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):

Report Date:

2015-07-14

Pagination or Media Count:

180.0

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.

Subject Categories:

  • Physical Chemistry
  • Chemical, Biological and Radiological Warfare
  • Fluid Mechanics
  • Optics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE