Recently, well-ordered biological materials have been exploited to pattern inorganic nanoparticles into linear arrays that are of particular interest for nanoelectronic applications. In this work, a de novo designed E. coli-expressed polypeptide (previously shown to form highly rectilinear, β-sheet-containing structures) operates as a template for divalent metal cations.
View Article and Find Full Text PDFThe electronic structure and transport properties of silver (Ag) and copper (Cu) nanowires of diameters up to 1.7 nm are investigated using first principles density functional theory and the Landauer formalism in conjunction with a supercell approach. A direct comparison of the ballistic conductances, quantum capacitances, and kinetic inductances indicates that Ag and Cu nanowires show very similar performances.
View Article and Find Full Text PDFCorrelations between the local diameter and local radial elastic modulus in multiwalled carbon nanotubes (MWNTs) were investigated via ultrasonic force microscopy. Spatial cross-correlation analysis showed that local radial modulus variations were inversely correlated with local diameter gradients ("bamboo" structures) in MWNTs grown via chemical vapor deposition (CVD). In contrast, uniform MWNTs grown via arc discharge exhibited no such correlation, indicating that reductions of elastic modulus previously reported for CVD-grown MWNTs originated from increased defect density associated with local increases in diameter.
View Article and Find Full Text PDFA de novo, genetically engineered 687 residue polypeptide expressed in E. coli has been found to form highly rectilinear, beta-sheet containing fibrillar structures. Tapping-mode atomic force microscopy, deep-UV Raman spectroscopy, and transmission electron microscopy definitively established the tendency of the fibrils to predominantly display an apparently planar bilayer or ribbon assemblage.
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