441 research outputs found
Adsorption of choline benzoate ionic liquid on graphene, silicene, germanene and boron-nitride nanosheets: a DFT perspective
The adsorption of choline benzoate ([CH][BE]) ionic liquid (IL) on the surface of different hexagonal nanosheets has been studied using Density Functional Theory (DFT) methods. For this, the interaction mechanism, binding energies and electronic structure of [CH][BE] ionic liquid on four types of nanosheets, i.e., graphene, silicene, germanene and boron-nitride, were estimated and compared. The adsorption of [CH][BE] ionic liquid on different nanosheets is mainly featured by van der Waals forces, leading to strong benzoate ion–surface π-stacking. Likewise, there is also an important charge transfer from the anion to the sheet. The electronic structure analysis shows that Si- and Ge-based sheets lead to the largest changes in the HOMO and LUMO levels of choline benzoate. This paper provides new insights into the capability of DFT methods to provide useful information about the adsorption of ionic liquids on nanosheets and how ionic liquid features could be tuned through the adsorption on the suitable nanosheet.Ministerio de Economı´a y
Competitividad (Spain, project CTQ2013-40476-R) and Junta de
Castilla y León (Spain, project BU324U14)
A density functional theory insight towards the rational design of ionic liquids for SO2 capture
A systematic density functional theory (DFT) analysis has been carried out to obtain information at the molecular level on the key parameters related to efficient SO2 capture by ionic liquids (ILs). A set of 55 ILs, for which high gas solubility is expected, has been selected. SO2 solubility of ILs was firstly predicted based on the COSMO-RS (Conductor-like Screening Model for Real Solvents) method, which provides a good prediction of gas solubility data in ILs without prior experimental knowledge of the compounds' features. Then, interactions between SO2 and ILs were deeply analyzed through DFT simulations. This work provides valuable information about required factors at the molecular level to provide high SO2 solubility in ILs, which is crucial for further implementation of these materials in the future. In our opinion, systematic research on ILs for SO2 capture increases our knowledge about those factors which could be controlled at the molecular level, providing an approach for the rational design of task-specific ILs.Ministerio de Economı´a y Competitividad
(Spain, project CTQ2013-40476-R) and Junta de Castilla y León
(Spain, project BU324U14
Impact of Ionic Liquids on Silver Thermoplastic Composite Membrane Polyurethane for Propane/Propylene Separation
This work describes newly synthesized composite polymeric membranes and their utilization in propane/propylene separation in a gas mixture. The nonporous composite polymers were successfully synthesized by using thermoplastic polyurethane (TPU) and several silver salts/silver salts with ionic liquids (ILs). Our studies showed that silver bis(trifluoromethanesulfonyl)imide (Ag[Tf2N]) containing membranes outperformed other silver salt containing membranes in terms of selectivity. In addition, to this finding, ILs, as additives for the membranes, enhanced the selectivity by facilitating improved coordination of the olefin with the silver ions in the dense composite polymers.Scopu
A detailed study of cholinium chloride and levulinic acid deep eutectic solvent system for CO2 capture via experimental and molecular simulation approaches
Choline chloride + levulinic acid deep eutectic solvent is studied as a suitable material for CO2 capturing
purposes. The most relevant physicochemical properties of this solvent are reported together with the
CO2 solubility as a function of temperature. The corrosivity of this solvent is studied showing better
performance than amine-based solvents. A theoretical study using both density functional theory and
molecular dynamics approaches is carried out to analyze the properties of this fluid from the
nanoscopic viewpoint, and their relationship with the macroscopic behavior of the system and its ability
for CO2 capturing. The behavior of the liquid–gas interface is also studied and its role on the CO2
absorption mechanism is analyzed. The reported combined experimental and theoretical approach leads
to a complete picture of the behavior of this new sorbent with regard to CO2, which together with its
low cost, and the suitable environmental and toxicological properties of this solvent, lead to a promising
candidate for CO2 capturing technological applicationsMinisterio de Economı´a y Competitividad (Spain, project
CTQ2013-40476-R) and Junta de Castilla y Leo´n (Spain, project
BU324U1
Catalytic membrane reactor for Suzuki-Miyaura C-C cross-coupling: Explanation for its high efficiency via modeling
