聚丙烯腈/离子液体体系研究进展

综述了丙烯腈(AN)在离子液体中的均聚共聚、聚丙烯腈(PAN)在离子液体中的溶解机理、溶液特性以及纺丝成形的研究进展。指出以离子液体为溶剂的AN均聚和共聚反应具有反应快,聚合物相对分子质量分布窄的特点,离子液体是PAN溶解的良好溶剂;PAN/离子液体体系随温度降低呈现出可逆物理凝胶特征,PAN/离子液体具有良好的可纺性,采用干喷湿纺、静电纺丝和增塑纺丝,已制备出各种纤维;建议应进一步加强对离子液体在PAN的聚合、溶解及纺丝成形方面的研究。     

专利文摘

一种间位芳纶纳米蛛网纤维膜的制备方法 本发明公开了一种间位芳纶纳米蛛网纤维膜的制备方法。所述的制备方法为：将间位芳纶溶解于卤盐和有机溶剂混合,配制成的离子液体溶剂体系中,得到间位芳纶电纺原料;将上述间位芳纶电纺原料加入到静电纺丝装置中进行静电纺丝,制得间位芳纶纳米蛛网纤维膜。本发明制备方法过程简单,制得的间位芳纶纳米蛛网纤维膜与普通静电纺纤维膜纤维相比,     

离子液体溶剂法制备再生纤维素纤维

离子液体是纤维素的有效溶剂,可以实现快速溶解。以离子液体生产的再生纤维素纤维较多地保留了纤维素的天然特性,易于生物降解,产品性能优于传统的粘胶工艺。介绍了离子液体的物性、作为纤维素溶剂的优点、对纤维素的溶解机理、纺丝原液制备及纺丝工艺。     

离子液体法纤维素纤维的制备及性能研究进展

对纤维素在离子液体中的溶解、溶解机理、纺丝原液的性质、纺丝工艺及纤维性能等进行了综述,认为离子液体作为一种新型纤维素溶剂,具有溶解速度快、溶解度大、对纤维素降解程度小、溶剂回收简单、回收率高等特点,且再生的纤维素具有良好的光泽和力学性能。     

纤维素在离子液体中的溶解及应用进展

综述了离子液体对纤维素的溶解作用及其应用,主要包括溶解现象、溶解机制以及溶解和再生前后纤维素化学物理结构的变化,并简述了现阶段离子液体在纤维素纺丝领域的应用进展。     

离子液体再生纤维素纤维工艺技术试验研究

介绍了纤维素在离子液体中的溶解与纤维成形机理和纤维素/离子液体溶体的制备,以及不同纤维素浓度、凝固浴浓度、凝固浴温度、拉伸比等条件的纺丝试验,对成形纤维的物理机械性能、截面形态进行了测试分析。纤维素/离子液体溶体的纺丝试验表明,采用干喷湿纺技术,以离子液体/水为凝固浴体系,成形纤维具有较高的强度。     

静电纺丝中电荷不平衡状态及临界电压的变化

通过测试聚乙烯醇(PVA)溶液静电纺丝过程中的剩余溶液离子电导率和表面张力的变化,研究了静电纺丝过程中溶液带电性质和表面张力的变化规律,揭示了引起临界电压变化的原因。结果表明:Taylor临界压力降与纺针直径、长度、溶液的表面张力及接收距离相关外,还受临界电压及溶液的介电常数、离子电导率等带电性质的影响;静电纺丝射流形式与电源极性及电场方向无关;静电纺丝过程中的剩余溶液的带电性质是不断变化的,随着静电纺丝的进行,剩余溶液将出现电荷不平衡状态,而去除强电场后,剩余溶液将恢复电荷平衡状态。     

不同溶解方法制备的纤维素/[BMIM]Cl纺丝液的性能比较

以离子液体1-丁基-3-甲基咪唑氯盐([BMIM]Cl)为溶剂,分别采用直接溶解法和间接溶解法(即在含水[BMIM]Cl中溶胀后再减压蒸馏去除多余的水使之溶解)制备了纤维素/[BMIM]Cl纺丝液,系统地比较了这两种纺丝液的流变行为及可纺性。结果表明:相同条件下,直接溶解法制备的纤维素/[BMIM]Cl纺丝液的表观黏度最大,而间接溶解法制得的纺丝液的表观黏度随着溶胀时[BMIM]Cl的初始含水率的增加而下降。与直接溶解法相比,间接溶解法制得的纺丝液溶解均匀、流动性能好、纺丝过程中断头次数少、可纺性能提高,所得到的再生纤维素纤维具有更好的力学性能。     

