Abstract
Water uptake by a thermo-responsive gel is strongly affected by temperature: the gel swells below its volume phase transition temperature T c and shrinks above T c . Observations reveal two types of equilibrium swelling diagrams: discontinuous (with degree of swelling Q falling abruptly at T c ) and continuous (with Q decreasing smoothly with temperature). A constitutive model is developed for the mechanical behavior of a temperature-sensitive gel subjected to swelling that accounts for changes in its structure (phase separation) at T c . Adjustable parameters are found by fitting experimental data in equilibrium swelling tests, transient deswelling–reswelling tests, and tensile-compressive tests on poly(N, N-diethylacrylamide) gel with a continuous equilibrium swelling curve and poly(N−n-propylacrylamide) gel with a discontinuous diagram. Numerical simulation demonstrates qualitatively different responses of gels with discontinuous and continuous swelling diagrams.
Original language | English |
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Journal | International Journal of Engineering Science |
Volume | 128 |
Pages (from-to) | 79-100 |
Number of pages | 22 |
ISSN | 0020-7225 |
DOIs | |
Publication status | Published - 1 Jul 2018 |
Keywords
- Constitutive modeling
- Hydrophobic association
- Temperature-responsive gel
- Volume phase transition