Combustion Characteristics of Calcium Iodate Based Biocidal Formulations

Combustion Characteristics of Calcium Iodate Based Biocidal Formulations

Fidel D.Ruz-Nuglo, Lori J. Groven

Department of Chemical and Biological Engineering,

South Dakota School of Mines and Technology, Rapid City, South Dakota

Abstract

Biocidal formulations have been well explored by a number of researchers over the years and typically include a metal fuel such as Aluminum and iodates such as I₂O₅ or KIO₃. However, these formulations are plagued by aging and degradation of the iodate and/or the aluminum (fuel), which in turn reduces their efficacy.  To overcome this some type of protective agent for the iodates and for the aluminum is necessary.  In this effort, fluoropolymers serve as i) the protective agent for both the iodates and the aluminum within the formulations, and ii) as a polymer binder for the development of a printable biocidal. In this study, the fluoropolymer (THV) is found to be effective in protecting both the calcium iodate and the aluminum powder under accelerated aging conditions (70 °C, 30% RH).  Simultaneous differential scanning calorimetry (DSC) and thermo-gravimetric (TG) analyses were performed to elucidate the complex interactions between the fluoropolymer, iodate, and aluminum.  Inks were formulated with THF or DMF serving as the solvent and printed using a Nordson EFD system.  The combustion characteristics are presented as a function of polymer loading and line width.  Combustion velocities on the order of 150 mm/s were observed when nanoscale aluminum is used as the fuel. The necessary rheological characteristics and the associated safety characteristics of the printed formulations will also be detailed.