Structure factors for the simplest solvable model of polydisperse colloidal fluids with surface adhesion

Abstract

Closed analytical expressions for scattering intensity and other global structure factors are derived for a new solvable model of polydisperse sticky hard spheres. The starting point is the exact solution of the ``mean spherical approximation'' for hard core plus Yukawa potentials, in the limit of infinite amplitude and vanishing range of the attractive tail, with their product remaining constant. The choice of factorizable coupling (stickiness) parameters in the Yukawa term yields a simpler ``dyadic structure'' in the Fourier transform of the Baxter factor correlation function $q_{ij}(r)$, with a remarkable simplification in all structure functions with respect to previous works. The effect of size and stickiness polydispersity is analyzed and numerical results are presented for two particular versions of the model: i) when all polydisperse particles have a single, size-independent, stickiness parameter, and ii) when the stickiness parameters are proportional to the diameters. The existence of two different regimes for the average structure factor, respectively above and below a generalized Boyle temperature which depends on size polydispersity, is recognized and discussed. Because of its analycity and simplicity, the model may be useful in the interpretation of small-angle scattering experimental data for polydisperse colloidal fluids of neutral particles with surface adhesion.

32 pages, 7 figures, RevTex style, to appear in J. Chem. Phys. 1 December 2000

References in corpus (2)

• A scaling approximation for structure factors in the integral equation theory of polydisperse nonionic colloidal fluids
• A corresponding states approach to Small-Angle-Scattering for polydisperse ionic colloidal fluids

Cited by in corpus (13)

• Predicting phase equilibria in polydisperse systems
• Analytic solutions for Baxter's model of sticky hard sphere fluids within closures different from the Percus_Yevick approximation
• Multicomponent adhesive hard sphere models and short-ranged attractive interactions in colloidal or micellar solutions
• The thermodynamic instabilities of a binary mixture of sticky hard spheres
• Stability boundaries, percolation threshold, and two phase coexistence for polydisperse fluids of adhesive colloidal particles
• Contact values of the particle-particle and wall-particle correlation functions in a hard-sphere polydisperse fluid
• Pathologies in the sticky limit of hard-sphere-Yukawa models for colloidal fluids. A possible correction
• Phase behavior of polydisperse sticky hard spheres: analytical solutions and perturbation theory
• A numerical study of a binary Yukawa model in regimes characteristic of globular proteins in solutions
• Polydisperse fluid mixtures of adhesive colloidal particles
• On the compressibility equation of state for multicomponent adhesive hard sphere fluids
• On the absence of structure factors in concentrated colloidal suspensions and nanocomposites
• Effect of Polydispersity and Anisotropy in Colloidal and Protein Solutions: an Integral Equation Approach