Network structure of collagen layers absorbed on LB film

After the adsorption of 30 s in the diluted collagen acidic solution, the hole-like structures with the diameter of several hundred nm could be observed, as shown in figure, occasionally. The height of the patterns in the holes, indicated by the arrows, is approximately 0.4 nm and the height of the network structure varies from 1.4 to 2.9 nm, while the rims of the hole-like structures are ranged from 3.0 to 6.5 nm higher compared to the network structure.