Spray drying method was used to prepare cocrystals of hexanitrohexaazaisowurtzitane (CL-20) and cyclotetramethylene tetranitramine (HMX). Raw materials and cocrystals were characterized using scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, Raman spectroscopy, and Fourier transform infrared spectroscopy. Impact and friction sensitivity of cocrystals were tested and analyzed. Results show that, after preparation by spray drying method, microparticles were spherical in shape and 0.5–5 µm in size. Particles formed aggregates of numerous tiny plate-like cocrystals, whereas CL-20/HMX cocrystals had thicknesses of below 100 nm. Cocrystals were formed by C–H⋯O bonding between –NO2 (CL-20) and –CH2– (HMX). Nanococrystal explosives exhibited drop height of 47.3 cm, and friction demonstrated explosion probability of 64%. Compared with raw HMX, cocrystals displayed significantly reduced mechanical sensitivity.

No abstract

No abstract

A one-step method which involves exfoliating graphite materials (GIMs) off into graphene materials (GEMs) in aqueous suspension of CL-20 and forming CL-20/graphene materials (CL-20/GEMs) composites by using ball milling is presented. The conversion of mixtures to composite form was monitored by scanning electron microscopy (SEM) and powder X-ray diffraction (XRD). The impact sensitivities of CL-20/GEM composites were contrastively investigated. It turned out that the energetic nanoscale composites based on CL-20 and GEMs comprising few layers were accomplished. The loading capacity of graphene (reduced graphene oxide, rGO) is significantly less than that of graphene oxide (GO) in CL-20/GEM composites. The formation mechanism was proposed. Via this approach, energetic nanoscale composites based on CL-20 and GO comprised few layers were accomplished. The resulted CL-20/GEM composites displayed spherical structure with nanoscale, ε-form, equal thermal stabilities, and lower sensitivities.Electronic supplementary materialThe online version of this article (10.1186/s11671-017-2416-y) contains supplementary material, which is available to authorized users.

No abstract

No abstract

An emulsion is a multiphase dispersion system in which one or more liquids are dispersed in the form of particles in another immiscible liquid. Emulsion method has been applied for preparation of binder system via oil in water (O/W) emulsions. The formulation contains: 40 g 12 % a solution of polyvinyl alcohol (PVA) in water, 15 g 7.5 % a solution of Viton A (vinylidene hexafluoropropene copolymer) in ethyl acetate, 0.25 g sodium dodecyl sulfate (SDS) and 0.25 g Tween‐80.The emulsion as a binder system, sub‐micro CL‐20 (prepared by the ball milling method) as the body explosives to prepared CL‐20 based explosive ink (CL‐20 88 % concentration). Deposition of explosive inks via DIW technology and its properties were characterized. The results showed that the composite has fewer internal defects and low impact sensitivity, the crystal type has no change, critical detonation size is around 1×0.17 mm and detonation velocity is 8079 m/s.

The graphene (rGO) and carbon nanotube (CNT) were adopted to enhance the thermal conductivity of CL-20-based composites as conductive fillers. The microstructure features were characterized using scanning electron microscopy (SEM) and X-ray diffraction (XRD), and tested the properties by differential scanning calorimeter (DSC), static electricity accumulation, special height, thermal conductivity, and detonation velocity. The results showed that the mixture of rGO and CNT had better effect in thermal conductivity than rGO or CNT alone under the same loading (1 wt%) and it formed a three-dimensional heat-conducting network structure to improve the heat property of the system. Besides, the linear fit proved that the thermal conductivity of the CL-20-based composites were negatively correlated with the impact sensitivity, which also explained that the impact sensitivity was significantly reduced after the thermal conductivity increased and the explosive still maintained better energy.Electronic supplementary materialThe online version of this article (10.1186/s11671-018-2496-3) contains supplementary material, which is available to authorized users.