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Author ORCID Identifier


Campus-Only Access for One (1) Year

Document Type


Degree Name

Doctor of Philosophy (PhD)

Degree Program

Polymer Science and Engineering

Year Degree Awarded


Month Degree Awarded


First Advisor

Murugappan Muthukumar

Subject Categories

Polymer and Organic Materials


By experimentally investigating the invasion of a polyelectrolyte into a charged hydrogel, we report a novel coacervate band formation deep inside the gel, unlike in equilibrated coacervate gel composites. The mobility and the position of this band are found to be controlled by the concentration gradient of the invasive species and the pH gradient within the gel matrix. Using turbidimetry, static and dynamic light scattering, and rheology, we have monitored the beginning location and time of birth of the coacervate band inside the gel and its time evolution. Once a band is born, with time, it becomes more intense and broadens downstream with the permanent localization of the initial beginning location. Even more remarkably, it forms daughter bands upstream at later stages of the band’s life, suggesting a backflow of the guest molecules. The various quantitative features of the band depend crucially on the initial concentration gradient of the invader. Our observations open a new direction in coacervate gel systems under non-equilibrium conditions.


Available for download on Sunday, May 26, 2024