Architectural design of cellulose monolayer at au interface

Flat cellulose film surfaces were architecturally designed by spin-coating or self-assembling in the cellulose/N-methylmorpholine-N-oxide/H₂O system. Spin-coated cellulose films were allowed to stably separate out onto the silicon oxide wafer pretreated with cationic polymer. Atomic force microscopic (AFM) images of the cellulose surface pretreated with cationic polyvinylamine showed an anisotropic morphology, suggesting the specific interaction at a cellulose/polymer interface. Changing poor solvents provided the variation of the surface roughness, being possibly dependent on the behavior of cellulose precipitation. Cellulose self-assembled monolayer (SAM) was successfully formed on an Au plate with cellulose derivative whose reducing ends were selectively modified with thiosemicarbazide (TSC) in NMMO solution. The cellulose SAM at Au interface possessed a parallel-packed crystalline structure analogous to native cellulose, and a flat surface at sub nano-meter level from the results obtained by electron diffractometry and AFM observation, respectively. It was strongly suggested that the cellulose-TSC molecular chains were regularly arranged on the Au surface through a covalent S-Au bonding. These techniques would provide novel cellulose architectures designed for cellulose-based material science.