Abstract: first_pagesettingsOrder Article Reprints Open AccessArticle Disordering of Starch Films as a Factor Influencing the Release Rate of Biologically Active Substances by Ekaterina Podgorbunskikh 1,*ORCID,Timofei Kuskov 1,2ORCID,Anna Matveeva 1,Artem Ulihin 1,Aleksey Bychkov 1,3ORCID,Igor Lomovskiy 1ORCID andYuliya Polienko 4ORCID 1 Institute of Solid State Chemistry and Mechanochemistry SB RAS, 18 Kutateladze Str., 630090 Novosibirsk, Russia 2 Department of Natural Sciences, Novosibirsk State University, 2 Pirogova Str., 630090 Novosibirsk, Russia 3 Department of Business, Novosibirsk State Technical University, 20 Prospekt K. Marksa, 630073 Novosibirsk, Russia 4 Laboratory of Nitrogen Compounds, N. N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, 9 Lavrentiev Ave., 630090 Novosibirsk, Russia * Author to whom correspondence should be addressed. Polymers 2023, 15(10), 2303; https://doi.org/10.3390/polym15102303 Original submission received: 25 March 2023 / Revised: 4 May 2023 / Accepted: 11 May 2023 / Published: 13 May 2023 (This article belongs to the Special Issue Polymers in Food Science) Downloadkeyboard_arrow_down Browse Figures Versions Notes Abstract The release of a spin probe (nitroxide radical) from polymer films was studied by electron paramagnetic resonance (EPR). The films were fabricated from starch having different crystal structures (A-, B-, and C-types) and disordering degrees. Film morphology (analysis of the scanning electron microscopy (SEM)) depended on the presence of dopant (nitroxide radical) to a larger extent rather than on crystal structure ordering or polymorphic modification. The presence of nitroxide radical led to additional crystal structure disordering and reduced the crystallinity index from the X-ray diffraction (XRD) data. Polymeric films made of amorphized starch powder were able to undergo recrystallization (crystal structure rearrangement), which manifested itself as an increase in crystallinity index and phase transition of the A- and C-type crystal structures to the B-type one. It was demonstrated that nitroxide radical does not form an individual phase during film preparation. According to the EPR data, local permittivity of starch-based films varied from 52.5 to 60.1 F/m, while bulk permittivity did not exceed 17 F/m, which demonstrates that local concentration of water is increased in the regions near the nitroxide radical. The mobility of the spin probe corresponds to small stochastic librations and is indicative of the strongly a mobilized state. The application of kinetic models made it possible to find out that substance release from biodegradable films consists of two stages: matrix swelling and spin probe diffusion through the matrix. Investigation of the release kinetics for nitroxide radical demonstrated that the course of this process depends on the type of crystal structure of native starch.

Cite: Podgorbunskikh E. , Kuskov T. , Matveeva A. , Ulihin A. , Bychkov A. , Lomovskiy I. , Polienko Y.
Disordering of Starch Films as a Factor Influencing the Release Rate of Biologically Active Substances
Polymers. 2023. V.15. N10. P.2303. DOI: 10.3390/polym15102303 WOS РИНЦ

Dates:

Submitted:	Mar 25, 2023
Accepted:	May 11, 2023
Published print:	May 13, 2023

Identifiers:

Web of science	WOS:000998215000001
Elibrary	54397091
OpenAlex	W4376614850

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