To impact carbon emissions, new materials for carbon capture must be inexpensive, robust, and able to adsorb CO2 specifically from a mixture of other gases. In particular, materials must be tolerant to the water vapor and to the acidic impurities that are present in gas streams produced by using fossil fuels to generate electricity. We show that a porous organic polymer has excellent CO2 capacity and high CO2 selectivity under conditions relevant to precombustion CO2 capture. Unlike polar adsorbents, such as zeolite 13x and the metal-organic framework, HKUST-1, the CO2 adsorption capacity for the hydrophobic polymer is hardly affected by the adsorption of water vapor. The polymer is even stable to boiling in concentrated acid for extended periods, a property that is matched by few microporous adsorbents. The polymer adsorbs CO2 in a different way from rigid materials by physical swelling, much as a sponge adsorbs water. This gives rise to a higher CO2 capacities and much better CO2 selectivity than for other water-tolerant, nonswellable frameworks, such as activated carbon and ZIF-8. The polymer has superior function as a selective gas adsorbent, even though its constituent monomers are very simple organic feedstocks, as would be required for materials preparation on the large industrial scales required for carbon capture.
Infrared spectroscopy and spectroscopic imaging, are robust, label free and inherently non-destructive methods with a high chemical specificity and sensitivity that are frequently employed in forensic science research and practices. This review aims to discuss the applications and recent developments of these methodologies in this field. Furthermore, the use of recently emerged Fourier transform infrared (FT-IR) spectroscopic imaging in transmission, external reflection and Attenuated Total Reflection (ATR) modes are summarised with relevance and potential for forensic science applications. This spectroscopic imaging approach provides the opportunity to obtain the chemical composition of fingermarks and information about possible contaminants deposited at a crime scene. Research that demonstrates the great potential of these techniques for analysis of fingerprint residues, explosive materials and counterfeit drugs will be reviewed. The implications of this research for the examination of different materials are considered, along with an outlook of possible future research avenues for the application of vibrational spectroscopic methods to the analysis of forensic samples.
The poor aqueous solubility of many active pharmaceutical ingredients presents challenges for effective drug delivery. In this study, the combination of attenuated total reflection (ATR)-FTIR spectroscopic imaging with specifically designed polydimethylsiloxane microfluidic devices to study drug release from pharmaceutical formulations has been developed. First, the high-throughput analysis of the dissolution of micro-formulations studied under flowing conditions has been introduced using a model formulation of ibuprofen and polyethylene glycol. The behaviour and release of the drug was monitored in situ under different pH conditions. In contrast to the neutral solution, where both the drug and excipient dissolved at a similar rate, structural change from the molecularly dispersed to a crystalline form of ibuprofen was characterised in the obtained spectroscopic images and the corresponding ATR-FTIR spectra for the experiments carried out in the acidic medium. Further investigations into the behaviour of the drug after its release from formulations (i.e., dissolved drug) were also undertaken. Different solutions of sodium ibuprofen dissolved in a neutral medium were studied upon contact with acidic conditions. The phase transition from a dissolved species of sodium ibuprofen to the formation of solid crystalline ibuprofen was revealed in the microfluidic channels. This innovative approach could offer a promising platform for high-throughput analysis of a range of micro-formulations, which are of current interest due to the advent of 3D printed pharmaceutical and microparticulate delivery systems. Furthermore, the ability to study dissolved drug in solution under flowing conditions can be useful for the studies of the diffusion of drugs into tissues or live cells.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.