Nitroglycerin trapping in melamine matrices.

Melamine (Mel) was used as host matrix for liquid nitroglycerin (NG), to prepare Mel/NG solid powdered compounds containing up to 45 wt% of this explosive. The two preparation processes used for this purpose consisted in evaporating a solution of both components, either in ambient conditions or under reduced pressure by the Spray Flash-Evaporation (SFE) process. In Mel/NG materials, amorphous nitroglycerin is distributed in the crystallized melamine matrix as inclusions, which were found to be smaller in size in the material prepared by the SFE process.

3D Core-Shell TiO@MnO Nanorod Arrays on Microcantilevers for Enhancing the Detection Sensitivity of Chemical Warfare Agents.

Nanostructured microcantilevers have shown promise for sensing application of molecules in the vapor phase. Nanostructures have improved the molecule capture ability of microcantilevers by highly enhancing the surface of capture. Here, to improve the sensitivity and selectivity of a commercial microcantilever without functionalization, we developed 3D core-shell titanium dioxide@manganese dioxide (TiO@MnO) nanorod arrays on a microcantilever, which exhibited a high enhancement in the sensing performance beyond that of 1D nanostructures for the detection of dimethyl methylphosphonate, a simulant of sarin.

Formation mechanisms of sub-micron pharmaceutical composite particles derived from far- and near-field Raman microscopy.

Surface enhanced Raman spectroscopy (SERS) and confocal Raman microscopy are applied to investigate the structure and the molecular arrangement of sub-micron furosemide and polyvinylpyrrolidone (furosemide/PVP) particles produced by spray flash evaporation (SFE). Morphology, size and crystallinity of furosemide/PVP particles are analyzed by scanning electron microscopy (SEM) and X-ray powder diffraction (XRPD). Far-field Raman spectra and confocal far-field Raman maps of furosemide/PVP particles are interpreted based on the far-field Raman spectra of pure furosemide and PVP precursors.

Double-side microcantilevers as a key to understand the adsorption mechanisms and kinetics of chemical warfare agents on vertically-aligned TiO nanotubes.

Microgravimetric sensor platforms with physico- or chemo-selective interfaces offer promising sensing properties. They are widely used to detect chemical warfare agents (CWAs). However, a comprehensive insight into adsorption mechanisms and interactions between low concentrations of these adsorbates and low-mass adsorbents is still lacking.

Use of Spray Flash Evaporation (SFE) technology to improve dissolution of poorly soluble drugs: Case study on furosemide nanocrystals.

The poor solubility and related low bioavailability are a major concern for a large number of small molecule drugs, both on the market and in development. Several formulation strategies exist to overcome this issue. Among them, particle engineering is of outmost importance.

Double side nanostructuring of microcantilever sensors with TiO-NTs as a route to enhance their sensitivity.

We reported a new strategy to enhance the sensing performances of a commercial microcantilever with optical readout in dynamic mode for the vapor detection of organophosphorus compounds (OPs). In order to increase significantly the surface area accessible to the molecules in the vapor phase, we nanostructured both sides of the microcantilever with ordered, open and vertically oriented amorphous titanium dioxide nanotubes (TiO2-NTs) in one step by an anodization method. However, due to the aggressive conditions of anodization synthesis it remains a real challenge to nanostructure both sides of the microcantilever.

Surface characterization of nanoscale co-crystals enabled through tip enhanced Raman spectroscopy.

Atomic Force Microscopy coupled with Tip Enhanced Raman Spectroscopy (AFM-TERS) was applied to obtain information about the structure and surface composition of single nano co-crystals. For this purpose, a co-crystalline system consisting of 2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazatetracyclo-[5.5.

Detection of Organophosphorous Chemical Agents with CuO-Nanorod-Modified Microcantilevers.

Microcantilevers are really promising sensitive sensors despite their small surface. In order to increase this surface and consequently their sensitivity, we nanostructured them with copper oxide (CuO) nanorods. The synthesis of the nanostructure consists of the oxidation of a copper layer deposited beforehand on the surface of the sample.

