Fracture-Healing Kinetics of Thermoreversible Physical Gels Quantified by Shear Rheophysical Experiments.

Autor:	Thornell TL; School of Materials Engineering and ‡College of Science, Purdue University, West Lafayette, Indiana 47907, United States., Helfrecht BA; School of Materials Engineering and College of Science, Purdue University, West Lafayette, Indiana 47907, United States., Mullen SA; School of Materials Engineering and College of Science, Purdue University, West Lafayette, Indiana 47907, United States., Bawiskar A; School of Materials Engineering and College of Science, Purdue University, West Lafayette, Indiana 47907, United States., Erk KA; School of Materials Engineering and College of Science, Purdue University, West Lafayette, Indiana 47907, United States.
Jazyk:	angličtina
Zdroj:	ACS macro letters [ACS Macro Lett] 2014 Oct 21; Vol. 3 (10), pp. 1069-1073. Date of Electronic Publication: 2014 Oct 06.
DOI:	10.1021/mz500524d
Abstrakt:	The fracture-healing behavior of model physically associating triblock copolymer gels was investigated with experiments coupling shear rheometry and particle tracking flow visualization. Fractured gels were allowed to rest for specific time durations, and the extent of strength recovered during the resting time was quantified as a function of temperature (20-28 °C) and gel concentration (5-6 vol %). Measured times for full strength recovery were an order of magnitude greater than characteristic relaxation times of the system. The Arrhenius activation energy for post-fracture strength recovery was found to be greater than the activation energy associated with stress relaxation, most likely due to the entropic barrier related to the healing mechanism of dangling chain reassociation with network junctions.
Databáze:	MEDLINE
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