The detection of explosives is one of the current pressing concerns in global security. In the past few decades, a large number of emissive sensing materials have been developed for the detection of explosives in vapor, solution, and solid states through fluorescence methods. In recent years, great efforts have been devoted to develop new fluorescent materials with various sensing mechanisms for detecting explosives in order to achieve super-sensitivity, ultra-selectivity, as well as fast response time. This review article starts with a brief introduction on various sensing mechanisms for fluorescence based explosive detection, and then summarizes in an exhaustive and systematic way the state-of-the-art of fluorescent materials for explosive detection with a focus on the research in the recent 5 years. A wide range of fluorescent materials, such as conjugated polymers, small fluorophores, supramolecular systems, bio-inspired materials and aggregation induced emission-active materials, and their sensing performance and sensing mechanism are the centerpiece of this review. Finally, conclusions and future outlook are presented and discussed.

Fluorescence based explosive detection: from mechanisms to sensory materials.

Here we report a series of energetic–energetic cocrystals that incorporate the primary explosive diacetone diperoxide (DADP) with a series of trihalotrinitrobenzene explosives: 1:1 DADP/1,3,5-trichloro-2,4,6-trinitrobenzene (TCTNB), 1:1 DADP/1,3,5-tribromo-2,4,6-trinitrobenzene (TBTNB), and 1:1 DADP/1,3,5-triiodo-2,4,6-trinitrobenzene (TITNB). Acetone peroxides are attractive for their inexpensive and facile synthesis, but undesirable properties such as poor stability, intractably high sensitivity and low density, an indicator for low explosive power, have limited their application. Here through cocrystallization the density, oxygen balance, and stability of DADP are dramatically improved. Regarding sensitivity, in the case of the DADP/TCTNB cocrystal, the high impact sensitivity of DADP is retained by the cocrystal, making it a denser and less volatile form of DADP that remains viable as a primary explosive. Conversely, the DADP/TITNB cocrystal features impact sensitivity that is greatly reduced relative...

Energetic-energetic cocrystals of diacetone diperoxide (DADP): Dramatic and divergent sensitivity modifications via cocrystallization

Surface-enhanced Raman spectroscopy is one of the most sensitive spectroscopic techniques available, with single-molecule detection possible on a range of noble-metal substrates. It is widely used to detect molecules that have a strong Raman response at very low concentrations. Here we present photo-induced-enhanced Raman spectroscopy, where the combination of plasmonic nanoparticles with a photo-activated substrate gives rise to large signal enhancement (an order of magnitude) for a wide range of small molecules, even those with a typically low Raman cross-section. We show that the induced chemical enhancement is due to increased electron density at the noble-metal nanoparticles, and demonstrate the universality of this system with explosives, biomolecules and organic dyes, at trace levels. Our substrates are also easy to fabricate, self-cleaning and reusable.

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Photo-induced enhanced Raman spectroscopy for universal ultra-trace detection of explosives, pollutants and biomolecules

The present invention provides, inter alia, a device comprising a colorimetric detection layer configured to undergo a color change upon interaction with a first analyte of interest. The detection layer comprises a first plurality of self-assembled fiber bundles. At least a fraction of the fiber bundles undergo a change from a first conformation to a second conformation upon interaction with the first analyte of interest, thereby undergoing a color change. The invention also provides a method for using the system to detect an analyte of interest.

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Biomimetic virus-based colorimetric sensors

The vapor pressures (VPs) of many explosive compounds are extremely low, so determining accurate values proves difficult. Many researchers, using a variety of methods, have measured and reported the VPs of explosive compounds at single temperatures, or as a function of temperature using VP equations. There are large variations in reported VPs for many of these compounds, and some errors exist within individual papers. This article provides a review of explosive VPs and describes the methods used to determine them. We have compiled primary VP relationships traceable to the original citations and include the temperature ranges for which they have been determined. Corrected values are reported as needed and described in the text. In addition, after critically examining the available data, we calculate and tabulate VPs at 25°C.

