Introducing open films of nanosized cellulose-atomic force microscopy and quantification of morphology

A method for prepg. open, sub-monolayer cellulose films on a silicon substrate is introduced, and the open films were quantified using the three-dimensional information from at. force microscopy (AFM) height images. The prepn. method is based on spin coating low concns. of trimethylsilyl cellulose (TMSC) on silicon and hydrolyzing the TMSC to cellulose using a vapor phase acid hydrolysis. AFM showed that the surfaces consist of nanosized cellulose patches which are roughly 50-100 nm long, 20 nm wide, and 1 nm high. The vol. of the cellulose patches was quantified. Examn. of the cross section of the cellulose patches revealed that the exaggeration of the lateral dimensions by the AFM tip is small enough to account for a mere +-2% error in the vol. quantification. Pilot expts. showed that the vol. of the cellulose was largely restored in a wetting/drying cycle but the morphol. changed considerably. Because of their small size, the cellulose patches provide a novel approach for interpretation on the mol. architecture of cellulose. [on SciFinder (R)]