静电纺丝制备聚己内酯载药纤维工艺参数研究

选用聚己内酯作为载体材料、5-氟尿嘧啶作为承载药物,研究了静电纺丝过程中纺丝液浓度、纺丝电压及收集距离对纤维直径的影响,对制备的聚己内酯载药纤维膜进行元素检测分析及力学性能测试,通过体外药物释放实验,验证了聚己内酯载药纤维膜药物控释的效果.结果表明,随着纺丝液的浓度和收集距离增加,纤维的平均直径增大;随着纺丝电压增加,...     

静电纺丝法制备聚乳酸防粘连纤维膜的研究

对聚消旋乳酸(PLA)及改性材料通过静电纺丝法制备防粘连纤维膜,考察了不同纤维膜在Tg、形貌、力学性能以及降解时间等四个方面的异同。结果显示,不同纤维膜在静电纺丝参数相同的条件下获得的纤维直径相似,加入聚乙二醇(PEG)和ε-己内酯(ε-CL)均可降低PLA的Tg和降解时间,加入ε-CL可大大提高PLA纤维膜的断裂伸长率。     

静电纺丝装置:设计静电纺丝工艺制备纳米纤维

纳米纤维可以产泛用于制备多种材料,如过滤材料、生物传感器、军用防护涂层、三维组织支架、复合材料、药物释放、敷料以及电子器件.为了制备具有所要求物理化学性能的纳米纤维,研究人员提出了多种静电纺丝工艺,如利用特别设计的收集屏、微电机械加工而成的喷嘴以及利用辅助电极稳定纺丝射流;而且,开发新的静电纺丝工艺仍在继续,目的是为了获得某种场合专用的纳米纤维.通过这些工艺,像纤维取向以及纤维网的三维结构等参数最终可以得到控制.讨论了最近提出的静电纺丝工艺,这些工艺可以赋予纤维特定的功能,同时详细叙述了使用的工艺参数与获得的纤维物理性能之间的关系,最后提出了未来的设计方向,即设计出能够制备最佳结构纳米纤维的静电纺丝装置.     

静电纺丝法制备聚乙烯醇-纤维素纳米纤维膜

以废旧涤棉混纺面料为原料,采用化学法对含棉成分进行溶解回收,将得到的纤维素粉末与聚乙烯醇(PVA)、Na Cl配成纺丝液,通过静电纺丝法制备出PVA-纤维素纳米纤维膜。对所纺纤维进行电镜观察,分析静电压、纤维素与PVA质量比、纺丝液中溶质质量分数对纺丝效果的影响。结果表明:随着电压增大,纤维直径先下降后上升;随着纤维素含量的增加,纤维直径逐渐变小;随着溶液浓度的升高,纤维直径逐渐变大。     

静电纺丝制备纳米级纤维的研究

首先介绍了静电纺丝制备纳米纤维的原理及其影响因素,然后归纳、总结了当前国内外静电纺丝制备纳米纤维的研究内容,并对今后的研究提出了建设.     

静电纺丝法制备PVDF纳米纤维

静电纺丝法是聚合物溶液或熔体在静电作用下进行喷射拉伸而获得纳米级纤维的纺丝方法.聚偏氟乙烯(PVDF)具有优异的压电性能,而通过静电纺丝技术制得的聚偏氟乙烯静电纺丝膜具有高孔隙率、轻薄柔韧、透气性好等优点从而广泛应用在传感材料、电池隔膜和生物材料等领域.为了研究最适纺丝工艺,本文通过调节不同的纺丝电压、聚合物溶液浓度以...     

静电纺丝制备纳米级纤维的研究

介绍了静电纺丝制备纳米纤维的原理及其影响因素,归纳、总结了当前国内外静电纺丝制备纳米纤维的研究内容,并对今后的研究提出了建议.     

静电纺丝制备纳米纤维的研究进展

纳米纤维具有直径小、比表面积大和易于实现表面功能化等优点,受到了广泛的关注,而静电纺丝技术被认为是制备聚合物纳米纤维最简单有效的方法,因此国内外学者对静电纺丝技术进行了详细的研究。简单介绍了静电纺丝技术的工作原理,详细阐述了影响静电纺丝的主要工艺参数,包括溶剂、溶液的浓度及黏度、电导率、工作电压、纺丝速度和接收距离等,并叙述了静电纺丝纳米纤维在过滤材料、传感器和生物医学等方面的应用,也指出了该技术存在的一些问题及其应对措施。     

Preparation of core/shell PVP/PLA ultrafine fibers by coaxial electrospinning

This study investigated the process feasibility and stability of core/shell structured bicomponent ultrafine fibers of poly(vinyl pyrrolidone) (PVP) and poly(D ,L ‐lactide) (PLA) by coaxial electrospinning. The morphological structure of the core/shell ultrafine fibers was studied by means of scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. Results suggested that PVP/PLA core/shell ultrafine fibers with drawbacks could be produced from 6 or 8% PVP solutions (inner) in the mixture of N,N‐dimethlformamide (DMF) and ethanol and a 22% PLA solution (outer) in DMF and acetone when the flow rates of inner and outer fluids were 0.05 and 0.1 mL/h, respectively. The tensile modulus and tensile strength of the core/shell PVP/PLA membrane were dramatically lower than those of the electrospun PLA membrane, and its water uptake was twice more than that of the PLA membrane. Membranes made from the biodegradable core/shell ultrafine fibers could be potentially used in loading bioactive molecules for tissue regeneration. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 39–45, 2006     

