Urban Research Group Projects
Our current research includes the following:
Stimuli-Responsive Polymeric Surfaces: Mimicking Cilia
Our research interests are fairly diversified. One of the current efforts focuses on stimuli-responsive polymeric materials, molecular level events which govern their physico-chemical behaviors, and the influence of heterogeneity of networks on film formation. Mobility of individual components near surfaces and interfaces as well as responses of cilia-like morphologies are selected examples.
Stimuli-Responsive Photochromic Polymer Composites
We have developed a new family of azobenzene crosslinked brominated vinyl ester polymer networks that exhibit reversible photochromic and fluorescence properties in which azobenzene serves as a crosslinker as well as a molecular sensor of structural and conformational changes of the surrounding molecular segments. The “built-in” crosslinker functions as a highly sensitive light emitting group capable of sensing network stresses or damages. Such networks are also capable of sensing electromagnetic radiation that results in isomerization, thereby modifying the UV-Vis absorption and fluorescence emission properties. These reversible processes induced by structural network rearrangements may offer numerous application possibilities ranging from molecular stress sensors to nano-crack detectors in materials.
Self-Repairing Polymeric Nano-Materials
We are in the process of developing thermoplastics and thermosetting polymeric systems that are capable of self-repairing upon exposure to various physico-chemical conditions. Molecular level understanding of network remodeling events resulting from damage and self-repair will lead to a new generation of sustainable materials.
Nano-Structured Colloidal Particles
Utilization of bioactive molecules to prepare unique colloidal morphologies ranging from hollow or non-spherical particles to nanotubes and coalesced films is of significant importance. The use of colloidal synthesis facilitates various morphologies that often mimic Mother Nature resulting in unique film properties.
Magnetic Nanotubes from Phospholipids
Due to many applications ranging from biomedical devices to metamaterials and others, tailored magnetic nanomaterials continue to be of technological importance. We developed a prototype of ferromagnetic nanotubes (FMNTs) from biologically active nanotube-forming phospholipid templates. Using simple redox reactions and thermal treatments we can produce FMNTs that consist of magnetite/carbon/magnetite concentric nanotubes with the amorphous carbon phase sandwiched between the two magnetite layers. Their magneto-electric properties can be tailored, depending upon desired applications and needs.
Bioactive Polymeric Surfaces
Highly controllable microwave plasma reactions on surfaces of polymeric materials offer a platform of covalent bonding of acid groups via reactions and hydrolysis of maleic anhydride. Such functional groups can be further used for surface reactions leading to stimuli-responsive polymeric surfaces that are biologically active or may exhibit antibacterial, antithrombotic, or antifouling attributes. This process can be applied to almost any thermoplastic polymer. Several examples below show covalent attachment of various antibiotic molecules that, through a molecular spacer (PEG), exhibit antimicrobial properties.
Browse the documents below to see more about our ongoing research: