Journal
JOURNAL OF CHEMICAL PHYSICS
Volume 135, Issue 8, Pages -Publisher
AMER INST PHYSICS
DOI: 10.1063/1.3626803
Keywords
-
Funding
- Office of Science, Office of Basic Energy Sciences, U.S. Department of Energy (DOE) [DE-AC02-05CH11231]
- National of Institutes of Health (NIH) [GM34993]
- Defense Threat Reduction Agency [IACRO-B0845281]
- Sandler Family Foundation
Ask authors/readers for more resources
The crystallization of proteins or colloids is often hindered by the appearance of aggregates of low fractal dimension called gels. Here we study the effect of electrostatics upon crystal and gel formation using an analytic model of hard spheres bearing point charges and short range attractive interactions. We find that the chief electrostatic free energy cost of forming assemblies comes from the entropic loss of counterions that render assemblies charge-neutral. Because there exists more accessible volume for these counterions around an open gel than a dense crystal, there exists an electrostatic entropic driving force favoring the gel over the crystal. This driving force increases with increasing sphere charge, but can be counteracted by increasing counterion concentration. We show that these effects cannot be fully captured by pairwise-additive macroion interactions of the kind often used in simulations, and we show where on the phase diagram to go in order to suppress gel formation. (C) 2011 American Institute of Physics. [doi: 10.1063/1.3626803]
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available