Complex High-Aspect-Ratio Metal Nanostructures by Secondary Sputtering Combined with Block Copolymer Self-Assembly

2016 ◽  
Vol 28 (38) ◽  
pp. 8439-8445 ◽  
Author(s):  
Hwan-Jin Jeon ◽  
Ju Young Kim ◽  
Woo-Bin Jung ◽  
Hyeon-Su Jeong ◽  
Yun Ho Kim ◽  
...  
2019 ◽  
Author(s):  
Michael J. Strauss ◽  
Darya Asheghali ◽  
Austin Evans ◽  
Rebecca Li ◽  
Anton Chavez ◽  
...  

<p>Nanotubes assembled from macrocyclic precursors offer a unique combination of low dimensionality, structural rigidity, and distinct interior and exterior microenvironments. Usually the weak stacking energies of macrocycles limit the length or strength of the resultant nanotubes. Imine-linked macrocycles were recently found to assemble into high-aspect ratio (>10<sup>3</sup>), lyotropic nanotubes in the presence of excess acid. Yet these harsh conditions are incompatible with many functional groups and processing methods, and lower acid loadings instead catalyze macrocycle degradation. Here we report pyridine-2,6-diimine-linked macrocycles that assemble into high-aspect ratio nanotubes in the presence of less than 1 equiv of CF<sub>3</sub>CO<sub>2</sub>H per macrocycle. Analysis by gel permeation chromatography and fluorescence spectroscopy revealed a cooperative self-assembly mechanism. Nanofibers obtained by touch-spinning the pyridinium-based nanotubes exhibit Young’s moduli of 1.48 GPa, which exceeds that of many synthetic polymers and biological filaments. These findings will enable the design of structurally diverse nanotubes from synthetically accessible macrocycles. </p>


2019 ◽  
Vol 112 ◽  
pp. 704-713 ◽  
Author(s):  
Ú.M. Montoya Rojo ◽  
C.C. Riccardi ◽  
M.D. Ninago ◽  
A.E. Ciolino ◽  
M.A. Villar ◽  
...  

RSC Advances ◽  
2019 ◽  
Vol 9 (29) ◽  
pp. 16431-16438
Author(s):  
Kota Ito ◽  
Yuri Yamada ◽  
Atsushi Miura ◽  
Hideo Iizuka

High-aspect-ratio mushroom-like silica nanopillars fabricated from self-assembly of block-copolymers exhibit a uniaxial epsilon-near-zero response in the mid-infrared range.


2020 ◽  
Vol 117 (5) ◽  
pp. 2288-2293 ◽  
Author(s):  
Kyle Aleshire ◽  
Ilia M. Pavlovetc ◽  
Robyn Collette ◽  
Xiang-Tian Kong ◽  
Philip D. Rack ◽  
...  

Limited approaches exist for imaging and recording spectra of individual nanostructures in the midinfrared region. Here we use infrared photothermal heterodyne imaging (IR-PHI) to interrogate single, high aspect ratio Au nanowires (NWs). Spectra recorded between 2,800 and 4,000 cm−1 for 2.5–3.9-μm-long NWs reveal a series of resonances due to the Fabry–Pérot modes of the NWs. Crucially, IR-PHI images show structure that reflects the spatial distribution of the NW absorption, and allow the resonances to be assigned to the m = 3 and m = 4 Fabry–Pérot modes. This far-field optical measurement has been used to image the mode structure of plasmon resonances in metal nanostructures, and is made possible by the superresolution capabilities of IR-PHI. The linewidths in the NW spectra range from 35 to 75 meV and, in several cases, are significantly below the limiting values predicted by the bulk Au Drude damping parameter. These linewidths imply long dephasing times, and are attributed to reduction in both radiation damping and resistive heating effects in the NWs. Compared to previous imaging studies of NW Fabry–Pérot modes using electron microscopy or near-field optical scanning techniques, IR-PHI experiments are performed under ambient conditions, enabling detailed studies of how the environment affects mid-IR plasmons.


2019 ◽  
Author(s):  
Michael J. Strauss ◽  
Darya Asheghali ◽  
Austin Evans ◽  
Rebecca Li ◽  
Anton Chavez ◽  
...  

<p>Nanotubes assembled from macrocyclic precursors offer a unique combination of low dimensionality, structural rigidity, and distinct interior and exterior microenvironments. Usually the weak stacking energies of macrocycles limit the length or strength of the resultant nanotubes. Imine-linked macrocycles were recently found to assemble into high-aspect ratio (>10<sup>3</sup>), lyotropic nanotubes in the presence of excess acid. Yet these harsh conditions are incompatible with many functional groups and processing methods, and lower acid loadings instead catalyze macrocycle degradation. Here we report pyridine-2,6-diimine-linked macrocycles that assemble into high-aspect ratio nanotubes in the presence of less than 1 equiv of CF<sub>3</sub>CO<sub>2</sub>H per macrocycle. Analysis by gel permeation chromatography and fluorescence spectroscopy revealed a cooperative self-assembly mechanism. Nanofibers obtained by touch-spinning the pyridinium-based nanotubes exhibit Young’s moduli of 1.48 GPa, which exceeds that of many synthetic polymers and biological filaments. These findings will enable the design of structurally diverse nanotubes from synthetically accessible macrocycles. </p>


2014 ◽  
Vol 5 (5) ◽  
pp. 929-934 ◽  
Author(s):  
Andrew J. Hilmer ◽  
Darin O. Bellisario ◽  
Steven Shimizu ◽  
Thomas P. McNicholas ◽  
Qing Hua Wang ◽  
...  

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