Increasing ionic conductivity within thermoplastics via commercial additives results in a dramatic decrease in fiber diameter from melt electrospinning
Increasing ionic conductivity within thermoplastics via commercial additives results in a dramatic decrease in fiber diameter from melt electrospinning
复制标题
通过商业添加剂提高热塑性塑料内的离子电导率，导致熔融静电纺丝的纤维直径急剧减小
DOI：
10.1039/d1sm01101d
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发表时间：
2021
期刊：
影响因子：
3.4
通讯作者：
Clarke, Laura I.
中科院分区：
文献类型：
--
作者：
Sheoran, Neelam;Boland, Brent;Thornton, Samuel;Bochinski, Jason R.;Clarke, Laura I.
通过添加商品抗静电剂，提高了聚乙烯熔体的电导率，使电纺纤维直径减小了20倍，并形成了大量的亚微米直径纤维。使用两种聚乙烯配方和不同的添加剂浓度来跨越电导率和粘度的参数空间。在流体力学理论和以前的模拟的背景下，讨论了导电率在确定射流半径(设置纤维尺寸的上限)中的关键作用。概述了影响液体射流向固体纤维转化的参数和相关理论。采用“无限制”的实验配置，既可以避免潜在的针头堵塞，又可以直接观察与流体和外加电场相互作用有关的重要特征长度尺度。在这种方法中，流体自发地形成一系列锥形扰动，这些扰动充当固定的“喷嘴”，流动的流体通过这些喷嘴流动，形成射流。实验数据和理论考虑允许整体讨论流量、粘度、传导性以及所产生的射流和纤维尺寸之间的相互作用。重点介绍了通过观察电纺过程获得的流体粘度和电导率的信息。将理论预测锥射流密度、锥体尺寸和流量的方案与实验结果进行了比较。
Polyethylene melt conductivity was increased by adding a commercial anti-static agent, which resulted in a 20× decrease in electrospun fiber diameter and formation of a significant fraction of sub-micron diameter fibers. Two polyethylene formulations and varying additive concentrations were utilized to span the parameter space of conductivity and viscosity. The key role of conductivity in determining the jet radius (which sets the upper limit on the fiber size) is discussed in the context of fluid mechanics theory and previous simulations. Parameters which affect the conversion of the liquid jet to a solid fiber and the pertinent theory are outlined. An “unconfined” experimental configuration is utilized to both avoid potential needle clogging and enable direct observation of important characteristic length scales related to the interaction of the fluid and the applied electric field. In this approach, the fluid spontaneously forms an array of cone perturbations which act as stationary “nozzles” through which the mobile fluid flows to form the jet. The experimental data and theory considerations allow for a holistic discussion of the interaction between flow rate, viscosity, conductivity, and the resultant jet and fiber size. Information about the fluid viscosity and conductivity gained by observing the electrospinning process is highlighted. Schemes for theoretically predicting the cone-jet density, cone size, and flow rate are compared to experimental results.