摘要
静电纺丝(电纺)技术利用静电场将被极化的高分子射流拉成细丝,可以制备连续的超细纤维,纤维直径可能达到数百纳米的量级。有重要的工业应用价值。射流进入静电场后,其运动分为直线运动和曲线甩动两个阶段。在直线运动阶段,有可能发生失稳现象,称为轴对称失稳(也称曲张失稳)。轴对称失稳问题涉及纤维的制备质量,所以广受关注。Hohman等人提出了一种基于牛顿粘性流体的电动力学模型对这种失稳现象做了分析。但是,该模型没有考虑电场体积力影响。本文考虑了电场体积力的贡献。完成了全部控制方程的推导并进行了相应的数值计算。数值计算结果表明,当外电场较强时,电场体积力的影响不可忽略,电场体积力的存在增大了射流的轴对称不稳定性。
In electrospinning an external electrostatic field is used to accelerate and stretch a charged polymer jet,and may produce continuous extra-thin fibers whose diameter may arrive at even a few hundred nanometers.After the jet is injected into the electrostatic field,its movement is divided into two stages.Initially,the jet flows along a straight line.Afterwards,a banding occurs and spirals violently.In the first stage,the axisymmetric instability（varicose instability） takes much interest since it is essential for the quality of the nano-fibers.Hohman proposed an electrodynamic model for Newtonian jets to analyse the instability.However,the model does not consider the body forces caused by the electrostatic field.An improved model with the electrostatic body forces is introduced.Numerical results show that the effect of the electrostatic body forces on the instability is distinct when the electrostatic field is strong.In addition,the axisymmetric instability is then enlarged.
出处
《力学季刊》
CSCD
北大核心
2011年第4期480-485,共6页
Chinese Quarterly of Mechanics
基金
国家自然科学基金(10772136)
上海市重点学科建设项目(B302)
关键词
电纺
带电射流
曲张失稳
electrospinning
electrical jet
varicose instability
