ZIF-67/聚磷腈复合微球的可控制备及表征

Controllable Preparation and Characterizations of ZIF-67/Polyphosphazene Composite Microspheres

以聚(环三磷腈-co-4,4’-二羟基二苯砜)微球(PZS)作为ZIF-67晶体的生长基板,通过原位自组装法设计制备了一种新型核壳结构的ZIF-67/聚磷腈复合微球ZIF-67@PZS。通过调节原料配比确定了ZIF-67@PZS较佳的结构形貌。结果表明,在六水合硝酸钴∶2-甲基咪唑∶三乙胺的摩尔比为1∶4∶4,PZS与六水合硝酸钴的质量比为5∶1的条件下,制备的聚磷腈复合微球ZIF-67@PZS的品质较高;相较于ZIF-67和PZS,ZIF-67@PZS的初始分解温度分别提高了119℃和20℃,800℃的质量保留率分别提高了25.4%和4.7%,表现出更加优异的热稳定性能;通过观察梯度时间下的扫描电子显微镜照片,进一步推测了ZIF-67@PZS的可能形成机理。

In this study,a new type of ZIF-67/polyphosphazene composite microspheres(ZIF-67@PZS)was designed and prepared by an in-situ self-assembly method using poly(cyclotriphosphazene-co-4,4'-dihydroxydiphenylsulfone)microspheres(PZS)as a growth substrate for the ZIF-67 crystals.The optimum structural morphology of ZIF-67@PZS was determined by adjusting the mass ratio of raw materials.Scanning electron microscopy(SEM)characterizations indicated that the prepared ZIF-67@PZS presented a higher quality under a cobalt nitrate hexahydrate/2-methylimidazole/triethylamine molar ratio of 1/4/4 and a PZS/cobalt nitrate hexahydrate mass ratio of 5/1.The thermogravimetric analysis results showed that the initial decomposition temperature of ZIF-67@PZS increased by 119 and 20℃and its residual char yield at 800℃ increased by 25.4% and 4.7% compared to pure ZIF-67 and PZS,respectively,indicating an excellent thermal stability.According to the SEM observation under the gradient time,the possible formation mechanism of ZIF-67@PZS was further deduced.