聚合物熔体微分静电纺电场对射流的影响及其物理模型

为研究电场强度及接收装置材质对无针静电纺丝射流效率和射流分布均匀性的影响,在提出的熔体微分直线静电纺丝装置上,通过改变纺丝电压和接收装置材质,分析了喷头端最大电场强度和电离电荷对射流效率及均匀性的影响。结果表明:喷头端电场强度越大,射流效率越高,射流分布越均匀;当接收端的局部电压高于喷头端的电压时,电离离子宏观上表现出向喷头端运动,会抑制射流的形成;在高压收集端铺设电阻值为2.7×10⁵ Ω的纸,可以实现电离电荷的二次均匀分布,消除局部离子流引起的射流缺失现象;在接收装置上铺设电阻值大于1.0×10¹¹ Ω的聚对苯二甲酸乙二醇酯(PET)会增加纺丝回流的电阻,导致电荷在PET上聚集,反作用削弱喷头端的电场强度,引起射流效率的降低。

Physical model and effects of electric field on jets in polymer melt differential electrospinning

In order to study the influence of electric field intensity and material of receiving device on the jet efficiency and jet distribution uniformity in needleless electrospinning, a linear slot melt differential electrospinning device was proposed. The effects of the maximum electric field intensity and ionization charge on the jet density and distribution uniformity were studied by changing the electrostatic voltage and material of receiving device. The results showed that the jets efficiency and uniformity increased with increasing the electric field intensity at the spinneret. When the local voltage at the receiving end is higher than that of nozzle end, the ionized ions showed macroscopically a movement towards the nozzle end, which would result in the loss of melt-jets, and even inhibition of the jet formation. Laying a paper with resistance of 2.7×10⁵ Ω at the high-voltage collection can effectively redistribute the ionization charge in the spinning space uniformly, therefor eliminating the phenomenon of jet loss caused by local ion flow. Laying a sheet of polyethylene terephthalate (PET) with resistance greater than 1.0×10¹¹ Ω at the high-voltage collection would increase the resistance of spinning circuit and result in the accumulation of charge on the PET. Therefore, the electric field strength at the nozzle end was weakened and jets efficiency decreased.