Nanostructural and Functional Properties of Ag-TiO₂ Coatings Prepared by Co-Sputtering Deposition Technique

Abstract

Ag-TiO2 nanocomposite coatings with varying Ag content were prepared by co-sputtering from two separate sputter sources. This technique allows to prepare coatings not only with a large variation of Ag content and different gradient but also allows much better control of nanocomposite thickness and nanostructure compared with mostly used techniques based on wet chemical approaches. Various thicknesses of nanocomposite layers with different deposition parameters were studied to obtain a better understanding on the growth of Ag nanostructures in the TiO2 films. The metal-volume-fraction was varied between 15% and 47%. Structural and microstructural investigations of the nanocomposite films were carried out by transmission electron microscopy. Special attention was paid to surface segregation of Ag and its suppression. The observed segregation on TiO2 contrasts sharply with the well known embedding tendency of Ag clusters on polymers. Functionality of the Ag-TiO2 nanocomposites was demonstrated via UV-Vis spectroscopy and antibacterial tests. It was shown that a thin layer of TiO2 can be used as an effective barrier to tailor the release behaviour of Ag ions.

PVD-grown antibacterial Ag-TiN films on piezoelectric PVDF substrates for sensor applications

“…On the other hand, the surface of the Ag-TiN x coating system exhibited Ag clusters like the authors discussed in a previous paper [23]. Several studies reported that the co-deposition of Ag and titanium nitride (TiN) [26], carbonitride (TiCN) [27] and oxide (TiO 2 ) [28] results in the formation of nanocomposites with Ag nanoparticles embedded in the matrix coating, and the size of these nanoparticles strongly depends on the amount of silver incorporated in the coating. The formation of Ag nanoparticles is related to the immiscibility of Ag in these…”

Microstructural and plasmonic modifications in Ag–TiO2 and Au–TiO2 nanocomposites through ion beam irradiation

“…Detailed investigations on the particle size distribution of the Ag nanoparticles embedded in a TiO 2 matrix have been performed by 3D-tomography studies [39–40]. Tomography results have confirmed the bimodal distribution of Ag nanoparticles with the presence of larger nanoparticles on top of the surface and smaller nanoparticles embedded inside the matrix.…”

“…The pristine Ag–TiO 2 nanocomposite sample exhibits Ag nanoparticles with a bi-modal particle size distribution (Fig. 4 and the corresponding particle size distribution) [39–40]. After irradiation with 100 MeV Ag 8+ ions at a fluence of about 1 × 10 12 ions/cm 2 , the average diameter of the Ag nanoparticles is increased indicating the growth of nanoparticles.…”

Magnetron Sputtering Deposition of Ag/TiO2 Nanocomposite Thin Films for Repeatable and Multicolor Photochromic Applications on Flexible Substrates

“…[ 18,19 ] Some others authors prepared Ag/ TiO 2 nanocomposites by magnetron sputter deposition without addressing their photochromic properties. [20][21][22] Zuo et al used radio frequency (RF) sputtering of a TiO 2 polycrystalline and an Ag target on p-type Si wafers at room temperature. [ 20 ] Chakravadhanula et al used cosputtering of RF magnetron TiO 2 target and direct current (DC) magnetron of Ag target on Si wafers.…”

“…[ 20 ] Chakravadhanula et al used cosputtering of RF magnetron TiO 2 target and direct current (DC) magnetron of Ag target on Si wafers. [ 21 ] Recently, Dhar et al combined RF magnetron sputtering of a TiO 2 target and DC sputtering of a Ag target at room temperature to deposit TiO 2 /Ag/TiO 2 trilayer thin fi lms onto polyetylene naphtalate fl exible substrates. [ 22 ] Other studies report the synthesis of photochromic Ag-embedded TiO 2 nanocomposite materials by magnetron sputter-deposition of TiO 2 and Ag thin layers at high Ar pressure, but they did not address the issue of functionalizing plastic substrates with such materials.…”