ASM 2019

Talk (C20)


First Order to Second Order Crossover in Dewetting Transition of Water Near Nanostructured Surfaces

 

Debdas Dhabal, Nicolas B. Rego and Amish J. Patel*

 

Department of Chemical and Biomolecular Engineering, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States

 

Email: ddhabal[at]seas.upenn.edu

 

 

A knowledge of density fluctuations in bulk water and at interfaces has played a crucial role in understanding of hydrophobic effects, [1−2] which drive biomolecular and other aqueous assemblies. Here we examine the phase behavior associated with collective dewetting transition in bulk water and near different complex surfaces by computing free energetics of water density fluctuations in restricted geometry [3]. By changing the shape and contracting the size of the probe-volume we show that one can gradually change the transition associated to dewetting from first order to second order. We borne out that the first order derivative (which is related to the strength of the external perturbations) and second-order derivative of unbiased free energy of cavity formation could serve as a marker of bistability or monostabilty at liquid-vapor coexistence. This study reveals that this crossover is ubiquitous near a variety of surfaces, including surfaces with topographically rich structures, such as ubiquitin protein. As the interaction of proteins and its phase behavior are all influenced by the nature of its hydration waters, this study also sheds light on bio-molecular binding process. [4]

 

 

(1) Lum, K.; Chandler, D.; Weeks, J. D. J. Phys. Chem. B. 1999, 103, 4570-4577.

(2) Xi, E.; Patel, A. J. P. Natl. Acad. Sci. USA 2016, 113, 4549-4551.

(3) Dhabal, D.; Rego, N. B. and Patel, A. J. 2019 (Manuscript in preparation)

(4) Rego, N. B.; Xi, Erte, and Patel, A. J. J. Am. Chem. Soc. 2019, 141, 5, 2080-2086.

 

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