Chemical Sciences Seminars
Can EPR be used to probe solid-liquid phase transitions in confined systems?
by Dr. Vinayak Rane (Bhabha Atomic Research Centre, Mumbai)
Monday, July 22, 2019
from
to
(Asia/Kolkata)
at AG-69
at AG-69
Description |
Study of systems such as water under confined conditions is actively pursued because of its relevance to real systems, such as cells, microorganisms, etc. In this regard, EPR spectroscopy offers a convenient route due to its excellent sensitivity to micro viscosity and penetrability power. When used as a probe-based spectroscopy, however, the probe-system interactions need to be thoroughly examined beforehand. In this work, we consider a specific property: solid⇌liquid transition of water, and ask a fundamental question, “Can EPR detect the freezing of water at its conventional freezing point in bulk/confined conditions?” Our work convincingly demonstrates that the spin probe can itself induce liquid domains in ice, which could be mistaken as a depression in the freezing point. We propose a theory to account for these solute induced perturbations. Finally, it will be discussed how the proposed theory can be applied to the extreme dilution case of a solution containing a single solute molecule.
References Thangswamy, M.; Maheshwari, P.; Dutta, D.; Rane, V.*; Pujari, P. K. J. Phys. Chem. A 2018, 122, 5177-5189. Thangswamy, M.; Maheshwari, P.; Dutta, D.; Rane, V.*; Pujari, P. K. J. Phys. Chem. C 2019, 123, 11244-11256. |