A series of M x O y /SiO 2 (where M = Ni, Zn and Mn) nanocomposites were synthesized at different M x O y contents (0.2, 1 and 3 mmol per 1 g SiO 2) using a deposition method. The samples were characterized using nitrogen adsorption-desorption, X-ray diffraction, Fourier transform infrared spectroscopy, high resolution transmission electron microscopy and photon correlation spectroscopy. The heat of immersion in water (Q w) and n-decane (Q d) were measured using a microcalorimetry method, and the corresponding values of the hydrophilicity index K h = Q w /Q d were analysed. The formation of M x O y on a silica surface leads to diminishing of the Q w and Q d values (calculated per 1 g of nanocomposites) because of the specific surface area reduction. However, the Q w values calculated per 1 m 2 increase for Zn x O y /SiO 2 and Mn x O y /SiO 2 in comparison with the unmodified silica, and it remains unchanged for Ni x O y /SiO 2. Silica modification with M x O y significantly changes the pH dependence of zeta potential and affects the surface charge density. A shift of the isoelectric point (pH IEP) and a character of the zeta potential ζ (pH) curve are affected by the M x O y phase, and pH IEP shifts toward higher values as follows Mn < Zn < Ni. Keywords. Oxide nanocomposites; Zn x O y /SiO 2 ; Ni x O y /SiO 2 ; Mn x O y /SiO 2 ; physicochemical properties; heats of immersion.