NH₂-Terminated Poly(ethylene oxide) Containing Nanosized NiO Particles:  Synthesis, Characterization, and Structural Considerations

Abstract

Highly concentrated nanosized NiO particles have been prepared by means of vacuum evaporation of Ni on NH2-terminated poly(ethylene oxide) matrix film and subsequent purification by removal of a part of the matrix which was soluble in ethanol. TEM observation revealed that the purified composites contain uniformly dispersed NiO particles with an average diameter of less than 5 nm and fairly narrow size distribution. From the analyses including high-resolution TEM, electron diffraction pattern, and X-ray diffraction (XRD), the resultant particles were found to be fcc NiO, and significant lattice expansion was observed. The chemical bonding of amine end groups of the matrix molecules to NiO particle surfaces was suggested by XPS measurements. XRD and differential scanning calorimetry measurements indicate that the matrix structure in the composite is amorphous. This amorphous nature of the matrix could be caused by the restriction of molecular chain mobility through the chemical interaction between NiO particles and matrix molecules, leading to the insoluble nature of the composite in ethanol. On the other hand, the composite is soluble in propionic acid with no evidence for significant aggregation of NiO particles. The maximum content of NiO reaches ca. 50 wt % after purification, which is due to the localization of NiO particles into some parts of the matrix film during formation of NiO particles. The particle growth mechanism is discussed from the effect of initial amount of deposited Ni on the average particle diameter, its standard deviation, and the content of NiO in the composite.

Realizing NiO nanocrystals from a simple chemical method

“…Wang and coworkers prepared NiO nanowires by annealing the freshly prepared precursor (Xu et al 2003). Deki et al (2003) prepared highly concentrated nanosized NiO by means of vacuum evaporation of Ni on NH 2 -terminated PEO film. Zheng and Zhang (2007) reported a molten-salt synthesis method using NaCl as a flux at 1000°C to prepare NiO nanoparticles with uniform morphology of hexagon plates.…”

Practice of diclofenac sodium for the hydrothermal growth of NiO nanostructures and their application for enzyme free glucose biosensor

“…XRD analysis was carried to evaluate the crystalline nature and structural characteristic of synthesised NiO Figure 2a, b shows the obtained difractograms for both NiO nanoflakes and nanoflowers respectively. It can be seen in both patterns the obtained diffraction peaks are indexed to (111), (200), (220), (311) and (222) crystal planes of (FCC) cubic structure (Deki et al 2003;Wang et al 2005). There was a clear difference between the peak intensities of both nanostructures, higher peak intensities obtained for nanoflakes suggested higher crystalline nature of flakes compared to nanoflowers.…”

“…besides its excellent electrochemical properties, is also well known material for its useful and outstanding performance in various other practical applications. The synthesis methods which are most commonly used for the preparation of NiO nanostructured material include sol-gel (Huang et al 2014), surfactant mediated synthesis (Wang et al 2002), thermal decomposition (Xiang et al 2002), and polymer matrix assisted NiO nanostructured material (Deki et al 2003). Although efficient, but some of these strategies suffers drawbacks like non-uniform size distribution, tedious and expensive protocols and most important of all obtaining reproducible nanostructures.…”

Nanostructured Nickel Oxide by Hydrothermal Route for Gas Sensing Applications

“…1 Hydrothermal technology in the twenty-first century [1] and heterogeneous catalytic materials [9]. Several researchers have prepared NiO nanoparticles by various methods like sol-gel [10], surfactant-mediated synthesis [11], thermal decomposition [12], polymer-matrix assisted synthesis [13] and spray-pyrolysis [14]. Some of the above methods suffer from the difficulty in sizehomogeneity and well dispersion of NiO nanoparticles.…”