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Microrheology of the Liquid-Solid Transition during Gelation

2008; American Physical Society; Volume: 100; Issue: 14 Linguagem: Inglês

10.1103/physrevlett.100.146001

1092-0145

Travis H. Larsen, Eric M. Furst,

Polysaccharides Composition and Applications

The viscoelastic properties of physical and chemical polymer gels are characterized through the liquid-solid transition using particle tracking microrheology. Measurements of the probe particle mean-squared displacement are shifted as the extent of gelation increases to generate master curves. From the shift factors, we determine the gel point and critical scaling exponents. Both systems exhibit a critical relaxation exponent $n\ensuremath{\approx}0.6$, where ${G}^{\ensuremath{'}}\ensuremath{\sim}{G}^{\ensuremath{'}\ensuremath{'}}\ensuremath{\sim}{\ensuremath{\omega}}^{n}$ for the incipient gel, consistent with the Rouse model of dynamic scaling in the percolation universality class.