Preparation and properties of antibacterial,biocompatible core–shell fibers produced by coaxial electrospinning

Coaxial electrospinning is a method for producing fibrous mats with optional features, such as antibacterial properties, controllable release, and hydrophobicity based on shell materials. Because these features are important in biomedical applications, in this study, biocompatible hydrophobic polymer (polycaprolactone) and hydrophilic polymer [poly(vinyl alcohol)] with silver nanoparticles loaded in the core solution were coaxially electrospun. The effect of silver addition on the conductivity and viscosity of the solutions, chemical structure of the fiber mats, mechanical properties, porosity, hydrophobicity, water vapor transmission rate (WVTR), silver release, and antibacterial properties were investigated. Fibers with silver exhibited less porosity and a lower WVTR and a greater contact angle than the fibers without silver. Furthermore, the core–shell fibers reduced the burst release of silver and successfully prevented the growth of Escherichia coli and Staphylococcus aureus bacteria. Therefore, it seems that these fibers are suitable for providing electrospun mats with long‐term antibacterial properties. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44979.     

Fibrous membranes of cellulose acetate and poly(vinyl pyrrolidone) by electrospinning method: Preparation and characterization

Fibrous membranes of cellulose acetate (CA), poly(vinyl pyrrolidone) (PVP) and composite membranes of these polymers, were obtained by the electrospinning method. Using systematic method, the optimal conditions for preparation of fibrous membranes were found. Both CA and PVP a concentration of 8% weight was found. The CA was dissolved in a acetone:water solution, volume ratio 80 : 20 and the PVP is dissolved in ethanol:water solution, ratio volume 85 : 15. The flow rate for both polymers was 1.5 mL h^?1. The same applied voltage value and the distance between the needle and collection plate were for polymer both, 15 kV and 15 cm respectively. The morphology of fibrous membranes and composite membranes were evaluated by scanning electron microscopy (SEM). The CA fibers showed ribon morphology, while the PVP fibers were cilindric, in both cases with diameters in the micrometer range. Thermogravimetric analysis showed that CA had a complete degradation to 445°C, while the fibrous membranes PVP required a value of temperature for degradation of up to 571°C. Fibrous composite membrane PVP/CA/PVP shows a higher value of strain at break (%), and a lower value of tensile strength (MPa) compared to CA/PVP/CA. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

静电纺丝法纺制聚乳酸纳米纤维无纺毡

采用静电纺丝法制备了生物降解聚乳酸(PLLA)纳米纤维无纺毡。分析了纺丝液浓度、电压、接收距离、挤出速度等因素对纤维形态的影响。结果表明:纺丝液的浓度和挤出速度对纤维直径的影响较为明显,溶液挤出速度增大,所得纤维微孔含量及尺寸也增大;适当的电压和接收距离有利于收集无液滴纤维;随着纤维直径的减小,无纺毡的孔径呈减小趋势。在PLLA质量分数为5．7％、挤出速度0．8 mL／h、接受距离 15．5 cm、电压8 kV的静电纺丝条件下,可制备纤维直径为200-400 nm的PLLA纳米纤维无纺毡。     

Synthesis,properties, and applications of polylactic acid-based polymers

Polylactic acid (PLA) is known as one of the greatest promising bioabsorbable and compostable polyesters with the capability of high molecular weight synthesis. Lactic acid condensation, azeotropic dehydration, and condensation ring-open polymerize of lactide are three methods for PLA polymerization. Comprehension of material properties is critical for choosing the right processing method and adjusting PLA characteristics. A variety of mechanical properties of this material, from soft and elastic to stiff and high strength makes PLA suitable for a wide range of applications. Besides, PLA can be blended or copolymerized with other polymeric or non-polymeric substances. Thus, this polymer can achieve suitable chemical, mechanical, and rheological properties. Understanding the role of these properties and selecting a suitable processing technique is necessary for its intended consumer and various applications. This study elaborated a general summary of the polymerization, processing, and characteristics of PLA (i.e., structural diversities, rheological performances, mechanical properties, and permeability). Besides, this work presented some information regarding essential factors that can be used for modifying PLA properties to address the requirements for various applications such as biomedical, food packing, biocomposite, and additive manufacturing.     

