Surface Properties of Cellulose Acetate

Cellulose acetates with different substitution degrees were investigated as to their surface tension properties and morphology. Atomic force microscopy (AFM) studies on membranes, obtained from solution in acetone/water nonsolvent mixtures, evidenced pores and nodules of different size and intensity, depending on the substitution degrees of cellulose acetate and on the water contents in nonsolvent mixtures. Modification of hydrophilicity, put into evidence by the apolar components and by the electron acceptor and electron donor parameters of the polar components, was correlated with the pores volumes — influenced both by their diameter and depths, and by surface roughness as illustrated by AFM images. Surface wettability trends were also studied by means of the free energy of hydration between compounds and water.