基于反相微乳液法ZIF-8纳米晶体的制备及表征

Preparation and characterization of ZIF-8 nanocrystals via reverse microemulsions

以CTAB为表面活性剂、正丁醇为助表面活性剂、正辛烷为油相,通过反相微乳液法制备了纳米级ZIF-8晶体。研究了H_2O/CTAB摩尔比、2Ml/Zn^(2+)摩尔比和合成时间对制备ZIF-8晶体形貌及尺寸大小的影响。结果表明,在H_2O/CTAB摩尔比为30、2Ml/Zn^(2+)摩尔比为4、反应时间为1 h条件下,所制得的ZIF-8晶体形貌规则呈球状,结晶度高,粒径大小均一,约为100 nm;并随着2Ml/Zn^(2+)摩尔比由3.5增加为8时,ZIF-8晶体尺寸逐渐降低,由120 nm下降为50 nm;此外,ZIF-8纳米晶体尺寸及形貌不随反应时间的延长而发生明显变化。

ZIF-8 nanocrystals are prepared through the reverse microemulsion method using CTAB as an anionic surfactant,n-butanol as a cosurfactant and n-octane as an oil phase.The effects of molar ratio of H2O/CTAB,molar ratio of 2 Ml/Zn^2＋and synthetic time on the morphology and size of the as-synthesized ZIF-8 crystals are systematically investigated.It is found that the prepared ZIF-8 crystal exhibits sphere-like morphology,high crystallinity,uniform-sized particles with diameter about 100 nm when the molar ratio of H2O/CTAB is 30,the molar ratio of 2 Ml/Zn^2＋is 4 and reaction lasts for 1 h.As the molar ratio of 2 Ml/Zn^2＋increases from 3.5 to 8,the size of the as-synthesized ZIF-8 crystals decrease gradually,from 120 nm to 50 nm.Moreover,with the reaction time extending,the morphology and size of ZIF-8 nanocrystals change hardly.