Template etching time

A further means of gaining control over the diameter and diameter-dependent optical properties of Cu nanowires was proposed by Duan and coworkers [356], who identified a relationship between nanowire diameter and template etching time. By following this approach, they obtained Cu nanowires with a peculiar X-ray diffraction (XRD) pattern, which was suggestive of a preferential growth direction. They also observed a significant red-shift of the surface plasmon resonance peak as the wire diameter was increased. 

Elastomer templates for nanoimprinting of the type devised by Kostovski et al. for their optical fiber nanoimprint lithography could be used to rapidly reproduce the butterfly wing nanostructures or those produced by reactive ion etching. This would further reduce production time and costs. Whatever means are employed to improve the production techniques for these butterfly and cicada wing substrates, it is clear that there is great potential for their application in biosensing. 

PPy hollow nanoparticles have been commonly obtained using various template approaches [84,219-224]. A gold nanoparticle was utilized as a template for synthesis of a PPy hollow nanocapsule [219,220]. The nucleation and growth of PPy aroimd the gold nanoparticle, followed by dilute ferri-cyanide etching, led to the formation of a PPy hollow nanocapsule. The inner diameter (5-200 nm) of the PPy nanocapsule was governed by the size of the gold nanoparticle, and the shell thickness (5-100 nm) was determined by the polymerization time. 

In developing these template synthetic methods, we made an interesting discovery. When these polymers are synthesized (either chemically or electrochemically) within the pores of the track-etched polycarbonate membranes, the polymer preferentially nucleates and grows on the pore walls [11,14,46]. As a result, polymeric tubules are obtained at short polymerization times (Fig. 16.2A). These tubular structures have been quite useful in our fundamental investigations of electronic conductivity in the template-synthesized materials (see below). In addition, tubular structures of this type have a number... 

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