驰豫时间对电纺射流形成及纳米纤维形貌的影响  

The Impact from Relaxation Time on the Electrospinning Jet Forming and Nanofiber Morphology

作　　者：漆东岳[1] 刘延波[1,2] 陈威亚[1] 肖友华[1] 

机构地区：[1]天津工业大学纺织学部,天津300387 [2]天津工业大学先进纺织复合材料教育部重点实验室,天津300387

出　　处：《高分子通报》2013年第12期52-59,共8页Polymer Bulletin

基　　金：天津市自然科学基金项目(10JCYBJC03300)

摘　　要：近年来一些学者发现了电纺射流弛豫时间的存在,也部分解释了其形成原因,但并未研究其对电纺纤维形貌的影响;电纺射流弛豫时间与溶液的荷电性质有关,同时电纺纤维形貌与溶液带电性质之间也关系密切,这说明电纺射流弛豫时间与电纺纤维形貌存在重要的联系。本文通过三种不同原理的电纺丝装置对20%质量分数的PVA水溶液进行电纺丝实验,采用高速摄像的方式记录射流的形成过程,并结合所纺纤维的形貌特征对这些电纺丝装置的原理及电纺射流弛豫时间与纤维形貌之间的关系进行了系统分析。结果发现,电纺丝射流出现间歇现象的原因是由于电纺射流弛豫时间的存在,其与泰勒锥表面离子电荷的积聚速度有直接联系,后者又与很多因素有关,例如纺丝溶液所处位置的周边环境、溶液粘度、溶液中的离子浓度、溶液所处位置的电场强度和电压等。电纺射流弛豫时间的存在最终会引起电纺纤维的粗细不匀和纳米纤维材料表面形貌的变化。In recent years,some scholars have found that there exists the relaxation time for the electrospinning jets during electrospinning,and the forming reasons have been partially explained.The impact on the resultant nanofiber morphology from the relaxation time of the electrospinning jets has not been investigated.As a matter of fact,the relaxation time of the electrospinning jets is linked to the charged nature of the spinning solution;meanwhile the electrospun fiber morphology could be closely related to the charged nature of the spinning solution,indicating that there are important connections between the relaxation time of electrospinning jets and the charged nature of the spinning solution.In this study,20% w/w PVA solution was used to conduct electrospinning experiments on the needle electrospinning equipment based on three different electric field setups,and the spinning jets were recorded with a high-speed video camera.Furthermore,the electrospinning mechanisms of these setups and the relationships between the electrospun nanofiber morphology and the relaxation time of the electrospinning jets were analyzed systematically,in combination with the electrospun fiber morphological features.The results indicated that the reason for the intermittency of the electrospinning jets was due to the existence of the relaxation time of the electrospinning jets,which could be directly linked to the accumulation speed of the ionic charges on the surface of the Taylor cone,and the latter could be attributed to many factors,such as the ambient atmosphere of the position of the spinning solution,the viscosity of the solution,the ionic concentration of the solution,the electric field intensity and voltage of the position where the solution is located at,and so on.As a result,the ununiformity of the electrospun fibers and the change in the surface morphology of the nanofiber materials could be attributed to the presence of the relaxation time of the electrospinning time.

关 键 词：电纺射流弛豫时间 离子电荷 双电层 逆向电场 临界电压 

分 类 号：TQ340.6[化学工程—化纤工业]