Metal oxide nanoparticles, dispersions, composite materials, and methods for producing them

Abstract

This invention provides metal oxide nanoparticles in which the balance between the function as a metal oxide and the affinity for other components, including organic components, has been improved. [Solution] The metal oxide nanoparticles are particles composed of surface-modified metal oxides, the weight-average particle size measured using a dynamic light scattering photometer is in the range of 1 to 100 nm, the proportion of the mass of the metal oxide to the total mass of the metal oxide nanoparticles is 70% or more, and when 1 g of the metal oxide nanoparticles and 10 g of one of the solvents, hexane, toluene, acetone, or ethanol, are added to a 20 mL lidded container, and the mixture is shaken at 100 rpm for 1 hour using a reciprocating shaker to obtain a dispersion, and the average transmittance of the dispersion with an optical path length of 10 mm is measured using a spectrophotometer, the dispersion gives an average transmittance of 80% or more in the wavelength range of 400 to 800 nm.