Strain rate and temperature dependence of collapse pressure in Langmuir monolayer of cholesteryl dimers

Sarkar, A and Suresh, KA and Kumar, P and Jayaraman, N (2021) Strain rate and temperature dependence of collapse pressure in Langmuir monolayer of cholesteryl dimers. In: Thin Solid Films, 735 .

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Abstract

We have synthesized two amphiphilic cholesteryl dimers, bis(cholesterylsuccinamidoethyl) ether (NHSCE)2 and bis(cholesterylphthalamidopropyl) ether (NHPCE)2. They form stable Langmuir monolayer films at air-water interface. (NHSCE)2 exhibits only liquid condensed phase, whereas (NHPCE)2 exhibits both liquid expanded and liquid condensed phases. The collapse phenomenon of a Langmuir monolayer has relevance to biological processes like control of surface tension in lung alveolar and so on. Our studies show that the collapse pressure (�c) of (NHPCE)2 Langmuir monolayer is invariant with the strain rate of compression and temperature. Interestingly, the �c of (NHSCE)2 Langmuir monolayer depends on the strain rate of compression and temperature. A power law relation is used for analysis of the strain rate dependence of �c. On varying the temperature, initially we find an increase in �c with increase in temperature, a behavior known as alpha (α) flow. On further increase in temperature, we find decrease in �c, a behavior known as kappa (κ) flow. The α- flow is very unusual and has not been reported in literature for dimers. An analogy is drawn between the observed α- flow in (NHSCE)2 dimer and the yield strength anomaly reported for alloys. © 2021

Item Type:	Journal Article
Publication:	Thin Solid Films
Publisher:	Elsevier B.V.
Additional Information:	The copyright for this article belongs to Elsevier B.V.
Keywords:	Air; Ethers; Liquids; Phase interfaces; Strain rate; Temperature distribution, Cholesteryl dimer; Collapse pressure; Condensed phase; Condensed phasis; Langmuir monolayers; Strain rate dependence; Strain-rates; Strain-temperature; Synthesised; Temperature dependence, Monolayers
Department/Centre:	Division of Chemical Sciences > Organic Chemistry
Date Deposited:	02 Dec 2021 12:52
Last Modified:	02 Dec 2021 12:52
URI:	http://eprints.iisc.ac.in/id/eprint/70066

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