Figure 3: Remarkable surface topography and stiffness change induced by Neu5Ac adsorption.

Surface topography (a,b) and Young’s modulus images (c,d) of PAM-g-lactose0.11 film before (a,c) and after (b,d) being treated by a Neu5Ac solution with a concentration of 0.02 mol · L−1 and a pH value of about 3.0. (e,f) Young’s modulus images or PAM-g-lactose0.11 film after being treated by the galactose solution (e) and glucose (f) solution, respectively. Inserts of (a,b) are surface water drop profiles, inserts of (c,d,e,f) are corresponding Young’s moduli histograms. Each CA measurement or AFM image was conducted at least 3 times in different position of a film to ensure the reliability of data.