Large-Strain Deformation of Polymer Gels
Mon, Nov 18
2:00 PM — 3:15 PM
Steinman Hall 160 - Lecture Hall
The ChE Department would like to welcome Santanu Kundu from Miss. State. UniversityAs the properties of polymer gels can be tuned, polymer gels consisting of both synthetic and biopolymers are found in many applications ranging from bioimplants to food materials to tissue scaffold to oil recovery to drug delivery. In many of these applications swollen gels are subjected to large-strain deformation, which result in elastic instabilities (cavitation, creasing) and failure (fracture). Here, we present large-strain deformation behavior of a physically associating thermoreversible gel and an iononically bonded alginate gel. The physically associating gel, consisting of a triblock copolymer, poly(methyl methacrylate)–poly(n-butyl acrylate)–poly(methylmethacrylate) in 2-ethyl-1-hexanol, displays strain-stiffening behavior as investigated by small- and large-amplitude oscillatory (LAOS) shear experiments. In contrast, the alginate gel strain-softens at large shear-strain. Gel deformation behavior is also investigated using newly developed cavitation rheology technique. This technique involves pressurization of a defect introduced by inserting a needle at an arbitrary location within a gel and monitoring the pressure as a function of time. At a critical pressure the gel either cavitates or fracture and the critical pressure scales with the local elastic modulus of the gel. The transition from cavitation to fracture has been studied as a function of gel network structure.
Dr. Santanu Kundu is an Assistant Professor in the Dave C. Swalm School of Chemical Engineering of Mississippi State University since January 2012. Before joining Mississippi State Dr. Kundu performed postdoctoral research in the Sustainable Polymers Group (Polymers Division) of the National Institute of Standards and Technology (NIST) and with Prof. Alfred Crosby at the Polymer Science and Engineering Department of the University of Massachusetts-Amherst. Dr. Kundu has received his PhD in Chemical Engineering from Clemson University in 2006. His PhD work, which linked flow, microstructure, and the processing of liquid crystalline carbonaceous materials, has been awarded the best dissertation in Carbon Science (2004-2006) by the Elsevier-Carbon journal. Dr. Kundu’s research interest is investigating the processing-structure-property relationships for various soft materials towards different applications ranging from bioimplants to energy storage to water purification to structural composites.