Understanding how water-soluble cellulose derivative behaves in sea-water via statistical thermodynamics

Noriyuki Isobe, Seishi Shimizu

Research output: Contribution to journalArticle


What drives the LCST-type thermal gelation of water-soluble cellulose derivative, methylcellulose (MC), in seawater was quantified on a molecular scale using statistical thermodynamic fluctuation theory. Quantifying MC-water and MC-salt interactions enabled us to identify the dominant interaction for thermal gelation. The Kirkwood-Buff integrals for intermolecular interactions, calculated from the published calorimetric and volumetric data, showed that 1) the accumulation of salts around MC molecules (favourable interaction between salts and MC) inhibits thermal gelation and the depletion of salts from MC (unfavourable interaction between salts and MC) promotes the gelation, and 2) this salt-MC interaction is the dominant factor (50-100 times stronger than the water-MC interaction).
This insight from the fluctuation theory is at odds with the age-old consensus regarding the driving force of thermal
gelation: water structure change in the presence of salts induces the promotion or inhibition of thermal gelation
Original languageJapanese
Pages (from-to)91-95
Number of pages5
JournalCellulose Communications
Issue number3
Publication statusAccepted/In press - 7 Aug 2020

Cite this