Supramolecular network formation through inclusion complexation of an α‐cyclodextrin‐based molecular tube

The supramolecular network formation through inclusion complexation between α‐cyclodextrin‐based molecular tube (MT) and poly(ethylene oxide) monocetylether‐graft‐dextran (5C₁₆PEO‐g‐Dex40) was demonstrated. From isothermal titration calorimetric (ITC) measurement, it was confirmed that MT formed an inclusion complex with two C₁₆PEO side chains in 5C₁₆PEO‐g‐Dex40. From viscosity measurements, the specific viscosity of the solution containing MT and 5C₁₆PEO‐g‐Dex40 was much larger than that containing 5C₁₆PEO‐g‐Dex40. It is considered that MT participates in the supramolecular network formation of 5C₁₆PEO‐g‐Dex40 through inclusion complexation with two C₁₆PEOs grafted to independent Dex40s.     

Synthesis and surface characterization of novel perfluorooctyl-functionalized polymers with well-defined architectures

We have successfully synthesized two kinds of novel well-defined chain-end-functionalized polystyrenes with one, two, three, and four perfluorooctyl (C₈F₁₇) groups and structurally analogous block copolymers, poly[styrene-b-4-(3-perfluoroocyl)propoxystyrene], by means of living anionic polymerization, followed by the Williamson reaction with C₈F₁₇(CH₂)₃Br. The surface properties and compositions of the films prepared from both C₈F₁₇-functionalized polymers have been characterized by contact angles using water and dodecane droplets and angle-dependent XPS measurement. It was observed that C₈F₁₇ groups were segregated and preferentially enriched at their topmost surfaces and the extent of the enrichment increased with the number of C₈F₁₇ group. The dependence of extent of C₈F₁₇ group enrichment on fluorine content however appears to be different between chain-end-functionalized polymer and block copolymer.     

The Reductive Leaching of Chalcopyrite by Chromium(II) Chloride for the Rapid and Complete Extraction of Copper

A hydrometallurgical process is developed to lower the costs of copper production and thereby sustain the use of copper throughout the global transition to renewable energy technologies. The unique feature of the hydrometallurgical process is the reductive treatment of chalcopyrite, which is in contrast to the oxidative treatment more commonly pursued in the literature. Chalcopyrite reduction by chromium(II) ion is described for the first time and superior kinetics are shown. At high concentrate loadings of 39, 78, and 117 g L⁻¹, chalcopyrite reacted completely within minutes at room temperature and pressure. The XRD, SEM-EDS, and XPS measurements indicate that chalcopyrite reacts to form copper(I) chloride (CuCl). After the reductive treatment, the mineral products are leached by iron(III) sulfate to demonstrate the complete extraction of copper. The chromium(II) ion may be regenerated by an electrolysis unit inspired by an iron chromium flow battery in a practical industrial process.