二氧化硅晶面对甲基铝氧烷吸附行为分析  

Study on the Adsorption of MAO on Different Silica Crystal Surfaces

作　　者：刘文霞 王金道[2] 许有伟 LIU Wen-xia;WANG Jin-dao;XU You-Wei(Lanzhou Petrochemical Research Center,Lanzhou 730060,Gansu,China;Petro China Lanzhou Petrochemical Company,Lanzhou 730060,Gansu,China)

机构地区：[1]中国石油兰州化工研究中心,甘肃兰州730060 [2]中国石油兰州石化公司,甘肃兰州730060

出　　处：《合成材料老化与应用》2020年第2期40-43,共4页Synthetic Materials Aging and Application

摘　　要：采用Material Studios对二氧化硅形成的三种晶面进行计算,并模拟甲基铝氧烷(MAO)在不同晶面产生的吸附行为。结果表明,当形成不同的晶面时,二氧化硅晶体的带宽变宽,表明频带中电子的有效质量越小,非局域性越大,并且频带的原子轨道扩展越强。MAO在SiO2(100)面吸附形成的带隙为0.016eV,在Si(110)面吸附形成的带隙为0.086eV,而在SiO2(111)面形成的带隙为0.180eV,表明MAO在SiO2(111)面产生的吸附最强。MAO在SiO2(111)形成的吸附行为与自由羟基形成映衬,而自由羟基的减少是由桥连羟基随机缩合反应导致。The three crystal faces formed by silica were calculated using Material Studios, and the adsorption behavior of methylaluminoxane(MAO) on different crystal faces was simulated. The results show that when different crystal faces are formed, the bandwidth of the silica crystal becomes wider, indicating that the smaller the effective mass of electrons in the band, the greater the nonlocality, and the stronger the atomic orbital expansion of the band. The band gap of MAO adsorbed on the SiO2(100) plane is 0.016 eV, the band gap formed on the SiO2(110) plane is 0.086 eV, and the band gap formed on the SiO2(111) plane is 0.180 eV, indicating that MAO is in SiO2(111) surface produces the strongest adsorption. The adsorption behavior of MAO in SiO2(111) forms a contrast with the free hydroxyl group, while the reduction of free hydroxyl groups is caused by the random condensation reaction of bridged hydroxyl groups.

关 键 词：二氧化硅晶体 甲基铝氧烷 态密度 羟基类型 

分 类 号：TQ115[化学工程—无机化工]