Polymerization-Induced Phase Segregation and Self-Assembly of Siloxane Additives to Provide Thermoset Coatings with a Defined Surface Topology and Biocidal and Self-Cleaning Properties

Jaleh Mansouri; Vi Khanh Truong; Shane MacLaughlin; David E Mainwaring; Graeme Moad; Ian J Dagley; Elena P Ivanova; Russell J Crawford; Vicki Chen

doi:10.3390/nano9111610

Polymerization-Induced Phase Segregation and Self-Assembly of Siloxane Additives to Provide Thermoset Coatings with a Defined Surface Topology and Biocidal and Self-Cleaning Properties

Nanomaterials (Basel). 2019 Nov 13;9(11):1610. doi: 10.3390/nano9111610.

Authors

Jaleh Mansouri^{1

2}, Vi Khanh Truong^{2

3

4}, Shane MacLaughlin⁵, David E Mainwaring³, Graeme Moad⁶, Ian J Dagley^{2

7}, Elena P Ivanova^{3

4}, Russell J Crawford⁴, Vicki Chen^{1

8}

Affiliations

¹ UNESCO Centre for Membrane Science and Technology, School of Chemical Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
² Cooperative Research Centre for Polymers, Notting Hill, VIC 3168, Australia.
³ Faculty of Science, Engineering and Technology, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, Australia.
⁴ Nanobiotechnology Laboratory, School of Science, College of Science, Engineering and Health, RMIT University, Melbourne, VIC 3001, Australia.
⁵ BlueScope Steel Research, Port Kembla, NSW 2505, Australia.
⁶ CSIRO Manufacturing, Clayton, VIC 3168, Australia.
⁷ Defence Science and Technology, Department of Defence, 506 Lorimer Street, Port Melbourne, VIC 3207, Australia.
⁸ School of Chemical Engineering, University of Queensland, Brisbane, QLD 4072, Australia.

Abstract

In this work, we report on the incorporation of a siloxane copolymer additive, poly((2-phenylethyl) methylsiloxane)-co(1-phenylethyl) methylsiloxane)-co-dimethylsiloxane), which is fully soluble at room temperature, in a rapid-cure thermoset polyester coating formulation. The additive undergoes polymerization-induced phase segregation (PIPS) to self-assemble on the coating surface as discrete discoid nanofeatures during the resin cure process. Moreover, the copolymer facilitates surface co-segregation of titanium dioxide pigment microparticulate present in the coating. Depending on the composition, the coatings can display persistent superhydrophobicity and self-cleaning properties and, surprisingly, the titanium dioxide pigmented coatings that include the siloxane copolymer additive display high levels of antibacterial performance against Gram-positive (Staphylococcus aureus) and Gram-negative (Pseudomonas aeruginosa) bacteria. This antibacterial performance is believed to be associated with the unique surface topology of these coatings, which comprise stimuli-responsive discoid nanofeatures. This paper provides details of the surface morphology of the coatings and how these relates to the antimicrobial properties of the coating.

Keywords: antibacterial; cleanability; dynamic nano-topography; polyester coatings; siloxane copolymer additives; surface segregation.