高价金属离子对聚乙烯醇水溶液电纺性的影响

Effect of High Valence Metal Ions on the Electrospinnability of Poly(Vinyl Alcohol) Aqueous Solution

研究了聚乙烯醇(PVA)溶液性能对静电纺丝过程及纳米纤维形态的影响。试验得出,PVA中的高价金属离子在溶液中与PVA大分子链上的羟基相互作用,形成了分子内和分子间的交联结构,从而降低了可纺性。通过透析和络合来去除、屏蔽金属离子的影响,处理后的溶液可稳定地纺丝。

The electrospinnability of polyvinyl alcohol （PVA） aqueous solutions from three different suppliers （S1, S2 and F16） was carried out. The solutions of the sample F16 behaved best in electrospinning, whereas the worst S1 solutions only experienced electro-spraying. The measurements of the spinning solution properties show, the electric conductivity of S1 solutions in- creases almost linearly with the dosages of PVA, and the surface tension presents U-shaped curves with the dosages of PVA, and the viscosity is slightly escalated at lower concentrations and then soars up rapidly at higher concentrations. The metal element analysis with plasma of the sample S1 indicates that the content of calcium ions and aluminum ions is about 47.8 ×10^-6and 53. 4 ×10^-6respectively. The electrospinnability of S1 is substantially improved both by dialysis and complexation with ethylene diamine tetra-acetic acid （EDTA）. The dosage of calcium chloride into F16 aqueous solutions also aggravates electrospinnability. It is intramolecular crosslinking at low concentrations and intermolecular crosslinking at high concentrations occurred between PVA chains and high valence metal ions that coins the abnormal behaviors in surface tension and electric conductivity and viscosity and thus deteriorates electrospinnability of the sample S1.