Study on Fabrication of Porous Nanosheets by Roll Nanoimprinting Method

In this research, the fabrication of polymer ultra-thin films (nanosheets) using a micro gravure printing method was studied. The effects of the conveying speed of the plastic film substrate, the concentration of solution and rotating speed of the micro gravure roll on the film thickness of the nanosheets were investigated through experimental approach. The polyethylene terephthalate film was placed as a substrate by a roller. After applying the tension load directly to the film, polyvinyl alcohol was coated on the PET film in order to release the nanosheets from the PET film by the sacrificial layer method. After that, polylactic acid (PLLA) was coated. Thickness of nanosheets was measured by using a stylus type surface profile. In addition, in the micro / nano field, nanoimprint technology is capable of pressing a mold having an irregular pattern of several tens nanometer level onto a resin. In order to further enhance the functionality of the nanosheets, the press method and the roll nanoimprinting method can be used to produce a fine structure, and press the nanosheets without heating. As a result, since the shape of the mold could be transferred, it is possible to fabricate the nanosheets with the microstructures by the roll nanoimprinting method. In the case of fabricating porous nanosheets by the roll nanoimprinting method, the microstructures were smaller than a hot press method. And the pressed microstructures on the nanosheets without heating were smaller than the microstructures with heating.