Self-assembled nanoparticle (NP) clusters exhibit unique electromagnetic responses and have attracted considerable interest due to their potential for controlling colors, refractive indices, and electromagnetic enhancement via the strong interaction between light and matter. Surface-enhanced Raman scattering (SERS) from molecules adsorbed on the nanoparticle clusters is one of the notable properties of NP clusters. In this report, gold NP clusters based on polymer core−shell particles incorporating magnetic iron oxide NPs were prepared via a self-assembly method.The enhancement factor of the SERS signal was determined by the size of composited gold nanoparticles.These composite particles are expected to be applicable to the is situ SERS analysis of chemical species in chemical reaction media and biological samples.
Pitcher plants have liquid-infused structured surfaces to slip and digest insects, which have oily surfaces on their body, inside of their pods. By mimicking the slipping mechanism of pitcher plant pods, the omniphobic slippery surface has been created by infusing liquid lubricants into porous materials.
We have reported honeycomb-patterned porous films can be prepared by casting polymer solution under humid conditions. By using condensed water droplets onto the surface of cast solutions of polymers as templates, uniformly sized pores were formed on the polymer films after evaporation of solvent and template water droplets. By peeling the top layer of honeycomb films with adhesive tape, the pincushion-like surface structure can be created. This pincushion surface has high water repellency due to their high surface porosity and hydrophobic nature. By infusing lubricants into the pincushion film, omniphobic slippery surfaces can be prepared. When fluorinated lubricants infuse into fluorinated pincushion film, they slip both oil and water droplets with inclined the film only a few angle. Furthermore, the motion of sliding liquids can be controlled by stretching of the film or surface patterning.
In the presentation, we will show the biomimetic liquid repellent surfaces based on self-organized honeycomb films. Moreover, other applications of honeycomb films for stretchable electrodes for epidermal sensing and on-demand separation systems.
We have demonstrated the simple preparation of structurally colored composite films by stacking alternating Os and PB
layers. Os has a much higher refractive index than PB, which causes the strong reflection at the interface between these
two materials. Strong reflection colors were observed because of the interference between the multi-layers. Active
control of the reflection peaks was achieved by swelling the PB layers. From these results, we conclude that black thin
layers enhance the reflection of structural colors.