New dispersions of liquid crystals in polymer matrices with improved wear and scratch resistance.

New compositions of polymer-dispersed thermotropic liquid crystals for moving parts sliding against metals. Properties of the new materials are a function of the concentration and distribution of the liquid crystal in the polymer matrix and depend on the mixing and molding proceses.Composition and manufacturing processes of blends containing thermoplastic polymers with additives based on ordered fluids such as thermotropic liquid crystals dispersed in the polymer matrix in order to modify the surface and improve the friction and wear resistance of the material and its processability. With this technological offer we try to collaborate with licence agreement and comercial agreement with technical assistance.Control of the additive proportion and distribution within a surface layer. This new technology increases the autolubricating ability of the polymers in applications where a high wear and scratch resistance are essential. The liquid crystalline additives can be removed from the matrix by supercritical CO2 extraction, thus allowing complete reciclyng. The new materials are homogeneous with a composition gradient. The new compositions containing thermotropic liquid crystals with controlled distribution and ease of processing allow surface modification with friction and wear reduction without changing the bulk material propertiesAditivos de polímeros. Fricción, lubricación, desgaste. Propiedades de materiales

Caracterización de dispositivos de lámina delgada mediante microscopía óptica, electrónica de barrido y microanálisis

En este trabajo se presentan los resultados de la aplicación de las técnicas de microscopía óptica y electrónica de barrido (SEM), así como de microanálisis para la caracterización de dispositivos optoelectrónicos de lámina delgada

New graphene/ionic liquid nanolubricants

In this work, we have prepared new graphene/ionic liquid dispersions by adding a 0.1wt.% proportion of 1-2 layers graphene (G1) or 1-10 layers graphene (G2) to the ionic liquid 1-octyl-3-methylimidazolium tetrafluoroborate (IL). The new dispersions (IL+G1) and (IL+G2) have been used as external lubricants in polymer-steel and ceramic-steel contacts. For AISI 316L stainless steel/epoxy resin, the order of friction reduction is (IL+G2)>IL>(IL+G1). The wear reducing order is the same, as abrasive wear takes place for (IL+G1), while G2 prevents any degree of surface damage on both materials, even the very mild wear observed for neat IL. The poor performance of G1 is related to the formation of abrasive graphene-IL aggregates. The (IL+G2) dispersion also shows superior friction reducing and anti-wear behavior under more severe contact conditions, for AISI316L against sapphire.The authors thank the financial support of the Ministerio de Economia y Competitividad (MINECO, Spain; FEDER, EU) (Grant MAT2014-55384-P). “Este trabajo es resultado de los proyectos de investigación (19292/PI/14, 19544/GERM/14 and 19877/GERM/14) financiados por la Fundación Séneca-Agencia de Ciencia y Tecnología de la Región de Murcia en el marco del PCTIRM2011-2014”. N. Saurin is grateful to MINECO (Spain) for a FPI research Grant (BES-2012-056621)

Estudio tribológico del contacto acero AISI316L/Zafiro con películas autolubricantes de líquidos iónicos próticos

[ESP] Los líquidos iónicos han demostrado un comportamiento excelente en su uso como lubricantes de diferentes contactos mecánicos. En el presente trabajo se han generado y caracterizado capas finas de un líquido iónico prótico, el Adipato de Di-[bis(2-hidroxietil)amonio](DAd), sobre discos de acero inoxidable AISI 316L y, posteriormente, se ha estudiado su comportamiento tribológico frente a bolas de zafiro, en ensayos punzón-sobre-disco. Se ha demostrado que se consigue reducir el periodo de alta fricción inicial, el desgaste generado y el volumen de lubricante utilizado respecto a los resultados obtenidos cuando se usan como lubricantes disoluciones acuosas o el líquido iónico puro. [ENG] Ionic liquids have shown an outstanding performance as lubricants in different contacts. In the present work, the protic ionic liquid di[bis-(2-hydroxyethyl)ammonium] adipate (DAd) has been used to generate thin surface films on AISI316L stainless steel and their lubricating performance against sapphire balls has been studied. The results described in the present study show a good tribological performance of these thin surface films, in pin-on-disc tests, reducing the running-in period of high friction coefficient, preventing wear and reducing the volume of lubricant with respect to the results obtained when water+1%DAd and neat DAd are used as lubricants.Centro Universitario de la Defensa. Escuela de Turismo de Cartagena. Escuela Técnica Superior de Ingeniería Industrial UPCT. Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT). Escuela de Ingeniería de Caminos y Minas (EICM). Escuela de Arquitectura e Ingeniería de Edificación (ARQ&IDE). Parque Tecnológico de Fuente Álamo. Navantia. Campus Mare Nostrum. Estación Experimental Agroalimentaria Tomás Ferr

