全氟烷基乙烯基醚合成的研究进展

全氟烷基乙烯基醚(PAVE)作为含氟单体,与含氟烯烃发生共聚,得到具有特殊功能的有机高分子材料,广泛用于含氟塑料、含氟橡胶和功能材料等领域。在合成方法上,主要包括直接热解法、催化热解法、Zn还原法、加氢脱氯法和含氟砌块法,通过分析这些方法的特点,认为催化热解法和含氟砌块法是比较有应用前景的两种方法。     

含氟高分子基因载体

阳离子高分子被广泛应用为非病毒类基因载体,但这类高分子材料的转染效率与细胞毒性之间通常存在"恶性"关联,即获得高转染效率时往往会伴随严重的细胞毒性.如何制备兼具高效、低毒特点的高分子载体是成功实施基因治疗的关键.含氟高分子是一类具有独特理化性质的高分子,能够在低电荷密度条件下与核酸形成稳定的复合物,从而实现高效、低毒的基因转染.含氟功能基团可帮助阳离子高分子改善复合物稳定性、细胞内吞、内涵体逃逸、胞内核酸释放等多个环节,从而赋予了含氟高分子在基因递送过程中的氟效应.该专论系统地总结了含氟高分子基因载体的研究,介绍了含氟高分子的基因递送性能、作用机理以及在基因治疗、基因编辑中的应用,并对含氟高分子载体的未来发展进行了展望.     

含氟高分子/SiO_2杂化疏水材料的制备及涂层表面性质

采用自由基溶液聚合与溶胶-凝胶法相结合的方法制备了含氟高分子/SiO2杂化疏水材料.通过甲基丙烯酸十二氟庚酯(FA)与乙烯基三乙氧基硅烷(VTES)共聚合成了含氟硅共聚物(PFAS),进一步通过原硅酸乙酯(TEOS)与PFAS共聚物溶液共水解缩聚制备了具有含氟侧基的碳碳主链高分子和硅氧网络的含氟高分子/SiO2杂化疏水材料.研究结果表明,SiO2组分含量提高可以显著增加杂化材料薄膜的涂敷厚度,改善其耐久性能,而对杂化材料疏水性能的影响不大.     

生物基类玻璃高分子材料的研究进展

高分子材料在人类生活中应用广泛,它给人类带来便利的同时也存在2个急需解决的问题.其一,使用后产生的塑料垃圾正在破坏人类赖以生存的环境,尤其是热固性塑料,受到交联网络的限制,材料一旦成型就难以被再次加工.通过引入"类玻璃(vitrimer)"高分子概念,能够使损坏的热固性塑料得到修复,延长其使用寿命并减少塑料垃圾.其二,高分子材料的制备往往需要消耗不可再生的化石资源.面对化石资源的减少及其造成的污染问题,使用可再生的生物质资源制备高分子材料成为有效的解决办法.本文以交联高分子材料为主线,综述了近年来关于使用可再生生物质资源制备类玻璃高分子材料的研究进展,其内容主要包括两方面.第一个方面综述了类玻璃高分子材料的发展史和特点,着重强调了动态共价键往往同时具有重排和分解2种机理;第二个方面综述了生物基类玻璃高分子材料的研究进展,其中涉及的动态共价键种类包括羟基-酯、席夫碱、二硫键和羟基-氨酯,涉及的生物质原料主要包括植物油、木质素、纤维素、天然橡胶、松香及香草醛等.本综述旨在推动解决塑料污染治理及绿色材料的研究和应用.     

含氟芳杂环高分子及其在微电子工业中的研究进展

综述了近年来国内外在含氟芳杂环高分子方面的研究及应用进展情况。主要介绍了含氟聚苯并睬咪唑(PBI)、聚苯并喏唑(PBO)、聚芳醚(PAE)及其衍生物等材料。从含氟单体的合成、聚合物的合成及其应用等几个方面进行了阐述。     

超临界二氧化碳中聚合体系的发展与新型功能高分子材料的制备

因拥有诸多特性,超临界二氧化碳作为聚合反应介质受到了学术界和工业界的广泛关注。近十余年来,超临界二氧化碳中聚合体系的研究有了新的进展,反应介质由单一二氧化碳发展为二氧化碳/水或二氧化碳/有机溶剂复合物,得益于连续搅拌反应装置的出现,聚合方式由间歇式发展为连续式。同时,在超临界二氧化碳中制备得到了多种新型功能高分子材料,例如含氟塑料、含氟弹性体、核壳复合材料、多孔材料以及膜材料,显示出传统溶剂无法比拟的优越性。本文对以上两方面作一介绍和评述。     

New Polymerization Systems in Supercriticai Carbon Dioxide and Related Functional Polymer Materials

