纳米铜/聚丙烯腈纤维抗菌性能、力学性能研究

通过对纳米铜/聚丙烯腈纤维进行抗菌性能研究,结果表明,纳米铜/聚丙烯腈纤维对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌、白色链球菌等微生物有明显的抗菌效果,抗菌15h,抗菌率均达90%以上;纳米铜/聚丙烯腈纤维对大肠杆菌、枯草芽孢杆菌、金黄色葡萄球菌的抗菌效率高于非纳米铜/聚丙烯腈纤维对其的抗菌效率.力学性能测试表明:纳米铜/聚丙烯腈纤维的断裂强力、初始模量、应力均优越于非纳米级铜/聚丙烯腈纤维.     

纳米抗菌PET纤维的制备及性能研究

采用高速熔融纺丝制备纳米抗菌涤纶PET纤维。扫描电镜分析表明改性后纳米抗菌粒子在PET中分散良好。纳米抗菌剂的加入，对纤维的结晶性能、伸长率、断裂强度等均有影响。纳米抗菌材料的添加量为5％时，纤维的断裂强度和伸长率都有较大值。在PET中添加了少量抗菌剂后，抗菌剂起了成核剂的作用，使共混体系的冷却结晶温度Tc较纯PET的Tc升高了1-5℃，但熔体的熔点％基本无变化。抗菌PET纤维具有良好的抗菌性（〉90％）和耐洗性。     

天然纤维素/聚丙烯腈抗菌纳米纤维的制备与表征

为了拓展天然纤维素材料的应用,在综合国内外对天然纤维素材料、纳米材料和抗菌材料相关研究的基础上,首先,利用LiCl/二甲基乙酰胺(DMAC)溶剂体系配置了不同共混比例的天然纤维素/聚丙烯腈纺丝液,采用静电纺丝技术制备了纤维素/聚丙烯腈纳米纤维。然后,用铜氨溶液对纳米纤维进行了抗菌处理,制备了具有一定抗菌功能的纤维集合体。最后,采用SEM观察不同共混比例下纳米纤维的微观形貌;采用TG和DSC表征其热性能;采用FTIR和表面接触角测量仪表征共混后纳米纤维的化学组成和亲水性的变化;采用振荡法测定纳米纤维的抗菌性能。结果表明:通过静电纺丝技术可制得直径在200~400nm范围内的纤维素/聚丙烯腈纳米纤维。随着纤维素含量的提高,纳米纤维的表面越来越粗糙,粘连愈加严重,且直径离散度也变大。当纤维素与聚丙烯腈的共混质量比大于75∶25时,纤维的直径标准偏差由纯聚丙烯腈纤维的100nm以下变为150nm以上。纤维素/聚丙烯腈纳米纤维具有良好的热性能,与纯纤维素纳米纤维相比热稳定性有一定提高,当纤维素与聚丙烯腈的共混质量比为25∶75时热稳定性最好。纤维素/聚丙烯腈纳米纤维的亲水性优于普通医用纱布的。经过铜氨溶液抗菌处理的纳米纤维具有良好的抗菌性能,对金黄色葡萄球菌和大肠杆菌的抑菌率分别为82%和75%。     

静电纺聚丙烯腈纳米纤维膜的制备及性能研究

目前,采油废水随着石油开采难度的增加,治理难度也相应提高。采用静电纺丝技术,以聚偏氟乙烯(PVDF)、聚丙烯腈(PAN)为原料,N,N-二甲基酰胺(DMF)、N-甲基吡咯烷酮(NMP)为溶剂,制得了不同比例的PVDF/PAN纳米纤维膜。并对所做出来的PVDF/PAN纳米纤维膜的形貌和性质进行表征,优选出了最佳比例,在最佳质量比PVDF∶PAN=3∶2的基础上,优选出质量分数12%的PVDF/PAN纳米纤维膜进行实验。结果表明:此膜对采油废水的处理效果显著。     

