Effects of Ag on TiO2 dip-coating on unglazed ceramic substrates for anti-microbial coating

• المؤلف الرئيسي: Ahmad Rusli, Nurhamizah
• التنسيق: أطروحة
• اللغة: الإنجليزية; الإنجليزية
• منشور في: 2015
• الموضوعات: T Technology (General); TP Chemical technology
• الوصول للمادة أونلاين: http://eprints.utem.edu.my/id/eprint/16860/; https://plh.utem.edu.my/cgi-bin/koha/opac-detail.pl?biblionumber=96106

Ag-TiO2 coating has been of interest for the purpose of antimicrobial application because silver (Ag) is well-known as antimicrobial agent and TiO2 possess as self-cleaning agent. In this research, it is aims to investigate the antimicrobial performance of Ag-TiO2 coating on unglazed ceramic substrate where the effects of additives and number of layers on the characteristic of Ag-TiO2 coating were investigated. The effect of PEG 2000 and Degussa P25 as additives on the characteristic of Ag-TiO2 coating was reported. The TiO2 coatings were produced via sol gel method using titanium tetraisopropoxide as a precursor from solutions that contains additive and without additive. Seven layers of TiO2 coating were deposited on unglazed ceramic substrate produced from waste glass. All coatings were deposited using dip coating technique and were sintered at 500ºC. The TiO2 coating was then immersed in an Ag nanoparticles solution before dried at 90o C in an oven to form Ag-TiO2 coating. Besides, the effects of number of layers on Ag-TiO2 coating with additive (Degussa P25) were characterized at five, seven and ten layers using dip coating technique. TiO2 coating at different layers was then sintered at 500oC before immersed in Ag nanoparticle solution. All coatings were evaluated using GAXRD and SEM analysis to characterized crystalline phase and coatings (surface morphology and thickness), respectively. Furthermore, Ag-TiO2 coating with two concentrations of silver nanoparticles (50 ppm and 1000 ppm) were prepared and antimicrobial analysis according to McFarland standard against E.coli, S.aerues, Fungus and MRSA were carried out and zone of inhibition are measured. Ag-TiO2 coating with additive (Degussa P25) shows anatase phases and homogeneous coating (morphology and Ag distribution) with the highest thickness (8.80 μm) which gives advantages to the coating for antimicrobial application as compared to others (without additive and with additive-PEG 2000). Besides, Ag-TiO2 coating with Degussa P25 at 10 layers shows the best result where the coating exists in anatase phases and homogenous coating structure with the highest coating thickness (11.80 μm) compared to 5 layers (5.85 μm) and 7 layers (8.80 μm). As a result, Ag-TiO2 coating with Degussa P25 as an additive with 10 layers at high concentration of Ag (1000 ppm) showed good performance in inhibiting E.coli growth on unglazed ceramic with a zone of inhibition of 8 mm.