静电纺丝制备有序纳米纤维的研究进展

2000年以来,静电纺丝技术成为高分子材料和纳米技术研究领域的一个新的热点。综述了近年来采用静电纺丝法制备有序纳米纤维的研究进展,并讨论了有序纳米纤维的潜在应用。     

Electrospinning of Tough and Elastic Liquid Crystalline Polymer–Polyurethane Composite Fibers: Mechanical Properties and Fiber Alignment

Tough and elastic microfiber composites composed of an elastic polyurethane (Hydrothane) and a liquid crystalline polymer (Vectran) are fabricated via electrospinning. The composite fibers (HVC) are examined as a function of the mixing ratio of the polymers and evaluated on the bases of fiber formation, morphology, thermal properties, mechanical performance, and fiber alignment. The fiber diameters of the HVCs decrease as the content of Vectran increases. When the fibers are aligned via a rotating target, they have even smaller diameters and increased uniformity than when a static target is employed. Surprisingly, the aligned fibers’ mechanical properties are different than those of random orientation; the HVC fibers of random orientation display increases in strength, toughness, and elastic modulii when increasing amounts of Vectran are incorporated in the fibers. The aforementioned mechanical properties of the aligned fibers decrease somewhat as the content of Vectran is increased. Further, the durability of the aligned fibers is examined by extensional durability tests over ten cycles. The tests indicate that the HVC fibers are very durable and can function as tunable, tough, and elastic fibrous polymer scaffolds and have potential applications in high‐performance composites, polymeric filtration devices, and fibrous bioengineering materials.     

静电纺丝法制备醋酯纳米纤维的最新研究进展

采用静电纺丝法制备醋酯纳米纤维,既可以保留醋酯纤维的耐化学性和可生物降解性等优点,又具有纳米材料的高比表面积、高孔隙率和量子效应。综述了近几年国内外静电纺丝法制备纳米级醋酯纤维的最新研究进展,系统介绍了几种新型纳米纤维结构的制备方法、原理及影响因素,同时对醋酯纳米纤维在吸附过滤方面的应用研究状况进行了概述,最后对静电纺丝法制备醋酯纤维的发展前景进行了展望。     

熔体静电纺丝装置中内外锥面喷头电场的研究

研制了一种新型熔体静电纺丝装置,研究其纺丝喷头为内外锥面不同形状时的电场分布规律及电场对纺丝过程和纤维直径的影响。采用有限元法(ANSYS软件)模拟纺丝电场,并与实验对照分析,发现两种情况下电场分布基本相同,外锥面喷头的最大场强明显比内锥面喷头大,纤维直径也较小,同时发现纺丝距离和外加电压对电场和纤维直径有较大影响。为进一步细化纤维,对内锥面喷头装置通入热风辅助纺丝,发现纺得纤维较外锥面更细,直径在10μm以内,最小平均直径约为3μm。     

坩埚拉丝监控系统及软件的设计

针对中小工厂拉丝工艺控制自动化程度较低的情况,本文介绍了一种坩埚拉丝监控系统及其软件的设计。该系统利用工控机和自行研制的基于AT89S52,PIC16F628A单片机的智能控制仪实现了40路铂金坩埚工作情况的在线监控,并在九江长江玻璃纤维有限公司获得成功应用,取得了明显的经济效益。     

Molecularly Imprinted Electrospinning Polyethersulfone Nano-Scale Fibers for the Binding and Recognition of Bisphenol A

Molecularly imprinted polyethersulfone (PES) nano-scale fibers were prepared by using electrospinning technique, and then used for the recognition and binding of endocrine disrupter bisphenol A (BPA) from aqueous solutions. As an alternative to synthesizing molecularly imprinted nanofibers using ‘template-guided’ or molecular self-assembly method, the route has proven to be one of simplicity and convenience. The imprinted PES nano-scale fibers with the diameter ranged from 200 nm to 500 nm could be easily used for the binding and recognition of BPA as that by using PES microfibers and particles, and the nano-scale fibers showed good performance for specific recognition of BPA. Significantly higher binding amount and speed were observed compared to the imprinted PES particles and microfibers.     

