共查询到17条相似文献,搜索用时 109 毫秒
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静电纺丝方法制备的纳米纤维膜的强度主要来源于其纤维间的缠接,因此强度较低。对壳聚糖(CS)/聚乙烯醇(PVA)纳米纤维膜采用了热熔处理的方法,使纳米纤维之间发生热熔,研究了热熔处理对纳米纤维微观结构、力学性能和亲水性能的影响。扫描电镜结果显示,热熔处理后的纳米纤维间出现熔接的现象,同时伴有部分纤维的断裂。力学性能测试表明,热熔处理能够提高纳米纤维膜的力学性能,热熔温度为100℃时,纳米纤维膜的力学性能提升最高。水接触角测试表明,热熔处理会使得纤维结构更为致密,导致其水接触角增大;XRD和FT-IR测试表明,热熔处理在增大纳米纤维膜结晶性的同时,未明显改变纳米纤维膜的化学结构。 相似文献
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以聚乙烯醇(PVA)为原料、去离子水为溶剂,通过静电纺丝制备PVA纳米纤维膜,利用正交实验探讨静电纺丝过程中纺丝液PVA浓度、纺丝距离、纺丝电压和注射速度对PVA纳米纤维膜形貌及纤维直径的影响,得出制备纤维膜的较佳工艺条件,并分析了纺丝液PVA浓度对纤维膜的力学性能和亲水性能的影响。结果表明:随着纺丝液PVA浓度的增加,PVA纤维的直径逐步变小,直径分布变窄;当纺丝液PVA质量分数为7%、纺丝电压为14 kV、纺丝距离为14 cm、注射速度为0.5 mL/h时,纤维膜的纤维直径最小,为203 nm;正交实验中PVA浓度、纺丝电压、纺丝距离、注射速度4个因素的极差值分别为87.00,49.67,18.33,11.67;纺丝液PVA质量分数从5%增加到7%,纤维膜的断裂强度从2.21 MPa提高至2.81 MPa,断裂伸长率从31.63%提高至56.39%,水接触角从37.7°提高至48.7°。 相似文献
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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. 相似文献
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以水为溶剂,采用明胶、海藻酸钠、水溶性壳聚糖及其混合物进行螺旋静电纺丝,考察溶液粘度、电导率、表面张力对螺旋静电纺丝的影响。研究发现:明胶、明胶/海藻酸钠、明胶/水溶性壳聚糖静电纺丝,可得到直径分别为176nm、112nm、103nm的光滑连续纤维;海藻酸钠具有较高的电导率,纺丝得到平均直径为93nm的超细纤维;纯的水溶性壳聚糖,由于具有较高的表面张力,在收集器上仅得到细小的液滴。结果表明:溶液粘度、电导率直接影响纺丝纤维的形态,而表面张力的大小则关系到溶液的可纺性。 相似文献
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Katarzyna Bialik-Ws Klaudia Pluta Dagmara Malina Mateusz Barczewski Katarzyna Malarz Anna Mrozek-Wilczkiewicz 《International journal of molecular sciences》2021,22(21)
The impact of different amounts of glycerin, which was used in the system of sodium alginate/poly(vinyl alcohol) (SA/PVA) hydrogel materials on the properties, such as gel fraction, swelling ability, degradation in simulated body fluids, morphological analysis, and elongation tests were presented. The study shows a significant decrease in the gel fraction from 80.5 ± 2.1% to 45.0 ± 1.2% with the increase of glycerin content. The T5 values of the tested hydrogels were varied and range from 88.7 °C to 161.5 °C. The presence of glycerin in the matrices significantly decreased the thermal resistance, which was especially visible by T10 changes (273.9 to 163.5 °C). The degradation tests indicate that most of the tested materials do not degrade throughout the incubation period and maintain a constant ion level after 7-day incubation. The swelling abilities in distilled water and phosphate buffer solution are approximately 200–300%. However, we noticed that these values decrease with the increase in glycerin content. All tested matrices are characterized by the maximum elongation rate at break in a range of 37.6–69.5%. The FT-IR analysis exhibits glycerin changes in hydrogel structures, which is associated with the cross-linking reaction. Additionally, cytotoxicity results indicate good adhesion properties and no toxicity towards normal human dermal fibroblasts. 相似文献
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Hyun Woo Lee Mohammad Rezaul Karim Hyun Mi Ji Jin Hyun Choi Han Do Ghim Sung Min Park Weontae Oh Jeong Hyun Yeum 《应用聚合物科学杂志》2009,113(3):1860-1867
Poly(vinyl alcohol) (PVA)/montmorillonite clay (MMT) nanofiber mats have been fabricated by the electrospinning technique. The PVA/MMT nanofiber mats were characterized by X‐ray diffraction (XRD), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), and mechanical measurements. The study showed that the introduction of MMT results in improvement in tensile strength, and thermal stability of the PVA matrix. XRD patterns and SEM micrographs suggest the coexistence of exfoliated MMT layers over the studied MMT contents. FTIR revealed that there might be possible interaction occurred between the MMT clay and PVA matrix. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009 相似文献
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肝素化聚乙烯醇性能研究 总被引:1,自引:0,他引:1
用聚乙烯醇(PVA)缩醛化方法,共价键结合肝素。用Schiff试剂染色法、红外光谱分析、X射线光电子能谱法(ESCA)、元素分析等测试方法证明醛基和肝素的存在。力学性能测定表明,肝素化聚乙烯醇的拉伸强度达到12 25MPa,断裂伸长率为400%。生物学指标说明,在全血凝固时间实验(CT)中,肝素化聚乙烯醇的抗凝时间达3h,在活性部分凝血时间实验(APTT)中,缩醛化聚乙烯醇共价键结合肝素非常牢固,没有肝素脱落到血液中,证明肝素化聚乙烯醇具有显著的抗凝血性。 相似文献
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We aim to couple the electrospinning in‐line with solution chemistry to fabricate novel crosslinked polymer nanofibers. Poly(vinyl alcohol) (PVA) was used as a model polymer due to its high amount of hydroxyl groups. To obtain ideal parameters for electrospinning, pure PVA was explored primarily. To gain crosslinked fibers, PVA was first crosslinked partially with glutaraldehyde (GA) followed by transferring this precursor to a long hot tube which was used as reactor and then electrospun right before gelation. The preheating time and tube‐passing time were determined with viscometer and rheometer. The reactive as‐spun fibers could maintain their original morphology after water immersion due to their high crosslinking degree. The thermal stability and mechanical property of reactive as‐spun fibers were improved drastically compared with pure and GA vapor crosslinked PVA fibers. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
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Poly(vinyl alcohol) modified with carboxylic acid anhydrides: crosslinking through carboxylic groups
The reaction of carboxylic acid anhydride with poly(vinyl alcohol) (PVA) leads to vinyl alcohol—vinyl ester copolymers which contain carboxylic acid groups. Esterification enables degrees of modification to be reached which depend on the chemical structure of the anhydride introduced and the ratio of the reagents in the feed. The copolymers obtained were characterized by spectroscopic techniques, elemental analysis, and thermal methods. These half-esters reacted in a second step with aromatic diglycidyl ethers to obtain tridimensional networks. This crosslinking reaction through the carboxylic groups was studied by differential scanning calorimetry. The water absorption of the linear and crosslinked polymers was determined gravimetrically as a function of time at room temperature. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:1643–1651, 1997 相似文献