因拥有诸多特性,超临界二氧化碳作为聚合反应介质受到了学术界和工业界的广泛关注。近十余年来,超临界二氧化碳中聚合体系的研究有了新的进展,反应介质由单一二氧化碳发展为二氧化碳／水或二氧化碳／有机溶剂复合物,得益于连续搅拌反应装置的出现,聚合方式由间歇式发展为连续式。同时,在超临界二氧化碳中制备得到了多种新型功能高分子材料,例如含氟塑料、含氟弹性体、核壳复合材料、多孔材料以及膜材料,显示出传统溶剂无法比拟的优越性。本文对以上两方面作一介绍和评述。     

导热塑料的研究与应用

随着科学的进步导热塑料应用领域不断扩大,尤其近些年来蓬勃发展的信息产业,为导热塑料提供了新的发展空间.本文对比了高分子材料、金属材料及金属氧化物导热性能,介绍了聚合物的导热机理,并对不同填充含量可适用的导热模型进行了介绍.讨论了提高塑料导热性能的途径和近年来提高导热性能新的研究方法,对非绝缘导热塑料、绝缘导热塑料的应用研究和最新进展作了综述,提出了导热塑料目前存在的问题,展望了导热塑料的应用前景.     

高分子材料的生物降解性能表征

生物降解能够使高分子材料回归自然界物质循环,被认为是解决塑料污染的一大重要途径.高分子材料的生物降解性能表征对相关材料开发、改性和产业应用十分重要.本文针对高分子材料的需氧生物降解,从降解产物和降解残留材料两个方面介绍常用表征方法 .降解产物的表征主要从CO2生成量、O2消耗量和小分子产物三方面开展,降解残留材料的表征围绕其组成结构变化和性能变化.介绍了各表征方法的简单原理和典型案例,并对未来发展进行了展望.     

新型聚(甲基)丙烯酸酯/盐透明材料的制备及其性能

聚(甲基)丙烯酸酯具有优异的透光性、耐光性和耐候性,广泛用作光学塑料.研制高折射率、高耐热性、低吸湿性的透明高分子材料是近年来光学塑料研究和开发的重点之一.本文介绍了新型聚(甲基)丙烯酸酯/盐透明高分子材料的主要制备方法,即新型单体合成-聚合法、共聚法、共混-聚合法和有机-无机纳米杂化法,并系统地总结了各方法的特点以及所制备的材料的性能,展示了目前应用最为广泛的新型单体合成-聚合法和有机-无机纳米杂化法的潜在的应用前景.     

Modeling interband transitions in silver nanoparticle-fluoropolymer composites

The interband transition contributions to the optical properties of silver nanoparticles in fluoropolymer matrices are investigated. For the materials in this study, nanoparticle synthesis within the existing polymer matrix is accomplished using an infusion process that consists of diffusing an organometallic precursor gas into the free volume of the fluoropolymer and decomposing the precursor followed by metal nanoparticle nucleation and growth. The resulting polymer matrix nanocomposite has optical properties that are dominated by the response of the nanoparticles owing to the broadbanded transparency of the fluoropolymer matrix. The optical properties of these composites are compared to Maxwell-Garnett and Mie theory with results indicating that interband transitions excited in the silver nanoparticles affect the optical absorption over a range of frequencies including the surface plasmon resonance. It is shown that calculations of the optical absorption spectrum using published data for the silver dielectric function do not accurately describe the measured material response and that a classical model for bound and free electron behavior can best be used to represent the dielectric function of silver.     

有机光纤研究进展

综述了近年来有机光纤(塑料光纤) 研究状况, 对有机光纤的分类及适用范围也给予了简单的说明。讨论了影响信号传输的因素和有机光纤光传输损耗的极限, 并对当前受到广泛重视的渐变型有机光纤的研究进展给予了特别的关注。     

Properties of thin Teflon AF 2400 coatings deposited onto carbon fabric from solutions in supercritical carbon dioxide

For the design of hydrophobized conductive gas diffusion layers of the electrodes of polymercontaining fuel cells, of great interest is the method for the formation of a fluoropolymer film from fluoropolymer solution in supercritical carbon dioxide. The present work describes the systematic studies on the carbon-fabric-deposited Teflon AF 2400 coatings obtained by this method. The electrical and geometric characteristics of the coatings, their elemental compositions, and stabilities are studied. It is shown that supercritical carbon dioxide allows the deposited fluoropolymer to penetrate homogeneously into the depth of carbon fabric to form a uniform coating around single individual fibers. The optimum limits of variation in the Teflon AF 2400 amount upon production of the gas diffusion layers of polymer electrolyte, alkaline, and phosphoric acid fuel cells are determined.     

