Alcohol and phenolic hydrogen-bond (HB) acidic sorbents with electron withdrawing fluorine atoms acting on the hydroxyl moiety have been previously developed at the U.S. Naval Research Laboratory and by other researchers to augment sorbent HB acidity, reduce sorbent HB basicity and target complementary HB basicity of a wide range of hazardous target chemicals. Although these interactions have been studied in some detail and a wide range of related HB acidic sorbents have been developed, a significant limitation with them to date has been the propensity for sorbent self-association. This intermolecular bonding between sorbent molecules limits sorbate access to active HB acid sites in the sorbent, limiting the overall efficacy of the sorbent.<br/>In this current work our aim has been to develop improved HB acidic sorbent structures, activated by fluorine chemistries, which minimize undesired sorbent self-association. By significantly freeing up sorbent HB acid sites we offer the potential for a leap forward in sorbent performance by improved sorptivity for target chemicals at trace levels, sorption kinetics and capacity. These improved hypersorbents are expected to provide physicochemical properties suitable for a wide range of applications including analyte collection, chromatography separation, transducer sensing, and protection applications employing sorbents as filtration media. A series of new HB acidic sorbents have been synthesized and the subsequent sorbent-sorbate interactions have been tested by coating onto an attenuated total reflection (ATR) crystal used with a Fourier transform infrared (FTIR) spectrometer. Differential IR spectra before and during vapor exposure help elucidate sorbent-vapor interactions. Additional characterization has been performed with quartz crystal microbalance (QCM) gravimetry to quantify sorption kinetics and gas partitions. Finally, inverse gas chromatography (IGC) has been used to develop gas-sorbent solvation equations from a series of empirically measured gas-sorbent partition coefficients. The solvation equations produced help quantify sorbent properties of polarizability, dipolarity, HB basicity, HB acidity, and dispersion/cavity effects and allow gas-sorbent gas partitions to be predicted for a wide range of hazardous chemicals.

Advances in hypersorbent materials for detection and protection applications

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.