This document describes compositions of surface modified nanoparticles that can be used to treat soft and hard substrates. The nanoparticles are modified on their surface with fluoroalkylsilyl groups and made into an aqueous dispersion. The dispersion can be applied to substrates like fabrics, carpets, paper and other articles to impart properties like water and oil repellency. The process involves creating an aqueous dispersion of nanoparticles, adding a fluoroalkylsilane reagent to modify the nanoparticle surface, and applying the dispersion to a substrate and drying.