Accession Number:

ADA193572

Title:

Colloidal Assemblies Effect on Chemical Reactions.

Descriptive Note:

Periodic rept. no. 3, Feb-Jul 86,

Corporate Author:

TURIN UNIV (ITALY)

Personal Author(s):

• Pelizzetti, E.

Report Date:

1986-07-01

Pagination or Media Count:

45.0

Abstract:

The influence that organized assemblies micelles, microemulsions and semiconductor colloids exhibits on chemical reactions has been investigated. In particular electron transfer reactions induced by light in the presence of semiconductor particles have been shown to completely degrade several haloaromatic compounds. Phenol degradation has been investigated by carrying out experiments at different pH, phenol and TiO2 content, oxygen partial pressure. Intermediate compounds quinol and catechol were detected and quantitative formation of CO2 was assessed. Similarly, the photocatalytic degradation of 2,4,5-trichlorophenoxy acetic acid 2,4,5-T and 2,4,5-trichlorophenol on TiO2 led to complete mineralization into CO2 and HCl. In the degradation of 2,4,5-T several intermediates were detected by GC-MS and a scheme for the photodegradation pathways was formulated. The applicability of this degradation process to other haloaromatic compounds was preliminarily assessed. Keywords Oxidation Photocatalysis Surfactants Reaction mechanisms.

Descriptors:

• *CHEMICAL REACTIONS
• *COLLOIDS
• *ELECTRON TRANSFER
• *PHENOLS
• CATALYSIS
• DEGRADATION
• MINERALIZATION
• OXIDATION
• OXYGEN
• PARTIAL PRESSURE
• PARTICLES
• PHOTOCHEMICAL REACTIONS
• PHOTODEGRADATION
• RESPONSE
• SEMICONDUCTORS
• SURFACE ACTIVE SUBSTANCES

Subject Categories:

• Organic Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE