静电纺丝技术制备无机功能复合纳米纤维的研究进展

目前,静电纺丝技术是唯一能够直接、连续制备聚合物纳米纤维的方法。随着功能材料的发展,单一组分的聚合物纳米纤维在功能上已经不能满足现有的应用领域。由于一些纳米无机功能粉体在光学、电学、催化等方面具有优越的性能,因此逐渐发展成在聚合物中加入纳米级无机功能粉体,采用静电纺丝技术可以得到无机复合纳米纤维,不仅满足了原有的应用性能,而且在一些特殊的领域能够表现出更加优越的性能。为此本文概述了静电纺丝技术在无机复合纳米纤维制备方面的最新研究进展,分析了静电纺丝工艺在制备无机复合纳米纤维方面存在的主要问题。最后指出了静电纺丝技术制备硅藻土复合纳米纤维所面临的问题,以及应该采取的对策。     

静电纺丝技术发展简史及应用

静电纺丝现已成为一种重要的纳米纤维成形技术,制备的纳米纤维也得到了广泛应用。介绍了静电纺丝技术的基本原理及发展历程,以及采用静电纺丝技术制备的纳米纤维品种、纳米纤维的应用领域等。采用静电纺丝技术可以制备各种不同结构和形态的纳米纤维,如有机纳米纤维、有机/无机杂化复合纳米纤维、无机纳米纤维、碳纳米纤维等;通过静电纺丝制备的纳米纤维因具有特殊结构和优异性能,在过滤材料、能源材料、生物医用材料、传感器和光催化等领域得到广泛应用。今后在完善实验室技术的基础上,应加强静电纺丝技术的产业化研究。     

静电纺丝纤维在抗菌领域的应用研究进展

静电纺丝技术是一种特殊的纳米纤维制造工艺,该技术是一种便捷高效的制备纳米纤维的方法,具有技术成本低,工艺成熟等优点。采用静电纺丝技术制备的纳米抗菌纤维具有孔隙率高、比表面积大、纤维均匀和抗菌性能优异等特点。纳米抗菌纤维主要分为无机抗菌纤维、有机抗菌纤维和有机无机复合抗菌纤维。本文主要对这三类抗菌纤维进行总结并对未来抗菌纤维发展进行展望。     

压电纤维的制备及应用研究进展

综述了无机陶瓷压电纤维、有机聚合物压电纤维及复合压电纤维的制备方法,介绍了压电纤维在可穿戴领域、能量收集领域、医疗领域、结构健康监测领域的应用情况。无机陶瓷压电纤维的制备技术包括热塑性挤压法、黏性溶液纺丝法、溶胶-凝胶法,其中热塑性挤压法和黏性溶液纺丝法具有操作简单、绿色环保的特点。有机聚合物压电纤维的制备技术包括熔融纺丝法、湿法纺丝法和静电纺丝法等,其中静电纺丝法制备有机聚合物压电纤维是当前的研究热点。指出未来压电纤维的研究在高压电响应压电纤维的制备、压电纤维与功能性纺织品的整合、压电纺织品的结构设计方面仍有待突破。     

碳纳米管/聚合物纳米复合纤维静电纺丝研究进展

简述了静电纺丝装置的发展及其基本原理;介绍了静电纺丝制备碳纳米管/聚合物纳米复合纤维的技术进展,主要技术是碳纳米管在聚合基体中的分散性以及二者之间的界面结合力;详述了碳纳米管/聚丙烯腈纳米复合纤维和碳纳米管/聚氧乙烯(PEO)纳米复合纤维的制备及技术进展。指出今后应进一步发挥碳纳米管的性能,改进静电纺丝装置。     

聚丙烯腈/氧化铁纳米粒子复合纳米纤维的制备及表征

利用静电纺丝技术制备了一种聚丙烯腈(PAN)/氧化铁(Fe_2O_3)纳米粒子复合纳米纤维。不同分子量的PAN得到不同直径的纤维薄;将PAN的N,N-二甲基甲酰胺溶液(DMF)与纳米Fe_2O_3混合得到PAN/Fe_2O_3溶液,然后利用静电纺丝技术制备PAN/Fe_2O_3纳米粒子复合纳米纤维;将静电纺丝制备的PAN纳米纤维膜与氯化铁(FeCl_3)溶液在不同p H条件下水热合成PAN/Fe_2O_3纳米粒子复合纳米纤维。采用扫描电子显微镜(SEM)、热重分析仪(TGA)对纳米纤维膜进行表征。结果表明:静电纺丝制备的PAN纳米纤维在水热条件下可以一定程度上克服Fe_2O_3纳米粒子易团聚问题。     