Study of the abrasion resistance of new epoxy (ER) – ionic liquid (IL) materials with self-healing ability

In the present work, new epoxy resin (ER) – ionic liquid (IL) dispersions have been obtained and their abrasion resistance has been determined by multiple scratch tests. The IL was added in a range of concentrations between 7 and 12 wt. %.After the scratch tests, the viscoelastic recovery and healing ability of the damaged surface has been monitorized using optical and electronic microscopy and profilometry. The results are discussed on the basis of the curing procedure and are related to mechanical, thermal and dynamic-mechanical properties, and to surface porosity of the new dispersions.The authors acknowledge the financial support of the Ministerio de Economía y Competitividad (MINECO, Spain) (Grant # MAT2014-55384-P). N. Saurín is grateful to MINECO (Spain) for a FPI research (Grant # BES-2012-056621)

Tribological study of the AISI316L/Sapphire contact with self-lubricating films of protic ionic liquids

Ionic liquids have shown an outstanding performance as lubricants in different contacts. Protic ammonium carboxylate ionic liquids (PILs), both neat and as additives in water, are being studied as friction-reducing and wear prevention lubricants in stainless steel-sapphire contacts. When a PIL was used as additive in water, the high temperature reached at the sliding contact produced the evaporation of water and the formation of a low friction PIL boundary layer. In the present study, the formation of the PIL boundary layer on AISI316L stainless steel under static conditions is described and its lubricating performance against sapphire balls has been studied. The effect of relative humidity has been studied using a vacuum chamber. The results described in the present study show a good tribological performance of these thin surface films, in pin-on-disc tests, reducing the running-in period of high friction coefficient, preventing wear and reducing the volume of lubricant with respect to the results obtained when water+1%PIL and neat PIL are used as lubricants.Competitividad (MINECO, Spain) (MAT2011-23162 and MAT2014-55384-P) for financial support. T. Espinosa is grateful to the Ministerio de Educación, Cultura y Deporte (MECD, Spain) for a research Grant (AP2010-3485)

Nuevos líquidos iónicos de tiazolio en lubricación de contactos acero-zafiro

Los líquidos iónicos (LIs) son fluidos respetuosos con el medio ambiente que están siendo utilizados en numerosas aplicaciones, entre ellas la tribología, ya que presentan un excelente comportamiento en su uso como lubricantes, tanto en estado puro como aditivos de otros lubricantes. La mayoría de LIs estudiados hasta el momento en tribología contienen el catión imidazolio, amonio o fosfonio. En el presente trabajo se han sintetizado nuevos líquidos iónicos que contienen el catión tiazolio con diferentes sustituyentes y se ha estudiado su uso como lubricantes en contactos acero-zafiro. Para el estudio del comportamiento tribológico y de las interacciones superficiales, se han realizado ensayos con discos de acero inoxidable y de acero de rodamientos con bolas de zafiro bajo la configuración punzón-sobre-disco. Los resultados se presentan en función de la composición de los LIs y se comparan con los obtenidos con los líquidos de imidazolio usados previamente como lubricantes.Asociación de Jóvenes Investigadores de Cartagena, (AJICT). Universidad Politécnica de Cartagena. Escuela Técnica Superior de Ingeniería Industrial UPCT, (ETSII). Escuela Técnica Superior de Ingeniería Agronónica, (ETSIA), Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT). Escuela de Ingeniería de Caminos, Canales, y Puertos y de Ingeniería de Minas, (EICM). Fundación Séneca, Agencia Regional de Ciencia y Tecnología. Parque Tecnológico de Fuente Álamo. Grupo Aquilin

