Ph.D., Princeton University, 1989
Research Interests: Polymer Films
Professor Hirt's primary research interests are in the area of surface modification of polymer films. One way to modify a film surface is to blend an additive into a film and allow time for the additive to segregate to the surface. Research focuses on quantifying the amount of additive exuded to the surface over time and relating surface concentration to surface properties. Work is also conducted to measure the time-dependent spatial distribution of additives across the thickness of polymer films using FTIR microspectroscopy.
Professor Hirt's group also conducts work on chemically grafting various species to polymer films to carefully control the chemical functionality on the surface and to enhance the permanence and effectiveness of the surface modification. Current research involves the grafting of amino acids as well as the photografting of multifunctional polymer layers for applications such as biocompatible implants, microfluidics, and bioMEMs.
Rasal, R. M. and Hirt, D.E., "Poly(lactic acid) Toughening with a Better Balance of Properties," Macromolecular Materials and Engineering, 295, 204-209 (2010).
Rasal, R. M., Janorkar, A.V., and Hirt, D. E., "Poly(lactic acid) Modifications," Progress in Polymer Science, 35, 338-356 (2010).
Rasal, R. M. and Hirt, D.E., "Micropatterning of Covalently Attached Biotin on Poly(lactic acid) Film Surfaces," Macromolecular Bioscience, 9, 989-996 (2009).
Zhu, S. and Hirt, D. E., "Improving the Wettability of Deep-Groove Polypropylene Fibers by Photografting," Textile Research Journal, 79, 534-547 (2009).
Rasal, R. M., Bohannan, B. G, and Hirt, D. E., "Effect of the Photoreaction Solvent on Surface and Bulk Properties of PLA and PHA Films," Journal of Biomedical Materials Research: Part B - Applied Biomaterials, 85B, 564-572 (2008).
Zhang, C. and Hirt, D. E., "Layer-by-layer Self-assembly of Polyelectrolyte Layers on Cross-section Surfaces of Multilayer Polymer Films: A Step Toward Nanopatterning Flexible Substrates," Polymer, 48, 6748-6754 (2007).
Janorkar, A. V., Metters, A. T., and Hirt, D. E., "Degradation of Neat and Surface-Modified Poly(L-Lactide) Films Under UV Induced Photografting and Sterilization Conditions," Journal of Applied Polymer Science, 106, 1042-1047 (2007).
Walters, K. B. and Hirt, D. E., "Synthesis and Characterization of a Tertiary Amine Polymer Series from Surface-Grafted Poly(tert-Butyl Acrylate) via Diamine Reactions," Macromolecules, 40, 4829-4838 (2007).
Zhu, S. and Hirt, D. E., "Hydrophilization of Polypropylene Films Using Migratory Additives," Journal of Vinyl and Additive Technology, 13, 57-64 (2007).
Janorkar, A. V., Fritz, E. W., Burg, K. J. L., Metters, A. T., and Hirt, D. E., "Grafting Amine-terminated Branched Architectures from Polylactide Film Surfaces for Improved Cell Proliferation," Journal of Biomedical Materials Research: Part B - Applied Biomaterials, 81, 142-152 (2007).
Janorkar, A. V., Proulx, S. E., Metters, A. T., and Hirt, D. E., "Surface-Confined Photopolymerization of Single- and Mixed-Monomer Systems to Tailor the Wettability of Poly(L-Lactide) Film," Journal of Polymer Science Part A: Polymer Chemistry, 44, 6534-6543 (2006).
Walters, K. B. and Hirt, D. E., "Surface Grafting of Poly(tert-butyl acrylate) on Poly(ethylene-co-acrylic acid) Film," Polymer, 47, 6567-6574 (2006).
Zhang, C., Luo, N., and Hirt, D. E., "Surface Grafting Polyethylene Glycol (PEG) onto Poly(ethylene-co-acrylic acid) Films," Langmuir, 22, 6851-6857 (2006).
Zhang, C., Husson, S. M., and Hirt, D. E., "Patterning Proteins on Surfaces of Cross-sectioned Multilayer Polymer Films," Macromolecular Rapid Communications, 27, 1173-1179 (2006).
Ramirez, M. X., Walters, K. B., and Hirt, D. E., "Relationship Between Erucamide Surface Concentration and Coefficient of Friction of LLDPE Film," Journal of Vinyl & Additive Technology, 11, 9-12 (2005).