一种在离子液体中制备高性能碳纤维用聚丙烯腈纺丝原液的方法

正一种在离子液体中制备高性能碳纤维用聚内烯腈纺丝原液的方法,将丙烯腈二元共聚体系中的单体或丙烯腈三元共聚体系中的单体依次加入离子液体中,室温溶解,加入引发剂,并通入惰性气体,进行自由基聚合反应。反应结束后用冰浴停止聚合反应,以水凝固聚合产物并反复进行水洗烘干纯化后得到聚丙烯腈粉料。利用二甲基亚砜作为溶剂将上述得到的聚丙烯腈粉料搅拌溶解,得到高性能碳纤维聚内烯腈纺丝原液。该方     

氮化硼纤维合成工艺与结构表征

硼酸和三聚氰胺以一定配比合成氮化硼前驱体高聚物.将该前驱体超声溶于甲酸溶液,在静电纺丝电压25 kV,正负极距离18 cm的条件下,可通过静电纺丝法制备直径均匀的纤维.将该电纺纤维放入马弗炉,以10℃/min升温速率加热至600℃和850℃,保温不同时间,可制备白色BN纤维.利用SEM、TEM、TG-DSC、XPS和IR对BN纤维的结构,性能进行详细表征.结果表明,前驱体高聚物具有良好的静电纺丝性能,提高煅烧温度、延长煅烧时间可制备较纯的氮化硼纤维.     

PBO的合成及其纺丝技术研究进展

概述了聚对苯撑苯并二(?)唑(PBO)及PBO纤维国内外的发展现状;详述了PBO的合成方法:对苯二甲酸法、对苯二甲酰氯法、三甲基硅烷基化法、对苯二甲酸盐法、对羟基苯甲酸酯法等,以及PBO纤维的制备:液晶纺丝法和静电纺丝法;建议今后国内PBO纤维的发展应开发具有自主知识产权的高性能PBO纤维生产技术。     

静电纺丝的研究进展

简述了国内外静电纺丝的研究现状;介绍了静电纺丝的制备原理、静电纺丝装置的改进、影响纤维成形的主要工艺参数及纤维形态;叙述了静电纺丝纳米纤维在过滤材料、生物医学和传感器等方面的应用;展望了静电纺丝的发展方向。指出静电纺丝是纳米纤维的新型生产技术,今后应进一步调整静电纺丝工艺,开发绿色溶剂,以尽早实现静电纺丝的工业化。     

静电纺丝的技术进展

简述了静电纺丝的原理、装置及发展历程;比较了溶剂静电纺丝法和熔融静电纺丝法;介绍了静电纺丝法的技术进展。指出在熔融型静电纺丝法的研究中,开发了具有激光加热部的熔融型静电纺丝装置,进一步突破了纳米纤维的制造技术。随着纳米技术的不断发展,静电纺丝法制造的纳米纤维应用广泛,其发展前景看好。     

RECOVERY OF ACETIC ACID OVER WATER BY PERVAPORATION WITH A COMBINATION OF HYDROPHOBIC IONIC LIQUIDS

The present work considers the application of an integrated pervaporation process to improve the pervaporation performance of acetic acid over water. This integrated pervaporation process was based on a plain PDMS membrane with a hydrophobic ionic liquid composed of a heterocyclic cation and [PF₆]^- anions. The hydrophobic ionic liquid was introduced as the third phase between the aqueous phase and the plain PDMS membrane for improving mass-transfer of acetic acid from its aqueous matrix to the PDMS membrane. The primary results indicated that the ionic liquid as an extractant prior to pervaporation was favorable for improving the permeate selectivity and the permeate flux of acetic acid compared with using only a plain PDMS membrane. This performance could be attributed to the acetic acid concentrated and the water molecules rejected by ionic liquid prior to pervaporation. Extraction of a real effluent containing acetic acid from an antibiotic pharmaceutical plant was carried out using the above integrated pervaporation, and the results imply that this integrated pervaporation process could be scaled up for recovering acetic acids over its water-rich effluents.     

