TY - JOUR
T1 - Hysteresis in the thermally induced phase transition of cellulose ethers
AU - Bizmark, Navid
AU - Caggiano, Nicholas J.
AU - Liu, Jason X.
AU - Arnold, Craig B.
AU - Prud’homme, Robert K.
AU - Datta, Sujit S.
AU - Priestley, Rodney D.
N1 - Publisher Copyright:
© 2022 The Royal Society of Chemistry.
PY - 2022/8/3
Y1 - 2022/8/3
N2 - Functionalized cellulosics have shown promise as naturally derived thermoresponsive gelling agents. However, the dynamics of thermally induced phase transitions of these polymers at the lower critical solution temperature (LCST) are not fully understood. Here, with experiments and theoretical considerations, we address how molecular architecture dictates the mechanisms and dynamics of phase transitions for cellulose ethers. Above the LCST, we show that hydroxypropyl substituents favor the spontaneous formation of liquid droplets, whereas methyl substituents induce fibril formation through diffusive growth. In celluloses which contain both methyl and hydroxypropyl substituents, fibrillation initiates after liquid droplet formation, suppressing the fibril growth to a sub-diffusive rate. Unlike for liquid droplets, the dissolution of fibrils back into the solvated state occurs with significant thermal hysteresis. We tune this hysteresis by altering the content of substituted hydroxypropyl moieties. This work provides a systematic study to decouple competing mechanisms during the phase transition of multi-functionalized macromolecules.
AB - Functionalized cellulosics have shown promise as naturally derived thermoresponsive gelling agents. However, the dynamics of thermally induced phase transitions of these polymers at the lower critical solution temperature (LCST) are not fully understood. Here, with experiments and theoretical considerations, we address how molecular architecture dictates the mechanisms and dynamics of phase transitions for cellulose ethers. Above the LCST, we show that hydroxypropyl substituents favor the spontaneous formation of liquid droplets, whereas methyl substituents induce fibril formation through diffusive growth. In celluloses which contain both methyl and hydroxypropyl substituents, fibrillation initiates after liquid droplet formation, suppressing the fibril growth to a sub-diffusive rate. Unlike for liquid droplets, the dissolution of fibrils back into the solvated state occurs with significant thermal hysteresis. We tune this hysteresis by altering the content of substituted hydroxypropyl moieties. This work provides a systematic study to decouple competing mechanisms during the phase transition of multi-functionalized macromolecules.
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U2 - 10.1039/d2sm00564f
DO - 10.1039/d2sm00564f
M3 - Article
C2 - 35946517
AN - SCOPUS:85136235681
SN - 1744-683X
VL - 18
SP - 6254
EP - 6263
JO - Soft matter
JF - Soft matter
IS - 33
ER -