Nano-emulsions and nano-latexes comprising functionalized cellulose nanocrystals (CNCs) as a surfactant that impacts the stability and size of the emulsion droplets of oil-in water emulsions. Stable emulsions can be accessed by adding a desired organic, non-water soluble molecule as the oil phase to an aqueous CNC suspension followed by agitation. Depending on the functionalization of the CNCs, their hydrophilic/hydrophobic balance can be modified, which allows the ability to control the stability and droplet size of the emulsion. Methods for producing nano-emulsions and nano-latexes, when the oil phase contains a polymerizable monomer, are disclosed.