Cellulose microfibrils obtained by acid hydrolysis of cellulose paper were used as filler in polystyrene composite films. The nonionic surfactant sorbitan monostearate was used to improve the dispersion properties of the hydrophilic filler in the (hydrophobic) matrix and also to prevent formation of aggregates. Turbidity tests were used to measure dispersion stability of the cellulose particles in hydrophobic solvent. A correlation was established between the dispersion stability in solvent, measured by turbidity, and the formation of aggregates in the polymeric composites. The effect of nonionic surfactant on thermal properties of the composite films was examined by thermal analysis. The formulation of the mixture was optimized and mechanical properties as a function temperature were investigated via the storage modulus of the cast films at different temperatures. Finally, cellulose-filled polymer matrices were electrospun and the produced webs were characterized using scanning electron microscopy (SEM) as well as transmission electron microscopy (TEM).