Chromium-Based Complexes Bearing Aminophosphine and Phosphine-Imine-Pyrryl Ligands for Selective Ethylene Tri/Tetramerization.

A series of Cr-based complexes bearing aminophosphine (P,N) ligands PhP-L-NH [L = CHCH (), L = CHCHCH (), and L = CHCH ()] and phosphine-imine-pyrryl (P,N,N) ligands 2-(PhP-L-N=CH)CHNH [L = CHCHCH () and L = CHCH ()] were prepared, and their catalytic properties were examined for ethylene tri/tetramerization. X-ray crystallographic analysis of complex indicated the κ-P,N bidentate coordination mode at the Cr(III) center and the distorted octahedral geometry of monomeric P,N-CrCl. Upon activation by methylaluminoxane (MAO), complexes bearing P,N (PCN backbone) ligands showed good catalytic reactivity for ethylene tri/tetramerization.

Chromium-Based Complexes Bearing N-Substituted Diphosphinoamine Ligands for Ethylene Oligomerization.

A range of novel N-substituted diphosphinoamine (PNP) ligands PhPN(R)PPh [R = FCHCH (); R = MeCHCH (); R = MeCHCHCH ()] have been synthesized via one-step salt elimination reaction. The ligand-coordinated chromium carbonyls [PhPN(R)PPh]Cr(CO) () were further synthesized, and X-ray crystallography analysis of complex revealed the κ-P,P bidentate binding mode of Cr center and the molecular structure of PNP ligand . Then the catalytic ethylene oligomerization behaviors of PNP ligands bridging chromium chloride complexes {[PhPN(R)PPh]CrCl(μ-Cl)} () were further discussed in depth.

Reversible self-assembly of terpyridine-functionalized graphene oxide for energy conversion.

Terpyridine-functionalized graphene oxides were prepared for self-assembly into 3D architectures with various metal ions (e.g., Fe, Ru).

Carbon nanotube-coated macroporous poly(N-isopropylacrylamide) hydrogel and its electrosensitivity.

A facile method of fabricating novel CNT-coated macroporous PNIPAAm hydrogel composite was proposed. The method was based on the deposition of a dense and compact CNT layer on the pore walls of the preformed macroporous PNIPAAm hydrogel scaffold. The resulted hydrogel composite exhibited an electric current sensitivity resulting from electro-thermal conversion.

Membranes of vertically aligned superlong carbon nanotubes.

In the present work, we have developed a simple but effective method to prepare superlong vertically aligned carbon nanotubes (SLVA-CNT) and epoxy composite membranes, and we have demonstrated that various liquids, including water, hexane, and dodecane, can effectively pass through the SLVA-CNT membranes. These results were confirmed by molecular dynamics simulations. While the mechanical densification was used to further enhance the flow transport through the SLVA-CNT membranes, we developed in this study a magnetic-nanoparticle switching system to turn on and off the flow through the nanotube membrane by simply applying an alternating voltage.

[Characterization of insoluble polyamide-6,T by MALDI-TOF MS].

Five different sample solvents (trifluoroacetic acid, tetrahydrofuran, formic acid, acetonitrile, 60% acetonitrile /5% trifluoroacetic acid) and two kinds of sample preparation methods were chosen for characterizing the structure, mole mass and mass distribution of insoluble polymer of polyamide-6, T (PA6T) by matrix assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). It was shown that the spectra with wide mole mass and high signal-to-noise (S/N) ratio were obtained, when using 60% acetonitrile /5% trifluoroacetic acid as solvent, and solvent sample preparation with one step droplet method was better than non-solvent sample preparation. The main chain structure of PA6T polymerized in ionic liquid was analyzed, which was linear without the presence of cyclic polymer.

Superhydrophobic electrospun POSS-PMMA copolymer fibres with highly ordered nanofibrillar and surface structures.

A POSS-PMMA copolymer has been synthesised by conventional free-radical polymerisation reaction. Uniform electrospun fibres from this copolymer showed a water contact angle as high as 165 degrees with a sliding angle as low as 6 degrees . For the first time, we found that the electrospun fibres had a bundled nanofibril secondary structure with an ordered POSS morphology on the fibre surface.