Amish Patel

Post-doctoral researcher Chandler Group  Room 39, Pitzer Center Department of Chemistry University of California at Berkeley Berkeley, CA 94720 Phone: 510-643-7128 Fax: 510-643-1566 Email: am1sh"AT"berkeley"DOT"edu

Research Interests

The Hydrophobic Effect 

The Hydrophobic Effect is at the heart of several relevant and interesting problems ranging from detergency to protein folding. The macroscopic and often simplistic interpretation is embodied in the notion that "Oil and water do not mix", i.e. a hydrophobic solute, such as oil will not solvate in water and instead phase separate. At the microscopic scale, however, the situation is a lot richer and more complex. The free energy of solvation of a solute in water depends on how the solute affects the structure of the water molecules around it. Any hydrophobic solute interferes with the H-bonding network of water, but the manner in which it does so, depends on the size of the solute. Small hydrophobes (smaller than 1 nm) allow the H-bonding network to extend around its volume, thus invoking an entropic penalty for solvation that scales as the solute volume. Larger hdrophobes, on the other hand, make it impossible for the H-bonding network to accomodate them. This results in a net loss of H-bonds for water molecules close to the solute and results in the formation of an interface with a depletion of solvent molecules around the solute (the resultant free energy of solvation, thus scales as the surface area of the solute). The fluctutions of the solvent near this interface are believed to be similar to the equilibrium fluctuations near a liquid/vapor interface at phase coexistence. (for a more detailed description of hydrophobic effect click here).

It has recently been shown that the nature of the solvent fluctuations close to a hydrophobic solute do not change when soft attractive interactions, such as dispersive attractions are introduced between the solute and the solvent. I am currently trying to ascertain whether having strong attractions between the solute and the solvent, such as H-bonding, changes the nature of the solvent fluctuations. 

Education

• 2001-2007: Ph.D., Chemical Engineering, University of California, Berkeley
  Thesis: Dynamic Studies of a Block Copolymer Melt
  Advisor: Nitash Balsara
• 1997-2001: B.Tech., Chemical Engineering, Indian Institute of Technology, Bombay
  Advisor: Anurag Mehra

Publications

7.       "Effect of Molecular Weight on the Mechanical and Electrical Properties of Block Copolymer Electrolytes", M. Singh, O. Odusanya, G. M. Wilmes, H. B. Eitouni, E. D. Gomez, A. J. Patel, V. L. Chen, M.-J. Park, P. Fragouli, H. Iatrou, N. Hadjichristidis, D. Cookson and N. P. Balsara, accepted, Macromolecules, 2007.

6.       "Observing Nucleation Close to the Binodal by Perturbing Metastable Polymer Blends", A. J. Patel and N. P. Balsara, vol. 40, p. 1675-1683, Macromolecules, 2007.

5.       " Condensed Exponential Correlation Functions in Multicomponent Polymer Blends Measured by X-ray Photon Correlation Spectroscopy ", M. L. Ruegg, A. J. Patel, S. Narayanan, A. Sandy, S. G. J. Mochrie, H. Watanabe and N. P. Balsara, vol. 39, p. 8822-8831, Macromolecules, 2006.

4.       "Relationship between Structural and Stress Relaxation in a Block-Copolymer Melt", A. J. Patel, S. Narayanan, A. Sandy, S. G. J. Mochrie, B. A. Garetz, H. Watanabe and N. P. Balsara, vol. 96, p. 257801, Physical Review Letters, 2006.

3.       "Observation of nematic texture in a diblock copolymer melt", F. M. Abuzaina, B. A. Garetz, A. J. Patel, M. C. Newstein, S. P. Gido, X. C. Hu and N. P. Balsara, vol. 39, p. 3377-3385, Macromolecules, 2006.

2.       "Grain structure in block copolymer thin films studied by guided wave depolarized light scattering", B. A. Garetz, M. C. Newstein, J. D. Wilbur, A. J. Patel, D. A. Durkee, R. A. Segalman, J. A. Liddle and N. P. Balsara, vol. 38, p. 4282-4288, Macromolecules, 2005.

1.   "Structure and phase behavior of block copolymer melts near the sphere-cylinder boundary", F. M. Abuzaina, A. J. Patel, S. Mochrie, S. Narayanan, A. Sandy, B. A. Garetz and N. P. Balsara, vol. 38, p. 7090-7097, Macromolecules, 2005.

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Last updated: 1/31/2008