熔体静电纺丝中电极结构对电场和纤维的影响

采用Ansys数值模拟方法,建立了电场分析的有限元模型,研究了电极结构不同时的电场分布及其对纤维直径的影响,以及电压大小对纤维直径的影响。并进行了实验对照分析,发现电极结构包括圆板电极和圆环电极影响熔体静电纺丝的电场分布,但场强最大都出现在喷嘴处,并随接收距离的增大成不同趋势减小,但中空电极能集聚电场,稳定场强,获得更细的纤维。     

Controlling Fiber Morphology and Scaffold Design for Treatment of Dry Age-Related Macular Degeneration

Polystyrene (PS), poly(ethylene terephthalate) (PET), and polyurethane (PU) were electrospun in various solvents, to ascertain the ideal conditions for reproducible scaffold production, in order to develop a synthetic Bruch's membrane. Effects of different environmental factors under laboratory conditions and controlled conditions, with and without 1% NaCl, were investigated. For PS, environmental conditions were more important than NaCl addition in fiber diameter reduction; however, NaCl addition showed reduced fiber size variation. For PET, reduction in fiber diameter on addition of NaCl compared to controlled environmental conditions was observed. Fiber size variation for PET was unaffected by NaCl addition or controlled conditions.     

Electrospinning polycaprolactone dissolved in glacial acetic acid: Fiber production,nonwoven characterization,and In Vitro evaluation

The electrospinning of polycaprolactone (PCL) dissolved in glacial acetic acid and the characterization of the resultant nonwoven fiber mats is reported in this work. For comparison purposes, PCL fiber mats were also obtained by electrospinning the polymer dissolved in chloroform. Given the processing parameters chosen, results show that 14 and 17 wt % PCL solutions are not viscous enough and yield beaded fibers, 20 and 23 wt % solutions give rise to high quality fibers and 26 wt % solutions yield mostly irregular and fused fibers. The nonwoven mats are highly porous, retain the high tensile strain of PCL, and the fibers are semicrystalline. Cells adhere and proliferate equally well on all mats, irrespective of the solvent used in their production. In conclusion, mats obtained by electrospinning PCL dissolved in acetic acid are also a good option to consider when producing scaffolds for tissue engineering. Moreover, acetic acid is miscible with polar solvents, which may allow easier blending of PCL with hydrophilic polymers and therefore achieve the production of electrospun nanofibers with improved properties. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 41068.     

An Explicit Solution for Concentration Polarization for Gas Separation in a Hollow Fiber Membrane

In the present work, a one-dimensional mathematical model is developed to analyze the concentration polarization phenomenon for the separation of gas mixtures in composite hollow fiber membranes. An analytical expression is developed for determining the interfacial concentration at the interface of dense and porous support layers. Further, the model accounts for the non-ideality of the gas mixture. Both co-current and counter-current flow configurations for the separation of hydrogen from a three-component mixture are studied. The effects of feed side pressure and velocity as well as permeability on concentration polarization are probed. It is apparent from this study that the concentration polarization phenomenon significantly affects the separation efficiency at higher permeability values.     

聚酯纤维阻燃技术研究进展

综述了聚酯纤维阻燃化处理方法,分析了卤系和磷系阻燃剂及其对聚酯的阻燃改性作用.介绍了聚酯阻燃的新技术如纳米技术、微胶囊技术、硅系阻燃剂和复配技术.指出了今后聚酯阻燃改性的发展方向.     

