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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.

Small copper(I) oxide, Cu 2 O, particles dispersed in diamine-terminated poly(ethylene oxide) (PEO-NH 2 ) matrices have been successfully prepared by vacuum evaporation of copper on to molten PEO-NH 2 , followed by heat treatment. The obtained composites were characterized by TEM, electron diffraction, viscometry, TG-DTA and FT-IR spectroscopy. The mean size of the Cu 2 O nanoparticles could be controlled from 2.5 to 3.5 nm in diameter by changing the amount of initial Cu deposition. The composites obtained here have a wax-like texture and are soluble in many organic solvents with no evidence for aggregation. The formation mechanism of Cu 2 O nanoparticles and the interaction between the nanoparticles and the matrix is also discussed.

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