Effect of nanocellulose length on emulsion stabilization and microparticle synthesis

Surface engineering is crucial for designing nano/microparticles with chemical and physical properties for various applications, such as pharmaceuticals, cosmetics, and therapeutics. Nanocelluloses satisfy the demand for particle surfaces owing to their biocompatibilities and chemical stabilities under physiological conditions. Nanocellulose-coated polymer microparticles are prepared by templating the structure of nanocellulose-stabilized monomer-in-water emulsions. Although emulsion stabilization is essential for controlling the sizes and shapes of microparticles, optimum emulsion preparation conditions have not been determined. This study investigated the emulsion stabilization conditions suitable for microparticle syntheses by changing the lengths of nanocelluloses. Three nanocelluloses of different lengths were used to control the viscosities of aqueous continuous phases. The optimal nanocellulose concentration for stabilizing the emulsion was found to vary with nanocellulose length, with longer nanocelluloses efficiently stabilizing the emulsion at lower concentrations due to the higher viscosity. Nanocellulose-coated microparticles were successfully prepared from the stable emulsions. Emulsions stabilized by shorter nanocelluloses were found to be more suitable for the preparation of fine microparticles because the nanocelluloses effectively covered the surfaces of oil droplets in the emulsions, precluding coalescence. These results will aid in the understanding of emulsion stabilization mechanisms and the development of emulsion-templated nanocellulose-based materials.

Automated summary

Surface engineering is essential for designing nano/microparticles with desired properties for various applications. Nanocelluloses are suitable for particle surfaces due to their biocompatibilities and chemical stabilities. This study investigated the emulsion stabilization conditions suitable for microparticle syntheses by changing the lengths of nanocelluloses. The results will contribute to the understanding of emulsion stabilization mechanisms and the development of nanocellulose-based materials.