Development of universal vapor-diffused molecular assembly techniques

We show a new fabrication technique of a molecular order thin film utilizing a simple molecular diffusion method. Hydrophilic polymers of different molecular weights are used for the examination. The mechanism and the standard procedure of the technique are analyzed by a quartz crystal microbalance and an atomic force microscope. The results show the molecularly flat nanostructure of the final film can be fabricated by the technique. In our experimental condition, lower molecular weighted hydrophilic polymers (Mw<10,000) such as PEG, PVA and PAA are spontaneously self-assembled on mica and gold surfaces. We believe the technique can be useful in many other surface-related studies and applications.