聚丙烯腈/石墨烯纳米复合物的制备、表征及其热性能

采用以水和N,N-二甲基甲酰胺的混合溶剂作反应介质的沉淀聚合法制备了聚丙烯腈/石墨烯纳米复合物。利用傅里叶红外光谱(FT-IR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)和广角X射线衍射(XRD)研究了聚丙烯腈/石墨烯复合物的组成、结构、形貌及两组份的相互作用。利用差式扫描量热分析(DSC)研究了聚丙烯腈及纳米复合物的热性能。结果表明,强极性的聚丙烯腈与石墨烯之间存在较强的非共价相互作用;由于石墨烯的加入,聚丙烯腈的玻璃化转变温度提高了30℃;石墨烯添加量为3%(质量分数)时,聚丙烯腈在氮气和空气中的环化反应放热峰值分别提高了3和11℃;石墨烯使聚丙烯腈在热稳定化过程中的环化反应和氧化反应放热峰宽化、缓和。     

聚丙烯腈纳米纤维的辐射氧化及热性能变化

采用静电纺丝法制备出平均直径300nm左右的聚丙烯腈(PAN)纤维,利用γ射线在室温及空气气氛中对PAN纳米纤维进行辐照处理,吸收剂量50~500kGy。采用红外光谱仪、X射线光电子能谱仪、差示扫描量热仪及热失重分析仪研究了辐射氧化对PAN纳米纤维结构以及热性能的影响。结果表明,辐射氧化可直接在PAN纳米纤维分子链上引入含氧官能团,有利于预氧化过程中脱氢反应的发生。同时可在室温下引发PAN纳米纤维的部分环化反应生成-C=N-共轭结构,其含量随吸收剂量的增加而增加,可有效降低环化放热峰的强度并缓和放热行为。这些结果表明辐射氧化工艺在碳纳米纤维制造领域有很好的潜在应用价值。     

静电纺丝法制备聚丙烯腈/聚醋酸乙烯酯复合纳米纤维膜

采用静电纺丝法制备了聚丙烯腈(PAN)/聚醋酸乙烯酯(PVAc)复合纳米纤维膜。利用原子力显微镜(AFM)、电子显微镜(SEM)分析了纤维的直径分布、整体形貌及单根纳米纤维的表面形貌;利用傅里叶变换红外光谱(FT-IR)分析了PAN、PAN/PVAc、PVAc纳米纤维膜的化学组成;同时借助热重(TG)分析了PVAc的加入对复合纤维膜热性能的影响。结果表明,当m(PAN)∶m(PVAc)=5∶5、质量分数为10%时,所得纤维膜最有利于制备聚合物电解质膜;PAN与PVAc之间产生配位键,从而提高了纤维膜的热性能。     

甲壳素纳米纤维/蒙脱土复合材料的制备与性能

采用超声混溶-真空抽滤法制备了甲壳素纳米纤维(CNF)/蒙脱土(MMT)插层复合材料,通过FE-SEM和FTIR对复合材料的结构进行表征,并研究了MMT含量对复合材料力学性能、吸水性能、热膨胀系数(CTE)和热稳定性的影响。结果表明: 当MMT含量较少时,CNF与MMT的复合状态较好,CNF较均匀分散在片状MMT的片层间,形成了CNF/MMT插层复合材料;随着MMT含量的增加,复合材料的力学性能和吸水率降低;CNF的增多会抑制MMT的热膨胀,使复合材料的CTE降低;添加MMT可以减少材料的失重率,提高起始降解温度,有利于改善CNF/MMT复合材料的热稳定性。     

聚苯胺/氧化铜纳米复合材料的制备及抗菌性能

通过水热法制得长2μm,直径100 nm~200 nm的氧化铜纳米棒,然后以此纳米棒采用原位聚合法得到了聚苯胺/氧化铜纳米复合材料。并用傅立叶红外光谱（FT-IR）、扫描电镜（SEM）、热重分析（TG）等测试方法对所得复合材料进行了表征。结果表明,聚苯胺对纳米氧化铜表面包覆,得到了棒状核壳结构的复合材料,当氧化铜添加质...     

