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Ten PILs based on the combination of methylimidazolium ([MIMH]), 4-picolinium ([4-picH]), pyridinium ([PyrH]), 1,8-diazabicyclo[5.4.0]-undec-7-ene-8-ium ([DBUH]) and tetramethylguanidinium ([TMGH]) cations with hydrogen sulfate([HSO4]) and mesylate ([MeSO3]) anions were tested as additives in polyethylene glycol (PEG200) to lubricate steel\/silicon and silicon\/silicon contacts. The best additive was [4-picH][HSO4], which adsorbed strongly on the Si surface, leading to a protective film that reduced wear by up to 15 times compared to PEG200.<\/jats:p>","DOI":"10.3390\/molecules28062678","type":"journal-article","created":{"date-parts":[[2023,3,16]],"date-time":"2023-03-16T02:40:11Z","timestamp":1678934411000},"page":"2678","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["New Protic Ionic Liquids as Potential Additives to Lubricate Si-Based MEMS\/NEMS"],"prefix":"10.3390","volume":"28","author":[{"ORCID":"https:\/\/orcid.org\/0000-0003-4045-2696","authenticated-orcid":false,"given":"Mariana T.","family":"Donato","sequence":"first","affiliation":[{"name":"Centro de Qu\u00edmica Estrutural, Institute of Molecular Sciences, Departamento de Engenharia Qu\u00edmica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal"},{"name":"LAQV-REQUIMTE, Departamento de Qu\u00edmica, NOVA School of Science and Technology, Universidade NOVA de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2764-3124","authenticated-orcid":false,"given":"Jonas","family":"Deuermeier","sequence":"additional","affiliation":[{"name":"CENIMAT|i3N and CEMOP\/UNINOVA, Departamento de Ci\u00eancia dos Materiais, Faculdade de Ci\u00eancias e Tecnologia, Universidade Nova de Lisboa, Campus da Caparica, 2829-516 Caparica, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5529-1621","authenticated-orcid":false,"given":"Rog\u00e9rio","family":"Cola\u00e7o","sequence":"additional","affiliation":[{"name":"IDMEC-Instituto de Engenharia Mec\u00e2nica, Departamento de Engenharia Mec\u00e2nica, Instituto Superior T\u00e9cnico, Universidade de Lisboa, Av. 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