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Therkildsen Richmond opublikował 1 rok, 8 miesięcy temu
98 mW cm-2, external quantum efficiency of 2.30%, electroluminescence peak at 400 nm and full width at half maximum of 47 nm, which is superior to the performance of the corresponding reference materials. The mechanism of charge transfer from the PEDOT polycation to WOx, enhancing conductivity, is responsible for the robust hole injection/transport and is further elucidated by ultraviolet photoelectron spectroscopy and impedance spectroscopy, contributing to the optimization of the carrier balance and recombination zone. Our results illustrate an alternative approach for boosting UV OLED performance and advancing organic electronics.Commercial nickel nanoparticles (Ni NPs) were directly converted to efficient electrocatalysts for CO2 reduction by urea-Ni solid powder pyrolysis, in which a Ni, N-co-doped graphite carbon shell wraps the Ni NPs in situ. 98.3% CO selectivity was realized with a current density of -20.2 mA cm-2 and an overpotential of 0.69 V.Droplets moving on solid surfaces are at the heart of many phenomena of fundamental and applied interest in chemistry, physics and materials science. On the fundamental side, as they are often subject to evaporation, these droplets are a beautiful and complex example of non-equilibrium physical chemistry, whose explanation and understanding still capture the imagination of multiple researchers around the world. In technology, droplets on solid surfaces are of widespread use for handling small amounts of matter, for harvesting energy, for manufacturing materials and for sensing chemical and biological analytes. A key underlying factor of their widespread applicability is the degree of control that can be achieved over their transport on surfaces. This tutorial review provides an overview of recent progress towards the programmable transport of droplets on solid surfaces. We will first present the physical principles behind the main experimental strategies for droplet transport. We will then review the most inspiring applications where these strategies have been employed in chemistry, materials science and engineering. Finally, we will outline possible future research directions for the programmable transport of droplets. Beyond projecting the reader at the forefront of this exciting field of physical chemistry, we believe that this tutorial review will inspire diverse, multidisciplinary scientific communities to devise novel ways of manipulating the flow of matter, energy and information on solid surfaces using programmable droplets as vessels.In two decades of development, impressive strides have been made for automating basic laboratory operations in droplet-based microfluidics, allowing the emergence of a new form of high-throughput screening and experimentation in nanoliter to femtoliter volumes. Despite advancements in droplet storage, manipulation, and analysis, the field has not yet been widely adapted for many high-throughput screening (HTS) applications. Broad adoption and commercial development of these techniques require robust implementation of strategies for the stable storage, chemical containment, generation of libraries, sample tracking, and chemical analysis of these small samples. We discuss these challenges for implementing droplet HTS and highlight key strategies that have begun to address these concerns. Recent advances in the field leave us optimistic about the future prospects of this rapidly developing technology.With the rapid growth and appearance of novel psychoactive substances (NPS) onto the global drug market, the need for alternative screening methodologies for implementation within clinical environments is substantial. The immunoassay methods currently in use are inadequate for this new drug trend with the potential for misdiagnosis and subsequent administration of incorrect patient treatment increased. This contribution illustrates a strong proof-of-concept for the use of electrochemiluminescence (ECL) as a screening methodology for NPS within biological fluids, using the hallucinogen scopolamine as a model compound. A low cost, easy-to-use and portable sensor has been developed and successfully employed for the detection of scopolamine at clinically relevant concentrations within a variety of biological matrices, including human pooled serum, urine, artificial saliva and sweat, without any prior sample preparation required. Moreover, assessment of the sensor’s potential as a point-of-care wearable device was performed with sample collection from the surface of skin, demonstrating its capability for the qualitative identification of scopolamine despite collection of only minimal volumes off the skins surface. The developed sensor described herein exhibits a strong proof-of-concept for the employment of such ECL sensors as point-of-care devices, where the sensors ease of use and removal of time-consuming and complex sample preparation methods will ultimately increase its usability by physicians, widening the avenues where ECL sensors could be employed.A new Cu(ii) pyrazoledicarboxylate coordination polymer [Cu(Hpdc)(ImH)]n (1) (H3pdc = 3,4-pyrazoledicarboxylic acid; ImH = imidazole) has been hydrothermally synthesized and characterized by elemental analysis, FT-IR, X-ray diffraction, and thermogravimetric analysis. In 1, the tetradentate Hpdc2- anion coordinated to three Cu(ii) ions in a μ3-κO κN, O’ κN’ mode, forming a two-dimensional (2D) (4,4) network; the other ImH ligand acted as a terminal ligand. Cu(ii)-MOF 1 displayed high activity and selectivity in the base-free aerobic oxidation of benzyl alcohol to benzaldehyde combined with the green oxidant H2O2. The catalytic system of 1 could