INNOVATIVE ANTIMICROBIAL STRATEGIES: SYNTHESIS, COATING, AND BIOEFFICACY ASSESSMENT OF COVALENTLY BONDED PHOSPHONIUM ANCHORED QUATERNARY ONIUM COMPOUNDS

Candidate: Liam Brennan
Supervisor: Dr. Daniel Foucher

Abstract:

A series of novel quaternary onium compounds (QOCs) were synthesized containing either a central positively charged phosphorus or nitrogen atom. These compounds contained an anchor phosphonate or benzophenone functional group which enabled them to covalently bond to textile substrates. Furthermore, novel QOCs using ‘click’ chemistry were pioneered. The phosphonate QOCs were thermally cured onto cotton swatches and then tested to determine surface charge via anionic dye absorption and UV-vis spectrometry. The QOC compounds were also tested for antimicrobial effectiveness at solid/air interfaces using the large droplet inoculation (LDI) method, using test microorganisms including both gram-positive and gram-negative bacteria, Glutamicibacter soli (G. soli), Pseudomonas aeruginosa, (P. aeruginosa), Escherichia coli (E.coli), and Staphylococcus aureus (S. aureus). Increased antimicrobial effectiveness was seen when the substrate was allowed to dry for a full 24 hours prior to bacterial inoculation.