Nanosheet Synthesis of Metal Organic Frameworks in a Sandwich-like Reaction Field for Enhanced Gate-Opening Pressures

Elastic layer-structured metal-organic frameworks (ELMs) are a family of flexible nanoporous metal organic frameworks (MOFs) showing gate-opening gas adsorption. The gate-opening pressure shifts to a higher value by crystal downsizing. However, the MOF nanoparticles and nanorods showing the gate-opening gas adsorption grow more than 50 nm even for their shortest sides. Here, we describe the synthesis and unique gas adsorption behavior of the first example of nanosheets of ELMs (ELM-NSs). The thickness and horizontal width of the ELM-NSs obtained from a new synthetic method using the inside the bilayers in hyperswollen lyotropic lamellar (HL) phases as sandwich-like reaction fields (SRFs) are a few nanometers and several hundreds of nanometers, respectively. The previously reported rationalization of the temperature dependence of the gate-opening pressures for ELMs enables us to discuss the size effects in terms of the adsorption-induced structural transitions and the Helmholtz free energy change of the host.Takeru Omiya, Koki Sasaki, Yoshiaki Uchida et al. Nanosheet Synthesis of Metal Organic Frameworks in a Sandwich-like Reaction Field for Enhanced Gate-Opening Pressures. ACS Applied Nano Materials, 1 (8), 3779-3784, August 18, © 2018 American Chemical Society. https://doi.org/10.1021/acsanm.8b0115

Nanosheet Formation in Hyperswollen Lyotropic Lamellar Phases

Nanosheets (∼1 nm) are formed using a nonionic hyperswollen lyotropic lamellar phase as a template. The accumulation and reaction of ingredients in the highly separated (several hundred nm) bilayers in the hyperswollen lyotropic lamellar phase should result in very thin nanosheets. This method could be applied to the synthesis of a wide variety of two-dimensional organic and inorganic materials.Yoshiaki Uchida, Takuma Nishizawa, Takeru Omiya et al. Nanosheet Formation in Hyperswollen Lyotropic Lamellar Phases. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 138 (4), 1103-1105, February 16, ©2016 American Chemical Society. https://doi.org/10.1021/jacs.5b1125

Tribological Behavior of Doped DLC Coatings in the Presence of Ionic Liquid Additive under Different Lubrication Regimes

Diamond-like carbon (DLC) coatings are widely used in industries that require high durability and wear resistance, and low friction. The unique characteristics of DLC coatings allow for the possibility of creating adsorption sites for lubricant additives through the doping process. In this study, the combined use of europium-doped diamond-like carbon (Eu-DLC), gadolinium-doped diamond-like carbon (Gd-DLC), and pure DLC coatings and an ionic liquid (IL) additive, namely, trihexyltetradecylphosphonium bis (2-ethylhexyl) phosphate [P66614] [DEHP], with a 1 wt.% concentration in polyalphaolefin (PAO) 8 as a base lubricant was investigated. Higher hardness, higher thin-film adhesion, a higher ratio of hardness to elastic modulus, and a higher plastic deformation resistance factor were achieved with the Gd-DLC coating. The CoF of the Gd-DLC coating paired with the IL was superior compared to the other pairs in all lubrication regimes, and the pure DLC coating had a better performance than the Eu-DLC coating. The wear could not be quantified due to the low wear on the surface of the DLC coatings. The friction reduction demonstrates that tribological systems combining Gd-DLC thin films with an IL can be a potential candidate for future research and development efforts to reduce friction and increase the efficiency of moving parts in internal combustion engines, for instance.info:eu-repo/semantics/publishedVersio

Nanosheet Formation in Hyperswollen Lyotropic Lamellar Phases

Documentos apresentados no âmbito do reconhecimento de graus e diplomas estrangeirosNanosheets (∼1 nm) were formed using a nonionic hyperswollen lyotropic lamellar phase as a template. The accumulation and reaction of ingredients in the highly separated (several hundred nm) bilayers in the hyperswollen lyotropic lamellar phase resulted in very thin nanosheets. This method was applied to the synthesis of a wide variety of two-dimensional organic and inorganic materials

Impact of Temperature Variation on Friction Behaviour of Rare Earth-Doped Diamond-like Carbon Coatings with Ionic Liquid Lubricants

This research paper investigates the tribological performance of diamond-like carbon (DLC) coatings doped with rare earth metals (europium and gadolinium) as well as pure DLC lubricated with ionic liquid additives (trihexyltetradecylphosphonium bis(2-ethylhexyl) phosphate {[P66614][DEHP]} and 1-ethyl-3-methylimidazolium diethyl phosphate {[EMIM][DEP]}) in Polyalphaolefin 8 (PAO8). The study aims to examine the effect of temperature on the interaction between the coatings and additives by conducting tribological experiments using a block-on-disk setup at temperatures of 60 C, 80 C, and 100 C. The primary objective is to evaluate the performance of doped DLC coatings compared to pure DLC coatings with ionic liquid additives in the lubricant in boundary lubrication conditions at various high working temperature environments. The experiments reveal that doped DLC coatings with ionic liquid additives exhibit superior tribological performance compared to pure DLC coatings. The rare earth metal dopants play a positive role in the formation of a tribofilm on the surface of the coatings as it interacts with ionic liquids, resulting in a lower coefficient of friction (CoF). Temperature influences the performance of the coatings and additives. The CoF increases with temperature for pure DLC coatings, while for doped DLC coatings it was significantly less. These findings highlight the influence of temperature on the tribological behavior of DLC coatings. Overall, this study contributes valuable insights into the impact of rare earth metal dopants and ionic liquid additives on the tribological performance of DLC coatings under different temperature conditions. The results demonstrate the potential of utilizing doped DLC coatings with ionic liquid additives as an effective approach to enhance the performance of mechanical systems