On the Sputtering of Titanium and Silver onto Liquids, Discussing the Formation of Nanoparticles

Abstract

Titanium and silver atoms were magnetron-sputtered either onto pentaerythritol ethoxylate (PEEL) or 1-butyl-3-methylimidazolium bis­(trifluoromethanesulfonyl)­imide (BMIMTFSI) ionic liquid (IL), and the formation of nanoparticles (NPs) is discussed based on the chemical interaction between the metal atoms and the host liquid. In the case of PEEL, our data reveal that titanium atoms sputtered in low-pressure argon plasma first form a film over the liquid surface. However, the latter dissolves as the film gets oxidized when vented to the air; asymmetric and faceted titanium dioxide NPs are finally obtained as if they were originating from a dismantled polycrystalline thin film. In the case of silver sputtered on PEEL, a film forms and solvation never occurs even after exposing the sample to air because the oxidation of silver is thermodynamically much less favorable than titanium. Quantum-chemical calculations confirm that the chemical interaction of TiO2 with PEEL molecules is favored as compared to metallic Ag or Ti. In contrast to what is observed with PEEL, when silver is sputtered onto the BMIMTFSI IL, no film is observed and spherical and crystallized silver NPs are found. These results suggest that the Ag-NP grows inside the IL because the chemical interaction of the Ag atoms with the BMIMTFSI molecules is highly favorable.

Silver nanoparticles by atomic vapour deposition on an alcohol micro-jet

“…[42][43][44] Both ionic liquid (IL) and sufficiently low vapour pressure solvent surfaces are stable in low vacuum and have been investigated as targets for metal deposition and nanoparticle formation. [45][46][47][48][49][50][51][52][53][54] In general, the synthesis in mineral oils is predominantly governed by physical parameters of the plasma, [47][48][49] whilst synthesis in ILs is signicantly governed by the chemistry of the IL. 46,50,53,54 In both systems, particles are commonly stable without added stabilisers or capping agents.…”

“…[45][46][47][48][49][50][51][52][53][54] In general, the synthesis in mineral oils is predominantly governed by physical parameters of the plasma, [47][48][49] whilst synthesis in ILs is signicantly governed by the chemistry of the IL. 46,50,53,54 In both systems, particles are commonly stable without added stabilisers or capping agents. [45][46][47][48][49][50][51][52][53][54] In this work we extend on the technique of sputter deposition onto liquid surfaces by introducing liquid into vacuum in the form of a liquid microjet.…”

“…46,50,53,54 In both systems, particles are commonly stable without added stabilisers or capping agents. [45][46][47][48][49][50][51][52][53][54] In this work we extend on the technique of sputter deposition onto liquid surfaces by introducing liquid into vacuum in the form of a liquid microjet. Liquid micro-jets have been widely used as a tool for studying molecular processes in liquids under vacuum conditions, [55][56][57][58][59] and narrow jets or surfaces of high vapour pressure liquids can be generated which are stable in vacuum over timescales of hours.…”

Insights into the growth of nanoparticles in liquid polyol by thermal annealing

“…Indeed, the enthalpy of formation of Ag2O and Cu2O is negative, i.e., -31.1 kJ.mol -1 and -168.6 kJ.mol -1 , respectively. 25,26 In spite of the negative enthalpy of silver oxide formation, a previous study reports the formation of metallic silver NPs after sputtering onto PEEL. 25 Please do not adjust margins Please do not adjust margins sputtering onto liquids after few days of storage for the sputtering of copper.…”

“…25,26 In spite of the negative enthalpy of silver oxide formation, a previous study reports the formation of metallic silver NPs after sputtering onto PEEL. 25 Please do not adjust margins Please do not adjust margins sputtering onto liquids after few days of storage for the sputtering of copper. 26 In this study, annealing of solutions and characterization were carried out a few days after the synthesis of the NPs.…”