A5086235916- Energetic Materials and Combustion
- Spectroscopy and Chemometric Analyses
- Chemical Thermodynamics and Molecular Structure
- Spectroscopy Techniques in Biomedical and Chemical Research
- Spectroscopy and Laser Applications
- Mass Spectrometry Techniques and Applications
- Crystallization and Solubility Studies
- Analytical Chemistry and Chromatography
- X-ray Diffraction in Crystallography
- Rocket and propulsion systems research
- Gas Sensing Nanomaterials and Sensors
- Pharmacological Effects and Assays
- Thermal and Kinetic Analysis
- Metal-Organic Frameworks: Synthesis and Applications
- Analytical Chemistry and Sensors
- Covalent Organic Framework Applications
- Membrane Separation and Gas Transport
- Transition Metal Oxide Nanomaterials
- Crystallography and molecular interactions
- Chemistry and Chemical Engineering
- Synthesis and Characterization of Heterocyclic Compounds
- Nonlinear Optical Materials Research
University of Puerto Rico-Mayaguez
2016-2025
George Mason University
2019
University of Puerto Rico System
2018
A new hyphenated technique using thin-layer chromatography (TLC) to separate analytes in mixtures, coupled with mid-infrared (MIR) laser spectroscopy for identification and quantification, is presented. The method, which provides a means rapid screening of that practical, low-cost, fast, robust, reproducible, was tested nitroaromatic aliphatic nitro high explosives (HEs) as target analytes. HEs are anthropogenic contaminants containing an -NO2 group. For validation the technique, direct...
The highly energetic material (HEM) hexahydro-1,3,5-trinitro-s-triazine, also known as RDX, has two stable conformational polymorphs at room temperature: α-RDX (molecular conformation of −NO2 groups: axial–axial–equatorial) and β-RDX axial–axial–axial). Both can be formed by deposition on stainless steel substrates using spin coating methodology. is the most crystal form temperature ambient pressure. However, β-RDX, which been reported to difficult obtain in bulk temperature, was readily...
Mid-infrared (MIR) laser spectroscopy was used to detect the presence of residues high explosives (HEs) on fabrics. The discrimination vibrational signals HEs from a highly MIR-absorbing substrate achieved by simple and fast spectral evaluation without preparation standards using classical least squares (CLS) algorithm. Classical focuses minimizing differences between features actual spectra acquired MIR calculated modeled linear combinations neat components: HEs, fabrics, bias. Samples in...
A pillared layer network containing amide functional groups (Cu(pzdc)(pia); pzdc = pyrazine-2,3-dicarboxylate; pia N-(4-pyridyl)isonicotinamide) was used to test a postsynthesis metalation rationale insert lithium and create porous surface with enhanced CO2 adsorption capacity. Synchrotron powder X-ray diffraction (XRD) determine variations after lithiation in long-range textural properties. measurements at room temperature showed concave up isotherm shape an increasing high pressures,...
Abstract A simple optical layout for a grazing‐angle probe (GAP) mount coupling to midinfrared (MIR) quantum cascade laser (QCL) spectrometer is described. This assembly enables reflectance measurements at high incident angles. In the case of optically thin films and deposits on MIR reflective substrates, double‐pass effect occurs, which accompanied by absorption deposited samples in reflection‐absorption infrared spectroscopy modality. The system allows light pass through sample twice....
In the fields of Security and Defense, explosive traces must be analyzed at sites terrorist events. The persistence on surfaces these depends sublimation processes interactions with surfaces. This study presents evidence that process stainless steel (SS) is very different than in bulk quantities. enthalpies four highly energetic materials: triacetone triperoxide (TATP), 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), 1,3,5- trinitrohexahydro-s-triazine (RDX) deposited SS substrates...
Abstract Owing to scientific advances in the field of materials sciences and engineering, researchers have developed new energy sources used for spectroscopic applications measurements properties resulting from interaction matter electromagnetic radiation mid-infrared (MIR) region. MIR lasers, such as quantum cascade lasers (QCLs), spectroscopy quickly found numerous a wide cadre IR techniques. This provides opportunity study highly energetic (HEM), among many other applications. laser based...
The optical properties for crystalline films of the highly energetic material (HEM) hexahydro-1,3,5-trinitro-s-triazine, which is also known as RDX, deposited on gold (Au) and stainless steel (SS) substrates are presented. RDX has two important stable conformational polymorphs at room temperature: α-RDX β-RDX. obtained in present work correspond to thin film samples predominantly β-RDX polymorph. infrared spectroscopic intensities measured showed significant differences with respect...
The sublimation enthalpies of four highly energetic materials (HEMs): triacetone triperoxide (TATP), 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT) and 1,3,5-trinitrohexahydro-s-triazine (RDX) deposited on stainless steel (SS) substrates were determined by optical fibre coupled-grazing angle probe (GAP) FTIR spectroscopy thermogravimetric analysis (TGA) for bulk crystaline HEMs samples. desorption energy RDX SS was also studied using grazing microscopy. Metastable phases 2,4-DNT TNT...