|1Filatova, KO |
1O. O. Chuiko Institute of Surface Chemistry of the NAS of Ukraine, Kyiv
|Dopov. Nac. akad. nauk Ukr. 2017, 5:80-88|
The states of water and an aqueous solution of trifluoroacetic acid in a swollen chitosan and chitosan filled with nanosilica A-300 by low-temperature 1H NMR spectroscopy are studied. It is shown that the main part of water in the polymer matrix is included in the domains with R > 10 nm. Introduction of nanosilica into the polymer matrix reduces the binding energy by almost 30 % through the formation of bonds between chitosan and silica (water displacement in the gaps between the biopolymer and SiO2). In the presence of a strong acid (TFA), polyassociations of water with varying solubility relative to acids within the polymeric matrix of pure chitosan and chitosan filled with SiO2 are present, while a large part of water refers to the domains, which dissolve the acid poorly.
|Keywords: 1H NMR spectroscopy, chitosan, hydration, nanosilica|
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