Aqueous silsesquioxane dispersions having low concentrations of reaction byproducts

Methods of making a composition are disclosed, which comprises: i) forming a dispersion of particles comprising: a) silica, b) a non-volatile cation, and c) water, wherein the non-volatile cation is not ammonium; ii) adding at least one organosilyl coupling agent of formula R 1 —(R 2 —O) 3 —Si where R 1 is selected from the group consisting of a substituted alkyl and unsubstituted alkyl, and R 2 is selected from the group consisting of methyl, ethyl, propyl and butyl, wherein the substituted alkyl of R 1 is not aminoalkyl; iii) reacting the organosilyl coupling agent with the dispersion of particles to form a mixture comprising a silsesquioxane and an alcohol; and iv) removing the alcohol from the mixture by vacuum distillation, wherein final concentration of the alcohol is about 1% by weight or less of the total mixture. Further disclosed are compositions comprising an aqueous dispersion comprising silsesquioxane, a non-volatile cation and an alcohol, and methods of using the composition.