Density dependent interactions and structure of charged colloidal dispersions in the weak screening regime.
We determine the structure of charge-stabilized colloidal suspensions at low ionic strength over an extended range of particle volume fractions using a combination of light and small angle neutron scattering experiments. The variation of the structure factor with concentration is analyzed within a one-component model of a colloidal suspension. We show that the observed structural behavior corresponds to a nonmonotonic density dependence of the colloid effective charge and the mean interparticle interaction energy. Our findings are corroborated by similar observations from primitive model computer simulations of salt-free colloidal suspensions.
Departamento de Física, Cinvestav-IPN, Av. Instituto Politécnico Nacional 2508, 07360 México D. F., Mexico.
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Rojas-Ochoa
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R
Castañeda-Priego
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Lobaskin
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A
Stradner
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F
Scheffold
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Schurtenberger