled by varying the concentration of the silver colloid solution. Compared with the non‐hierarchically‐structured Ag/PA6 nanofiber membrane, HS‐Ag/PA6 NM has a higher specificsurface area and exhibits a higher degradation rate for methylene blue of 81.8%–98.1% within2 h. HS‐Ag/PA6 NM can be easily recycled and exhibits good reusability. It retains a degradation rate for methylene blue of 83.5% after five consecutive cycles. The hierarchically‐structured nanofiber membrane is therefore a potential nanocatalyst.

High-performance all-solid-state polymer electrolyte with fast conductivity pathway formed by hierarchical structure polyamide 6 nanofiber for lithium metal battery

The utilization of all-solid-state electrolytes is considered to be an effective way to enhance the safety performance of lithium metal batteries.However,the low ionic conductivity and poor interface compatibility greatly restrict the development of all-solid-state battery.In this study,a composite electrolyte combining the electrospun polyamide 6(PA6)nanofiber membrane with hierarchical structure and the polyethylene oxide(PEO)polymer is investigated.The introduction of PA6 nanofiber membrane can effectively reduce the crystallinity of the polymer,so that the ionic conductivity of the electrolyte can be enhanced.Moreover,it is found that the presence of finely branched fibers in the hierarchical structure PA6 membrane allows the polar functional groups(C=O and N-H bonds)to be fully exposed,which provides sufficient functional sites for lithium ion transport and helps to regulate the uniform deposition of lithium metal.Moreover,the hierarchical structure can enhance the mechanical strength(9.2 MPa)of the electrolyte,thereby effectively improving the safety and cycle stability of the battery.The prepared Li/Li symmetric battery can be stably cycled for 1500 h under 0.3 mA cm^(-2) and 60℃.This study demonstrates that the prepared electrolyte has excellent application prospects in the next generation all-solid-state lithium metal batteries.

Rational construction and decoration of Li_(5)Cr_(7)Ti_(6)O_(25)@Cnanofibers as stable lithium storage materials

Li_(5)Cr_(7)Ti_(6)O_(25) is regarded as a promising anode material for Li-ion batteries(LIBs)because of its low cost and high theoretical capacity.However,the inherently poor conductivity significantly limits the enhancement of its rate capability and cycling stability,especially at high current densities.In this work,we construct one-dimensional Li_(5)Cr_(7)Ti_(6)O_(25)/C nanofibers by electrospinning method to enhance the kinetic,which realizes high cycling stability.Carbon coating enhances the structure stability,insertion/extraction reversibility of Li-ions and electrochemical reaction activity,and facilitates the transfer of Li-ions.Benefited from the unique architecture and component,the Li_(5)Cr_(7)Ti_(6)O_(25)/C(6.6 wt%)nanofiber shows an excellent rate capability with a reversible de-lithiation capacity of 370.8,290.6,269.2,254.3 and 244.9 m Ah g^(-1) at 200,300,500,800 and 1000 m A g^(-1),respectively.Even at a higher current density of 1 A g^(-1),Li_(5)Cr_(7)Ti_(6)O_(25)/C(6.6 wt%)nanofiber shows high cycling stability with an initial de-lithiation capacity of 237.8 m Ah g^(-1) and a capacity retention rate of about 84%after 500 cycles.The density functional theory calculation result confirms that the introduction of carbon on the surface of Li_(5)Cr_(7)Ti_(6)O_(25) changes the total density of states of Li_(5)Cr_(7)Ti_(6)O_(25),and thus improves electronic conductivity of the composite,resulting in a good electrochemical performance of Li_(5)Cr_(7)Ti_(6)O_(25)/C nanofibers.Li_(5)Cr_(7)Ti_(6)O_(25)/C nanofibers indicate a great potential as an anode material for the next generation of high-performance LIBs.

Electrospun MgO/Nylon 6 Hybrid Nanofibers for Protective Clothing

Magnesia(MgO) nanoparticles were produced from magnesite ore(MgCO3) using ball mill. The crystalline size, morphology and specific SSA were characterized by X-ray diffraction analysis, transmission electron microscopy and Brunauer-Emmett-Teller method, respectively. MgO nanoparticle-incorporated nylon6 solutions were electrospun to produce nanofiber mats. Surface morphology and internal structure of the prepared hybrid nanofiber mats were examined by scanning electron microscopy and high-resolution transmission electron microscopy, respectively. The fire retardancy and antibacterial activity(Staphylococcus aureus and Escherichia coli) of coated fabrics made from MgO/nylon 6 hybrid nanofiber are better than those from nylon6 nanofiber.