Composite core-double sheath fibers based on some biodegradable polyesters obtained by self-organization during electrospinning

Obtaining core-sheath fibers by single-spinneret electrospinning is a recent and straightforward approach to prepare composite fibers. Fibers of more complex architecture consisting of poly(ethylene oxide) (PEO) core, inner poly(l -lactide) sheath sd and outer beeswax (BW) sheath may also be obtained using this method. In the present study we report its applicability for a large series of (bio)degradable polyesters such as poly(ε-caprolactone), poly(d ,l -lactide-co-glycolide), poly(butylene succinate), poly(3-hydroxybutyrate), and poly(l -lactide-co-d ,l -lactide). The fibers have a well-differentiated PEO core, polyester inner sheath and BW outer sheath. The possibility for targeted location of hydrophilic or hydrophobic substances in the core or in the sheaths of the PEO/polyester/BW fibers has been demonstrated using nanosized zinc oxide with unmodified (hydrophilic) or silanized (hydrophobic) surface. PEO/polyester/BW fibrous materials loaded with a model drug (5-nitro-8-hydroxyquinoline) exhibit antimicrobial activity. The obtained results show that single-spinneret electrospinning is a novel and versatile method to prepare core-double sheath composite fibers prospective for various applications such as biomedicine, cosmetics, and food packaging.     

The thermal effects on electrospinning of polylactic acid melts

We demonstrate that melt electrospinning can be a feasible way to produce sub-micron scale polylactic acid (PLA) fibers in this paper. This solvent-free approach to produce sub-micron scale fibers is more environmentally benign than common solution electrospinning processes, and has a potential to increase the production rate significantly. Our experimental results show that temperatures at the spinneret and in the spinning region are critical to produce sub-micron sized fibers: a high-speed photographic investigation reveals that when spinning temperature is below glass transition temperature, whipping of the jet is suppressed by fast solidification in the spinning region, leading to a larger jet diameter. Both thermal and mechanical degradations of PLA in melt electrospinning can be significant but no change in chemical composition is found. Due to rapid solidification, melt electrospun PLA fibers are mostly amorphous, and the small presence of β crystals is noted in the sub-micron scale PLA fibers by XRD studies. The highly oriented structure of PLA fibers gives rise to cold crystallization at around 95 °C, and the degree of crystallinity of fibers increases with increasing the degree of annealing. Finally, PLA nanofibers have directly been electrospun onto cellulose filter media, and a drastic enhancement in collection efficiency of sub-micron sized dust particles is presented. Melt electrospun PLA nanofiber mats with no residual solvent may serve as better filter media and tissue scaffolds than those obtained from solution electrospinning processes.     

Fabrication and morphology control of poly(methyl methacrylate) hollow structures via coaxial electrospinning

A modified electrospinning method known as coaxial electrospinning was used to fabricate poly(methyl methacrylate) (PMMA) hollow structures. In this study to understand morphology control, the effect of processing parameters such as concentration of polymer sheath solution, size of core/sheath capillaries, feed rate, and applied voltage had been evaluated. Morphological observations via scanning electron microscope (SEM) revealed that via the control of polymer concentration within the sheath solution, morphologies such as hollow particles and fibers could be obtained. With the use of fine core/sheath capillaries, micron hollow fibers with walls of less than 20 nm were obtained. This study has demonstrated how the investigated processing parameters have a direct influence on the structures and how these parameters have supported the notion that effective encapsulation process is the key to the dual layer bicomponent structures. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

聚乳酸基纳米纤维素/石墨烯导电复合膜的制备与表征

利用真空抽滤方法,制备了纳米纤维素/石墨烯导电膜,将其嵌在聚乳酸表面得到聚乳酸基纳米纤维素/石墨烯导电复合膜。傅里叶红外（FT-IR）表征结果表明石墨烯与纳米纤维素之间存在一定的相互作用;当纳米纤维素与石墨烯质量比为1：2时,导电复合膜的电导率为12 S·cm^-1,抗张强度达到13.62 MPa,水接触角为80.6°。热重分析（TGA）表征结果表明导电复合膜有良好的热稳定性,300℃时不同质量比的导电复合膜的失重量低于10%,相比纳米纤维素,在相同温度下失重量减少了20%。以聚乳酸材料为基体的导电复合膜,其抗张强度比未被嵌聚乳酸基体的纳米纤维素/石墨烯导电膜提高15～23倍,将聚乳酸基纳米纤维素/石墨烯导电复合膜埋在土壤中5周后,质量损失了3.7%。聚乳酸材料优异的力学性能和可降解性,扩展了纳米纤维素/石墨烯导电复合膜的应用范围。制备的导电复合膜在柔性导电材料领域有潜在的应用前景。     

Orthogonal design study on factors affecting the degradation of polylactic acid fibers of melt electrospinning

Melt electrospinning is a much simpler and safer method in the production of ultra-fine fibers compared with solution electrospinning. However, high-spinning temperature usually leads to serious degradation of polymer materials. In determining factors that affect the relative molecular mass of polylactic acid (PLA) fibers during melt electrospinning, an orthogonal design method was used to examine the influence of melting temperature, spinning distance, and species and content of antioxidants. Results showed that antioxidant content at the present three levels (i.e., 0.1%, 0.3%, and 0.5%) has the most considerable effect on the relative molecular mass of PLA fibers. Error analysis showed that changes in temperature, distance, and antioxidant content influence the experiment's results significantly. All interaction effects were larger than those of the single factor in the experimental results. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012