David M. Ronis
 Address
 Department of Chemistry, McGill University
 Otto Maass Chemistry Building, 801 Sherbrooke Street West
 Montreal, Quebec H3A 0B8, CANADA
 Tel: (514) 3985099 Fax: (514) 3985099 or 3983797
 Email: david.ronis@mcgill.ca


Personal Data
Ph.D. Massachusetts Institute of Technology 1978; Miller Fellow,
University of California at Berkley, 1978; Camille and Henry Dreyfus
TeacherScholar 1985; Alfred P. Sloan Research Fellow 1985; Assistant
and Associate Professor, Harvard University, 1980; Professor, McGill
University 1988.
Research Interests
We use the tools of statistical mechanics to solve equilibrium and
nonequilibrium problems in condensed complex systems; specific
examples include:
Transport in membrane and zeolite channels.
In these systems, pores or channels selectively
allow ions or neutral molecules to pass through the system, and play
important roles in cell biology and industrial filtration processes.
Our goal is to develop molecular theories of passive transport through
channels in biologicalmembranes and zeolites that can be compared
with experiment.
Here are the slides of a talk I gave on this topic.
Static and dynamic properties of suspensions of highly charged colloidal particles.
In many respects, dilute colloidal suspensions mimic atomic systems
and can be used to study static and dynamic processes such as
solidification, rheology, shear induced melting, and shear induced
order or pattern formation. The Ronis group has developed several
simple, but successful, theoretical models that explain many features
of experiments on these systems.
Correlations and conformations in polymercoated colloids.
A key way in which colloidal suspensions are stabilized is by coating
the individual colloidal particles with charged or neutral polymer
chains that keep the particles from coming into contact and
flocculating. Here we are developing theories to describe the coupled
intra and interparticle interactions in systems comprised of
colloidal particles coated with charged or neutral, polymeric chains,
(e.g, as shown above). Our goal is to
quantitatively answer the following questions: How to calculate the
average distribution of neighboring colloids around any particle?
What is the distribution of counterions in the polymer layer and in
the space between the colloidal particles? What is polymer
configuration and how does it change when macroscopic conditions
change? What is the degree of overlap of polymer layers? Finally,
what role does chemical equilibrium (e.g., that associated with weak
acid/base or neutral binding equilibria) play in the conformations and
correlations in these systems.
Here are the slides of a talk I gave on this topic.
Surface Texturing in Polymer Extrudates.
We have developed a simple theory that explains the defect texturing
seen on the surfaces of extruded plastics. Our approach, while
mathematically simple, brings together many ideas from works on
hydrodynamics and rheology, reptation physics, the kinetics of phase
transitions, and dynamical systems analysis and chaos, and describes a
surprisingly rich range of phenomena including chaotic behavior (
here is an example) and pattern formation (
here is an example).
Dynamics in critical fluids far from equilibrium.
We are studying turbulent fluid flow and its effects on the
thermodynamics and kinetics of phase transitions in binary liquid
mixtures using renormalizationgroup methods.
EnergyTransfer.
The mechanisms of radiative energytransfer processes in
microparticles can differ from those in the bulk, and experiments
find large enhancements in the quantum yield for transfer and
anomalous kinetics. We are using electrodynamic, multiplescattering
methods to explain this phenomena with applications to colloidal and
cellular systems.
Representative Publications
 M. Vertenstein and D. Ronis,
Microscopic Theory of Membrane Transport III: Transport in Multiple
Barrier Systems,
J. Chem. Phys. 85, 1628 (1986).
 D. Ronis and S. Khan,
Stability and Fluctuations in Sheared Colloidal Crystals, ,
Phys. Rev. A, 42, 4694 (1990).
 J.Y. Yuan and D. Ronis, Instability and pattern formation in
colloidal suspension TaylorCouette flow, Phys. Rev. E 48,
2280 (1993).
 D. Ronis,
Statistical mechanics of ionomeric colloids: thermodynamics,
correlations, and scattering,
Phys. Rev. A 44, 3769 (1991).
 D. Ronis,
Statistical mechanics of ionomeric colloids II: Ionomer
Conformational Equilibria,
Macromolecules 26, 2016 (1993).
 D. Ronis,
Statistical mechanics of ionic colloids: Interparticle
correlations and conformational equilibria in suspensions of polymer
coated colloids,
Phys. Rev. E 49, 5438 (1994).
 Y. Drossinos and D. Ronis,
Critical Dynamics of Unstable States,
Phys. Rev. B 42, 4694 (1990).
 J.Y. Yuan and D. Ronis,
Theory of fully developed hydrodynamic turbulent flow:
Applications of renormalization group methods,
Phys. Rev. A 45, 55785595 (1992).
 A. C. Pineda and D. Ronis,
A Classical Model for Energy Transfer
in Microspherical Droplets,
Phys. Rev. E 52, 51785194 (1995).
 B. Morin and D. Ronis,
Disorder and Order in Sheared Colloidal Suspensions,
Phys. Rev. E 54, 576 (1996).
 J. D. Shore, D. Ronis, L. Piche, and Martin Grant,
Model for melt fracture instabilities in capillary flow
of polymer melts,
Phys. Rev. Lett. 77, 655 (1996).
Some Preprints and Reprints (NEW)

T. Croteau and D. Ronis, Nonequilibrium velocity
distributions in liquids: Systems under shear,
Phys. Rev. E 66, 066109 (2002).

B. Palmieri and D. Ronis, Diffusion in channeled
structures: Xenon in crystalline sodalites, Phys. Rev. E,
Phys. Rev. E, 68, 046127 (2003).

Benoit Palmieri and David Ronis, Diffusion in channeled
structures II: Systems with large energy barriers,
J. Phys. Chem. B, 109, 21334 (2005).

Benoit Palmieri and David Ronis, Effective classical
partition functions with an improved timedependent reference
potential , Phys. Rev. E, 73, 061105 (2006).

David L. Kolin, David Ronis and Paul W. Wiseman, kSpace
Image Correlation Spectroscopy (kICS): A Method for Accurate
Transport Measurements Independent of Fluorophore
Photophysics , Biophysical J., 91, 3061
(2006).

Benoit Palmieri and David Ronis, The Jarzynski equality:
Connections to thermodynamics and the Second Law,
Phys. Rev. E, 75, 011133 (2007).

Benoit Palmieri and David Ronis, Diffusion in Channeled
structures III: Quantum corrections induced by lattice
vibrations, Phys. Rev. E, 76, 011124 (2007).

David Ronis, Response Theory and Reduced Equations of
Motion, Phys. Rev. E, 79, 031106 (2009).

Carl Bartels and David Ronis, Competition between
conformational and chemical equilibrium in suspensions of
polyelectrolytecoated particles, Macromolecules,
44, 31743178 (2011).
Here are some useful links
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