海藻酸钠的疏水改性对其电纺性能的影响

以聚乙烯醇(PVA)作为助纺剂,对疏水改性的海藻酸钠衍生物海藻酸辛酰胺(ACA)进行电纺性能研究。采用透射电镜、激光粒度和zeta电位分析仪、表面张力仪、电导率仪和流变仪对ACA的胶体界面性能进行表征,并采用扫描电镜、红外光谱仪和多晶X射线衍射仪对ACA/PVA电纺纳米纤维膜的形貌、官能团和晶型结构进行测试。结果表明:疏水改性使海藻酸钠(SA)分子灵活性增强,ACA分子可以蜷曲形成水动力学粒径大小为324 nm(PDI=0.38),zeta电位为-43.8 m V的胶束。疏水改性和添加PVA助纺剂可以有效地降低SA溶液的表面张力和电导率,使其有效链缠结增多,ACA/PVA电纺纳米纤维膜的形貌更加规整均一。光谱分析结果表明,ACA和PVA两者间的氢键作用力是其增加链缠结点,实现静电纺丝的主要作用力。

Effects of hydrophobic modification of sodium alginate on its electrospinning performance

With poly(vinyl alcohol) (PVA) as spinning accessory, the electrospinning of hydrophobically modified sodium alginate derivative, alginate caprylamide (ACA), was studied. The colloidal and interfacial performance of ACA were characterized by transmission electron microscope, laser particle size and zeta potential analyzer, surface tensiometer, conductivity meter and rheometer. In addition, the morphology, functional group and crystalline structure of ACA/PVA electrospun nanofiber membranes were measured by scanning electron microscope, Fourier transform infrared spectroscopy and poly-crystalline X-ray diffraction. Experimental results showed that the hydrophobic modification upgrades flexibility of sodium alginate (SA) molecules, which can curlily form micelles with the hydrodynamic particle size of 324 nm (PDI=0.38) and zeta potential value of -43.8 mV. Furthermore, the hydrophobic modification and the addition of PVA as the spinning accessory can effectively reduce the surface tension and conductivity of SA solution, enhance chain entanglements and cause the morphology of ACA/PVA electrospun nanofiber membranes more regular and uniform. Spectroscopy analysis results showed that the hydrogen bonding force between ACA and PVA is still the main force to increase chain entanglements and thus realize the electrospinning.