Positionally controlled growth of cells using a cytophobic fluorinated polymer

This paper presents a novel method for cell positioning on a substrate which combines the optical quality of glass and the cell-repelling property of fluoropolymers. The process employs plasma lithography, which utilizes the high-resolution patterning of photolithography along with the versatility of the plasma polymerization. When mammalian cells were grown over these substrates, they avoided the fluoropolymer regions and grew almost exclusively within the exposed glass areas (windows). The patterned surface reproduces the initial design of the mask, offering the possibility to control cell distances and interactions with a versatile arrangement whilst keeping the optical quality of glass for microscopy observation, in particular, when a pristine substrate in needed. This approach opens up possibilities for analysis of biological processes, such as studying cell interactions, with the integration of optical or electrical sensors.     

溶液沉淀法制备ZnS-氟碳聚合物电纺纤维光催化复合材料

利用含有羧基的氟碳聚合物电纺纤维为载体和模板材料,常温溶液条件下利用均匀沉淀法,在纤维表面负载硫化锌纳米粒子。通过控制反应条件,得到氟碳聚合物电纺纤维表面均匀分布、无团聚的直径在十几纳米左右的硫化锌-氟碳聚合物电纺纤维光催化复合材料。光催化复合材料的高比表面积和水中有机物富集能力使其在紫外光辐照条件下对次甲基蓝降解效率明显高于ZnS粉体。重复降解实验显示复合材料具有较好的稳定性和重复光催化能力。     

Capillary zone electrophoresis in laboratory-made fluorinated ethylene propylene capillaries

Capillaries made of fluorinated ethylene propylene (FEP) with an inner diameter of 50 microm have been employed in capillary zone electrophoresis with UV-Vis absorbance detection. The capillaries were made in the laboratory with a recently developed technique using fluoropolymer heat shrink/melt tubing and a tungsten wire as a template for the channel. An electroosmotic flow was obtained in the channels and it is shown that an FEP capillary is more effective for a cationic test solute than a fused-silica capillary. The compatibility of FEP capillaries with optical detection is evaluated briefly.     

EFFECT OF IRRADIATION TEMPERATURE ON GENERAL EQUATION OF SOL FRACTION-DOSE RELATIONSHIP FOR FLUOROPOLYMERS

In this paper, the effect of irradiation temperature on sol fraction-dose relationship of tluoropolymers was studied. It was found that the increasing of irradiation temperature can result in the decreasing of βvalue of fluoropolymer, which increases the crosslinking probability of fluoropolymer. The relationship between crosslinking parameter βand irradiation temperature (T_i)of fluoropolymer is established as follows:β=2.2×10~(-3) T_g+4×10~(-4)(T_g-T_i)+0.206.values of some tluoropolymers calculated from the above expression are in agreement with the experimental values.     

Fluoropolymer chemistry in Russia: Current situation and prospects

The current situation in the fluoropolymer chemistry and industry in Russia was overviewed, including the fluoropolymer manufacture and market related issues. Also, the research and manufacturing cooperation in the framework of the “Fluoropolymer Materials and Nanotechnology” joint venture was discussed.     

Fibroporous polytetrafluoroethylene modified with iron nanoparticles: Structure and electronic and magnetic properties

A method for synthesizing iron-containing nanocomposite based on fibroporous polytetrafluoroethylene (PTFE) is described. Fibroporous PTFE obtained under the radiation of a CO₂ laser on block PTFE is modified in supercritical carbon dioxide (sc CO₂) to form micro- and nanoporous structures. Porous fluoropolymer is treated with a solution of bis(toluene)iron(0) obtained by metal-vapor synthesis (MVS). The composition and structure of iron-containing fluoropolymer is studied by transmission electron microscopy and X-ray photoelectron and Mössbauer spectroscopy. Fe nanoparticles with an average size of 9 nm, consisting of ～30% FeO and ～70% Fe³⁺, are registered in the sample. Fe⁰ nanoparticles are stabilized in fluoropolymer pores and are coated with nanoparticles of nonstoichiometric iron oxides that have superparamagnetic properties.     

Fluorescence detection system for capillary separations utilizing a liquid core waveguide with an optical fibre-coupled compact spectrometer

A fluorescence detection system for capillary liquid separation methods is described. The system is based on a silica capillary coated with a low refractive index fluoropolymer Teflon AF that serves both as a separation channel and as a liquid core waveguide (LCW). A fibre-coupled laser excites separated analytes in a detection point and arising fluorescence is collected at one end of the LCW capillary into the other optical fibre which brings it to a compact charge-coupled device (CCD) array spectrometer installed in a desktop computer. No additional components such as focusing optics or filters are necessary. This system was used for detecting isoelectrically focused fluorescent low-molecular-mass pI (isoelectric point) markers and fluorescein isothiocyanate (FITC) labelled proteins. The ability of the system to acquire fluorescent spectra is also demonstrated.