高强度聚乙烯醇水凝胶微球的制备

以三氯甲烷/丙酮为凝固液, 用高压静电技术制备了高强度、物理交联的聚乙烯醇(PVA)水凝胶微球. 研究了凝固液组成、PVA溶液浓度、温度和湿度、电场强度、进样速度及微球冷冻次数等对PVA微球的形貌、粒径和强度的影响. 结果表明, 采用常压水蒸气控制PVA溶液温度与湿度的高压静电技术, 可克服高浓度PVA溶液在强电场下出现微丝现象, 形成的水凝胶微球具有强度高、粒径在一定范围内可控的特点.

Preparation of Polyvinyl Alcohol Hydrogel Microspheres with High Strength

Physical cross-linked polyvinyl alcohol(PVA) hydrogel microspheres with high strength were prepared by a modified high-voltage electrostatic technique. The hydrogel microspheres were solidified and suspended in coagulation liquid composed of chloroform and acetone, then the microspheres in coagulation liquid were frozen and thawed to get PVA cross\|linked. The influence factors of PVA microspheres' diameter and morphology, such as, coagulation liquid, PVA solution concentration and flow rate, temperature and humidity and electrostatic field strength of high-voltage electrostatic system, the number of froze and thaw cycle of PVA were investigated. The results showed that high-voltage electrostatic system modified with atmospheric steam to control temperature and humidity  of PVA microsphere formation area was an effective method to overcome microfilament formation while PVA solution was in higher concentration, the optimized condition for prepare PVA hydrogel microspheres with high strength and controlled diameter was coagulation liquid of chloroform/acetone(2∶1, volume ratio), frozen at -20 ℃ and thawed at room temperature for five cycles, PVA solution concentration of 12% in weight, flow rate of 2 mL/h, electrostatic field strength of 12-15 kV, electrode distance of 3 cm, and the PVA hydrogel microsphere has a widely potential use in the field of tissue engineering.