Electron Microscope Studies of Solids Produced by alpha-Radiolysis of Carbon Monoxide

Baird, Thomas (1969) Electron Microscope Studies of Solids Produced by alpha-Radiolysis of Carbon Monoxide. PhD thesis, University of Glasgow.

Abstract

A study has been made of the solids produced by radiolysis of carbon monoxide gas at room temperature using principally 5 MeV alpha-particles from plutonium-240. The solids were produced in situ within a Siemens Elmiskop I electron microscope and were examined directly The morphological nature of the solid particles has been studied and the effect of subsequent exposure of the particles to the atmosphere has been investigated using transmission electron microscopy and electron diffraction techniques. It has been established that the particles grow in the gas phase and are of an amorphous nature. The effect on the radiolysis of varying the gas composition has been investigated. Metallic carbonyl impurities in the carbon monoxide have been found to influence the nature and composition of the solids produced, Two distinct types of solid particles can be obtained. Initially these have a similar appearance but they behave differently on subsequent exposure to water vapour. Solids from carbon monoxide containing nickel tetracarbonyl impurity are hygroscopic and they become fluid on absorption of water vapour. Electron diffraction and electron probe microanalysis studies reveal the presence of several per cent of nickel in these solids. The presence of iron pentacarbonyl impurity in the carbon monoxide yields solids which are inert towards water vapour; these solids contain several per cent of iron. Higher yields of solid are obtained with the iron pentacarbonyl impurity. When both iron and nickel carbonyls are present in the carbon monoxide the influence exerted by the iron carbonyl predominates and the solids produced have all the characteristics of the material formed when iron carbonyl alone is present. A possible explanation to account for this phenomenon is proposed. Infrared spectroscopy studies of the alpha-radiolytic solids and of the solid from complementary proton radiolysis experiments provide evidence which suggests that the solids are composed of linear polymeric carbon suboxide units. The nature of the bonding between the basic polymer units and the iron and nickel is discussed. The alpha-radiolysis of carbon monoxide in the presence of graphite has been studied. It has been found that in addition to the gas-phase deposits which are produced there is a solid which grows on the surface of the graphite. This solid has similar characteristics to the nickel-containing gas-phase material.

• Item Type: Thesis (PhD)
• Qualification Level: Doctoral
• Keywords: Physical chemistry
• Date of Award: 1969
• Depositing User: Enlighten Team
• Unique ID: glathesis:1969-78508
• Copyright: Copyright of this thesis is held by the author.
• Date Deposited: 28 Feb 2020 12:09
• Last Modified: 28 Feb 2020 12:09
• URI: https://theses.gla.ac.uk/id/eprint/78508