Fabrication of free-standing ultrathin film organized with polymer nanosheets

Recently, a free-standing ultrathin film has been expected as the next-generation sensing membranes for photo-, electro-, and thermal microdevices. We fabricated a free-standing ultrathin hybrid polymer films with photoreactive polymer nanosheets and gold nanoparticles. At the film preparation, UV irradiation was introduced to promote photo-crosslinking reaction between pDDA-M layers. Gold nanoparticles were immobilized on pDDA-DADOO layer through electrostatic interaction. The film was peeled off from a supported substrate by dipping into a chloroform solution. The prepared film thickness was estimated to be approximately 30 nm, corresponding to the diameter of gold nanoparticles by AFM observation. Besides, this film surface showed marvelously smooth surface. Furthermore, we succeeded in a deposition of LB layers onto the free-standing ultrathin films, which transferred onto a TEM grid.