Orange-emitting photoluminescent silicon nanocrystals have been grafted with pairs of compounds to produce mixed monolayers on their surfaces. Vinyl acetic acid (VA) is used to enhance dispersibility in water by providing carboxyl termination, while alkyl groups are used to improve photoluminescence (PL) stability. The grafting of these molecules to the surface is enabled by an etching procedure that leaves a hydrogen-terminated surface on the silicon nanocrystals. Multiple molecules can be grafted in series by taking advantage of the residual hydrogen present after initial grafting with a first compound. Multiple molecules can also be grafted in parallel by allowing them to compete for surface reactive sites and varying their concentrations in solution to control the composition of the mixed surface layer. Both series and parallel grafting result in particles that have a mixture of two distinct molecules on their surface, and thereby allow control of the particle dispersibility in different solvents and the density of reactive groups for subsequent functionalization steps. Optimizing the surface composition may allow production of particles that can be reacted with proteins via carbodiimide linking chemistries while maintaining their PL and their dispersibility in water and buffer solutions. Here we focus on the parallel grafting approach.