LBL技术制备有机/无机纳米复合薄膜研究进展

将高分子和各种功能的无机纳米粒子通过层层吸附自组装技术进行组装,制备厚度可控和稳定性好的有机/无机纳米复合薄膜。综述了该领域研究的最新进展,介绍了利用LBL技术制备有机/无机纳米复合薄膜的方法,并对利用LBL技术制备有机/无机纳米复合薄膜的发展趋势作了展望。     

聚合物电纺纤维的研究进展

静电纺丝(简称电纺)技术是一种制备聚合物纳米纤维的新方法,它可制备出直径为纳米级的超细纤维,最小直径可至1 nm。电纺法制备聚合物纳米纤维具有设备简单、操作容易、成本低廉以及高效等优点,它是目前能直接连续制备聚合物纳米纤维的有效方法。本文介绍了电纺过程、原理及影响纤维性能的主要因素,综述了电纺技术在生物医学材料,复合增强纤维,无机纳米纤维等方面的应用进展,最后对电纺技术在制备聚合物纳米纤维方面的发展前景作出了展望。     

聚合物/无机纳米复合材料研究进展

综述了提高有机,无机纳米复合材料性能的技术。聚合物的纳米复合技术经历了一个从物理到化学的过程。多面体低聚倍半硅氧烷的出现,实现了通过制备可官能化的纳米粒子,使聚合物和无机纳米材料达到真正意义上的化学结合。     

基于乳液聚合法制备无机纳米粒子/聚合物复合粒子及其应用研究进展

综述了国内外通过乳液聚合制备聚合物包覆无机纳米复合粒子的方法及包覆效果,包括纳米SiO2/聚合物、CaCO3/聚合物、TiO2及其他无机粒子/聚合物,介绍了复合粒子的形成机理及其在电极材料、阻燃和感光树脂中的应用,并对其前景作了展望。     

Preparation of atactic poly(vinyl alcohol)/silver composite nanofibers by electrospinning and their characterization

Poly(vinyl alcohol) (PVA)/silver composite nanofibers were successfully prepared by the electrospinning method. Water‐based colloidal silver in a PVA solution was directly mixed without any chemical or structural modifications into PVA polymer fibers to form organic–inorganic composite nanofibers. The ratio of silver colloidal solution to PVA played an important role in the formation of the PVA/silver composite nanofibers. We prepared two different atactic PVA/silver nanocomposites with number‐average degrees of polymerization of 1700 and 4000 through electrospinning with various processing parameters, such as initial polymer concentration, amount of silver colloidal solution, applied voltage, and tip‐to‐collector distance. The PVA/silver composite nanofibers were characterized by field emission scanning electron microscopy and transmission electron microscopy (TEM). TEM images showed that silver nanoparticles with an average diameter of 30–50 nm were obtained and were well distributed in the PVA nanofibers. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Fabrication of Multifunctional Composite Nanofibers by Green Electrospinning

The present work takes advantage of green electrospinning to create novel composite multifunctional nanofibers (NFs) bearing inorganic nanoparticles (NPs), more specifically quantum dots (QDs), cerium oxide nanoparticles (CeO₂ NPs) and iron oxide nanoparticles (Fe₃O₄ NPs). This is achieved by first encapsulating the desired inorganic NPs into polymer particles by the use of miniemulsion polymerization, and second, spinning the hybrid polymer particles using polyvinyl alcohol (PVA) as template polymer. It is proved that using green electrospinning, it is not only possible to ensure an excellent distribution and encapsulation of the inorganic NPs along the NFs, but also allows to control and change the concentration, size, and type of the inorganic NPs without altering the NFs size, a fact that is not possible by conventional solution electrospinning. As proof of concept, NFs with up to three different types of inorganic NPs have been created in a single electrospinning step, but this technology allows to incorporate as much inorganic NPs as desired without altering the NFs morphology and ensuring a good distribution and encapsulation of the NPs. This paper demonstrates that green electrospinning is a powerful and attractive technology to create multifunctional NFs that are promising materials for sensing and biomedical applications.     

