TY - JOUR
T1 - Thermothickening Behavior of Self-Stabilized Colloids Formed from Associating Polymers
AU - Chen, Yaoyao
AU - Shull, Kenneth R.
N1 - Publisher Copyright:
© 2019 American Chemical Society.
PY - 2019/7/9
Y1 - 2019/7/9
N2 - The complexation of partially ethyl-quaternized poly(4-vinyl pyridine) (QVP) and poly(methacrylic acid) (PMAA) induces a dramatic change in solution viscoelasticity. In this work, we investigated a model system consisting of QVP (with 2% charge), PMAA, and dimethyl sulfoxide (DMSO)-water mixed solvent (85 wt % DMSO-15 wt % water), which exhibits a remarkable thermothickening behavior, characterized by an increase of viscosity by 3 orders of magnitude when the temperature is increased by 20 °C. At low temperatures, this system behaves as a low-viscosity milky colloidal suspension that remains stable for periods of at least 1 year. At higher temperatures, the colloids swell, increasing their effective volume fraction and giving rise to the observed viscosity increase. The thermothickening/thermothinning transition temperature could be tuned by varying the stoichiometry of the mixed polymers. We utilized rheometry, UV-vis spectroscopy, and dynamic light scattering to shed light on the mechanism of this phenomenon. This simple approach for achieving tunable thermothickening capability provides a new platform for designing thermoresponsive solutions from simple polymer mixtures.
AB - The complexation of partially ethyl-quaternized poly(4-vinyl pyridine) (QVP) and poly(methacrylic acid) (PMAA) induces a dramatic change in solution viscoelasticity. In this work, we investigated a model system consisting of QVP (with 2% charge), PMAA, and dimethyl sulfoxide (DMSO)-water mixed solvent (85 wt % DMSO-15 wt % water), which exhibits a remarkable thermothickening behavior, characterized by an increase of viscosity by 3 orders of magnitude when the temperature is increased by 20 °C. At low temperatures, this system behaves as a low-viscosity milky colloidal suspension that remains stable for periods of at least 1 year. At higher temperatures, the colloids swell, increasing their effective volume fraction and giving rise to the observed viscosity increase. The thermothickening/thermothinning transition temperature could be tuned by varying the stoichiometry of the mixed polymers. We utilized rheometry, UV-vis spectroscopy, and dynamic light scattering to shed light on the mechanism of this phenomenon. This simple approach for achieving tunable thermothickening capability provides a new platform for designing thermoresponsive solutions from simple polymer mixtures.
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U2 - 10.1021/acs.macromol.9b00973
DO - 10.1021/acs.macromol.9b00973
M3 - Article
AN - SCOPUS:85068166000
SN - 0024-9297
VL - 52
SP - 4926
EP - 4933
JO - Macromolecules
JF - Macromolecules
IS - 13
ER -