Patterned nanostructures

The self-assembly of block polymers, in the bulk, thin film and solution states, produces uniformly sized nanostructured patterns that are very useful for nanofabrication. Optimal utilization of these nanoscopic patterns requires complete spatial and orientational control of the microdomains. However, the microdomains in the bulk state normally have grain sizes in the submicron range and have random orientations. In block copolymer thin films, the natural domain orientations are generally not desirable for nanofabrication. In particular, for composition-asymmetric cylindrical thin films, experimental... 

Within the last decade, comparatively inexpensive and scaleable tchniques known as soft lithography have been the focus of much development. Patterning of a substrate is afforded by using a master elastomeric stamp that contains a nanostructured pattern, known as a relief on its surface. Contrary to photolithography, the resolution of the final pattern is not limited by light diffraction, but only depends on the... 

The electrodeposition technology has proven to be the least expensive, effective, and readily adoptable method to deposit Ag substrates for reliable SERS substrates with good reproducibility. It allows the preparation of nanostructure patterns by controlling the amount of composition, deposition time, temperature, and applied potential. The SERS substrates prepared by electrodeposition were a good candidate for the fabrication of a reproducible substrate. In principle, most of the metals including Au [55], Cu [56], and Ag [57-59] can be electrodeposited from aqueous solutions. 

Hasegawa M, Ikawa T, Tsuchimori M, Watanabe O, Kawata Y. 2001. Topographical nanostructure patterning on the surface of a thin film of polyurethane containing azobenzene moiety using the optical near field around polystyrene spheres. Macro molecules 34(21) 7471 7476. 

Trujillo, N.J., Baxamusa, S.H., and Gleason, K.K. (2009) Grafted functional polymer nanostructures patterned bottom-up by colloidal lithography and initiated chemical vapor deposition (iCVD). Chem. Mater, 21 (4), 742-750. 

Fig. 3 TEM-BF images showing the oriented nanostructured patterns of P3HT formed on substrates of KBrBz (a, b) and KAP (c, d) after removal of the substrate. Note the unidirectional pattern obtained in the case of KAP versus the cross-hatched pattern on KBrBz due to a twofold in-plane orientation of P3HT domains, as indicated by the blue and orange arrows. (Adapted from [42] 2010, American Chemical Society)...

Nanostructured, patterned surfaces are of special importance for applications that require the presence of specific domains (bioassays [98], cell culture [101], surfaces of controlled wettability [113,114], etc.). Coatings with metals and metal oxides can effectively tailor the surface energy and protect the underlying surface during the manufacturing process [75]. 

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