Photocatalytic Deposition of Silver Nanoparticles onto Organic/Inorganic Composite Nanofibers

Summary: In this work, silver nanoparticles were embedded in electrospun organic/inorganic composite nanofibers consisting of PAN and TiO₂ through photocatalytic reduction of the silver ions in silver nitrate solutions under UV irradiation. The morphology and diameter of PAN/TiO₂ composite nanofibers could be controlled by varying the initial contents of TiO₂ in the spinning solution. From TEM images and UV‐Vis spectra, it has been confirmed that monodisperse silver nanoparticles with a diameter of ≈2 nm were deposited selectively upon the titania of the as prepared composite nanofibers. The amount of Ag nanoparticles embedded on composite nanofibers was greatly influenced by the amount of TiO₂ in composite nanofibers, reflecting the role of titania as the inorganic stabilizer and photocatalyst.

Morphology of silver nanoparticles embedded on PAN/TiO₂ composite nanofibers.     

聚合物/纳米无机粒子复合材料的制备方法

概述了直接分散法、溶液共混法、溶胶-凝胶法等制备聚合物/纳米无机粒子复合材料的原理和主要工艺,重点介绍用超重力法和微乳液法制备纳米无机粒子。多种制备方法结合使用将非常有效。     

Electrospinning silica/polyvinylpyrrolidone composite nanofibers

Small diameter nanofibers of silica and silica/polymer are produced by electrospinning silica/polyvinylpyrrolidone (SiO₂/PVP) mixtures composed of silica nanoparticles dispersed in polyvinylpyrrolidone solutions. By controlling various parameters, 380 ± 100 nm diameter composite nanofibers were obtained with a high silica concentration (57.14%). When the polymer concentration was low, “beads‐on‐a‐string” morphology resulted. Nanofiber morphology was affected by applied voltage and relative humidity. Tip‐to‐collector distance did not affect the nanofiber diameter or morphology, but it did affect the area and thickness of the mat. Heat treatment of the composite nanofibers at 200°C crosslinked the polymer yielding solvent‐resistant composite nanofibers, while heating at 465°C calcined and selectively removed the polymer from the composite. Crosslinking did not change the nanofiber diameter, while calcined nanofibers decreased in diameter (300 ± 90 nm) and increased in surface area to volume ratio. Nanofibers were characterized by scanning electron microscopy (SEM) and thermogravimetric analysis (TGA). © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40966.     

Study on the mechanical and thermal properties of polylactic acid/hydroxyapatite@polydopamine composite nanofibers for tissue engineering

Electrospun nanofibers have attracted tremendous attention because of their similar structure with extracellular matrix. In this work, the polydopamine (PDA) coating layer was first applied to modify hydroxyapatite (HA) nanoparticles and obtain functional HA@PDA nanoparticles. Subsequently, the polylactic acid (PLA)/HA@PDA composite nanofibers were prepared via electrospinning. The hydrophilicity and water absorption of PLA/HA@PDA composite nanofibers were larger than those of PLA and PLA/HA composite nanofibers. The thermal stability, static and dynamic mechanical properties of PLA/HA@PDA composite nanofibers significantly increased because the PDA coating layer on the surface of the HA nanoparticles acted like a glue-like transition layer, which led to an increase in interfacial adhesion between HA@PDA nanoparticles and the PLA matrix. The attachment and viability of mouse embryonic osteoblast cells (MC3T3-E1) cultured on the PLA/HA@PDA composite nanofibers were significantly increased compared with those cultured on the PLA and PLA/HA composite nanofibers. These results suggested that the PLA/HA@PDA composite nanofibers have superior mechanical and biological properties, which makes it potentially useful for tissue engineering scaffolds.     

