Visible light photoactivity of Polypropylene coated Nano-TiO2 for dyes degradation in water

The use of Polypropylene as support material for nano-TiO2 photocatalyst in the photodegradation of Alizarin Red S in water solutions under the action of visible light was investigated. The optimization of TiO2 pastes preparation using two commercial TiO2, Aeroxide P-25 and Anatase, was performed and a green low-cost dip-coating procedure was developed. Scanning electron microscopy, Atomic Force Microscopy and X-Ray Diffraction analysis were used in order to obtain morphological and structural information of as-prepared TiO2 on support material. Equilibrium and kinetics aspects in the adsorption and successive photodegradation of Alizarin Red S, as reference dye, are described using polypropylene-TiO2 films in the Visible/TiO2/water reactor showing efficient dyes degradation

Predicting detonation velocity of ideal and less ideal explosives via specific impulse

429-432A novel method is given to estimate the detonation velocity of mostly ideal and less ideal composition explosives. This method is based on the utilization of theoretical specific impulse of the explosive, which can be designated as a monopropellant, and loading density. The simple empirical equation in calculating the detonation velocity has the form: DCJ=1.453ISPρ0 + 1.98, where DCJ is the Chapman-Jouguet detonation velocity, ISP is the specific impulse and ρ0 is the initial density. Calculated detonation velocity by this procedure shows good agreement with respect to measured detonation velocity

The Catalytic Effect of Mn2O3 Nanoparticles on the Ignition Reaction of Pyrotechnic of Ammonium Nitrate(V)/Thiourea

The non-isothermal TG/DSC technique has been used to study the kinetic triplet and heat of ignition reaction of ammonium nitrate(V) (AN)/thiourea (TU) pyrotechnic in the presence of Mn2O3 catalyst nanoparticles under an argon atmosphere at different heating rates (5 K·min−1, 10 K·min−1, 15 K·min−1 and 20 K·min−1). The activation energies for the ignition reaction of AN/TU were calculated using the non-isothermal isoconversional Kissinger-Akahira-Sunose (KAS) and Friedman equations for different conversion fraction (α) values in the range 0.1-0.9. The pre-exponential factor and kinetic model were determined by means of the compensation effect and the selected model was confirmed by a nonlinear fitting method. The average activation energies in the absence and presence of 5 wt.% Mn2O3 nanoparticles were 110.1 kJ·mol−1 to 117.3 kJ·mol−1 for the reaction model A3 (g(α) = [−ln(1−α)]1/3), and 86.5 kJ·mol−1 to 101.8 kJ·mol−1 for the reaction model A4 (g(α) = [−ln(1−α)]1/4). The evolved heat (ΔH) of ignition reaction in the presence of Mn2O3 was about 4 times that in the absence of the nano-sized Mn2O3

Relationship between thermal stability and molecular structure of polynitro arenes

61-64A simple relationship has been derived to predict thermal stability of CHNO polynitro arenes on the basis of onsets of thermal decomposition, which can be obtained by means of non-isothermal differential thermal analysis (DTA). The model is optimized using a set of 12 polynitro arenes so that R-squared value or the coefficient of determination of the new correlation is 0.95. The new correlation has also been applied to 6 polynitro arenes explosives from a variety of chemical families in order to assess the predictive capability of new method. Predicted results are close to the measured values for all of tested polynitro arenes on the basis DTA