Dr. Julie Albert, Tulane University Department of Chemical and Biomolecular Engineering
How to Leverage Processing Conditions to Control Crystallization of Biodegradable Poly Thin Films
Poly(ε-caprolactone) (PCL) is a semi-crystalline, hydrophobic, biodegradable polymer with applications in biomedical engineering including anti-adhesion biomaterial films, drug delivery media, and others. Degree of crystallinity, crystal morphology, and crystallite size are known to affect the biodegradation profile of PCL fibers and films by enzymes, so morphological control is important to designing PCL coatings and films. The Albert Lab is interested in how morphological control can be achieved through confinement during crystal growth. This idea will be illustrated in the telling of three short vignettes. In the first study, spatial confinement is imposed on growing PCL crystals by using a thin film geometry to limit crystal growth in the vertical direction and by blending PCL with a second, non-crystallizable polymer that acts as a barrier to crystal growth in the lateral direction. The interfacial interactions between PCL, the substrate, and the non-crystalline polymer coupled with confinement effects give rise to beautiful spiraling PCL crystals, which we refer to as “nano-roses” for their resemblance to a bouquet of 500 nanometer diameter roses. The second study focuses on technique development aimed at facile characterization PCL crystallization kinetics and thermal transitions in thin films in situ during film processing, under conditions for which traditional calorimetry techniques may be difficult and/or unsuitable. Finally, the presentation will conclude with a preliminary application of this technique to monitoring film changes during exposure to solvent vapor and correlating these measurements with structural changes in the film detected by grazing-incidence wide-angle X-ray scattering. These results show that solvent vapor treatments provide access to unconventional crystal structures in PCL.
Julie N. L. Albert received her B.S. in Chemical Engineering from the University of Florida in 2005 and her Ph.D. in Chemical Engineering from the University of Delaware in 2012. Subsequently, she pursued postdoctoral research studies at North Carolina State University. Albert’s primary research interests are centered on engineering nano- and micro-structured block copolymer and semi-crystalline polymeric materials for applications related to technology development in the energy, health, and environmental sectors. During her doctoral studies, Albert received an NSF Graduate Research Fellowship and a Teaching Fellowship, and during her postdoctoral studies, she received the AIChE Women’s Initiative Committee Travel Award in 2012. As a faculty member, in 2015, she was selected for a prestigious Early-Career Research Fellowship by the National Academy of Sciences Gulf Research Program to develop nanoporous membranes for enhanced oil recovery from spills. In 2016 she was awarded a National Science Foundation Early-Career Development Program Grant (NSF-CAREER) to study the effects of solvent vapor processing on polymer thin film morphology. In addition to her research-related activities at Tulane, Julie also serves as the faculty advisor for the undergraduate Society of Women Engineers (SWE) and the graduate Women+ in Science and Engineering student organizations on campus. In 2017, she was selected for the Academic Leadership for Women in Engineering (ALWE) Program and an ASSIST Travel Grant to attend the workshop held during the SWE National Conference.