载Ag/Cu纳米粒子多孔聚丙烯腈复合纤维膜的制备及其抑菌性

金属纳米粒子因其独特的物理化学性能,在催化、抑菌、水污染处理和生物医学等领域表现出巨大的应用前景。但是金属纳米粒子在制备和使用过程中容易发生团聚而影响其性能。因此,提高金属纳米粒子的稳定性,对提升其应用性能具有重大意义。本文在以聚丙烯腈(PAN)为基体,聚乙烯吡咯烷酮(PVP)为致孔剂,基于静电纺丝技术制得多孔聚丙烯腈纳米纤维(PPAN NFs)的基础上,通过浸渍沉积法分别制备出负载银纳米粒子(Ag NPs)复合纳米纤维(Ag-PPAN NFs)和负载铜纳米粒子(Cu NPs)复合纳米纤维(Cu-PPAN NFs)。在利用FESEM、EDS、XRD等方法对制备纤维膜的形貌和结构进行表征的基础上,通过抑菌圈法和FESEM观察经复合纳米纤维处理前后的细菌形貌来研究Ag-PPAN NFs和Cu-PPAN NFs对大肠杆菌、金黄色葡萄球菌和白色念球菌的抑菌性能。研究结果发现：PPAN NFs可有效解决Ag NPs和Cu NPs在制备和使用过程中易于聚集的问题,制得的复合纳米纤维对大肠杆菌、金黄色葡萄球菌和白色念球菌具有一定的抗菌活性,可成为一种新型的抗菌纤维材料。     

甲壳素纳米晶须/聚乳酸复合纤维膜的制备及其抗菌性能研究

采用静电纺丝技术,分别制备了纯聚乳酸(PLA)纳米纤维膜及不同甲壳素纳米晶须(CNW)含量的CNW/PLA复合纳米纤维膜。借助扫描电子显微镜(SEM)观察发现,CNW的添加对纳米纤维形貌的影响不大;通过傅里叶红外变换光谱仪(FT-IR)观察分析表明,CNW已成功加入到PLA纤维中,且未发生化学反应。同时利用改良后的振荡烧瓶法测定复合纳米纤维膜的抗菌性,结果表明:复合纳米纤维膜对大肠杆菌和金黄色葡萄球菌均有良好的抗菌效果,并随着CNW含量的增加,其抗菌效果趋于显著。     

Preparation and electrochemical properties of carbon nanofiber composite dispersed with silver nanoparticles using polyacrylonitrile and beta-cyclodextrin

A simple one-step method was used for preparing the beta-cyclodextrin/polyacrylonitrile (PAN) nanofibers deposited with silver nanoparticles by electrospinning and followed by the reduction of the Ag+ ions. The nano-composite fibers were stabilized at 280 degrees C in air and activated at 800 degrees C for 1 h in steam/N2. The structures of nano-composite fibers were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), fourier-transform infrared (FTIR) spectroscopy, and X-ray diffraction analysis (XRD). The electrochemical behaviors of the composite of carbon nano-fibers were investigated by cyclic voltammetry and charge/discharge tests.     

Preparation and tribological performance of chemically-modified reduced graphene oxide/polyacrylonitrile composites

Interface control and dispersion of graphene base nanomaterials in polymer matrix are challenging to develop high comprehensive nanocomposites due to their strong interlayer cohesive energy and chemical inertia. In this research, an efficient approach is presented to functionalize reduced graphene oxide nanosheets by N-[3-(trimethoxylsilyl)propyl]ethylenediamine, which is dispersed into polyacrylonitrile to prepare N-[3-(trimethoxylsilyl)propyl]ethylenediamine – reduced graphene oxide/polyacrylonitrile nanocomposites. A thermogravimetric analysis technique was employed to evaluate thermal properties of the nanocomposites. The tribological properties of the polyacrylonitrile/graphene nanocomposites were investigated. The morphologies and volume of the worn surface were examined using a 3D profilometer. The impact of loading ratio on friction coefficient, carry-bearing capacity and durability were studied. The N-[3-(trimethoxylsilyl)propyl]ethylenediamine – reduced graphene oxide/polyacrylonitrile nanocomposite with appropriate loading ratio of reduced graphene oxide exhibited a high load-bearing capacity and durability. Therefore, the polyacrylonitrile/graphene nanocomposite shows promising potential to industrial applications involving the lubrication and anti-wear.     

