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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 the existence of electro-spinning jet relaxation time, but also partly explain the reasons for its formation, but did not study its morphology on the electrospun fibers; electro-spinning jet relaxation time and charge properties of the solution , While the electrospun fiber morphology and charged solution properties are also closely related, indicating that electrospinning jet relaxation time and electrospun fiber morphology is an important link. In this paper, three different principles of electrospinning device for 20% aqueous solution of PVA electrospinning experiments using high-speed camera recording jet formation process, combined with the morphology of the spinning fibers of these electrospinning The principle of the device and the relationship between the relaxation time and fiber morphology of the electrospinning jet were systematically analyzed. It is found that the reason for the intermittent phenomenon of electrospinning jet is due to the existence of electrospinning jet relaxation time, which is directly related to the accumulation rate of ionic charge on the surface of Taylor cone. The latter is related to many factors such as spinning solution The location of the surrounding environment, solution viscosity, ion concentration in solution, the solution at the location of the electric field strength and voltage. The existence of electrospinning jet relaxation time will eventually lead to uneven thickness of the electrospun fibers and nanofiber material surface topography changes.