Accession Number : ADA625268


Title :   Ultrahigh Vacuum Studies of the Fundamental Interactions of Chemical Warfare Agents and Their Simulants with Amorphous Silica


Descriptive Note : Doctoral thesis


Corporate Author : VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG


Personal Author(s) : Wilmsmeyer, Amanda R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a625268.pdf


Report Date : 14 Jul 2015


Pagination or Media Count : 180


Abstract : Developing a fundamental understanding of the interactions of chemical warfare agents (CWAs) with surfaces is essential for the rational design of new sorbents, sensors, and decontamination strategies. The interactions of chemical warfare agent simulants, molecules which retain many of the same chemical or physical properties of the agent without the toxic effects, with amorphous silica were conducted to investigate how small changes in chemical structure affect the overall chemistry. Experiments investigating the surface chemistry of two classes of CWAs, nerve and blister agents, were performed in ultrahigh vacuum to provide a well-characterized system in the absence of background gases. Transmission infrared spectroscopy and temperature-programmed desorption techniques were used to learn about the adsorption mechanism and to measure the activation energy for desorption for each of the simulant studied. In the organophosphate series, the simulants diisopropyl methylphosphonate (DIMP), dimethyl methylphosphonate (DMMP), trimethyl phosphate (TMP), dimethyl chlorophosphate (DMCP), and methyl dichlorophosphate (MDCP) were all observed to interact with the silica surface through the formation of a hydrogen bond between the phosphoryl oxygen of the simulant and an isolated hydroxyl group on the surface.


Descriptors :   *AMORPHOUS MATERIALS , *HYDROGEN BONDS , *SILICON DIOXIDE , *ULTRAHIGH VACUUM , ABSORPTION , ACTIVATION ENERGY , ADSORPTION , CHEMICAL WARFARE AGENTS , DECONTAMINATION , DECOUPLING(INTERACTION) , DESORPTION , GAS SURFACE INTERACTIONS , HYDROXYL RADICALS , INFRARED SPECTROSCOPY , METHYL RADICALS , ORGANOPHOSPHATES , PHYSICAL PROPERTIES , SURFACE CHEMISTRY , THESES , TOXICITY , TRANSMITTANCE , VESICANTS


Subject Categories : Physical Chemistry
      Chemical, Biological and Radiological Warfare
      Fluid Mechanics
      Optics


Distribution Statement : APPROVED FOR PUBLIC RELEASE