5 research outputs found
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 + NH<sub>4</sub>SCN) 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 + NH<sub>4</sub>SCN, 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> polyÂ(chiral substituted
phenylacetylene) as a polymer initiator
(polyÂ(<b>1</b><sub>n</sub>)), helix-sense-selective polymerization
(<b>HSSP</b>) of an achiral phenylacetylene <b>2</b> having
two hydroxy groups successfully afforded a diblock copolyÂ(phenylacetylene)
(copolyÂ(<b>1</b><sub>n</sub>/<b>2</b><sub>m</sub>)) 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
(CsPbX<sub>3</sub>, 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 CsPbX<sub>3</sub> spherical cavity
at low threshold (∼0.42 μJ cm<sup>–2</sup>) 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