Sheema Khan - Academia.edu (original) (raw)

Papers by Sheema Khan

Physical Review A, Jun 1, 1990

Macroscopic equations of motion describing the coupled dynamics and fluctuations of a dilute coll... more Macroscopic equations of motion describing the coupled dynamics and fluctuations of a dilute colloidal crystal and the underlying fluid in the presence of shear are analyzed for plane Couette flow. The system becomes unstable through a transverse acoustic resonance mechanism at a critical shear rate tu, ". For large system size L, tu, "-[L in(L)]. The lattice displacement fluctuations excited by thermal motion only diverge logarithmically as the instability is approached, but cause the Debye-Wailer factors to become periodic functions of time. The theory is discussed in terms of recent scattering experiments and other theoretical work.

McGill-Queen's University Press eBooks, May 1, 2012

PhDT, 1989

The static correlations in highly charged colloidal and micellar suspensions, with and without ad... more The static correlations in highly charged colloidal and micellar suspensions, with and without added electrolyte, are examined within the context of the Ornstein-Zernike relation and choice of closure for the various species -species correlations in solution. By taking the point-ion ...

Molecular Physics, Feb 20, 1987

A variational approach to static correlations in dilute macro-ion suspensions II. Nonadditive dia... more A variational approach to static correlations in dilute macro-ion suspensions II. Nonadditive diameter reference systems with effective charges and radii

Physical review, May 1, 1987

The static correlations in highly charged colloidal and micellar suspensions, with and without ad... more The static correlations in highly charged colloidal and micellar suspensions, with and without added electrolyte, are examined using the hypernetted-chain approximation (HNC) for the macroionmacro-ion correlations and the mean-spherical approximation for the other correlations. By taking the point-ion limit for the counter-ions, an analytic solution for the counter-ion part of the problem can be obtained; this maps the macro-ion part of the problem onto a one-component problem where the macro-ions interact via a screened Coulomb potential with the Gouy-Chapman form for the screening length and an effective charge that depends on the macro-ionmacro-ion pair correlations. Numerical solutions of the effective one-component equation in the HNC approximation are presented, and in particular, the effects of macro-ion charge, nonadditive core diameters, and added electrolyte are examined. As we show, there can be a strong renormalization of the effective macro-ion charge and reentrant melting in colloidal crystals.

Physical Review A, 1987

Molecular Physics, 1987

The Gibbs-Bogoliubov inequality is used to determine an effective diameter and charge of a suspen... more The Gibbs-Bogoliubov inequality is used to determine an effective diameter and charge of a suspension consisting of highly charged colloid particles or micelles, point counter-ions and neutral particles. The reference system is analysed in terms of the mean spherical ...

The static correlations in highly charged colloidal and micellar suspensions, with and without ad... more The static correlations in highly charged colloidal and micellar suspensions, with and without added electrolyte, are examined within the context of the Ornstein-Zernike relation and choice of closure for the various species -species correlations in solution. By taking the point-ion ...

Physical Review A, 1990

Physical Review A, Jun 1, 1990

McGill-Queen's University Press eBooks, May 1, 2012

PhDT, 1989

The static correlations in highly charged colloidal and micellar suspensions, with and without ad... more The static correlations in highly charged colloidal and micellar suspensions, with and without added electrolyte, are examined within the context of the Ornstein-Zernike relation and choice of closure for the various species -species correlations in solution. By taking the point-ion ...

Molecular Physics, Feb 20, 1987

Physical review, May 1, 1987

The static correlations in highly charged colloidal and micellar suspensions, with and without ad... more The static correlations in highly charged colloidal and micellar suspensions, with and without added electrolyte, are examined using the hypernetted-chain approximation (HNC) for the macroionmacro-ion correlations and the mean-spherical approximation for the other correlations. By taking the point-ion limit for the counter-ions, an analytic solution for the counter-ion part of the problem can be obtained; this maps the macro-ion part of the problem onto a one-component problem where the macro-ions interact via a screened Coulomb potential with the Gouy-Chapman form for the screening length and an effective charge that depends on the macro-ionmacro-ion pair correlations. Numerical solutions of the effective one-component equation in the HNC approximation are presented, and in particular, the effects of macro-ion charge, nonadditive core diameters, and added electrolyte are examined. As we show, there can be a strong renormalization of the effective macro-ion charge and reentrant melting in colloidal crystals.

Physical Review A, 1987

Molecular Physics, 1987

The static correlations in highly charged colloidal and micellar suspensions, with and without ad... more The static correlations in highly charged colloidal and micellar suspensions, with and without added electrolyte, are examined within the context of the Ornstein-Zernike relation and choice of closure for the various species -species correlations in solution. By taking the point-ion ...

Physical Review A, 1990