Start
Dec 17, 2014 - 17:00
End
Dec 17, 2014 - 18:00
Venue
Room 118 Creativity Hall Chemical Engineering
Event Type
Speaker
Dr.Santanu Kundu Ph.D. Assistant Professor Dave C. Swalm School of Chemical Engineering Mississippi State University Miss. State MS 39762
Title
Large-strain Deformation Behavior of Swollen Polymer Gels
Abstract : Swollen polymer gels are used in a wide variety of applications ranging from bioimplants to food materials to drug delivery to tissue engineering. In many of these applications gels are subjected to large-strain deformation however very little is known how swollen gels with different structure behave at large-strain. In this presentation I will present our recent results on the non-linear mechanical response at large-strain elastic instability and failure behavior of two different gels: a physically crosslinked gel (triblock gel) and an ionically crosslinked gel (alginate). The physical gel is obtained by dissolving a triblock copolymer poly methylmethacrylate-poly n-butylacrylate-poly methylmethacrylate (PMMA-PnBA-PMMA) in a mid-block selective solvent 2-ethyl 1-hexanol. Alginate gels are obtained by crosslinking alginates using calcium salts. We use both cavitation and shear rheology to investigate the deformation behavior of polymer gels. Cavitation rheology is a new characterization technique for the measurement of mechanical properties of soft materials on small length scales e.g. 10 -1000 μm at any arbitrary location within a gel. The technique involves growing a cavity at the tip of a syringe needle and monitoring the pressure of the cavity at the onset of instability. This critical pressure Pc is directly related to the local elastic modulus of the material. The mechanical properties of these gels were also studied using large amplitude oscillatory shear (LAOS) experiments. Both cavitation and LAOS results capture distinctly different non-linear behavior and failure responses of triblock and alginate gels. The effect of graphene nanoplatelets on the self-assembly and mechanical properties of the triblock gel will also be presented. Our results provide a fundamental understanding gel failure mechanism at large-strain.Bio: 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 theprocessing 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. He is the recipient of the 2014 NSF Early Career Award. Venue: Room 118 Chemical Engg.