Amit Chakrbarti - Condensed Matter Physics Research

Amit Chakrabarti

Research Description

In a wide variety of natural and technical settings small particles in a dispersed phase come together to form larger clusters when the small particle system becomes, by some manner, unstable. From a broad perspective, the “particles” can be atoms, ions, or molecules, as well as colloidal particles, aerosols, and nanoparticles. The transition from a dispersed phase to clusters can include the formation of precipitated crystalline solids from solutions as well as the formation of fractal aggregates in colloids and aerosols. Formation of condensed, crystalline solids or open, random aggregates represent the equilibrium and nonequilibrium limits of this transition.

Parts of this grand problem have seen considerable previous research such as limiting nonequilibrium models of aggregation and gelation, models of nucleation and spinodal decomposition, and early studies of growth during precipitation. However, a general theory that encompasses all these related phenomena is lacking. We are trying to bridge this gap between the equilibrium and nonequilibrium limits by a focused combination of theoretical and experimental efforts.

Chakrabarti’s group is carrying out both large scale Monte Carlo and Molecular Dynamics simulations of realistic models while Sorensen’s group is carrying out experimental studies of aggregation in aerosols and superlattice formation in a variety of surface ligated nanoparticles. Our combined theoretical and experimental effort allows us to attack problems from different perspectives, lends a creative element to the work, and often leads to progress on more than one front or at least make progress in one direction when others have stalled. Furthermore, with our theory/experiment collaboration, our work aspires to establish a sound theoretical description for the new phenomena observed in experiments.

Research Funding

Chakrabarti’s recent research funding comes from the following funding agencies:

NASA (Aggregation in Dense Systems; $450,000; jointly with Chris Sorensen)

NSF Nanoscience Interdisciplinary Research Team (NIRT) program [Nanometer Stoichiometric Particle Compound Solutions and Control of their Self-Assembly into the Condensed Phase; $1,200,000 (2006-2009); jointly with Chris Sorensen and Bruce Law in physics, and Ken Klabunde and Christer Aakeroy in Chemistry].

Here is a news release on this NIRT award: http://www.mediarelations.k-state.edu/Web/News/NewsReleases/nsfgrant91406.html

Research Personnel

Graduate Students

Flint Pierce

Shruti Shrestha

Recent Publications (Total Refereed Publications 122)

Computer simulation of diffusion-limited cluster-cluster aggregation with an Epstein drag force, F. Pierce, C.M. Sorensen, and A. Chakrabarti, Phys. Rev. E. 74, 021411 (2006).
Hybrid superaggregate morphology as a result of aggregation in a cluster-dense aerosol, R. Dhaubhadel, F. Pierce, A. Chakrabarti, C.M. Sorensen, Phys. Rev. E, 73, 011404 (2006).
Aggregation-Fragmentation in a Model of DNA-Mediated Colloidal Assembly, F. Pierce, C.M. Sorensen, and A. Chakrabarti, Langmuir, 21, 8992 (2005).
Structural crossover in dense irreversibly aggregating particulate systems, D. Fry, A. Chakrabarti, W. Kim, and, C.M. Sorensen, Phys. Rev. E 69, 061401 (2004).
Molecular dynamics simulation of the transition from dispersed to solid phase, A. Chakrabarti, D. Fry, and C.M. Sorensen, Phys. Rev. E 69, 031408 (2004).
Computer Simulation of Selective Aggregation in Binary Colloids, F.Pierce, A. Chakrabarti, D. Fry, and, C.M. Sorensen, Langmuir 20, 2498 (2004).
Structure factor scaling in colloidal phase separation, J.J. Cerda, T. Sintes, C.M. Sorensen, A. Chakrabarti, Phys. Rev. E 70, 051405 (2004).
Kinetics of Phase Transformations in Depletion-Driven Colloids, J.J. Cerda, T. Sintes, C.M. Sorensen, and A. Chakrabarti, Phys. Rev. E 70, 011405 (2004).
Enhanced Kinetics and Free-Volume Universality in Dense Aggregating Systems, D. Fry, T. Sintes, A. Chakrabarti, and C.M. Sorensen, Physical Review Letters 89, 148301 (2002).

Condensed Matter Physics Talk - 2006 (pdf file)

Soft Matter Talks - May 16, 2007