A polymeric catalytic membrane was previously prepared that showed remarkable efficiency for Suzuki-Miyaura C-C cross-coupling in a flow-through configuration. A mathematic model was developed and fitted to the experimental data to understand the significant apparent reaction rate increase exhibited by the catalytic membrane reactor compared to the catalytic system under batch reaction conditions. It appears that the high palladium nanoparticles concentration inside the membrane is mainly responsible for the high apparent reaction rate achieved. In addition the best performance of the catalytic membrane could be achieved only in the forced flow-through configuration, that, conditions permitting to the reactants be brought to the catalytic membrane by convection
Review and Perspectives for Effective Solutions to Grand Challenges of Energy and Fuels Technologies via Novel Deep Eutectic Solvents
Sustainable technologies applied to energy-related applications should develop a pivotal role over the next decades. Therefore, the development of new materials for old processes has merged as a central research line lately. Deep eutectic solvents (DESs) have been recently considered alternative and economic task-specific solvents for many chemical and environmental processes. The low-cost production of DESs production from natural sources and their tunable properties, such as neat null toxicity and biodegradability, make these solvents suitable candidates for various processes within the green chemistry framework. Considering the millions of possible DES combinations yet to be explored, a detailed review of DES research’s current status that can elaborate on the structure–property relationship is an essential task to identify the missing links and strong points on DES research. Thus, this review work focuses on the recent research efforts on the utilization of DES on chemical processes, with the purpose of elucidation on gas capture/separation, fuel desulfurization, biodiesel production, and water treatment processes and provides a deeper understanding on outstanding scientific questions and identifies promising new research directions that involve DESs.Ministerio de Ciencia, Innovación y Universidades (Spain, Project No. RTI2018-101987-B-I00) and Western Michigan University Research Fund (No. 11-1211410-4850)
Attitudes towards Telecommuting: The Turkish Case
Examines the effects of demographic characteristics (gender, marital status), household attributes (small children, largeness of home and distance of home and workplace), support factors (supervisor, colleague and technological-bill support), and perceived advantages and disadvantages of telecommuting to individuals, organizations and society on individuals’ attitudes towards telecommuting. The sample comprised 664 IT professionals working in several internet (portal) companies in Turkey. Results suggest that women, married employees, employees who have children less than five years old, employees whose house is big enough, employees whose house is relatively farther to the workplace, and those who perceived more advantages accruing from telecommuting, to themselves, to their organization or to the society, have a more favorable attitude towards telecommuting. On the other hand, employees who perceived more disadvantages accruing from telecommuting to themselves or their organization have a less favorable attitude towards telecommuting. In addition, colleague support and technological-bill support positively influence the attitudes of employees towards telecommuting
Nanoscopic characterization of type II porous liquid and its use for CO2 absorption from molecular simulation
The properties of cage(33:133) macrocycle in perchloropropene (PCP) as model for type II porous liquids were studied using molecular simulation tools. Likewise, the behaviour of CO2 in these porous liquid phases were studied to analyse the nanoscopic mechanism for carbon capture purposes. Quantum chemistry calculations using Density Functional Theory were carried out to characterize the intermolecular forces between cage, solvent and CO2 molecules. Molecular dynamics simulations of liquid phases at different cage concentration provides information on the structuring, aggregation, solvation and dynamic properties of these porous liquids. The reported results led to a full characterization of the features controlling type II porous liquids properties as well as the behaviour of carbon dioxide in them, thus providing the required information for the proper design of porous liquids and their use for carbon capturing operations. The nanoscopic structure of the studied fluids showed that it is possible to solubilize suitable amounts of the cages in the solvents to develop a network of pores in the liquid to capture CO2 in an efficient way.Ministerio de Ciencia, Innovación y Universidades (Spain, project RTI2018-101987-B-I00) and by Junta de Castilla y León (Spain, project BU094G18). We acknowledge SCAYLE (Supercomputación Castilla y León, Spain) for providing supercomputing facilities
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