Faculty - William Gramlich
Polymer Chemistry in the Gramlich Group
The group is just beginning but it is focused on the design of complex polymer architectures and chemistries that allow for the temporal and spatial control over materials and their surfaces. We utilize controlled polymerization techniques, post-polymerization functionalization, and renewably sourced materials (whenever possible) to create block copolymers, graft copolymers, hydrogels, and stimuli responsive materials. Overall, any project involving polymeric materials is of interest to us as these chemistries have implications in a wide array of fields. We welcome any collaborations within and outside of the University of Maine. Currently, the group is focused on three distinct areas: creating tough sustainable materials, developing dynamic hydrogels for biomedical applications, and creating anti-biofouling surfaces.
Tough Sustainable Materials
The majority of commercial plastics and rubbers are derived from petroleum sources and as a result their cost is directly tied to the price of oil. Furthermore, most petroleum based polymers will not degrade in nature and few are currently recycled which results in many polymer based products being placed in landfills. Conversely, sustainable polymers are derived from plant based sources and can be broken down to their starting components (i.e. carbon dioxide and water). Commercially available sustainable polymers such as poly(lactic acid) exist, but tend to be brittle in nature limiting their applications. Our lab is interested in creating new renewably sourced modifiers through controlled polymerizations to improve the mechanical properties of these sustainable polymers.
Dynamic Hydrogels for Biomedical Applications
Cells respond to numerous mechanical, topological, and chemical cues from their surroundings (i.e. extracellular matrix) to determine their behavior. Stem cells sense the mechanical and chemical properties of the extracellular matrix (ECM) to help direct their differentiation to adult cell lines and cancer cells sense the mechanics around them to dictate their proliferation. By studying and controlling the properties of the ECM around the cells, researchers can develop new methods to control cell behavior. Hydrogels are an excellent synthetic mimic of the ECM and can be tuned for their desired application. Since cells in the body are structured into tissues with micrometer scale spacing, researchers rely on photopatterning the mechanical properties and molecules of interest in hydrogels to mimic this behavior. However, most of the time the chemistry that dictates the mechanical properties is also used to pattern molecules into the hydrogel and as a result independent patterning of molecules and mechanical properties is difficult. In our lab we work on orthogonal chemistry that allows us to independently pattern mechanical properties and chemicals in hydrogels, providing new systems for temporal and spatial control of properties.
Whenever a surface exists in nature, micro-organisms (e.g. bacteria) will attach to it. For everyday objects, such bacterial attachment is not an issue, but in systems such as water filtration, implanted medical devices, and the hulls of ships the attachment of organisms such as bacteria can lead to loss of performance and in the case of medical devices, serious medical complications. When possible, frequent cleaning is expensive and coatings that release antibiotics are being phased out due to their ability to generate resistant organisms. Current research aims to use thin coatings of anti-bacterial polymers to kill organisms as they attach to the surface. Unfortunately, these dead organisms provide a barrier to interaction with the anti-bacterial polymers and thus their effectiveness diminishes over time. Our group utilizes block copolymer phase separation to create nanometer scale domains of anti-microbial and anti-adhesion polymers on surfaces to combat the adhesion of bacteria. Furthermore, by using photopatterning we aim to use topography as another tool to combat adhesion to surfaces. With the block copolymer phase separation and photopatterning hierarchical surface structures can be produced.