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Dear All,
SOLID STATE & STRUCTURAL CHEMISTRY UNIT
INDIAN INSTITUTE OF SCIENCE
BANGALORE – 560 012

SPECIAL SEMINAR
by
Dr. Atanu Kumar Metya
Department of Chemical Engineering
Indian Institute of Technology Kanpur

Title

Molecular Simulation Study of Ice Nucleation in the Presence of Foreign Substances

Date & Time : Wednesday 3rd October 2018 at 3:00 PM
Venue : SSCU Auditorium
Abstract:
Ice formation from liquid water is one of the most common phase transitions on Earth, affecting everything from the global climate in the Earth’s atmosphere to cryopreservation of cells and tissues. Nucleation can either occur homogeneously or heterogeneously. In nature and industry, freezing almost generally induces by the presence of foreign seed (i.e., heterogeneous ice nucleation). Despite a large amount of experimental and theoretical studies on heterogeneous nucleation, still many aspects of the freezing process remain unsolved. For example, how do different wetting states on nanostructured surfaces affect the ice nucleation rate? What is the surface structure of ice near a solid surface in the presence of impurities? In experiments, accurate capture of nucleation events as well as quantification of the freezing process is difficult due to practical challenges in designing relevant experiments. However, in this direction, molecular simulations play an important role in the study of nucleation processes. This talk will present research work in the broad area of heterogeneous crystallization of supercooled pure water and solutions on the substrates using molecular dynamics simulation. First, I investigated the nucleation behavior of a supercooled water droplet on the textured surfaces. The simulation results show that the nucleation rate depends on the surface fraction of a substrate as well as the wetting states of the water droplets. Next, I studied the heterogeneous crystallization of supercooled water in the presence of nanoparticle (NP) and salt. At lower NP–water interactions, the nucleation rate is indifferent, while higher at NP–water interactions, the nucleation rate is found to reduce with the addition of nanoparticles. Furthermore, I worked on the structure and freezing temperature of binary water−salt solution on hydrophobicity/hydrophilicity of surfaces. Here we investigate the effects of salt concentrations and the solutesubstrate interaction strengths on nucleation behavior of the aqueous solutions. Finally, I studied the ice adhesion mechanism on lubricantimpregnated surfaces (LISs) using steered molecular dynamics simulations. We found that the adhesion strength of ice on nanotextured surfaces impregnated with lubricant films to be higher compared to that on textured surfaces in presence excess lubricant films and the ice adhesion strength depends on the texture density. This systematic study enhances our understanding of ice adhesion mechanism on LISs and the effect of texture density on the adhesion properties, which can be applied for designing novel anti-icing surfaces with extremely weak ice adhesion strength.

ALL ARE CORDIALLY INVITED TO ATTEND

Chairman, SSCU

Coffee/Tea : 2.30-2.45 PM

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