Kinn, B., Allgeier, A.M. (10/22/2018). NMR Relaxation as a Method of Exploring Soft Porous Networks. ACS Midwest Regional Meeting. Ames, IA.
Nuclear magnetic resonance (NMR) has a wide range of technological uses, from medical imaging to identifying unknown compounds. Many chemists use NMR data in the frequency domain but time domain methods can be useful in characterizing surface chemistry, surface area and porosity of colloids, soft porous, and hard porous materials wetted with solvents. Time-domain NMR data were evaluated for characterizing the porous network of a soft porous polymer, Gelatin Methacryloyl (GelMA), which is a widely used biocompatible hydrogel in biomedical engineering applications. Using a benchtop low-field NMR, three weight loadings of the hydrogel were analyzed yielding average spin-spin relaxation time constants (T2) of 597, 1172, and 1598 ms at 20°C for 14, 7, and 3.5 wt% GelMA. These average relaxation times correlated with the expected trend in porosity but do not require freeze-drying and subsequent microscopy or liquid mercury intrusion analysis. Additionally they can be completed in minutes instead of the many hours required by other methods. Time- domain NMR offers a convenient option for characterizing porosity in Gelatin Methacryloyl. Ongoing work seeks to elucidate a calibration curve quantitatively correlating T2 and pore size distribution.
Allgeier, A. M. (05/07/2018). Control of Mechanical Stability of Hollow Silica Particles, and Its Measurement by Mercury Intrusion Porosimetry. Characterization of Porous Materials - 8. Delray Beach, FL
This poster describes Allgeier’s collaborative research on hollow-sphere silica particles (HSPs), conducted while he was an employee in DuPont Central R&D. HSPs can be used in a variety of industrial applications including catalysis, enzyme supports, drug delivery and in photonic materials. Liquid mercury intrusion porosimetry (MIP) was deployed in a non-traditional way to characterize the cracking pressure of HSPs. MIP is typically used to characterize pore size distribution in the range nanometer to micrometer length scale but in this system the data were interpreted to identify the pressure at which HSPs lose mechanical integrity (i.e. crack). Other methods of characterizing the HSPs including microscopy, gas adsorption and small-angle X-ray scattering were applied to better understand the structure of HSPs.
Presented here is a research plan on the topic of mechanisms in biomass conversion. One of the most important steps in enabling biomass utilization to become economically feasible is the invention of catalysts that impart energy efficiency to the processes. Such inventions will be facilitated by first understanding what differentiates superior catalysts from inferior ones. This can be accomplished through mechanism studies which give insights to what is happening on the surface of the catalyst at the atomic level.
This work extend inventions and reactivity established by DuPont. The objective is to understand the 1,2,6-hexanetriol hydrodeoxygenation mechanism. This reaction is the final step in producing 1,6-hexanediol which is a very valuable chemical intermediate for polyesters, polyurethanes, and potentially Nylon-6,6. A route to this understanding is an isotopic labeling study. Here the substrate will be labeled (or reacted) with the hydrogen isotope, deuterium, to characterize the regioselectivity of deuterium incorporation. This with other reactivity data will elucidate the mechanism by which the reaction proceeds in the presence of the catalyst.
Velasquez Morales, S. (04/18/2018) - Continuous Manufacturing: A new perspective for the pharmaceutical industry. Great Plains Catalysis Society (GPCS). Manhattan, KS.
In this work, Simon Velasquez focuses on the challenges faced by the pharmaceutical industry, specifically, the difficulties involved in the transition from batch processing to continuous manufacturing. Additionally, the challenges determined by the ACS-GCI Pharmaceutical Round table are emphasized to share opportunities for innovation with the audience and to communicate our research interests.
During the 1st GPCS conference, Simon presented his preliminary work in green reaction engineering, especially focusing on opportunities that small-scale continuous manufacturing has with regards to handling harsh reaction conditions and dangerous reactive intermediates. Simon also shared the opportunities for technological innovation and the possible future for continuous manufacturing in the pharmaceutical industry.
This poster presentation sets precedent to the goals and challenges being address by Simon Velasquez in the Allgeier Research Group at the University of Kansas. Currently, his work focuses on continuous reaction engineering and downstream processing of hydrogenation reactions. He seeks to intensify unit operations that facilitate continuous manufacturing and develop strategies to meet regulations imposed by the Food Drug Administration.