Palomar Ricardo, Sesé Gemma
Departament de Física i Enginyeria Nuclear, Universitat Politècnica de Catalunya, Campus Nord-Modul B4, c/Jordi Girona 1-3, 08034 Barcelona, Spain.
J Phys Chem B. 2005 Jan 13;109(1):499-507. doi: 10.1021/jp047025v.
The role of hydrogen bonding on the microscopic properties of supercooled methanol has been analyzed by means of molecular dynamics simulations. Thermodynamic, structural, and dynamical properties have been investigated in supercooled methanol. The results have been compared with those of an ideal methanol-like system whose molecules have the same dipole moment as the methanol but lack sites for hydrogen bonding. Upon cooling the methanol samples, translational relaxation times increase more rapidly than reorientational ones. This effect is much more important when hydrogen bonds are suppressed. Suppression of hydrogen bonds also results in lower critical temperatures for diffusion and for several characteristic relaxation time constants. The anisotropy of individual dynamics and the existence of dynamical heterogeneities have also been investigated.
通过分子动力学模拟分析了氢键对过冷甲醇微观性质的作用。研究了过冷甲醇的热力学、结构和动力学性质。将结果与理想的类甲醇系统进行了比较，该系统分子的偶极矩与甲醇相同，但缺乏氢键位点。冷却甲醇样品时，平移弛豫时间的增加比取向弛豫时间更快。当氢键被抑制时，这种效应更为显著。氢键的抑制还导致扩散的临界温度和几个特征弛豫时间常数降低。还研究了个体动力学的各向异性和动力学非均匀性的存在。