RECOVERY OF ACETIC ACID OVER WATER BY PERVAPORATION WITH A COMBINATION OF HYDROPHOBIC IONIC LIQUIDS

The present work considers the application of an integrated pervaporation process to improve the pervaporation performance of acetic acid over water. This integrated pervaporation process was based on a plain PDMS membrane with a hydrophobic ionic liquid composed of a heterocyclic cation and [PF₆]^? anions. The hydrophobic ionic liquid was introduced as the third phase between the aqueous phase and the plain PDMS membrane for improving mass-transfer of acetic acid from its aqueous matrix to the PDMS membrane. The primary results indicated that the ionic liquid as an extractant prior to pervaporation was favorable for improving the permeate selectivity and the permeate flux of acetic acid compared with using only a plain PDMS membrane. This performance could be attributed to the acetic acid concentrated and the water molecules rejected by ionic liquid prior to pervaporation. Extraction of a real effluent containing acetic acid from an antibiotic pharmaceutical plant was carried out using the above integrated pervaporation, and the results imply that this integrated pervaporation process could be scaled up for recovering acetic acids over its water-rich effluents.     

Polylactide (PLA)-Based Electrospun Fibrous Materials Containing Ionic Drugs as Wound Dressing Materials: A Review

The effect of the electrospinning process parameters on the morphology, alignment, and self-organization of the fibers into bundles and/or yarns are outlined. The fabrication of polylactide materials containing ionic drugs by electrospinning is emphasized. The main approaches used for the preparation of electrospun drug-loaded materials: electrospinning of a mixed solution containing the polymer(s) and the drug(s) or dual spinneret electrospinning of separate drug-containing solutions are compared. The latter approach allows the obtaining of drug-loaded fibrous materials while avoiding the drug interaction. The potential application of the obtained materials containing ionic drugs as wound dressings is outlined.     

静电纺丝纳米纤维的制备工艺及其应用

简述了静电纺丝制备纳米纤维的原理;探讨了静电纺丝电压、流速、接收距离、溶剂浓度等工艺条件;介绍了同轴静电纺丝制备皮芯结构的超细纤维及中空纤维技术以及静电纺丝纳米纤维毡在生物医药方面的应用。指出静电纺丝纳米纤维材料在生物医用方面具有广阔的应用前景,进一步实现低压纺丝、开发无毒溶剂,控制同轴静电纺丝纳米纤维的释放性能是今后静电纺丝的研发方向。     

静电纺丝制备纳米纤维的进展及应用

简述了静电纺丝的制备原理和影响静电纺丝纤维成形的主要工艺因素;介绍了静电纺丝法制备高分子聚合物、生物大分子、无机物纳米纤维的最新进展,以及这些纳米纤维在过滤、传感器、超疏水性材料、生物医用功能材料、纳米模板等领域的应用;指出静电纺丝制备纳米连续长丝技术亟待发展。     

用于烷基化反应的离子液体催化剂研究进展

介绍了烷基化催化剂的特点及发展历程,概述了离子液体催化剂的分类和优点,讨论了离子液体催化烷基化的研究情况,包括异构烷烃与烯烃烷基化和芳香烃烷基化,最后,展望了离子液体催化剂在烷基化反应中的应用前景。     

Ionic liquid assisted electrospinning of quantum dots/elastomer composite nanofibers

Quantum dots (QDs)/elastomer (VM) composite nanofibers have been fabricated via electrospinning method with the assistance of small amount (1 wt%) of ionic liquid. Without ionic liquid, polymer solution underwent an electrospraying process within the electric field and only individual droplets rather than continuous fibers were observed. Both fixed electrode and rotating disk electrode were used to collect the products. The latter one turned out to be much more advanced in collecting separated, aligned and narrow-size distributed composite nanofibers. With fixed electrode, even though nanofibers were obtained initially, the as-spun fibers were easily to merge together due to the flexible non-crystalline nature of the VM chains and finally formed a condensed thin film. Strong fluorescent emission was observed in the composite nanofibers with a QD loading of 3 and 5 wt%, respectively. The optical property of QDs was not degraded after dispersing in the polymer solution as evidenced by the UV-Vis absorption at 562 nm and 592 nm, and strong photoluminescent emission at 612 nm. In addition, differential scanning calorimetry (DSC) analysis revealed a strong interaction between ionic liquid and the polymer chains, which well explains the function of the ionic liquid on producing fiber structure of VM. An enhanced thermal stability of the elastomer in the composite nanofibers is observed as compared to that of the pure elastomer fibers.