共查询到18条相似文献,搜索用时 46 毫秒
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为了开发高效低阻的空气过滤用纤维膜,采用静电纺丝的方法制备了聚丙烯腈(PAN)静电纺纳米纤维膜.通过改变PAN浓度及静电纺丝时长,得到了不同形貌及过滤性能的静电纺纳米纤维膜.结合场发射扫描电子显微镜等表征方式和过滤性能测试台对静电纺纳米纤维膜形貌及过滤性能进行测试与分析,获得性能最优的PAN静电纺纳米纤维膜的制备参数如下:PAN浓度为9wt%,静电纺丝时长为5.0 h.此条件下制备的静电纺纳米纤维膜厚度为0.0240 mm,平均纤维直径为396 nm,PM2.5过滤效率为99.99%,过滤压降为67Pa,品质因子最高,为0.137Pa-1. 相似文献
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针对传统光致变色纤维膜受酸碱等外界影响易导致变色效率低,以及稳定性不高的问题,提出在传统静电纺丝制备PVA/PEI纳米纤维膜的基础上,负载光致变色纳米微球,然后与戊二醛交联,得到性能稳定的光致变色纤维膜,并考察了PVA/PEI质量比、戊二醛交联以及光致变色纳米微球含量对光致变色纤维膜性能的影响。结果表明:在PVA/PEI的质量比为75∶25,光致变色微球的含量为10%时,经过戊二醛交联的光致变色纤维膜表面光滑,串珠连续且均匀;随着紫外光照的增加,纤维膜的颜色逐步加深,但当光致变色微球的含量大于10%时,颜色不再发生变化;将光致变色纤维膜浸水24h,纤维膜仍保持连续且均匀的多孔纤维结构。根据以上试验看出,纤维膜材料可用于环境领域中,以达到美化环境的目的。 相似文献
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摘要:从静电纺丝射流过程的基本原理出发,结合环境温湿度对同种溶液性能参数和静电纺丝过程中针尖处电荷和介电常数的影响进行理论分析,在现有实验设备的基础上增加了环境温湿度控制系统,通过其实现定温度变湿度、定湿度变温度和综合条件下的低温高湿、中温中湿、高温低湿三组参数进行实验。结果表明,湿度和温度对于静电纺丝过程中针尖之间以及针尖与接收装置之间的挂丝现象和成膜性都有影响,高温低湿的环境可以获得相对稳定且成膜性较好的纤维形貌,而且纤维膜的直径比较均匀,集中在200~350 nm。研究环境温湿度对静电纺丝稳定喷射的影响规律,有助于提高其产业化的可能性。 相似文献
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Xin Guo 《木材化学与工艺学杂志》2017,37(5):383-392
In situ micro-Fourier transform infrared (FTIR) spectra of a typical cellulose nanofiber (CNF) film (i.e., CNF with cellulose I structure) were collected within the full relative humidity (RH) range from 0% to 90%. Red shifts of two peaks at 1036 and 1204 cm?1 and the variation of different spectra indicated the chemical adsorption sites for adsorbed water. From component band analysis of the spectral range of 2900–3700 cm?1, three component peaks at 3293, 3397, and 3543 cm?1 were due to strongly, moderately, and weakly hydrogen-bonded water. The signatures of these three types of hydrogen-bonded water were then observed to rise with an increase in RH. Based on growth regularities of these three types of hydrogen-bonded water, the water adsorption process of CNF film was divided into three stages; most of the water absorbed in these three stages was demonstrated to be CNF???HOH???CNF, WATER????HOH????WATER, and five-molecule tetrahedral structure, respectively. 相似文献
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高度法和压力法测定粉末接触角的比较 总被引:2,自引:0,他引:2
粉体接触角的测定有着十分重要的理论和实际应用意义。根据Washburn方程,在渗透法测定粉末接触角的基础上,引入相对接触角的概念,并设计了测定石墨粉相对接触角的试验装置,以苯作为参比液,用高度法和压力法分别测定了25℃下蒸馏水对石墨粉的相对接触角,它们分别为83.50°和83.74°。试验结果表明,压力法和高度法均可用于粉末接触角的测定。 相似文献
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Xin Guo 《木材化学与工艺学杂志》2013,33(5):361-370
Hygroscopic behavior is an inherent characteristic of nanocellulose film which strongly affects its applications. In order to gain a better understanding of water adsorption, micro-Fourier transform infrared (FTIR) imaging was used to investigate the water adsorption in cellulose nanofiber film with a spatial resolution of 20 um. Four spectral peaks at 2905?cm?1, 1428?cm?1, 1371?cm?1, and 1317?cm?1 attributed to CH and CH2 groups were used to generate 2D micro-FTIR images of cellulose distribution, and the most intense peak at 3348?cm?1 was employed to generate 2D micro-FTIR image of OH group distribution. On this basis, difference 2D micro-FTIR images of OH group distribution at different relative humidity (RH) levels demonstrated the development of adsorbed water distribution in cellulose nanofiber film during the water adsorption process. The study results confirmed that the micro-FTIR imaging was one promising tool for in situ visualization of water adsorption with micron-scale resolution. 相似文献
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以聚丙烯腈与二甲基甲酰胺为原料配制纺丝溶液,采用静电纺丝技术制备玻璃纤维/聚丙烯腈纤维/玻璃纤维三层复合滤材,研究了纺丝溶液浓度与纺丝电压等参数对纤维形貌及尺寸的影响,分析了复合滤材的过滤性能. 结果表明,控制不同纺丝溶液浓度可得形貌不同的纤维,且溶液浓度越大纤维尺寸越大;纺丝电压对纤维形貌的影响较小,但增加纺丝电压使静电纺纤维层的孔径减小. 相比玻璃纤维滤材,复合滤材过滤效率明显提升,稳态效率最大可提升21%,最易穿透粒径效率最大可提升39%,但复合滤材孔径较小时,过程压降增加了一段跳跃阶段,纳米纤维层表面形成液膜,使复合滤材稳态压降升高. 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