Gels 2017, 3(2), 21; doi:10.3390/gels3020021
Temperature-Triggered Colloidal Gelation through Well-Defined Grafted Polymeric Surfaces
Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands
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Academic Editor: Clemens K Weiss
Received: 30 April 2017 / Revised: 27 May 2017 / Accepted: 30 May 2017 / Published: 3 June 2017
(This article belongs to the Special Issue Colloid Chemistry)
Abstract
Sufficiently strong interparticle attractions can lead to aggregation of a colloidal suspension and, at high enough volume fractions, form a mechanically rigid percolating network known as a colloidal gel. We synthesize a model thermo-responsive colloidal system for systematically studying the effect of surface properties, grafting density and chain length, on the particle dynamics within colloidal gels. After inducing an attraction between particles by heating, aggregates undergo thermal fluctuation which we observe and analyze microscopically; the magnitude of the variance in bond angle is larger for lower grafting densities. Macroscopically, a clear increase of the linear mechanical behavior of the gels on both the grafting density and chain length arises, as measured by rheology, which is inversely proportional to the magnitude of local bond angle fluctuations. This colloidal system will allow for further elucidation of the microscopic origins to the complex macroscopic mechanical behavior of colloidal gels including bending modes within the network. View Full-TextKeywords:
colloid gel; grafting density; temperature-triggered gelation; surface initiated atom transfer radical polymerization
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MDPI and ACS Style
van Doorn, J.M.; Sprakel, J.; Kodger, T.E. Temperature-Triggered Colloidal Gelation through Well-Defined Grafted Polymeric Surfaces. Gels 2017, 3, 21.
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