Preparation and Luminescence Properties of Nylon 6 Composite Nanofibers

The luminescent fibers have a good application prospect.The feature of this paper is that efficient luminescent nylon 6(PA6)composite nanofibers are successfully prepared by electrospinning.The luminescent PA6 composite nanofibers composed of PA6,Eu(BA)3Phen and Tb(BAO)3Phen(BA=P-methylbenzoic acid,BAO=P-methoxybenzoic acid,and Phen=1,10-phenanthroline).The structure and properties were characterized by scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR),fluorescence spectroscopy,and thermogravimetriy(TG)analysis.The correspondence between polymer matrix and as-prepared composite nanofibers properties has also been studied in detail.Through using hexafluoroisopropanol(HFIP)as solvent,Eu(BA)3Phen/PA6 and Tb(BAO)3Phen/PA6 composite nanofibers exhibit good luminescence properties.It is noted that only 5%rare earth luminescent materials are added to Tb(BAO)3Phen/PA6 composite nanofibers,and the luminescence intensity of the as-prepared nanofibers reaches half that of the pure rare earth luminescent materials.Furthermore,uniform dispersion of pure rare earth luminescent materials in the as-prepared nanofibers gives the composite nanofibers good mechanical properties and thermal stability.These results provide an important basis for the preparation and wide application of new PA6 luminescent fibers.

锦纶6/有机蒙脱土复合纳米纤维的制备与表征

通过高压静电纺丝制备锦纶6/有机蒙脱土复合纳米纤维。采用二步插层复合法对有机蒙脱土进行分散和剥离:先在N,N-二甲基甲酰胺中插层复合,然后在锦纶6溶液中深层复合。应用纳米粒度分析仪分析有机蒙脱土片层相对粒径大小和分布范围;利用扫描电镜观察并分析纳米纤维的直径、外观;运用轻敲模式下的原子力显微镜表征和分析纳米纤维的表面微观结构。结果表明有机蒙脱土加入量对纤维的形态和结构有影响。

尼龙6/聚乙烯醇超细纤维无纺布的制备与表征

静电纺丝是一种有效制备超细纤维的重要方法。本文应用同轴静电纺丝装置制备出外层为尼龙6(N y lon 6),内层为聚乙烯醇的壳-芯结构的复合功能型无纺布。通过TEM、SEM、红外光谱、力学性能表征探讨了它们的性能,同时将其应用到棉布衬里,测试其透湿性能。以期用于过滤膜、防护服及医疗纺织材料等领域。

尼龙6纳米纤维膜固相萃取-液相色谱法测定食用油中邻苯二甲酸酯

建立了溶剂提取、尼龙6（PA6）纳米纤维膜萃取净化,液相色谱-紫外法（HPLC-UV）检测食用油样品中5种邻苯二甲酸酯的方法。对洗脱溶剂的种类及用量、纳米纤维膜的用量、pH值、突破体积及过样速度等影响因素进行了考察。在最优化条件下,邻苯二甲酸二甲酯（DMP）、邻苯二甲酸二乙酯（DEP）、邻苯二甲酸二丁酯（DBP）、邻苯二甲酸二异辛酯（DEHP）和邻苯二甲酸二正辛酯（DOP）的检出限分别为0.020,0.030,0.080,0.100和0.150ng/mL,相对标准偏差（RSD）为5.3%～7.0%,回收率为85.9%～101.0%。将该方法应用于实际样品的检测,只需2.5mgPA6纳米纤维膜,即可完成对样品中的PAEs的萃取,方法精密度与回收率与相关文献方法相当,而检出限更低。

静电纺工艺参数对含银PA6纳米纤维直径的影响

为了研究静电纺工艺参数对含银PA6纳米纤维直径分布的影响,采用静电纺丝技术,在不同含银量、纺丝液质量分数、纺丝电压、接收距离(C-SD)、喷嘴直径条件下制备出含银PA6纳米纤维膜。利用扫描电镜(SEM)及相关软件分析纳米纤维直径分布及形态,在银溶胶质量分数0.2%～0.4%、纺丝液质量分数10%～16%、纺丝电压12～21kV、接收距离9～18cm、喷嘴直径0.5～1.2mm的实验范围内,纳米纤维的平均直径为70～90nm;纳米纤维直径随银溶胶质量分数的增加而减小,随纺丝液质量分数的增加而增大,随喷嘴直径的增大而增大;电压和接收距离对纳米纤维直径的影响较小。

