The focus of our research is the surface modification of materials and the development of innovative biomass-based polymeric materials. Surface modification of existing materials allows for the tailoring of surface properties while leaving key bulk properties intact. Functionalization of the surface of commercially available materials allows them to be used as 'value added' components in specialty technologies. Central to this research program in polymer and surface engineering is the design of well-defined molecules including chemical functionality and molecular architecture. Our group performs fundamental research activities in polymer synthesis, surface modification, grafting chemistries, and bulk and surface characterization. Current research projects include:
● stimuli-responsive polymers,
● microsensor technologies,
● synthesis and surface modification of bioplastics, and
● modeling of lung-particulate interactions.

Stimuli-Responsive Polymers
A rapidly growing area of materials research involves the surface-grafting of tethered layers that respond to external stimuli, such as pH. Grafting stimuli-responsive polymer layers to a surface creates materials with the ability to sense and respond to environmental conditions. We are currently using a variety of chemical synthesis techniques to create a series of tethered polymers with tertiary amine pendant groups. The in situ thickness change of the tethered polymer layer is then measured as a function of environmental pH and temperature.

Microsensor Technologies
We have two primary research interests related to the development of microsensors:
(i) synthesis of polymers with selective bioaffinities and (ii) control of fluid flow in micro (and/or nano) channels via grafting of responsive polymers.
○ We are working to develop polymers that incorporate functional groups that will allow for selective adsorption of specific analytes (e.g., enzymes, proteins, toxins). Potential applications include medical diagnostic platforms, biohazard and environmental remediation sensors, and separation devices.
○ Grafting of responsive polymer layers that can reversibly expand and contract inside micro- and nano-channels would provides the ability to control fluid transport in microfluidic devices. While our target substrates are polymeric, systems are being built using both polymeric and inorganic substrates and flow in the modified channels will be measured as a function of stimuli input.

Synthesis and Surface Modification of Bioplastics
Our interest lies in utilizing biomass to produce renewable polymers, also known as bioplastics. The term bioplastics is applied to polymers which are derived from agricultural and bacterial by-products and provide a sustainable alternative to petrochemical derived polymers. Depending on the monomer type and content, polymers can be produced with a wide range of crystallinities, glass transition temperatures, and melting temperatures which can be used in the production of both fibers and films. Bioplastics have a significant advantage over conventional plastics because in addition to providing a sustainable alternative to petroleum-based polymers, the bioplastic polymers we have targeted have the potential to be fully biodegradable as the ester bonds in the polymer backbone can be hydrolyzed.

Modeling of Lung-Particulate Interactions
Surface property characterization and deposition of drug molecules and particulate matter in airways is critical to understanding the delivery and absorption of desired (therapeutics) or undesired (contaminants) materials during inhalation. Inhaled therapeutics can be targeted for local delivery to the lungs or transportation across the endothelium into the circulatory system, but have been found to be inefficient and decreases further in patients with obstructive lung diseases such as asthma or COPD. In direct inhalation therapy as well as other transmucosal delivery methods (nasal and oral uptake via spray, gel, tablets, and lozenges), effective mucoadhesion of the drug formulation is key. By investigating the surface energetics of lung tissues, the wetting and adhesion properties can be modeled to determine the optimal chemical properties necessary in newly developed therapeutics in order to increase absorption. Models of wetting and adhesion interactions between the drug suspension and the lung tissues can be incorporated into computational simulations of the flow and may lead to better prediction of the distribution and absorption of inhalation therapeutics.