The vapor pressures of explosives

A critical review of vapor pressure data for military, civilian, and homemade explosives, explosive precursors, and explosive taggants is presented. It gives reference to a large number of papers and reports presenting original vapor pressure measurements and additionally an overview of measurements techniques for vapor pressure measurements and data analysis of vapor pressure measurements. Vapor pressure data, including Clausius–Clapeyron parameters (A and B in: log10(p)=A−B/T), calculated vapor pressure at room temperature, and heat of sublimation or heat of vaporization are included. The following classes of compounds are treated; military explosives (TNT, RDX, HMX, PETN, HNS, TATB, AP), civilian explosives (NG, EGDN, AN), explosive taggants (EGDN, DNMB, 2-NT, 4-NT), home-made explosives (TATP, DADP, HMTD). and explosive precursors [HP(aq), NM, IPN, DNT].

Vapor Pressure of Explosives: A Critical Review

Synthesis and thermal decomposition of GAP–Poly(BAMO) copolymer

POLYMERS AS BINDERS AND PLASTICIZERS - HISTORICAL PERSPECTIVE Nitrocellulose Polyslfides Polybutadienes (PBAA, PBAN, and CTPB) Polyurethanes Hydroxy Terminated Polybutadiene Explosive Binders Thermoplastic Elastomers Energetic Polymers (Other Than NC) as Binders Energetic Polymer Plasticizers HIGH NITROGEN CONTENT POLYMERS Introduction Preparation of Energetic Azido Polymers Physical Properties of Azido Polymers Curing of Azido Polymers Curing of Azido Polymers by Dipolarophiles Thermal Decomposition Characteristics of Azido Polymers Combustion of Azido Polymers Thermal Decomposition and Combustion of Energetic Formulations with Azido Polymers Performance of Azido Polymer-Based Propellants Azido Polymers as Explosive Binders Tetrazole Polymers and Their Salts N-N Bonded Epoxy Binders NITRO POLYMERS AS ENERGETIC BINDERS Introduction Preparation of Nitropolymers Thermal Decomposition Behavior of Nitropolymers Combustion of Nitrate Ester Polymers and Propellants Nitropolymer-Based Explosive Compositions ENERGETIC THERMOPLASTIC ELASTOMERS Introduction Preparation of Energetic Thermoplastic Elastomers Thermal Decomposition and Combustion of ETPEs Performance of ETPE Based Propellant Formulations Melt-Cast Explosives Based on ETPEs ETPE Based Polymer Nanocomposites FLUOROPOLYMERS AS BINDERS Introduction Poly(tetrafluoroethylene) (PTFE) Copolymers of Tetrafluoroethylene Energetic Polymers Containing Fluorine Miscellaneous Energetic Fluoropolymers PBX Formulations with Fluoropolymers ENERGETIC PLASTICIZERS FOR HIGHER PERFORMANCE Introduction Energetic Plasticizers Based on Azido Compounds Performance of Propellant Formulations Containing Azido Plasticizers Nitrate Ester Plasticizers Nitrate Ester Oligomers as Energetic Plasticizers Miscellaneous Plasticizers Based on Nitro-Groups APPLICATION OF COMPUTATIONAL TECHNIQUES TO ENERGETIC POLYMERS AND ITS FORMULATIONS Introduction Overview of Computational Techniques Application of Computational Modeling Techniques to Energetic Polymer Formulations Future Outlook

Energetic Polymers: Binders and Plasticizers for Enhancing Performance

TATP, prepared in the presence of catalysts methanesulfonic, perchloric, or sulfuric acid, has been found to undergo transformation to DADP. However, no transformation occurs if TATP is purified or prepared involving catalysts such as hydrochloric acid, tin(IV) chloride, and nitric acid. The transformation has been monitored by the methods of DTA and HPLC.

How Ghee Ang

Papers

Vapor Pressure of Explosives: A Critical Review

Synthesis and thermal decomposition of GAP–Poly(BAMO) copolymer

Energetic Polymers: Binders and Plasticizers for Enhancing Performance

Study of TATP: Spontaneous Transformation of TATP to DADP

Thermal decomposition kinetics of a mixture of energetic polymer and nitramine oxidizer