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61. Deep Eutectic Solvents (DES) based on sulphur for silicon surfaces as alternative lubricants

Author

Antunes, Mónica, Martins, Anne-Sophie, Freire, Mariana de Sá, Caetano, Fernando J. P., Diogo, Herminio, Colaco, Rogério, Branco, Luís C., and Saramago, Benilde

Subjects
Silicon, Deep eutectic solvents, Friction coefficient, Alternative lubricants
Abstract

Encontro realizado na Universidade Nova de Lisboa de 24-27 de junho de 2019. Deep eutectic mixtures composed of hydrogen-bond donors and hydrogen-bond acceptors, the so-called DESs, have recently being proposed as possible “green” alternatives to mineral oils and ionic liquids (ILs) in the lubrication of steel surfaces. DESs have similar physical properties to ILs but have the advantage of being cheaper and easier to prepare. In this work, new DESs containing sulphur units in their structure were prepared and tested in the lubrication of silicon surfaces which are relevant for nano/microelectromechanical systems (NEMS/MEMS). The following new DESs were prepared: dibutil-ethyl sulfonium ethylsulfate: polyethylene glycol ([S4,4,2][EtSO4]:PEG), ethyl-tetrahydrothiophenium ethylsulfate: polyethylene glycol ([C2-THT][EtSO4]:PEG, cis-1-ethyl-3methylimidazolium canforsulfonate: polyethylene glycol ([C2MIM][(S)-CSA]:PEG), and 1,3-dimethylpiridinium methyl sulfate: polyethylene glycol ([C1-3-pic][MeSO4]:PEG). Other DES, already known, were tested for comparison purposes: tetrabutylammonium bromide: ‎tetrahydrothiophene 1,1-dioxide ([N4,4,4,4][Br]:Sulfolane), choline chloride: polyethylene glycol (ChCl:PEG), and tetrabutylammonium bromide: polyethylene glycol ([N4,4,4,4][Br]:PEG). All DESs were characterized in terms of their water content, viscosity, wettability, and tribological properties. The friction coefficients were measured in a nanotribometer using steel spheres against Si surfaces. The new DES prepared from ILs based on the sulfur-containing anions showed good tribological performance, but the best results were obtained with [C2MIM][(S)-CSA]:PEG and [C1-3-pic][MeSO4]:PEG which reduced the friction coefficients to values < 0.1, typical of excellent lubrication conditions. Fundação para a Ciência e a Tecnologia (FCT-Portugal) and COMPETE (FEDER), within projects UID/QUI/00100/2013, UID/NAN/50024/2013 and PTDC/CTM-POL/3698/2014 info:eu-repo/semantics/draft

Published
2019

65. Synthesis and Antibacterial Activity of Ionic Liquids and Organic Salts Based on Penicillin G and Amoxicillin hydrolysate Derivatives against Resistant Bacteria

Author

Ferraz, Ricardo, primary, Silva, Dário, additional, Dias, Ana Rita, additional, Dias, Vitorino, additional, Santos, Miguel M., additional, Pinheiro, Luís, additional, Prudêncio, Cristina, additional, Noronha, João Paulo, additional, Petrovski, Željko, additional, and Branco, Luís C., additional

Published
2020
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89. Antitumor Activity of Ionic Liquids Based on Ampicillin

Author

Ferraz, Ricardo, primary, Costa-Rodrigues, João, additional, Fernandes, Maria H., additional, Santos, Miguel M., additional, Marrucho, Isabel M., additional, Rebelo, Luís Paulo N., additional, Prudêncio, Cristina, additional, Noronha, João Paulo, additional, Petrovski, Željko, additional, and Branco, Luís C., additional

Published
2015
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