Functionalized TiO Nanorods on a Microcantilever for the Detection of Organophosphorus Chemical Agents in Air.

We report the fabrication of nanostructured microcantilevers employed as sensors for the detection of organophosphorus (OPs) vapors. These micromechanical sensors are prepared using a two-step procedure first optimized on a silicon wafer. TiO one-dimensional nanostructures are synthesized at a silicon surface by a solvothermal method and then grafted with bifunctional molecules having an oxime group known for its strong affinity with organophosphorus compounds.

Synthesis of zinc oxide nanorods or nanotubes on one side of a microcantilever.

Cantilevers are really promising sensitive sensors despite their small surface. In order to increase this surface and consequently their sensitivity, we nanostructured them with zinc oxide (ZnO) nanorods or nanotubes having a diameter of approximately 100 nm and a length of 1 µm. The nanostructure growth was first optimized on a silicon wafer and then transferred to the cantilevers.

Cu(OH)₂ and CuO Nanorod Synthesis on Piezoresistive Cantilevers for the Selective Detection of Nitrogen Dioxide.

Self-controlled active oscillating microcantilevers with a piezoresistive readout are very promising sensitive sensors, despite their small surface. In order to increase this surface and consequently their sensitivity, we nanostructured them with copper hydroxide (Cu(OH)₂) or with copper oxide (CuO) nanorods. The Cu(OH)₂ rods were grown, on a homogeneous copper layer previously evaporated on the top of the cantilever.

Nanothermite with Meringue-like Morphology: From Loose Powder to Ultra-porous Objects.

The goal of the protocol described in this article is to prepare aluminothermic compositions (nanothermites) in the form of porous, monolithic objects. Nanothermites are combustible materials made up of inorganic fuel and an oxidizer. In nanothermite foams, aluminum is the fuel and aluminum phosphate and tungsten trioxide are the oxidizing moieties.

Evaluation of the digestibility of solid lipid nanoparticles of glyceryl dibehenate produced by two techniques: Ultrasonication and spray-flash evaporation.

Objective: To evaluate the digestibility of Solid Lipid Nanoparticles (SLN) of glyceryl dibehenate prepared either with surfactants by ultrasonication or without surfactant by spray-flash evaporation.

Methods: SLN of glyceryl dibehenate (Compritol® 888 ATO) were produced by two processes: (i) high-shear homogenization with a solution of water-soluble surfactants followed by ultrasonication (ii) and Spray-Flash Evaporation (SFE) of the pure lipid. The digestibility of these nanoparticles was then tested by in vitro lipolysis using a pH-stat apparatus and the assay of glycerides by gel phase chromatography.

Aluminum nanopowder: A substance to be handled with care.

Aluminum nanopowders are increasingly used in various areas of research in materials and physical chemistry. Their unconventional properties are still little understood and make their handling sometimes quite hazardous. In this article, we report the case of apparently benign mixtures of Al with sulfuric acid (HSO), which violently explode when they are exposed to a flame.

The longstanding challenge of the nanocrystallization of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX).

Research efforts for realizing safer and higher performance energetic materials are continuing unabated all over the globe. While the thermites - pyrotechnic compositions of an oxide and a metal - have been finely tailored thanks to progress in other sectors, organic high explosives are still stagnating. The most symptomatic example is the longstanding challenge of the nanocrystallization of 1,3,5-trinitroperhydro-1,3,5-triazine (RDX).

Surface Functionalization and Electrical Discharge Sensitivity of Passivated Al Nanoparticles.

Passivated aluminum nanoparticles are surface functionalized to elucidate their sensitivity against an electrical discharge. Two size fractions that differ in surface morphology are investigated. Electronic interactions between the partly inert, partly energetic organic molecules used for surface functionalization and the alumina surface are analyzed in detail.

High-resolution Raman Spectroscopy for the Nanostructural Characterization of Explosive Nanodiamond Precursors.

The specific attributes of nanodiamonds have attracted increasing interest for electronics or biomedical applications. An efficient synthetic route towards nanodiamonds is via detonation of hexolite (i.e.

