Energy dissipation in pH-sensitive hydrogels subjected to large amplitude oscillatory shear

Publication date: January 2020Source: Mechanics of Materials, Volume 140Author(s): Pranitha Prabhakaran, Chandler C. BenjaminAbstractStimuli-responsive hydrogels belong to a class of shape-memory elastomers that have gained immense popularity due to their applications in the fields of drug delivery, tissue engineering, implants, bio-sensors, and many more. The pH-responsive hydrogels 2-hydroxyethyl methacrylate (2-dimethylamino) ethyl methacrylate (HEMA-DMAEMA) and 2-hydroxyethyl methacrylate acrylic acid (HEMA-AA) exhibit swelling behavior in response to changes in pH. The present study characterizes the energy dissipation of HEMA-DMAEMA and HEMA-AA subjected to large amplitude oscillatory shear. The experiments were conducted at strain levels 0.5%, 1.0%, 1.5%, 2%, and 5% maximum amplitude strain at a constant frequency of 1 Hz. The results showed an increase in energy dissipation with an increase in shear strain for both buffer solutions. The energy dissipation obtained for the HEMA-DMAEMA samples was greater in 11.0 pH buffer solution as compared to 3.0 pH buffer solution. On the contrary, the energy dissipation for HEMA-AA samples was found to be greater in the 3.0 pH buffer solution as compared to the 11.0 pH buffer solution.
Source: Mechanics of Materials - Category: Materials Science Source Type: research