Shui Hu

Fabrication of highly oriented hexagonal boron nitride nanosheet/elastomer nanocomposites with high thermal conductivity.

A homogeneous dispersion of hexagonal boron nitride nanosheets (BNNSs) in elastomers is obtained by solution compounding methods, and a high orientation of BNNSs is achieved by strong shearing. The composites show high thermal conductivities, especially when BNNS loading exceeds 17.5 vol%, indicating that the material is promising for thermal-management applications which need high thermal conductivity, low dielectric constant, and adequate softness.

Pyridinium [2,6-bis-(5-phenyl-1H-pyrazol-3-yl-κN)pyridine-κN]tetra-nitrato-κO,O';κO-samarium(III) pyridine monosolvate.

In the title compound, (C5H6N)[Sm(NO3)4(C23H17N5)]·C5H5N, the SmIII atom is ten-coordinated by the N,N′,N′′-tridentate bis(pyrazole) ligand and seven O atoms from four nitrate anions (three bidentate and one monodentate). The dihedral angles between the central pyridine ring and adjacent pyrazole rings in the ligand are 1.3 (2) and 3.2 (2)°; the dihedral angles between the pyrazole rings and their pendant phenyl rings are 42.0 (3) and 16.1 (2)°. The conformation of the anionic complex ion is supported by an intramolecular N—H⋯O hydrogen bond. In the crystal, inversion dimers linked by pairs of N—H⋯O hydrogen bonds occur. The pyridinium cation forms an N—H⋯N hydrogen bond.

Preparation of Gd2O3 nano-flakes and fabrication/evaluation of their X-ray shielding rubber nanocomposites with improved mechanical properties

The aim of this study was to explore the development of lead-free X-ray shielding rubber nanocomposites with improved mechanical properties. In specific, gadolinium oxide (Gd2O3) nano-flakes (with thickness of ∼20 nm and sizes being tens of nanometers) were first prepared via the co-precipitation spray drying method; subsequently, the prepared Gd2O3 nano-flakes were uniformly dispersed into nitrile butadiene rubber (NBR) followed by vulcanization for the fabrication of flexible and lightweight X-ray shielding nanocomposites. Compared with the Gd2O3/NBR conventional composites made from a Gd2O3 powder with particle sizes in the range of 5–20 µm, the fabricated Gd2O3/NBR nanocomposites exhibited significantly higher tensile strength, Shore A hardness, and X-ray shielding properties while the rubbery characteristic (i.e. elasticity) was retained.

Diaqua-(2,2'-bipyridine-6,6'-dicarboxyl-ato)nickel(II).

In the title compound, [Ni(C12H6N2O4)(H2O)2], the NiII atom (site symmetry 2) displays a distorted cis-NiN2O4 octahedral coordination geometry with two N atoms and two O atoms of the tetradentate 2,2′-bipyridine-6,6′-dicarboxylate ligand in the equatorial plane and two water molecules in axial positions. The complete dianionic ligand is generated by crystallographic twofold symmetry. In the crystal, a two-dimensional supramolecular structure parallel to (001) is formed through O—H⋯O hydrogen-bond interactions between the coordinated water molecules and the O atoms of nearby carboxylate groups.