Preparation of polymer/inorganic nanoparticles composites through ultrasonic irradiation

In this paper, ultrasonic induced encapsulating emulsion polymerization was first used to prepare the novel polymer/inorganic nanoparticles composites. The behaviors of several inorganic nanoparticles (SiO₂, Al₂O₃, TiO₂) under ultrasonic irradiation, such as dispersion, crushing, and activation, were studied. The dispersion stability, morphology, and structure of the ultrasonic irradiated nanoparticles were characterized by means of transmission electron microscopy (TEM), Fourier transform infrared (FTIR), and spectrophotometry, respectively. The results show that the inorganic nanoparticles in the aqueous solution can redisperse more effectively by ultrasonic irradiation than by conventional stirring. This is the basis for preparation of polymer/inorganic nanoparticles composites. By this technique, the long‐term stable latex, which mainly consists of polymer/inorganic nanoparticles composite latex particles, were successfully prepared. TEM, FTIR, thermogravimetric analysis, X‐ray photoelectron spectroscopy, spectrophotometry, and element analysis confirmed that well‐dispersed nanoparticles were encapsulated by the formed polymer, and the thickness of encapsulating polymer layer was in the range of 5–65 nm. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1478–1488, 2001     

The optical properties of PVA/TiO2 composite nanofibers

The electrospun nanofibers emerge several advantages because of extremely high specific surface area and small pore size. This work studies the effect of PVA nanofibers diameter and nano‐sized TiO₂ on optical properties as reflectivity of light and color of a nanostructure assembly consisting polyvinyl alcohol and titanium dioxide (PVA/TiO₂) composite nanofibers prepared by electrospinning technique. The PVA/TiO₂ composite spinning solution was prepared through incorporation of TiO₂ nanoparticles as inorganic optical filler in polyvinyl alcohol (PVA) solution as an organic substrate using the ultrasonication method. The morphological and optical properties of collected composites nanofibers were highlighted using scanning electron microscopy (SEM) and reflective spectrophotometer (RS). The reflectance spectra indicated the less reflectance and lightness of composite with higher nanofiber diameter. Also, the reflectance and lightness of nanofibers decreased with increasing nano‐TiO₂ concentration. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Study on ultrasonic induced encapsulating emulsion polymerization in the presence of nanoparticles

In this paper, the ultrasonic induced encapsulating emulsion polymerization technique was used to prepare polymer/inorganic nanoparticle composites. The main affecting factors in ultrasonic induced encapsulating emulsion polymerization were studied systematically. The experimental results suggested that the pH value, the type of monomers, the type, content, and surface properties of nanoparticles, the type and concentration of surfactant have great influence on the ultrasonic induced encapsulating emulsion polymerization and the obtained latex stability. If selecting cationic emulsifier (such as cetyl trimethylammonium bromide), low water soluble monomer (such as n‐butyl acrylate and styrene), and hydrophobic nano silica, the inorganic nanoparticles could be encapsulated by polymers through ultrasonic irradiation successfully under alkalescent condition, forming a novel polymer/inorganic nanoparticles composite. The mechanism of ultrasonic induced encapsulating emulsion polymerization and the composite latex stabilization are proposed. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1130–1139, 2001     

A facile approach to fabricate porous nylon 6 nanofibers using silica nanotemplate

Porous Nylon 6 nanofibers were prepared using silica nanoparticles as the template. Firstly, Nylon 6/silica composite nanofibers were prepared as precursors by electrospinning Nylon 6 solutions containing different contents of silica nanoparticles. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) were used to examine the surface morphology and the inner structure of composite nanofibers; where it was found that silica nanoparticles were distributed both inside and on the surface of nanofibers. Analytical techniques [Fourier transform infrared (FTIR), differential scanning calorimetry, thermal gravimetric analysis (TGA), and wide‐angle X‐ray diffraction) were used to study the structure and properties of these composite nanofibers. The glass transition, melting, and crystallization processes of the fibers were affected by the addition of silica nanoparticles. Secondly, porous Nylon 6 nanofibers were obtained by removing silica nanoparticles via hydrofluoric acid treatment. The removal of silica nanoparticles was confirmed using FTIR and TGA tests. SEM and TEM observations revealed the formation of the porous structure in these nanofibers. After the formation of the porous structure, Brunauer–Emmett–Teller specific surface areas of nanofibers were increased as compared to solid Nylon 6 and composite nanofibers. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011