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NMR relaxation and self-diffusion in aqueous micellar gels of pluronic F-127

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dc.contributor.author Shaikhullina M.
dc.contributor.author Khaliullina A.
dc.contributor.author Gimatdinov R.
dc.contributor.author Butakov A.
dc.contributor.author Chernov V.
dc.contributor.author Filippov A.
dc.date.accessioned 2021-02-25T20:33:58Z
dc.date.available 2021-02-25T20:33:58Z
dc.date.issued 2020
dc.identifier.issn 0167-7322
dc.identifier.uri https://dspace.kpfu.ru/xmlui/handle/net/161759
dc.description.abstract © 2020 Elsevier B.V. We studied the transverse NMR relaxation of protons of different chemical groups and diffusion of molecules in an aqueous pluronic F-127 system. The system was studied at concentrations of 15, 21 and 28 wt% and in the temperature range of 293–333 K. The dynamic peculiarities in different phases were analyzed based on the NMR relaxation and diffusion data. Our study demonstrated a correlation between phase states, T2 relaxation times of “solid-like” and “liquid” protons of selected chemical groups of polypropylene oxide (PPO) and polyethylene oxide (PEO) blocks, and diffusion coefficients. Transverse NMR relaxation established that the presence of a “solid-like” component of CH3 protons of PEO blocks is observed only at temperatures and concentrations corresponding to the rigid-gel phase, due to entanglements between micellar coronas. At all temperatures and concentrations, some CH3 protons of PPO blocks and some CH2 protons of PEO blocks show “liquid-like” transverse NMR relaxation. Under the conditions corresponding to formation of the rigid-gel phase of the pluronic, relaxation of the “liquid-like” protons additionally accelerates due to entanglements of micellar coronas. Transition of the system to the rigid-gel phase is accompanied by decrease of diffusion coefficients by a factor of 10–104 relative to the diffusivity of free-moving pluronic micelles in the sol phase. Diffusion measurements show that there are pre-transition phenomena, which are characteristic for temperatures and concentrations near sol-gel phase boundaries.
dc.relation.ispartofseries Journal of Molecular Liquids
dc.subject Block-copolymer
dc.subject Molecular mobility
dc.subject NMR relaxation
dc.subject Phase diagram
dc.subject Poloxamer
dc.title NMR relaxation and self-diffusion in aqueous micellar gels of pluronic F-127
dc.type Article
dc.relation.ispartofseries-volume 306
dc.collection Публикации сотрудников КФУ
dc.source.id SCOPUS01677322-2020-306-SID85081697365

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  • Публикации сотрудников КФУ Scopus [24551]
    Коллекция содержит публикации сотрудников Казанского федерального (до 2010 года Казанского государственного) университета, проиндексированные в БД Scopus, начиная с 1970г.

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