聚吡咯/尼龙6纳米纤维膜对Pb^(2+)固相萃取的吸附效能研究

以电纺尼龙6纳米纤维膜为基底,原位氧化聚合制得聚吡咯/尼龙6纳米纤维膜(PPy/Nylon 6-NFsM)。通过静态和动态吸附实验考察PPy/Nylon 6-NFsM对pb^(2+)的吸附行为,探究其作为固相萃取介质富集水中痕量pb^(2+)的可行性。结果表明:298 K,pH=10时,PPy/Nylon 6-NFsM对pb^(2+)的静态饱和吸附量达542 mg/g;吸附动力学和吸附等温线分别符合准二级动力学模型和Freundlich模型;优化了PPy/Nylon 6-NFsM的固相萃取条件,采用火焰原子吸收光谱法检测实际水样中的pb^(2+),检出限为1.2μg/L(信噪比为3计)10μg/L加标水平加标回收率为95.3%~100.4%,相对标准偏差(RSD)为1.6%(n=3)可实现实际水样中痕量Pb^(2+)的准确、灵敏的检测。

基于聚酰胺6纳米纤维膜的固相萃取-高效液相色谱法测定兔血浆中酮康唑对映体

以基于聚酰胺6纳米纤维膜的固相萃取法,结合高效液相色谱手性流动相添加剂法测定了兔血浆中的酮康唑对映体的浓度。仅用1.5mg聚酰胺6纳米纤维膜、100μL甲醇即可完成目标物的富集和洗脱。酮康唑的2个对映体在50.0～400.0μg/L范围内呈良好的线性;方法的定量限为40.0μg/L;日内和日间精密度分别小于6.3%和8.6%;平均绝对回收率为79.4%～85.6%;平均相对回收率为90.0%～96.5%。本方法灵敏、准确、重现性好,符合生物样本中酮康唑对映体分析测定的要求。

静电纺PA 6纳米纤维膜的力学性能研究

利用静电纺丝可形成由纳米级纤维组成的纳米纤维膜,由于该膜孔径小并具有高比表面积和高孔隙率,可用作组织工程支架、传感器感知膜、过滤材料和防护材料等。静电纺纳米纤维膜的力学性能对其适用性和耐用性有重要影响。以PA 6甲酸溶液进行静电纺丝,研究了纺丝液喂入速度和纺丝距离对静电纺PA 6纳米纤维膜力学性能的影响。结果表明:纺丝液喂入速度较低时,形成的纳米纤维膜力学性能差;纺丝距离增大时,纳米纤维膜的断裂强度降低;PA 6溶解于98%甲酸中配制成13%(质量分数)纺丝液,在喷嘴口径0.9 mm、电压30 kV下进行静电纺丝,纺丝液喂入速度在0.2～0.3 ml/h、纺丝距离为8～10 cm时可获得具有良好力学性能的PA 6纳米纤维膜。

静电纺PA 6纳米纤维膜的过滤性能

用98%甲酸溶解聚酰胺6(PA 6)制备质量浓度为13%纺丝液,经静电纺丝获得厚度31～60μm、纤维平均直径217 nm、表面平均孔径为234 nm的纳米纤维非织造膜。由于该纤维膜的断裂强度仅为8.06 MPa,实验以普通聚酯纤维织物为支撑基布,测试了不同样品的过滤性能。结果发现:在气流速度为2.83 L/min时,普通聚酯纤维基布对1μm微粒的过滤效率仅为9.92%,对0.5和0.3μm微粒无过滤作用;而在基布上覆盖一层面密度为1.25 g/m2的PA 6纤维膜后,对1、0.5和0.3μm微粒的过滤效率分别为92.16%、89.66%和87.38%;当覆盖的PA 6纤维膜面密度达到2.5 g/m2时,相应的过滤效率分别增加到97.03%、96.23%和95.65%,但透气量增加不大。实验结果表明,聚酯纤维基布与静电纺PA 6纤维膜复合材料具有良好的过滤性能,显示出在高效、精密过滤材料中的应用潜力。

静电纺丝法制备尼龙-6/SiO_2-TiO_2杂化纳米纤维

采用静电纺丝法结合溶胶凝胶技术,制备了尼龙-6/SiO2-TiO2杂化纳米纤维。采用红外光谱(FT-IR)、X射线衍射(XRD)、UV-vis、热重分析(TG)和扫描电镜(SEM)等对杂化纳米纤维进行分析表征。结果表明,随着SiO2-TiO2溶胶的引入,电纺纤维的结晶度下降,耐热性能提升。尼龙-6电纺纤维的平均直径约为160 nm,杂化电纺纤维随无机组分中TiO2含量增加,纤维直径增大,直径分布变宽,当n(SiO2)∶n(TiO2)为1∶8时,纤维平均直径达到约250 nm;同时随TiO2含量增加,杂化电纺纤维对紫外光的吸收增强。

