Optical Properties of Nanocellulose Dispersions in Water, Dimethylformamide and Poly(Methyl Methacrylate)

The effects of cellulose nanocrystal filler concentration on the optical properties of transmittance, haze, and clarity were studied for solutions and composites. Cellulose nanocrystal (CNC) solutions were studied in both water and dimethylformamide (DMF). Cellulose composites employing poly(methyl methacrylate) (PMMA) as the matrix were tested with and without surfactants to aid dispersion. Increasing concentrations of cellulose in solution and in solid films caused light transmittance to decrease and light scattering, as measured by clarity and haze, to increase. The same optical trends were observed in solution samples as the path length (sample thickness) increased. The CNCs in DMF exhibited similar transmittance as those in water, but noticeably reduced light scattering. The original document contains color images. Prepared in collaboration with the USDA Forest Service.