Electronegativity and chemical hardness: two helpful concepts for understanding oxide nanochemistry

Abstract Electronegativity, χ , as defined by Mulliken and chemical hardness, η , as proposed by Pearson are used as fundamental tools for the preparation of oxide nanoparticles and for the interpretation of their physical and chemical properties. The evolution of electronegativity and chemical hardness from crystal to nanoparticles is studied. The formation of solid particles from inorganic salt solutions is described on the basis of a χ , η plot. The correlation between the point of zero zeta potential (PZZP) and pH is studied. A model approach concerning the surface modification of oxide nanoparticles by silanization is proposed.