球形氯化镁-乙醇络合物纳米颗粒的制备及其自组装

乙醇与氯化镁按摩尔比为20∶1的比例混合,升温至120℃溶解形成氯化镁醇溶液后,将氯化镁醇溶液冷却至70℃转移至处于搅拌状态的冷却液中,经过滤、正己烷洗涤、干燥后得到球形氯化镁-乙醇络合物纳米颗粒.经TEM表征颗粒粒径在30～100 nm之间.这种氯化镁-乙醇络合物纳米颗粒可在室温自组装,形成纳米线.WAXD结果表明,制备的球形氯化镁-乙醇络合物纳米颗粒的结晶行为受到影响,与纯氯化镁相比,氯化镁-乙醇络合物纳米颗粒的结晶度低.这种氯化镁-乙醇络合物纳米颗粒可作为Ziegler-Natta催化剂的载体材料,制备的催化剂可高效催化乙烯聚合,合成聚乙烯微纳米颗粒.

PREPARATION AND SELF-ASSEMBLY OF GLOBAL NANO-PARTICLES OF MgCl2-CH3 CH2OH COMPLEX

After MgCl2 was dissolved in ethanol with the ratio of 1∶20 in mole at 120℃,the solution was cooled to 70℃ and transferred to the cooling liquid consisting of n-hexane(30 mL) and wax(0.3 g) at 0℃.Precipitate was produced.Filtrated and washed with n-hexane,the residue was dried by vacuum at 50℃,and MgCl2-CH3CH2OH particles were obtained.The size of the particles determined by TEM was at the range from 30 nm to 100 nm.The nano-sized particles of MgCl2-CH3CH2OH could become nano wires by self-assembly technology at room temperature.WAXD results showed that the crystallinity of the obtained nano-sized MgCl2-CH3CH2OH particles became poor,just a broad and weak signal at 2θ = 32° ～ 35° was observed,while MgCl2 showed four sharp signals at 2θ = 15°,30°,35° and 50°.The obtained particles were useful as support for preparing nano-sized Ziegler-Natta catalysts.It was confirmed that the prepared catalysts may efficiently polymerize ethylene to form polymer particles with 200 ～ 300 nm or 2 ～ 4 μm in diameter,respectively.