Advanced Materials: TechConnect Briefs 2015Advanced Materials TechConnect Briefs 2015

Polymers Chapter 9

New Insights into Microstructure, Rheology & Molecular Level Structural Changes During Self-Assembly & Gelation in Complex Fluids Through Combined DLS-Optical Microrheology-Raman Spectroscopy

S. Amin, S. Blake, L. Kidder, E.N. Lewis, S. Kenyon
Malvern Instruments, United States

pp. 556 - 558

Keywords: microrheology, Raman Spectroscopy, self-assembly, wormlike micelles, biopolymer

Soft Matter/Complex fluid systems are ubiquitous across a range of industrial and consumer sectors. In many instances the final product format of these complex fluids are gels or soft solids and the processing and product functionality attributes of such materials are often dependent on their rheological response and viscosity. The rheology evolution in such complex fluid systems as a function of formulation parameters (e.g. pH, ionic strength) is intimately connected to corresponding changes in micro/mesostructure and intermolecular and intramolecular associations and interactions. Most insights developed into understanding the self-assembly and rheology evolution process in such systems has primarily focused on elucidating the associated micro/mesostructural changes through various scattering (light, x-ray, neutron) and imaging techniques (cryo-TEM, SEM, AFM). Further more detailed insights into the associated chemical conformational/structural changes and various non-covalent interactions (e.g. H-bonds, hydrophobic interactions) leading to the self-assembly process has been very limited. In this talk we provide new structural/interaction insights into the self-assembly and gelation mechanism of complex fluids through combination of a number of well-established analytical techniques namely dynamic light scattering (DLS), Raman spectroscopy and Optical Microrheology. New insights into self-assembly and gelation will be presented for 3 different systems-wormlike micelles, PVA and Agarose.