Reversible monolayer-to-crystalline phase transition in amphiphilic silsesquioxane at the air-water interface

Banerjee, R. ; Sanyal, M. K. ; Bera, M. K. ; Gibaud, A. ; Lin, B. ; Meron, M. (2015) Reversible monolayer-to-crystalline phase transition in amphiphilic silsesquioxane at the air-water interface Scientific Reports, 5 (1). Article ID 8497. ISSN 2045-2322

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Official URL: https://www.nature.com/articles/srep08497

Related URL: http://dx.doi.org/10.1038/srep08497

Abstract

We report on the counter intuitive reversible crystallisation of two-dimensional monolayer of Trisilanolisobutyl Polyhedral Oligomeric SilSesquioxane (TBPOSS) on water surface using synchrotron x-ray scattering measurements. Amphiphilic TBPOSS form rugged monolayers and Grazing Incidence X-ray Scattering (GIXS) measurements reveal that the in-plane inter-particle correlation peaks, characteristic of two-dimensional system, observed before transition is replaced by intense localized spots after transition. The measured x-ray scattering data of the non-equilibrium crystalline phase on the air-water interface could be explained with a model that assumes periodic stacking of the TBPOSS dimers. These crystalline stacking relaxes upon decompression and the TBPOSS layer retains its initial monolayer state. The existence of these crystals in compressed phase is confirmed by atomic force microscopy measurements by lifting the materials on a solid substrate.

Item Type:Article
Source:Copyright of this article belongs to Nature Publishing Group.
ID Code:111447
Deposited On:30 Nov 2017 11:57
Last Modified:30 Nov 2017 11:57

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