Liquid–Liquid Equilibria of Benzene + <i>n</i>‑Heptane + <i>N</i>,<i>N</i>‑Dimethylformamide and Benzene + <i>n</i>‑Heptane + <i>N</i>,<i>N</i>‑Dimethylformamide + Ammonium Thiocyanate

The liquid–liquid equilibrium data for the systems including benzene + <i>n</i>-heptane + <i>N</i>,<i>N</i>-dimethylformamide (DMF) and benzene + <i>n</i>-heptane + DMF + ammonium thiocyanate were measured experimentally at 298.15 K or 303.15 K and atmospheric pressure. The selectivity coefficients of the complex solvent (DMF + NH₄SCN) are generally higher than those of DMF, derived from the tie-line data. For the high selectivity that is from 15.03 to 69.90 at 298.15 K or from 15.04 to 61.02 at 303.15 K, the complex solvent, DMF + NH₄SCN, could be used as an extracting agent to separate benzene from <i>n</i>-heptane

Synthesis of One-Handed Helical Block Copoly(substituted acetylene)s Consisting of Dynamic <i>cis-transoidal</i> and Static <i>cis-cisoidal</i> Block: Chiral Teleinduction in Helix-Sense-Selective Polymerization Using a Chiral Living Polymer as an Initiator

By using a living one-handed helical <i>cis-transoidal</i> poly­(chiral substituted phenylacetylene) as a polymer initiator (poly­(<b>1</b>_n)), helix-sense-selective polymerization (<b>HSSP</b>) of an achiral phenylacetylene <b>2</b> having two hydroxy groups successfully afforded a diblock copoly­(phenylacetylene) (copoly­(<b>1</b>_n/<b>2</b>_m)) consisting of a dynamic one-handed helical <i>cis-transoidal</i> block and a static one-handed helical <i>cis-cisoidal</i> block. The formation of the diblock structure was confirmed by consumption of the chiral initiator, appearance of characteristic CD indicating the one-handed helical <i>cis-cisoidal</i> block, and occurrence of the selective photocylic aromatization reaction in the <i>cis-cisoidal</i> block. Therefore, <b>HSSP</b> has been achieved by using the chiral alkenyl groups in the initiator as a chiral source for the first time. In addition, since the <b>HSSP</b> was achieved in spite of the long distance between the chiral initiation site and the propagating site, chiral teleinduction through the rigid and static one-handed helical <i>cis</i>-cisoidal block based on domino effects was confirmed

Hierarchical Self-Assembled Polyimide Microspheres Functionalized with Amidoxime Groups for Uranium-Containing Wastewater Remediation

Through molecule self-assembly and subsequent surface functionalization, novel uranium adsorbent AO–OB hierarchical self-assembled polyimide microspheres (AO-OBHSPIMs) were obtained by introducing the amidoxime groups into hierarchical self-assembled polyimide microspheres for the efficient and selective recovery of uranium from wastewater. The results of Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and nitrogen adsorption–desorption isotherm showed that AO-OBHSPIMs were a semicrystalline polymer material with self-supporting hierarchical structure and low pore volume, and they were equipped with abundant amidoxime groups. Given the recognized selectivity of amidoxime groups and their hierarchical structure, AO-OBHSPIMs exhibited excellent selectivity to uranyl ions. Moreover, AO-OBHSPIMs exhibited good stability and recyclability and remarkable removal percentage within low-concentration solution (99.4%) and simulated uranium-containing wastewater (97.3%). AO-OBHSPIMs could be applied to fixed-bed column adsorption due to their large particle size and self-supporting hierarchical structure that can facilitate water flow. The in-depth discussion of the adsorption mechanism showed that the adsorption mainly depended on the combined action of electrostatic interactions and complexation, and the adsorption process was a spontaneous endothermic monolayer adsorption. In summary, AO-OBHSPIMs exhibited good application prospects in uranium-containing wastewater remediation

Single-Mode Lasers Based on Cesium Lead Halide Perovskite Submicron Spheres

Single-mode laser is realized in a cesium lead halide perovskite submicron sphere at room temperature. All-inorganic cesium lead halide (CsPbX₃, X = Cl, Br, I) microspheres with tunable sizes (0.2–10 μm) are first fabricated by a dual-source chemical vapor deposition method. Due to smooth surface and regular geometry structure of microspheres, whispering gallery resonant modes make a single-mode laser realized in a submicron sphere. Surprisingly, a single-mode laser with a very narrow line width (∼0.09 nm) was achieved successfully in the CsPbX₃ spherical cavity at low threshold (∼0.42 μJ cm^–2) with a high cavity quality factor (∼6100), which are the best specifications of lasing modes in all natural nano/microcavities ever reported. By modulating the halide composition and sizes of the microspheres, the wavelength of a single-mode laser can be continuously tuned from red to violet (425–715 nm). This work illustrates that the well-controlled synthesis of metal cesium lead halide perovskite nano/microspheres may offer an alternative route to produce a widely tunable and greatly miniaturized single-mode laser

Rydberg State Single-Mode Polariton Lasing with Ultralow Threshold via Symmetry Engineering

Symmetry plays an essential role in the fundamental properties of a physical system. In this work, we report on the realization of tunable single-mode polariton lasing from highly excited Rydberg states via symmetry engineering. By breaking the symmetry of the polaritonic wave function through potential wells and controlling the spatial overlap between the gain region and the eigen mode, we are able to generate single-mode polariton lasing, reversibly and dynamically, from quantized polariton states. Increasing the asymmetry of the potential well, single-mode lasing can be achieved even for the highly excited Rydberg state with a principle quantum number of N = 14. Moreover, as a result of the excellent reservoir–eigen mode overlap and efficient spatial confinement, the threshold of lasing can be reduced up to 6 orders of magnitude, compared with those conventional pumping schemes. Our results present a new strategy toward the realization of thresholdless polariton lasing with dynamical tunability