Soft pinning: Experimental validation of static correlations in supercooled molecular glass-forming liquids.

Autor: Das R; Department of Chemistry, University of Texas at Austin, Austin, TX 78712, USA.; TIFR Center for Interdisciplinary Science, Tata Institute of Fundamental Research, Hyderabad 500046, India., Bhowmik BP; TIFR Center for Interdisciplinary Science, Tata Institute of Fundamental Research, Hyderabad 500046, India.; Department of Chemical Physics, The Weizmann Institute of Science, Rehovot 76100, Israel., Puthirath AB; TIFR Center for Interdisciplinary Science, Tata Institute of Fundamental Research, Hyderabad 500046, India.; Department of Materials Science and NanoEngineering, Rice University, 6100 Main Street, Houston, TX 77005, USA., Narayanan TN; TIFR Center for Interdisciplinary Science, Tata Institute of Fundamental Research, Hyderabad 500046, India., Karmakar S; TIFR Center for Interdisciplinary Science, Tata Institute of Fundamental Research, Hyderabad 500046, India.
Jazyk: angličtina
Zdroj: PNAS nexus [PNAS Nexus] 2023 Aug 25; Vol. 2 (9), pp. pgad277. Date of Electronic Publication: 2023 Aug 25 (Print Publication: 2023).
DOI: 10.1093/pnasnexus/pgad277
Abstrakt: Enormous enhancement in the viscosity of a liquid near its glass transition is a hallmark of glass transition. Within a class of theoretical frameworks, it is connected to growing many-body static correlations near the transition, often called "amorphous ordering." At the same time, some theories do not invoke the existence of such a static length scale in the problem. Thus, proving the existence and possible estimation of the static length scales of amorphous order in different glass-forming liquids is very important to validate or falsify the predictions of these theories and unravel the true physics of glass formation. Experiments on molecular glass-forming liquids become pivotal in this scenario as the viscosity grows several folds ( ∼ 10 14 ), and simulations or colloidal glass experiments fail to access these required long-time scales. Here we design an experiment to extract the static length scales in molecular liquids using dilute amounts of another large molecule as a pinning site. Results from dielectric relaxation experiments on supercooled Glycerol with different pinning concentrations of Sorbitol and Glucose, as well as the simulations on a few model glass-forming liquids with pinning sites, indicate the versatility of the proposed method, opening possible new avenues to study the physics of glass transition in other molecular liquids.
(© The Author(s) 2023. Published by Oxford University Press on behalf of National Academy of Sciences.)
Databáze: MEDLINE