TiO_2纳米纤维掺杂熔纺PA6基复合长丝的制备及性能研究

结合溶胶-凝胶、静电纺丝和高温煅烧的技术与原理,制备了TiO2纳米纤维,然后将研磨后的TiO2纳米纤维与PA6切片在双螺杆挤出机中进行共混、熔融纺丝制备出PA6基复合长丝。利用TEM、SEM表征了TiO2纳米纤维的结构形貌,通过视频显微镜观察了PA6基复合长丝的形貌,利用差式扫描量热仪(DSC)和流变仪对复合长丝的结晶性能及流变性能进行了测试分析,并且利用纤维强力测试仪对PA6基复合长丝的力学性能进行了测试。结果表明,当TiO2纳米纤维含量较低时PA6复合长丝的结晶度有所提高,剪切粘度变大,断裂强度有所提高。

聚酰胺6/纤维复合材料的进展

聚酰胺6(PA6)是一种重要的工程材料,但是,其强度的较差,限制了其更广泛的应用,对PA6进行增强改性是提高其强度最有效的方法之一,其中,纤维增强改性的增强效果较好,因此,制备PA6/纤维复合材料是解决该问题最简单、有效的方法。但是,在制备PA6/纤维复合材料的过程中或PA6/纤维复合材料的使用过程中仍存在一些问题。综述了3种常用纤维和1种新型纤维增强PA6,对各类纤维增强PA6中关键性问题的最新进展进行了整理,包括PA6/玻璃纤维中制品外观质量和抗老化能力、PA6/碳纤维表面改性工艺、PA6/晶须中晶须的新种类、PA6/纤维素纳米纤维中纤维素纳米纤维的降解温度低于PA6的熔融温度等问题。

PA6/CA复合纳米纤维膜的制备及调湿性能研究

利用电纺纳米纤维比表面积大的优势,将其应用于溶液调湿空调用电纺纳米纤维填料。采用静电纺丝技术制备聚酰胺6/柠檬酸(PA6/CA)复合纳米纤维膜,采用扫描电子显微镜(SEM)以及红外光谱(FT-IR)对纤维膜的表面形貌进行表征并解释柠檬酸改善PA6亲水性的机理,并测试其在不同温度、湿度下的吸湿性能。研究发现:膜的吸湿率随温度、湿度的升高而增大,最大可达到151.32%。

镀银聚酰胺6/聚酰胺6纳米纤维包芯纱电容传感器的构筑

为获得线形螺旋结构且具有良好传感性能的大应变柔性应变-电容传感器,采用水浴静电纺丝法以镀银聚酰胺6为芯纱,制备了镀银聚酰胺6/聚酰胺6纳米纤维包芯纱,并将其缠绕在橡筋上制备应变-电容式柔性传感器。对纳米纤维包芯纱的结构与力学性能进行表征与测试,分析了应变-电容传感器的传感性能,并探索了其在人体运动监测中的应用。结果表明:聚酰胺6纳米纤维在镀银聚酰胺6表面形成结构完整的包覆层,直径分布主要在80~100 nm范围内,平均直径为95.53 nm;相较于芯纱,纳米纤维包芯纱的力学性能基本保持不变;制备的柔性传感器表现出良好的应变-电容传感性能,在6.67%的应变下敏感因子可达3.93,并具有良好的重复性,该传感器可用于人体运动的实时监测。

静电纺丝工艺参数对聚酰胺6纳米纤维形态结构的影响

以聚酰胺6/六氟异丙醇(PA 6/HFIP)溶液作为纺丝液,采用静电纺丝法制备了PA 6纳米级纤维,并分析了PA 6/HFIP纺丝液浓度、纺丝电压和纤维接收距离等工艺参数的变化对纤维表面结构和直径的影响。结果表明:静电纺PA 6纤维的直径随纺丝液浓度的增高而显著增加,随纺丝电压的提高逐渐减小,随纤维接收距离的增大而减小;在纺丝液中PA 6质量分数为8%、纺丝电压15 kV和纤维接收距离20 cm的条件下进行静电纺丝,其纺丝效果比较好。