The effect of the molecular structure of hydroxypropyl methylcellulose on the states of water, wettability, and swelling properties of cryogels prepared with and without CaO 2 .

Autor: Chiaregato CG; Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, Brazil., Bernardinelli OD; Department of Physics, Federal University of São Carlos, 13565-905 São Carlos, Brazil., Shavandi A; BioMatter Unit, École Polytechnique de Bruxelles, Université Libre de Bruxelles (ULB), 1050 Brussels, Belgium., Sabadini E; Department of Physical Chemistry, Institute of Chemistry, State University of Campinas, 6154, 13083-970 Campinas, Brazil., Petri DFS; Department of Fundamental Chemistry, Institute of Chemistry, University of São Paulo, 05508-000 São Paulo, Brazil. Electronic address: dfsp@iq.usp.br.
Jazyk: angličtina
Zdroj: Carbohydrate polymers [Carbohydr Polym] 2023 Sep 15; Vol. 316, pp. 121029. Date of Electronic Publication: 2023 May 18.
DOI: 10.1016/j.carbpol.2023.121029
Abstrakt: Hydroxypropyl methylcellulose (HPMC) belongs to the cellulose ether family that has hydroxyl groups substituted by hydrophobic methyl groups (DS) and hydrophilic hydroxypropyl groups (MS). Herein, the interactions between water molecules and cryogels prepared with HPMC in the presence and absence of a linear nonionic surfactant, as well as CaO 2 microparticles, which react with water producing O 2 , were systematically investigated by sorption experiments and Time-Domain Nuclear Magnetic Resonance. Regardless of the DS and MS, most water molecules presented transverse relaxation time t2 typical of intermediate water and a small population of more tightly bound water. HPMC cryogels with the highest DS of 1.9 presented the slowest swelling rate of 0.519 ± 0.053 g water /(g.s) and the highest contact angle values 85.250 o  ± 0.004 o , providing the best conditions for a slow reaction between CaO 2 and water. The presence of surfactant favored hydrophobic interactions that allowed the polar head of the surfactant to be exposed to the medium, resulting in a higher swelling rate and lower contact angle values. The HPMC with the highest MS presented the fastest swelling rate and the lowest contact angle. These findings are relevant for the formulations and reactions, where tuning the swelling kinetics is crucial for the final application.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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