Adsorption of Cu(II), Zn(II), Ni(II), Pb(II), and Cd(II) from aqueous solution on Amberlite IR-120 synthetic resin

The adsorption of copper(II), zinc(II), nickel(II), lead(II), and cadmium(II) on Amberlite IR-120 synthetic sulfonated resin has been studied at different pH and temperatures by batch process. The effects of parameters such as amount of resin, resin contact time, pH, and temperature on the ion exchange separation have been investigated. For the determination of the adsorption behavior of the resin, the adsorption isotherms of metal ions have also been studied. The concentrations of metal ions have been measured by batch techniques and with AAS analysis. Adsorption analysis results obtained at various concentrations showed that the adsorption pattern on the resin followed Freundlich isotherms. Here we report the method that is applied for the sorption/separation of some toxic metals from their solutions.     

Conformational transitions of end-adsorbed triblock copolymers in a nonselective solvent

Conformational dynamics of triblock copolymers end-adsorbed onto a surface from a nonselective solvent have been studied by a Monte Carlo lattice simulation technique. The triblock copolymers are A B A with N_A = 10 and N_B = 5, 10, 20 and 40, at surface interaction parameters ε = −0.5 and −1.0. A is the adsorbing block and B is the nonadsorbing block. The number of chains in the periodic box is varied over the range 100 ≤ n ≤ 500. The triblock copolymer can exist in three states: loop (L), tail (T) and free (F) chain. Fractions of those conformations at different system parameters (n, N_B and ε) and the associated lifetimes are calculated from the simulations. A kinetic scheme is constructed and the corresponding transition rate matrix is used in the master formalism equation, the solution of which yields the dynamic modes of the system. A correlation function is defined to produce a single overall view of the rate of transitions between different conformational states. The degree of surface interaction has strong influence on the rate of transitions between the states, in particular, longer average lifetimes and a wider distribution of lifetimes of the loop conformation contribute to the slower decay of the correlation curves. At high surface adsorption, larger N_B decrease the rate of all transitions at all values of n. A weak dependence on n is observed for all sizes of N_B at both surface energies.     

Production of CoAl and CoAlCr FSMAs and determination of their thermal,microstructure, and magnetic properties

Journal of Thermal Analysis and Calorimetry - In this study, some thermal, mechanical, and magnetic properties of Co86Al14 and Co82Al14Cr4 (at.%) alloys have been investigated. The alloys were...     

Synthesis,spectroscopic properties,crystal structures,antioxidant activities and enzyme inhibition determination of Co(II) and Fe(II) complexes of Schiff base

Research on Chemical Intermediates - Considering the importance of metal complexes in the development of medical science, two different Schiff base Fe(II) and Co(II) metal complex compounds were...     

Microscopic interacting boson model calculations for even-even <Superscript>128–138</Superscript>Ce nuclei

In this study, we determined the most appropriate Hamiltonian that is needed for the present calculations of energy levels and B(E2) values of ^128–138Ce nuclei which have a mass around A≅130 using the interacting boson model (IBM). Using the best-fitted values of parameters in the Hamiltonian of the IBM-2, we have calculated energy levels and B(E2) values for a number of transitions in ^{128,130,132,134,136,138}Ce. The results were compared with the previous experimental and theoretical (PTSM model) data and it was observed that they are in good agreement. Also some predictions of this model have better accuracy than those of PTSM model. It has turned out that the interacting boson approximation (IBA) is fairly reliable for calculating spectra in the entire set of ^{128,130,132,134,136,138}Ce isotopes and the quality of the fits presented in this paper is acceptable.      

Back Cover: Manipulating Intermetallic Charge Transfer for Switchable External Stimulus-Enhanced Water Oxidation Electrocatalysis (Angew. Chem. Int. Ed. 44/2023)

Electrocatalytic processes involving the oxygen evolution reaction (OER) present a kinetic bottleneck due to the existence of linear-scaling relationships, which bind the energies of the different intermediates in the mechanism limiting optimization. Here, we offer a way to break these scaling relationships and enhance the electrocatalytic activity of a Co−Fe Prussian blue modified electrode in OER by applying external stimuli. Improvements of ≈11 % and ≈57 % were achieved under magnetic field (0.2 T) and light irradiation (100 mW cm⁻²), respectively, when working at fixed overpotential, η=0.6 V at pH 7. The observed enhancements strongly tie in with the intermetallic charge transfer (IMCT) intensity between Fe and Co sites. Density Functional Theory simulations suggest that tuning the IMCT can lead to a change of the OER mechanism to an external stimuli-sensitive spin crossover-based pathway, which opens the way for switchable electrocatalytic devices.