Engineering Commons^™

Production Of Nanocrystalline Rdx By Ress : Development And Material Characterization, Victor Stepanov

Dissertations

The aim of the present work was to address the hazardous vulnerability of energetic materials to accidental initiation. An improved form of the explosive RDX with a significantly reduced sensitivity to stimuli including shock and impact was sought. The direction of this research was to investigate the effect of RDX crystal size reduction down to nano-scale dimensions on the sensitivity characteristics. Although size reduction of energetic crystals has been demonstrated often to result in a sensitivity reduction, the effect at the nano-scale particle size has not been investigated.

To generate nanocrystalline RDX a recrystallization process was developed based on rapid …

Mixing Of Nanoparticles In A Stirred Tank In High Pressure Carbon Dioxide, Nitin Aggarwal

Theses

Mixing of nanoparticles of different compositions offers wide opportunities in manufacturing new nanocomposite materials with unique electronic, optical, mechanical, and chemical properties. However, due to large cohesive forces between nanoparticles, they often form large micron-sized agglomerates, thus losing their main advantage of small size and high surface area. Therefore, breaking of these agglomerates is necessary prior to mixing. One of the techniques to achieve deagglomeration and mixing of nanoparticles is based on rapid depressurization/expansion of supercritical suspensions. where the suspension of initially premixed agglomerates in supercritical CO₂ pass through the nozzle undergoing deagglomeration as a result of rapid expansion …

Magnetically Assisted Impaction Mixing Of Nanosize Particles, James V. Scicolone

Theses

Magnetically assisted impaction mixing (MAIM) is a novel dry mixing technique, which can be used to mix nanoparticles. Mixing of nanoparticles is usually conducted in solvent-based mixing techniques. The solvents used in these techniques are usually organic, which can be expensive and harmful to the environment. MAIM creates homogeneous nanoparticle mixtures while eliminating conditioning and drying steps associated with wet mixing techniques. To create the best mixing quality of nanoparticles, MAIM was optimized by studying the effects of magnet-to-sample ratio, time, magnet size, and constituents of the mixture. The results were then compared with other well-known mixing techniques.

To characterize …