Part 1. Synthesis of ceramic powders by electrospray pyrolysis. Part 2. An approach to interplanetary particle sampling

NOTE: Text or symbols not renderable in plain ASCII are indicated by [...]. Abstract is included in .pdf document. In Part 1, the application of electrospray atomization for the production of ceramic powders is described. A model of the Taylor cone was developed which predicts the droplet size, volumetric flow rate, and electrical current for atomization of electrolytic solutions as functions of the liquid's specific electrical conductivity, surface tension, absolute viscosity, and density, as well as the applied electrical potential and atomizer geometry. Experimental verification was obtained for atomization of sodium iodide in n-propyl alcohol. The knowledge gleaned from the sodium iodide experiments was used to apply electrospray atomization to the production of submicron, spheroidal, and yttria particles by atomization of yttrium nitrate in n-propyl alcohol and thermal decomposition of the resulting aerosol droplets. This process is named "electrospray pyrolysis." A means of increasing the ceramic powder production rate for industrial and more extensive laboratory use via arrays of Taylor cones was experimentally tested. In Part 2, a method of sampling interplanetary dust particles (IDPs) is described. IDPs move at speeds [...]10 km/s relative to an interplanetary probe. A gas-filled balloon stops the particles by drag and ablation after they penetrate the balloon's skin. A model for ablation and deceleration of particles in the continuum and transition regimes was developed and experimentally tested using 7 [...] diameter glass spheres moving with an initial speed of 5 km/s through xenon gas at 0.1 and 0.2 atm. To analyze stopped IDPs by mass spectrometry, microscopy, etc., they must be deposited on a small sample substrate. To this end, a method of inward electrostatic precipitation was devised, modelled, and experimentally tested for [...] carbon soot particles in a cylindrical chamber. By this method, [...] IDPs can be intercepted by a [...] m noble gas-filled balloon, and deposited on a [...] mm centrally located sample substrate for subsequent analysis