ABSTRACT
VISAI c, Alberto CIGADA a and Angelo MONTENERO b aPolitecnico di Milano, Dipartimento di Chimica, Materiali e Ingegneria Chimica “G. Natta”, Via Mancinelli 7, 20129 Milano, Italy, bUniversità di Parma, Dipartimento di
Chimica Generale ed Inorganica, Chimica Analitica e Chimica Fisica, Italy, cUniversità di Pavia, Dipartimento di Biochimica, dCentro di Ingegneria Tissutale
(C.I.T.), Italy
Abstract. We report on preliminary results of bactericidal activity of nanostructured titanium dioxide surfaces, obtained via two different techniques on titanium substrate: anodic oxidation and sol-gel film deposition. Anodic oxidation was performed in phosphoric acid in galvanostatic mode: obtained films showed typical interferometric colours, depending on the final applied voltage, and were amorphous (up to 40 V). Sols were obtained by hydrolysis of titanium isopropoxide in acidic environment and deposited via cold spray: films showed anatase crystallographic structure, without any further thermal treatment and did not show any evident alteration of the morphology and substrate colour. An appropriate testing chamber was then designed to perform bactericidal tests, by controlling UVA irradiation: bactericidal activity was assessed on two different bacteria strains (S. aureus and E. coli) and demonstrated to be photo-induced. These preliminary results show the ability of nano-structured surfaces in photoactivated biocidal activity of titanium dioxide surfaces.
