TY - JOUR
T1 - Tunable Assembly of Photocatalytic Colloidal Coatings for Antibacterial Applications
AU - Sofroniou, Constantina
AU - Scacchi, Alberto
AU - Le, Huyen
AU - Espinosa Rodriguez, Edgar
AU - D’Agosto, Franck
AU - Lansalot, Muriel
AU - Dunlop, PSM
AU - Ternan, Nigel G
AU - Martín-Fabiani, Ignacio
N1 - Publisher Copyright:
© 2024 The Authors. Published by American Chemical Society.
PY - 2024/8/23
Y1 - 2024/8/23
N2 - In this study, evaporation-induced size segregation and interparticle interactions are harnessed to tune the microstructure of photocatalytic colloidal coatings containing TiO2 nanoparticles and polymer particles. This enabled the fabrication of a library of five distinct microstructures: TiO2-on-top stratification, a thin top layer of polymer or TiO2, homogeneous films of raspberry particles, and a sandwich structure. The photocatalytic and antibacterial activities of the coatings were evaluated by testing the viability of Methicillin-resistant Staphylococcus aureus (MRSA) bacteria using the ISO-27447 protocol, showing a strong correlation with the microstructure. UVA irradiation for 4 h induces a reduction in MRSA viability in all coating systems, ranging from 0.6 to 1.1 log. Films with TiO2-enriched top surfaces exhibit better resistance to prolonged exposure to disinfection and bacterial testing. The remaining systems, nonetheless, present higher antibacterial activity because of a larger number of pores and coating defects that enhance light and water accessibility for the generation and transport of reactive oxygen species. This work establishes design rules for photocatalytic coatings based on the interplay between performance and film architecture, offering valuable insights for several applications, including antibacterial surfaces, self-cleaning/antifogging applications, and water purification.
AB - In this study, evaporation-induced size segregation and interparticle interactions are harnessed to tune the microstructure of photocatalytic colloidal coatings containing TiO2 nanoparticles and polymer particles. This enabled the fabrication of a library of five distinct microstructures: TiO2-on-top stratification, a thin top layer of polymer or TiO2, homogeneous films of raspberry particles, and a sandwich structure. The photocatalytic and antibacterial activities of the coatings were evaluated by testing the viability of Methicillin-resistant Staphylococcus aureus (MRSA) bacteria using the ISO-27447 protocol, showing a strong correlation with the microstructure. UVA irradiation for 4 h induces a reduction in MRSA viability in all coating systems, ranging from 0.6 to 1.1 log. Films with TiO2-enriched top surfaces exhibit better resistance to prolonged exposure to disinfection and bacterial testing. The remaining systems, nonetheless, present higher antibacterial activity because of a larger number of pores and coating defects that enhance light and water accessibility for the generation and transport of reactive oxygen species. This work establishes design rules for photocatalytic coatings based on the interplay between performance and film architecture, offering valuable insights for several applications, including antibacterial surfaces, self-cleaning/antifogging applications, and water purification.
KW - colloids
KW - titanium dioxide
KW - coatings
KW - photocatalysis
KW - self-assembly
KW - stratification
KW - antibacterial
UR - https://pure.ulster.ac.uk/en/publications/218eb9c2-2687-48cf-8a97-c2c17c6c82a6
UR - http://www.scopus.com/inward/record.url?scp=85201887543&partnerID=8YFLogxK
U2 - 10.1021/acsapm.4c01436
DO - 10.1021/acsapm.4c01436
M3 - Article
SN - 2637-6105
VL - 6
SP - 10298
EP - 10310
JO - ACS Applied Polymer Materials
JF - ACS Applied Polymer Materials
IS - 17
ER -