Nuevo nanocomposite de líquido iónico prótico en matriz epoxi

[ESP] En el presente estudio, se ha preparado un nuevo nanocomposite de matriz epoxi modificada mediante la adición de un líquido iónico prótico. Se han determinado sus propiedades térmicas, dinámicomecánicas y su dureza. También, se ha evaluado su comportamiento frente a fricción y desgaste mediante ensayos tribológicos en configuración de punzón sobre disco, obteniéndose mejoras sustanciales con respecto a la resina epoxi sin modificar. Además, se ha realizado un estudio superficial para determinar la distribución del líquido iónico en el interior de la matriz epoxi. [ENG] In the present study, we have prepared a new nanocomposite of epoxy resin modified by addition of a protic ionic liquid. Its thermal and dynamic-mechanical properties have been determined, and also its hardness. Friction and wear resistance have been evaluated by pin-on-disc tribological test, and if we compare its tribological performance with that of neat epoxy resin, better results have been found. Moreover, we have done a superficial study to determinate the ionic liquid distribution in the epoxy matrix.Escuela Técnica Superior de Ingeniería de Telecomunicación (ETSIT), Escuela Técnica Superior de Ingeniería Agronómica (ETSIA), Escuela Técnica Superior de Ingeniería Industrial (ETSII), Escuela Técnica Superior de Arquitectura y Edificación (ETSAE), Escuela Técnica Superior de Ingeniería de Caminos, Canales y Puertos y de Ingeniería de Minas (ETSICCPIM), Facultad de Ciencias de la Empresa (FCCE), Parque Tecnológico de Fuente Álamo (PTFA), Vicerrectorado de Estudiantes y Extensión de la UPCT, Vicerrectorado de Investigación e Innovación de la UPCT, y Vicerrectorado de Internacionalización y Cooperación al Desarrollo de la UPCT

Antiwear performance of ionic liquid+graphene dispersions with anomalous viscosity-temperature behavior

New dispersions of few-layers graphene (G) in 1-ethyl-3-methylimidazolium ([EMIM]) ionic liquids (ILs) with dicyanamide ([DCA]) or bis(trifluoromethylsulfonyl)imide ([TFSI]) anions have been obtained by mechanical mixing and sonication. IL+0.5 wt% G dispersions show constant viscosity values from 357K (for IL = [EMIM][DCA]) or from 385K (for IL = [EMIM][TFSI]) to 393K. IL + G dispersions with G > 0.5 wt% show linear viscosity increases with increasing temperature, from 306K (for [EMIM][DCA]+1 wt%G) and from 330K to 393K (for [EMIM][TFSI]+0.75 wt%G and [EMIM][TFSI]+1 wt%G). Addition of graphene improves the poor wear reducing performance of [EMIM][DCA], and prevents surface damage on steel when added to [EMIM][TFSI]. Graphene increases the load-carrying ability of ILs, forms a surface layer on the sliding path and retains wear debris, preventing the formation of large abrasive particles.Ministerio de Economía, Industria y Competitividad (MINECO, Spain), EU FEDER Program (Grant # MAT2017-85130-P) Este trabajo es resultado de la actividad desarrollada en el marco del Programa de Ayudas a Grupos de Excelencia de la Región de Murcia, de la Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia (Grant # 19877/GERM/15) M.D. Avilés ha recibido una beca del MINECO (BES-2015-074836)

Ionanocarbon lubricants. The combination of ionic liquids and carbon nanophases in tribology

The present overview will focus on the tribological applications of what we have called ionanocarbon lubricants, that is, the combination of carbon nanophases (graphene, carbon nanotubes, nanodiamonds, carbon nanodots) and room-temperature ionic liquids in new dispersions, blends, or modified nanostructures and their use in tribology, lubrication, and surface engineering as friction-reducing, antiwear, and surface-protecting agents in thin films and composite materials. Further research lines and factors that limit the practical applications of the outstanding research results are also highlighted. The very recent results in these lines of research make this a necessary brief review.The authors wish to thank the financial support of the Ministerio de Economía y Competitividad (MINECO, Spain) (MAT2014-55384-P). “Este trabajo es resultado de la actividad desarrollada en el marco del Programa de Ayudas a Grupos de Excelencia de la Región de Murcia, de la Fundación Séneca, Agencia de Ciencia y Tecnología de la Región de Murcia (19877/GERM/15)”. María-Dolores Avilés is grateful to MINECO for aresearch grant (BES-2015-074836)