Tailor-made ionic liquids based on imidazolium salts have recently attracted a large amount of attention because of their extraordinary properties and versatile functionality. An intriguing ability to interact with and stabilize membranes has already been reported for 1,3-dialkylimidazolium compounds. We now reveal further insights into the field by investigating 1,3-dimethyl-4,5-dialkylimidazolium (C-IMe·HI, n = 7, 11, 15) and 1,3-dibenzyl-4,5-dialkylimidazolium (C-IBn·HBr, n = 7, 11, 15) salts. Diverse alkyl chain lengths and headgroups differing in their steric demand were employed for the membrane interface interaction with bilayer membranes imitating the cellular plasma membrane. Membrane hydration properties and domain fluidization were analyzed by fluorescent bilayer probes in direct comparison to established model membranes in a buffered aqueous environment, which resembles the salt content and pH of the cytosol of living cells. Membrane binding and insertion was analyzed via a quartz crystal microbalance and confocal laser scanning microscopy. We show that short-chain 4,5-dialkylimidazolium salts with a bulky headgroup were able to disintegrate membranes. Long-chain imidazolium salts form bilayer membrane vesicles spontaneously and autonomously without the addition of other lipids. These 4,5-dialkylimidazolium salts are highly eligible for further biochemical engineering and drug delivery.
H diffusion constants, D H , have been obtained from steady-state fluxes through Pd membranes with the downstream side maintained at p H 2 ≈ 0. Good linearity of plots of H flux versus (1/d), where d is the thickness, attests to H permeation being bulk diffusion controlled in this temperature (423-523 K) and p H 2 range (≤0.2 MPa). D H values have been determined at constant p up and also at constant H content. H fluxes through Pd membranes with three different surface treatments have been investigated (polished (unoxidized), oxidized and palladized) in order to determine the effects of these pre-treatments. The palladized and oxidized membranes give similar D H values but the polished membranes give values about 12% lower.
Photocatalytic reduction of carbon dioxide can activate chemically inert carbon dioxide by the use of renewable energy. In the present work, the main products of photocatalytic reduction of CO 2 in aqueous TiO 2 suspensions were found to be methane, methanol, formaldehyde, carbon monoxide, and H 2 . Anatase TiO 2 catalysts with various morphologies, such as nanoparticle, nanotube, and nanosheet, were synthesized through a hydrothermal method. The TiO 2 nanosheets were more active than the nanotubes or nanoparticles in the reduction of CO 2 in aqueous solution. This is because the photogenerated carriers prefer to flow to the specific facets. The TiO 2 sheet with high-energy exposed {001} facets facilitates the oxidative dissolution of H 2 O with photogenerated holes, leaving more photogenerated electrons available for the reduction of CO 2 on {101} facets. Moreover, surface fluorination promotes the formation of Ti 3+ species, which is helpful in the reduction of CO 2 to CO 2 − and in extending the lifetime of photogenerated electron−hole pairs. The optimum ratio of exposed {001} to {101} facets for surface-fluorinated TiO 2 nanosheets was found to be ∼72:28, which corresponds to an initial F/Ti ratio of 1. From our analysis of the effect of adding of known intermediates on the photocatalytic reduction of CO 2 , we propose that the photocatalytic reduction of CO 2 with H 2 O on surface-fluorinated TiO 2 nanosheets proceeds via a mechanism involving generation of hydrogen radicals and carbon radicals.
MXene, an emerging family of 2D transition metal carbides/nitride (MXene) materials, has attracted growing attention since its initial discovery in 2011. Owing to their extraordinary electrical conductivity, high mechanical stability, various functional groups, and large interlayer space, MXene and MXene‐based nanomaterials have shown significant energy‐storage capability. Firstly, research progress on the preparation strategies and properties of MXene are summarized. Secondly, the current state‐of‐the‐art advances of MXene and MXene‐based nanomaterials as advanced electrodes for energy storage devices, including lithium‐ion batteries, sodium‐ion batteries, potassium‐ion batteries, and supercapacitors are reviewed. Finally, the key challenges and perspectives for further enhancing their electrochemical performances are also outlined. This Progress Report offers a reference and scientific inspiration for the design and preparation of high‐performance MXene and MXene‐based nanomaterials to meet the increasing need for next‐generation energy‐storage systems.
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