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Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution

The structure and conformation of methyl cellulose (MC) and hydroxypropyl methyl cellulose (HpMC) ether samples dissolved in dilute aqueous (D(2)O) solutions at a temperature of 25 °C were reconsidered in detail based on the experimental results obtained using small- and wide-angle neutron scatterin...

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Autores principales: Arai, Kengo, Horikawa, Yoshiki, Shikata, Toshiyuki, Iwase, Hiroki
Formato: Online Artículo Texto
Lenguaje:English
Publicado: The Royal Society of Chemistry 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9053864/
https://www.ncbi.nlm.nih.gov/pubmed/35518322
http://dx.doi.org/10.1039/d0ra03437a
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author Arai, Kengo
Horikawa, Yoshiki
Shikata, Toshiyuki
Iwase, Hiroki
author_facet Arai, Kengo
Horikawa, Yoshiki
Shikata, Toshiyuki
Iwase, Hiroki
author_sort Arai, Kengo
collection PubMed
description The structure and conformation of methyl cellulose (MC) and hydroxypropyl methyl cellulose (HpMC) ether samples dissolved in dilute aqueous (D(2)O) solutions at a temperature of 25 °C were reconsidered in detail based on the experimental results obtained using small- and wide-angle neutron scattering (S-WANS) techniques in a range of scattering vectors (q) from 0.05 to 100 nm(−1). MC samples exhibited an average degree of substitution (DS) by methyl groups per glucose unit of DS = 1.8 and the weight average molar mass of M(w) = 37 × 10(3) and 79 × 10(3) g mol(−1). On the other hand, HpMC samples possessed the average molar substitution number (MS) by hydroxypropyl groups per glucose unit of MS = 0.25, DS = 1.9, and M(w) = 50 × 10(3) and 71 × 10(3) g mol(−1). The concentration-reduced scattering intensity data gathered into a curve for the solutions of identical sample species clearly demonstrated the relationship I(q)c(−1) ∝ q(−1) in a q range from 0.05 to 2.0 nm(−1), and small interference peaks were found at q ∼ 7 and 17 nm(−1) for all examined sample solutions. These observations strongly revealed that form factors for both the MC and HpMC samples were perfectly described with that for long, rigid rod particles with average diameters of 0.8 and 0.9 nm, respectively, and with an inner structure with characteristic mean spacing distances of ca. 0.9 and 0.37 nm, respectively, regardless of the chemically modified conditions and molar masses. A rationally speculated structure model for the MC and HpMC samples dissolved in aqueous solution was proposed.
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spelling pubmed-90538642022-05-04 Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution Arai, Kengo Horikawa, Yoshiki Shikata, Toshiyuki Iwase, Hiroki RSC Adv Chemistry The structure and conformation of methyl cellulose (MC) and hydroxypropyl methyl cellulose (HpMC) ether samples dissolved in dilute aqueous (D(2)O) solutions at a temperature of 25 °C were reconsidered in detail based on the experimental results obtained using small- and wide-angle neutron scattering (S-WANS) techniques in a range of scattering vectors (q) from 0.05 to 100 nm(−1). MC samples exhibited an average degree of substitution (DS) by methyl groups per glucose unit of DS = 1.8 and the weight average molar mass of M(w) = 37 × 10(3) and 79 × 10(3) g mol(−1). On the other hand, HpMC samples possessed the average molar substitution number (MS) by hydroxypropyl groups per glucose unit of MS = 0.25, DS = 1.9, and M(w) = 50 × 10(3) and 71 × 10(3) g mol(−1). The concentration-reduced scattering intensity data gathered into a curve for the solutions of identical sample species clearly demonstrated the relationship I(q)c(−1) ∝ q(−1) in a q range from 0.05 to 2.0 nm(−1), and small interference peaks were found at q ∼ 7 and 17 nm(−1) for all examined sample solutions. These observations strongly revealed that form factors for both the MC and HpMC samples were perfectly described with that for long, rigid rod particles with average diameters of 0.8 and 0.9 nm, respectively, and with an inner structure with characteristic mean spacing distances of ca. 0.9 and 0.37 nm, respectively, regardless of the chemically modified conditions and molar masses. A rationally speculated structure model for the MC and HpMC samples dissolved in aqueous solution was proposed. The Royal Society of Chemistry 2020-05-19 /pmc/articles/PMC9053864/ /pubmed/35518322 http://dx.doi.org/10.1039/d0ra03437a Text en This journal is © The Royal Society of Chemistry https://creativecommons.org/licenses/by-nc/3.0/
spellingShingle Chemistry
Arai, Kengo
Horikawa, Yoshiki
Shikata, Toshiyuki
Iwase, Hiroki
Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution
title Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution
title_full Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution
title_fullStr Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution
title_full_unstemmed Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution
title_short Reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution
title_sort reconsideration of the conformation of methyl cellulose and hydroxypropyl methyl cellulose ethers in aqueous solution
topic Chemistry
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9053864/
https://www.ncbi.nlm.nih.gov/pubmed/35518322
http://dx.doi.org/10.1039/d0ra03437a
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