be reused for several cycles without any obvious decay of the catalytic efficiency.Covalent adaptable hydrogels (CAHs) reversibly adapt their structure in response to external stimuli, emerging as a new platform for biological applications. Due to the unique and complex nature of these materials, a characterization technique is needed to measure the rheology of these CAHs in biological processes. μ2rheology, microrheology in a microfluidic device, is a technique that can fully characterize real-time CAH degradation in a changing environment, such as the pH environment of the GI tract. This characterization will enable design and tailoring of these materials for controlled and targeted oral drug delivery. Using μ2rheology, we can exchange the fluid environment without sample loss and measure the change in CAH rheological properties. We show degradation kinetics and material property evolution are independent of degradation history. However, the initial cross-link density at each pH exchange can be decreased by degradation history which decreases the time for the CAH to degrade to the gel-sol transition. These results indicate that CAH degradation can be tuned by changing the initial material properties by varying polymer concentration and ratio of functional groups. We also show that μ2rheology will enable the design of new dynamic materials for targeted drug delivery by enabling these materials to be characterized and tailored in vitro.An expedient cyclopropanation of α-methylene-β-lactams with α-ketoesters mediated by P(NMe2)3 has been developed. This reaction enables rapid access to a series of functionalized spirocyclopropyl β-lactams in good yields from bench-stable starting materials under mild conditions. The experimental results indicated that the C3-substituent of the α-methylene-β-lactam not only significantly impacted the reaction efficiency and stereochemistry but also played a pivotal role in determining the chemoselectivity of the reaction.A new experimental method for the determination of equilibrium isotopic properties of substances based on inelastic neutron scattering (INS) is proposed. We present a mathematical formalism, which allows the calculation of the beta-factor of single-element solids based on INS-derived Phonon Density of States (PDOS). PDOS data for nanodiamonds of widely different sizes and of macroscopic diamond were determined from inelastic neutron scattering experiments. This allowed the determination of heat capacities and, for the first time, β-factors of the diamond nanoparticles. We demonstrate a considerable size-dependent increase of the heat capacities and decrease of the beta-factors for nanodiamonds relative to bulk diamond. Contributions of surface impurities/phases and phonon confinement to the size effects are evaluated. Applications in the formation of diamond nanoparticles in nature are briefly discussed.Classical molecular dynamics simulations have been combined with quantum calculations of CD spectra in order to fruitfully relate the experimental CD spectra, not only to the overall conformation of chiral α-peptoids, but also to their structure at the atomic scale, including the dihedral feature of the backbone (ψ,φ) and the orientation of the chiral side-chain (χ1). These simulations have been performed up to the hexamer Ac-(stbe)6-CO2tBu. We have shown that the number of states has a significant impact on the shape of the spectrum below 215 nm. The number of states computed is also critical to simulate the spectra of long oligomers. While 10 to 20 states are sufficient to simulate the CD spectra of short oligomers, 100 states or more are mandatory to converge the CD spectral shape for longer oligomers. The conformational sampling and the analysis of the intramolecular interactions responsible for the specific folding of the objects have been jointly explored by means of Replica Exchange MD and DFT calculations.The potential energy surfaces (PESs) of the ethanol clusters become increasingly complex as the cluster size increases. This is mainly due to the fact that there are up to three stable structures on the PES of the ethanol monomer yielding a huge number of possible structures of the ethanol clusters. In this work, we have thoroughly explored the PESs of neutral ethanol clusters from dimer to pentamer. For each cluster size, we have identified all possible combinations of the three monomers to build a structure of that cluster size. For each combination, we have used ABCluster to generate initial guessed geometries. These geometries have been fully optimized at the MP2/aug-cc-pVDZ level of theory. The results show that the PESs of the neutral ethanol clusters are symmetric due to enantiomerism of the clusters. For each cluster size, several isomers have been located as global minima energy structures. Globally, we have found that cyclic structures are the most stable, followed by branched cyclic and linear structures. The branched linear structures are found to be among the least stable structures on the PESs of the neutral ethanol clusters. The infrared spectra of the most stable structures are calculated and compared to experiment. The calculated infrared spectra are found to be in qualitative agreement with experiment. In addition, we have calculated the binding energies of the investigated ethanol clusters using MP2, some density functional theory (DFT) functionals (MN15, ωB97XD and PW6B95D3) and DLPNO-CCSD(T)/CBS levels of theory. As a result, we have found that the PW6B95D3 functional has the smallest mean absolute deviation (MAD) as compared to ωB97XD and MN15, when benchmarked to the DLPNO-CCSD(T)/CBS. Thus, we recommend the PW6B95D3 functional for affordable, yet accurate, exploration of neutral ethanol clusters.