Review of the mechanical properties of carbon nanofiber/polymer composites

In this paper, the mechanical properties of vapor grown carbon nanofiber (VGCNF)/polymer composites are reviewed. The paper starts with the structural and intrinsic mechanical properties of VGCNFs. Then the major factors (filler dispersion and distribution, filler aspect ratio, adhesion and interface between filler and polymer matrix) affecting the mechanical properties of VGCNF/polymer composites are presented. After that, VGCNF/polymer composite mechanical properties are discussed in terms of nanofibers dispersion and alignment, adhesion between the nanofiber and polymer matrix, and other factors. The influence of processing methods and processing conditions on the properties of VGCNF/polymer composite is also considered. At the end, the possible future challenges for VGCNF and VGCNF/polymer composites are highlighted.     

Preparation of single-walled carbon nanotube/silicon composites and their lithium storage properties

Single-walled carbon nanotube (SWCNT)/silicon composites were produced from the purified SWCNTs and Si powder by high-energy ball-milling and then electrochemically inserted with Li using Li/(SWCNT/Si) cells. The highest reversible capacity and lowest irreversible capacity of the SWCNT/Si composites were measured to be 1845 and 474 mAh g(-1) after ball-milling for 60 min, respectively. During the charge/discharge process, most of the Li ions were inserted into the SWCNT/Si composites by alloying with Si particles below 0.2 V and extracted from the SWCNT/Si composites by dealloying with Si particles around 0.5 V. The enhanced capacity and cycle performance of the SWCNT/Si composites produced by high-energy ball-milling were due primarily to the fact that SWCNTs provided a flexible conductive matrix, which compensated for the dimensional changes of Si particles during Li insertion and avoided loosening of the interparticle contacts during the crumbling of Si particles. The ball-milling contributed to a decrease in the particle size of SWCNTs and Si particles and to an increase in the electrical contact between SWCNTs and Si particles in the SWCNT/Si composites.     

超声作用下树脂基磁致伸缩复合材料的制备及其性能

树脂基磁致伸缩复合材料是由Terfenol-D颗粒分散在树脂基体内形成的一类复合材料,颗粒的分散均匀性以及颗粒与基体界面的粘结紧密性是影响其性能的两个重要因素.由于颗粒与基体润湿性差,机械搅拌制备的磁致伸缩复合材料,普遍存在分散不均,孔隙率高等缺点.高强度超声在液态树脂中传播时,会产生空化、声流等非线性声学效应,对促进颗粒分散和改善固液界面具有一定的作用.以环氧树脂为基体,分别采用机械搅拌法和高能超声法制备了Terfenol-D颗粒体积含量为50%的树脂基磁致伸缩复合材料.对两种材料进行了SEM分析及力学和磁致伸缩性能测试.实验结果表明,较之机械搅拌法,超声分散法制得的磁致伸缩复合材料具有颗粒分散均匀,孔隙率低,颗粒与基体的界面结合性好,弹性模量高,磁致伸缩应变大等优点.     

Preparation of acetylcellulose/silica composites by sol-gel method and their mechanical properties

Acetylcellulose (AC)/silica composites were prepared by sol-gel method in an attempt to realize materials with Young's moduli and bending strengths similar to those of cortical bones. Si(OCH₃)₄ (TMOS)-AC-H₂O-HNO₃-tetrahydrofuran-CH₃OC₂H₄OH solutions were allowed to be gelled, where AC/TMOS mole ratios were defined for AC monomers, and the gels were dried at 30–70^∘C to obtain composites. The composites prepared from solutions of mole ratios of AC/TMOS = 0.5 and 1.0 were composed of micrometer-sized particles rich in silica surrounded by the matrix rich in AC. The composites from solutions of AC/TMOS = 2.0, on the other hand, the interface between the particles and the matrix was much less distinct. All the composite samples showed good machinability, which could be cut into 5 mm × 2 mm × 4.4 mm rectangular specimens by an electric saw without cracking or fracture. The specimens were subjected to three-point bending test, where the degree of plastic deformation and the fracture strain increased, and Young's modulus and bending strength decreased with increasing AC/TMOS ratio in the starting solutions. When the gels were dried at higher temperatures, Young's modulus and strength increased. Young's modulus and bending strength could be varied in the range of 1.8–3.9 GPa and 48–100 MPa, respectively, by varying the AC/TMOS ratio in solutions and the drying temperature.