PREPARATION OF TITANIA SOL-GEL COATINGS CONTAINING SILVER IN VARIOUS FORMS AND MEASURING OF THEIR BACTERICIDAL EFFECTS AGAINST E. COLI

• Published in: Ceramics (Praha) 2015-01, Vol.59 (3), p.238-243
• Main Authors: Horkavcova, D, Zmeskal, Z, Sanda, L, Zlamalova, Clova Z, Jablonska, E, Helebrant, A
• Format: Article
• Language: English
• Subjects: Bacteria; Brushes; Coatings; Dip coatings; Dip-coating technique; E. coli; Escherichia coli; Silver; Sol gel process; Titania sol-gel coatings; Titanium; Titanium dioxide; Titanium substrate
• ISSN: 0862-5468; 1804-5847

Titania coatings, containing various forms of silver, were deposited on titanium substrates by a dip-coating sol-gel technique. Silver was added into the basic titania sol in the form of colloid particles of Ag, crystals of AgNO3, particles of AgI, particles of Ag3PO4 and Ag3PO4 developed in situ (in the sol) by reaction of AgNO3 with added calcium phosphate (brushite or monetite). Mechanically and chemically treated titanium substrates were dipped at a constant rate into the different sols and then slowly fired. The fired coatings contained microcracks and the surface of the coatings consisted of evenly distributed spherical nanoparticles of silver (Ag, AgNO3) or microcrystals of AgI and Ag3PO4. The prepared coatings were tested under static conditions for their bactericidal effects against gram-negative bacteria Escherichia coli (E. coli). The coated substrates were immersed in a suspension of E. coli in physiological solution for 24 and 4 h. The undoped titania coatings showed no bactericidal properties but all the coatings with the various forms of added silver showed good bactericidal effect against E. coli in both types of bactericidal test.