Nonlinear optical behavior of porphyrin functionalized nanodiamonds: an efficient material for optical power limiting.

The nonlinear optical mechanisms and the optical limiting behavior of porphyrin functionalized detonation nanodiamonds are investigated and compared to the conventional detonation nanodiamonds (DNDs). The optical limiting behavior is characterized by means of nonlinear transmittance, Z-scan, and scattered intensity measurements when submitted to a nanosecond pulsed Nd:YAG laser operating at the second harmonic wavelength. We found that the largest nonlinear attenuation was observed on the 4,4,4,4-(porphyrin-5, 10, 15, 20-tetrayl) tetrakis benzoic acid (PCOOH) suspension.

Chip calorimetry for the sensitive identification of hexogen and pentrite from their decomposition inside copper oxide nanoparticles.

Smart detection systems for explosive sensors are designed both to detect explosives in the air at trace level and identify the threat for a specific response. Following this need we have succeeded in using microthermal analysis to sensitively identify and discriminate between RDX and PETN explosive vapors at trace level. Once the explosive vapor is trapped in a porous material, heating the material at a fast rate of 3000 K/s up to 350 °C will result in a thermal pattern specifically corresponding to the explosive and its interaction with the porous material.

Nanodiamond for tuning the properties of energetic composites.

Bismuth oxide (Bi2O3) particles were coated by detonation nanodiamonds. The resulting nanocomposite materials were mixed with an aluminum nanopowder (≈ 100 nm) to prepare nanothermites, with reduced sensitivity to friction and electrostatic discharge (ESD). The use of nanodiamond for this purpose is reported here for the first time.

Sulfates-based nanothermites: an expanding horizon for metastable interstitial composites.

Metal sulfates (Ba, Bi, Ca, Cu, Mg, Mn, Na, Zn, Zr) were used as oxidizers in reactive compositions with Al nanopowder. These new kinds of nanothermites have outstandingly high reaction heats (4-6 kJ g(-1) ) compared to conventional Al/metal oxides (1.5-4.

Biophotonic ring resonator for ultrasensitive detection of DMMP as a simulant for organophosphorus agents.

Combining photonic integrated circuits with a biologically based sensing approach has the ability to provide a new generation of portable and low-cost sensor devices with a high specificity and sensitivity for a number of applications in environmental monitoring, defense, and homeland security. We report herein on the specific biosensing under continuous air flow of DMMP, which is commonly used as a simulant and a precursor for the synthesis of Sarin. The proposed technology is based on the selective recognition of the targeted DMMP molecule by specifically modified proteins immobilized on photonic structures.

High-resolution thermal imaging with a combination of nano-focus X-ray diffraction and ultra-fast chip calorimetry.

A microelectromechanical-systems-based calorimeter designed for use on a synchrotron nano-focused X-ray beamline is described. This instrument allows quantitative DC and AC calorimetric measurements over a broad range of heating/cooling rates (≤100000 K s(-1)) and temperature modulation frequencies (≤1 kHz). The calorimeter was used for high-resolution thermal imaging of nanogram-sized samples subjected to X-ray-induced heating.

Local detection of nitrogen-vacancy centers in a nanodiamond monolayer.

Nitrogen-vacancy defect centers (NV) contained in nanodiamonds (NDs) are a promising candidate in quantum information processing and single photon sources due to the capability of controlling their assembly on various surfaces. However, their detection with traditional optical techniques becomes challenging when probing high NV densities at the nanometer scale. Here, we combine scanning probe techniques to characterize in a monolayer the structural and electronic properties of bucky-diamonds with sizes below 10 nm.

Understanding ultrafine nanodiamond formation using nanostructured explosives.

The detonation process is able to build new materials with a bottom-up approach. Diamond, the hardest material on earth, can be synthesized in this way. This unconventional synthesis route is possible due to the presence of carbon inside the high-explosive molecules: firing high-explosive mixtures with a negative oxygen balance in a non-oxidative environment leads to the formation of nanodiamond particles.