Dipolar Order in Molecular Fluids: II. Molecular Influence
Dipolar Order in Molecular Fluids: II. Molecular Influence
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DOI：
10.1007/s10955-011-0352-2
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发表时间：
2011-10-01
影响因子：
1.6
通讯作者：
Karlstrom, Gunnar
中科院分区：
文献类型：
--
作者：
Linse, Per;Karlstrom, Gunnar
通过分子动力学模拟，研究了分子形状和附加高阶静电矩对偶极流体中短程堆积的影响。当粒子平行于偶极伸长时，偶极极化减小，垂直于偶极伸长时，偶极极化增大，最终形成向列型有序。四极杆的加入导致极化减小，轴向八极杆的影响较弱且较为复杂。极化的减小和增大都是可能的，这取决于偶极-偶极和八极-八极相互作用的相对强度和力矩对称轴的相对方向。这些观测结果归因于偶极和四极的不同宇称，以及反射作用下偶极和轴向八极的相同宇称。此外，对偶极子极化的形成也有了进一步的认识。短极半径和长赤道半径以及强偶极子-偶极相互作用是促进具有高偶极子极化的流体的粒子属性。
The influence on the short-range packing in dipolar fluids by molecular shape and by additional higher order electrostatic moments has been investigated by molecular dynamic simulations. The dipole polarization was found to decrease as the particles were elongated parallel to the dipole and to increase for elongation perpendicular to the dipole, eventually forming a nematic order. The addition of a quadrupole lead to a reduction of the polarization, and the influence of an axial octupole was weaker and more complex. Both a decrease and an increase of the polarization is possible depending on the relative dipole-dipole and octupole-octupole interaction strengths and the relative direction of the symmetry axes of the moments. These observations were attributed to the different parity of a dipole and a quadrupole and the same parity of a dipole and an axial octupole under reflection. In addition, further insights into the formation of dipole polarization were obtained. Short polar and long equatorial radii and strong dipole-dipole interaction are particle properties that promote a fluid with a high dipole polarization.