Thermo-Reversible Gelation of Aqueous Hydrazine for Safe Storage of Hydrazine

A reversible gelation–release system was developed for safe storage of toxic hydrazine solution based on gelation at lower critical solution temperature (LCST). Poly(N-isopropylacrylamide) (PNIPAM) and its copolymer could form gels of 35wt% hydrazine by dissolution under low temperature and storage at ambient temperatures. For example, PNIPAM gelled a 63 fold heavier amount of 35wt% hydrazine. Aqueous hydrazine was released from the gels by compression or heating, and the gelation–release cycles proceeded quantitatively (> 95%). The high gelation ability and recyclability are suitable for rechargeable systems for safe storage of hydrazine fuels.

Room-temperature synthesis of a new stable (N2H4)WO3 compound: a route for hydrazine trapping

A new (N2H4)WO3 compound has been obtained by mixing WO3 and aqueous hydrazine solution at room temperature for 24 h. The reaction is catalyzed by the presence of lithium. X-ray, synchrotron and neutron diffraction techniques have shown that the material crystallizes in trigonal space group P3221 (No. 154). Chains of distorted WO4 tetrahedra extend along the a axis of the unit cell, linked by a corner-sharing oxygen atom: the N2H4 are in the voids between them. The thermal characterization shows that this new compound is stable up to 220°C, greatly beyond the boiling point of N2H4 (114°C); thus making it a promising candidate for catalysis or trapping applications.

Noble-metal-free NiFe nanoparticles immobilized on nano CeZrO2 solid solutions for highly efficient hydrogen production from hydrous hydrazine

Noble-metal-free NiFe nanoparticles were successfully immobilized on nano CeZrO2 solid solutions by a simple impregnation–reduction method, exhibiting a high catalytic activity and 100% H2 selectivity for hydrogen generation from hydrazine solution.

ELECTROCHEMICAL CHARACTERIZATION OF POLYLACTIC ACID-BLOCK-POLY(2-VINYLPYRIDINE)/GOLD NANOPARTICLE COMPOSITES FOR GLUCOSE BIOSENSOR DEVELOPMENT

Nanocomposites that consist of diblock copolymer (BCP) and gold nanoparticles (AuNPs) can be applied as a matrix to immobilize enzymes or other molecules based on the well-defined core/shell nanostructures of these composites. In this research, polylactic acid-block-poly(2-vinylpyridine) (PLA-b-P2VP)/hydrogen tetrachloroaurate(III) hydrate (HAuCl4.3H2O) composites were hybridized and then reduced in dichloromethane (DCM) solution. The hybridizations between gold precursors and the P2VP domain were prepared with different ratios of gold to P2VP block (1:1, 1:5, 1:10, 5:1, 10:1) by taking advantage of the association between the long-pair nitrogen of the pyridine group of P2VP. The reduction of the Au3+/PLA-b-P2VP composite was accomplished by hydrazine solution in order to get gold nanoparticle/PLA-b-P2VP composites, which was visually confirmed by a direct color change from bright yellow to purple. In this work, ultraviolet–visible (UV-vis) spectroscopy and Fourier transform infrared spectroscopy (FTIR) were used to confirm the association between gold precursors and pyridine groups as well as the synthesis of gold nanoparticles.The composite which labeled as R3 (Au3+: P2VP = 10:1) showed the highest peak current based on the cyclic voltammetry (CV) measurment. Furthermore, graphene oxide (GO) was added into R3 to prepare BCP/AuNPs/GO composite and reduced to BCP/AuNPs/rGO through electrochemical reduction. The resulting BCP/AuNPs/rGO showed high potential to be used in amperometric biosensor.