Goyal Amit, Hall Carol K, Velev Orlin D
Department of Chemical and Bimolecular Engineering, North Carolina State University, Raleigh, North Carolina, USA.
Phys Rev E Stat Nonlin Soft Matter Phys. 2008 Mar;77(3 Pt 1):031401. doi: 10.1103/PhysRevE.77.031401. Epub 2008 Mar 3.
Dipolar colloidal particles self-assemble into a rich variety of microstructures ranging from co-crystals of unusual symmetry, to open networks (gels) of cross-linked chains of particles. We use molecular dynamics computer simulation to explore the self-assembly, structure, crystallization and/or gelation of systems of colloid particles with permanent dipole moments immersed in a high-dielectric solvent. Particle-particle interactions are modeled with a discontinuous potential. The phase diagram in the temperature-packing fraction plane is calculated. Several types of phases are found in our simulations: ordered phases including face-centered-cubic, hexagonal-close-packed, and body-centered-tetragonal at high packing fractions, and fluid, string-fluid, and gel phases at low packing fractions. The very low volume fraction gel phases and the well-ordered crystal phases are promising for advanced materials applications.
偶极胶体粒子自组装成丰富多样的微观结构，从具有异常对称性的共晶体到粒子交联链的开放网络（凝胶）。我们使用分子动力学计算机模拟来探索浸没在高介电溶剂中的具有永久偶极矩的胶体粒子系统的自组装、结构、结晶和/或凝胶化。粒子间相互作用用不连续势进行建模。计算了温度-堆积分数平面中的相图。在我们的模拟中发现了几种类型的相：在高堆积分数下有序相包括面心立方相、六方密堆积相和体心四方相，在低堆积分数下有流体相、串流体相和凝胶相。极低体积分数的凝胶相和有序良好的晶体相对先进材料应用很有前景。