Intercalated clays from pentaerythritol stearate for use in polymer nanocomposites

Smectite clays treated with quaternary ammonium salts have been utilized for decades in paints, greases, cosmetics, and personal care products as rheological modifiers. They have also been used in industrial wastewater treatment extensively. In more recent times these surface modified clays have demonstrated benefits in polymer/clay nanocomposites. The use of quaternary ammonium modifiers limits the usefulness of these composites in food packaging because they are not approved for direct food contact. It would be advantageous to have surface modifying chemicals acceptable for direct food contact in these composites. This article reports research conducted on a promising surface modifier pentaerythritol stearate (PS), which is approved by the FDA for inclusion in food as a preservative. The surface modification of montmorillonite with PS is reported in detail as well as the production of nanocomposites with selected polymers made with the modified clay. Molecular modeling and purification of commercial PS samples indicate that the mono‐ and diesters are the critical surface modifiers, although the as received commercial material works well in forming intercalated clay complexes. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

石墨烯/SnO2改性碳纤维阳极降解水中普萘诺尔

采用水热法在碱性条件下制备了石墨烯(G)/SnO₂纳米复合材料,并应用静电纺丝技术以及通过预氧化、碳化等程序制备了基于聚丙烯腈(PAN)掺杂G/SnO₂的改性碳纤维膜(MCFs),并对其进行了SEM、TEM、XRD等表征;将MCFs负载于支撑材料上制成改性碳纤维阳极,同时搭建了电催化反应模块,探究不同条件对所制备阳极催化降解普萘诺尔(PRO)的影响。结果表明,阳极电势和改性碳纤维膜的质量是影响降解率的主要因素;当阳极负载膜的质量相同时,在负载MCFs的情况下催化体系对PRO的降解率远高于负载未掺杂G/SnO₂的碳纤维膜(CFs)的情况;阳极负载MCFs的质量约为80 mg时,体系的PRO的降解率达到了82.6%。     

复合材料用高性能纤维及热塑性树脂发展现状

介绍了芳纶、碳纤维和超高相对分子质量聚乙烯等3种纤维的基本性能、国内外生产及应用情况,还介绍了聚酰胺、聚醚醚酮、聚苯硫醚及聚酰亚胺等4种热塑性树脂的性能及在研发和生产方面与国外的差距,由此提出了加强研究机构与企业充分合作、国产材料应用及原材料质量控制的建议,并对今后热塑性复合材料的发展进行了展望。     

静电纺丝接收装置和辅助电极的研究进展

介绍了圆柱状转鼓、凝固池、旋转圆盘框架、相对圆环、平行电极等静电纺丝的接收装置;简述了刀锋型、平行、圆筒型及其改进的静电纺丝辅助电极;分析了接收装置和辅助电极对静电纺丝制备微/纳米纤维外貌观形貌和性能的影响;通过对静电纺丝接收装置的改进和增加辅助电极,可获得不同形态和结构的微/纳米纤维。     

2014年合成纤维及原料市场回顾与2015年展望

2014年,世界及中国经济增长放缓,合成纤维行业需求增长有限,产能过剩日趋严重,价格及毛利大幅下跌。预计2015年,全球经济增速有所加快,拉动国内合成纤维产品需求及出口增长,但行业过剩状况依旧,特别是亚洲地区产能过剩现象突出;国内对二甲苯及乙二醇缺口仍较大。     

中国化纤产业技术发展之路

简要回顾了中国化纤工业技术的发展历程,客观分析了中国化纤产业未来发展的技术基础,探讨了化纤产业"十一五"和更长时间内技术发展的方向。     

合成纤维阻燃改性的技术进展

介绍了聚酯、聚酰胺、聚丙烯腈及聚丙烯等合成纤维的阻燃改性技术现状,主要有添加共混型、共聚反应型阻燃改性。纤维阻燃改性的新技术有超细/纳米技术、微胶囊技术、硅系阻燃、复配技术及功能复合化。指出了今后合成纤维阻燃技术应向多功能化发展。     

间位芳纶中残留溶剂的检测方法

建立了气相色谱法测定间位芳纶中残留溶剂——N,N-二甲基乙酰胺的分析方法。通过试验筛选确定了萃取剂为丙酮、萃取时间为2 h,经过萃取后对萃取液进行气相色谱分析,采用标准加入法进行定量。该方法具有灵敏度高、检出限低、操作简便等特点;同时可以用于企业进行工艺优化和质量控制,为今后研究间位芳纶等高性能纤维中残留溶剂的检测方法提供了技术支撑。