Borregaardcorcoran0476
Low resistance of Li-intercalated negative electrodes is important for the safe and fast charging required for large-scale batteries. Here, we demonstrated that nanosized two-dimensional crystalline aromatic dicarboxylate negative electrode materials synthesized via spray drying exhibit low internal resistances at approximately 0.7 V vs Li/Li+, while retaining flat potential profiles. The spray-dried sample with a hollow structure is crushed into nanoflakes during ink preparation for electrode coating and forms a uniform and highly dispersed electrode structure. The charge-discharge evaluation indicates that the nanoflake sample showed smaller charge-discharge polarization than the bulk sample with stable cycling characteristics, resulting in significant high-rate property enhancement. Charge-transfer resistance of the nanoflake sample exhibits the lowest value (ca. 2.2 Ω cm2) among those reported for existing intercalation electrodes (5.2 to 235 Ω cm2). In comparison of the negative electrodes, the estimated maximum current density without Li deposition (ca. 316 mA cm-2) is more than 1 order of magnitude higher than that for currently used graphite (ca. ON-01910 11 mA cm-2) and is also higher than those for high-rate oxides (137-298 mA cm-2). The resistance-crystal correlation using multiple regression analysis predictions and its verification reveal that this low resistance is owing to an improved Li acceptability associated with selective structural defects induced by the loss of incorporated crystallized water during drying. The crystal plane exposed by the selective structural defects is perpendicular to electronic and ionic conduction directions inside the solid, resulting in improved kinetics. Therefore, the proposed negative electrode allows safe and fast charging, with easy scale-up and sustainable resources.Nanomedicine developed to date by means of directly encapsulating cytotoxins suffers from crucial drawbacks, including premature release and detoxification prior to arrival at pharmaceutics targets. To these respects, redox-responsive polymeric prodrugs of platinum (Pt) and camptothecin (CPT), selectively and concomitantly activated in the cytoplasm, were elaborated in manufacture of dual prodrug nanomedicine. Herein, multiple CPTs were conjugated to poly(lysine) (PLys) segments of block copolymeric poly(ethylene glycol) (PEG)-PLys through the redox responsive disulfide linkage [PEG-PLys(ss-CPT)] followed by reversible conversion of amino groups from PLys into carboxyl groups based on their reaction with cis-aconitic anhydride [PEG-PLys(ss-CPT&CAA)]. On the other hand, Pt(IV) in conjugation with dendritic polyamindoamine [(G3-PAMAM-Pt(IV)] was synthesized for electrostatic complexation with PEG-PLys(ss-CPT&CAA) into dual prodrug nanomedicine. Subsequent investigations proved that the elaborated nanomedicine cli before approaching pharmaceutic action targets, thus shedding important implication in development of advanced nanomedicine to seek maximized pharmaceutic outcomes.The increasing demand for energy storage materials has gained considerable attention of scientific community toward the development of hydrogen storage materials. Hydrogen has become more important, as it not only works efficiently in different processes but is also used as an alternative energy resource whenever it is combined with a cell technology like fuel cell. Herein, efforts are being made to develop efficient hydrogen storage materials based on alkaline earth metal (beryllium, magnesium, and calcium)-encapsulated B12N12 nanocages. Quantum chemical calculations were performed using density functional theory (DFT) and time-dependent DFT at B3LYP/6-31G(d,p) and CAM-B3LYP/6-311+G(d,p) levels of theory for all the studied systems. The adsorption energies of Be-B 12 N 12 , Mg-B 12 N 12 , and Ca-B 12 N 12 systems suggested that Mg and Ca are not fitted accurately in the cavity of nanocages because of their large size. However, H2 adsorbed efficiently on the metal-encapsulated systems with high adsorption energy values. Furthermore, dipole moment and QNBO (Charges-Natural Bond Orbital) calculations suggested that a greater charge separation is seen in H2-adsorbed metal-encapsulated systems. The molecular electrostatic potential analysis also unveiled the different charge sites in the studied systems and also demonstrated the charge separation upon hydrogen adsorption on metal-encapsulated systems. Partial density of states analysis was performed in the support of frontier molecular orbital distribution that indicates the narrow highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap in hydrogen-adsorbed metal-encapsulated systems. Results of all analyses and global descriptions of reactivity suggested that the designed H2-adsorbed metal-encapsulated B12N12 systems are efficient systems for designing future hydrogen storage materials. Thus, these novel kinds of systems for efficient hydrogen storage purposes have been recommended.The synthesis of the enantiomerically pure, D3-symmetric covalent hydrocarbon cages (+)-(M,M)-4 and (-)-(P,P)-4 bearing two C3-symmetrically functionalized tribenzobenzotriquinacene (TBTQ) vertices is reported. The enantiomerically pure TBTQ building blocks (+)-(M)-5 and (-)-(P)-5 were prepared via the diastereomeric TBTQ triamides obtained by use of both Boc-d- and Boc-l-phenylglycine as chiral auxiliaries.Diethyl carbonate (DEC) oxidation with different levels of O3 addition was performed in an atmospheric laminar flow reactor from 400 to 850 K. Experimental results showed that, without O3 addition, the oxidation of DEC began from 650 K with no low-temperature reactivity, while with O3 addition the low-temperature chemistry of DEC was observed from 450 K. A DEC/O3 kinetic model was developed, and the model predictions agreed with the experimental data reasonably well with a slight overprediction of DEC oxidation between 550 and 750 K. The low-temperature chemistry of DEC with O3 addition was described in the reaction pathway of DEC. It was found that O3 assisted the low-temperature oxidation of DEC mainly through the production of the active O atom instead of the direct reaction with the fuel molecule. The present work indicated that the Li-ion battery degradation at 400-500 K might result from the low-temperature chemistry of DEC with active oxygen supplies from the cathode metal oxide materials or from singlet O2 during the battery discharge process.