Seed‐Mediated Growth Approach for Shape‐Controlled Synthesis of Spheroidal and Rod‐like Gold Nanoparticles Using a Surfactant Template

the cross-sectional SEM image, the contact angle is estimated to be about 85 . When we insert into Equation 1 the surface tension (~30 dyne/cm) and density (0.95 g/cm) of SBS and L of 300 nm, a maximum height of 1.87 m is obtained, which indicates that the height of the patterned polymer can be made quite large. In fact, we were able to fabricate polymer structures with a step height as high as 5 lm for an 80 lm line-and-space pattern. If we take into account the interaction at the polymer/substrate interface and the solid-like properties of the polymer melt, the theoretical maximum height would be reduced. For a more accurate model, further study would be required. The time it takes for the polymer melt to fill up the void space between the mold and the polymer film can be estimated. If we neglect the effect of gravity, then the surface tension and viscosity of the polymer melt and the size of the capillary determine the rate of flow such that the time is given by t ˆ 2 z 2