(490f) A Composite-Sphere Model for Janus Colloids with Central Force Potentials: Structures, Thermodynamic Properties, and Phase Behavior

We construct a
“composite-sphere” model for polyatomic molecules characterized by a group of
spheres that can “polymerize” by assembling into a structured molecule with
prescribed bond lengths. A simplest example is a pair of spheres of species A
and B with hard-core diameters d_Aand d_B that can form a
dimer (a dumbbell molecule) with bond length L_AB such that L_AB < d_A
+ d_B (fused spheres).   L_AB can assume arbitrary value so as to produce the desired
dimeric molecule that can be either a tangent disphere or a fused disphere.  In the limit L_AB à δ (very small but >0), the dumbbell approaches the Janus-type
colloidal particle.  Since we preserve
the central forces as the interactions of these moieties, the isotropic
Ornstein-Zernike equation can be use.  An
accurate closure relation is applied.  We
shall present the structure, thermodynamic properties and phase diagrams of
such colloids.

Reference:

Lloyd L. Lee, Giuseppe Pellicane “Towards composite spheres as
building blocks for structured molecules, J. Phys.: Condens. Matter 28,
414008 (2016)

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