HO-PAMAM-2.5G保护下镧原子簇的分子动力学模拟与制备  

Molecular Dynamics and Preparation of HO-PAMAM-2.5G Protected Lanthanum Cluster

作　　者：莫尊理[1] 刘艳芝[1] 陈红[1] 李贺军[2] 孙亚玲[1] 孙万虹[1] 孙银霞[1] 

机构地区：[1]西北师范大学化学化工学院,甘肃兰州730070 [2]西北工业大学材料科学与工程学院,陕西西安710072

出　　处：《中国稀土学报》2006年第1期12-17,共6页Journal of the Chinese Society of Rare Earths

基　　金：国家自然科学基金(29875018);甘肃省自然科学基金(3ZS051-A25-050ZS991-A25-008-Z);西北工业大学博士论文创新基金(CX200309);甘肃省高分子材料重点实验室重点项目;甘肃省环境科研项目(GH2005-10)

摘　　要：应用Virtual Materiale（VM）软件对HO-PAMAM-2．5G保护下的镧原子簇进行分子动力学模拟，从分子结构和能量变化角度研究了正则（恒定的NVT）系统中不同比例的羟基修饰的2．5代聚酰胺-胺（HO-PAMAM-2．5）与镧（La）复合的稳定性及其机制。分子动力学模拟结果显示，当每个HO-PAMAM-2．5G分子中的镧原子数在0-60之间时，回转半径明显减小；镧原子的数量不同，对体系的稳定性起决定作用的势能也不同，当镧原子数（nLa）在1～50之间时，HO-PAMAM-2．5／La纳米复合体系的能量波动较大；当nLa在50～80之间时，变化缓慢，nLa=60时，复合体系能量落到最低点，处于较稳定状态。以此预测为基础，通过实验合成HO-PAMAM-2．5／La纳米复合物，并用透射电镜（TEM）对所制得的HO-PAMAM-2．5／La纳米颗粒进行了表征，结果表明实验与分子动力学模拟一致。HO-PAMAM-2. 5 G-protected lanthanum cluster was studied by Virtual Molecule （VM） soft- ware. Molecular dynamics （MD） simulation of the nanoeomposite system was performed from the viewpoints of molecular structure and energy＇ s fluctuation in NVT system. The motivation of this work was to understand the stability and mechanism of the nanoeomposite in different proportion. The molecular dynamics simulation results reveal that when the quantity of La in per HO-PAMAM-2.5G amounted to 0-60, the radius of gyration of HO-PAMAM-2.5/La nanoeomposite is decreased considerably. The potential energy （PE） that determines the stability of nanocomposite is different according to the quantity of La. The energy of the nanocomposite fluctuated clearly within the range of 0-50 La atoms and this fluctuation gradually tends to flatness in 50-80. While the quantity of La reaches 60, the energy otr the nanoeomposite drops to the lowest point, the system is relatively steady. Whereafter, according to the simulation results, HO-PAMAM-2.5 G-protected lanthanum clusters were prepared and characterized by transmission electron microscopy （TEM）. The result is consistent with MD simulation.

关 键 词：分子模拟 PAMAM-OH树形分子 模板合成 镧原子簇 稀土 

分 类 号：O641.3[理学—物理化学] O641.13[理学—化学]