Ambient synthesis of nanomaterials by in situ heterogeneous metal/ligand reactions

Coordination polymers are ideal synthons for high aspect ratio nanomaterials. Using conjugate acid-base pairs, liquid metals are etched and chelated in situ. Solubility-driven polymerization, precipitation, and self-assembly gives tunable structures.

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Cooperative Self-Assembly of Pyridine-2,6-Diimine-Linked Macrocycles into Mechanically Robust Nanotubes

10.26434/chemrxiv.8080043 ◽

2019 ◽

Author(s):

Michael J. Strauss ◽

Darya Asheghali ◽

Austin Evans ◽

Rebecca Li ◽

Anton Chavez ◽

...

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Self Assembly ◽

Gel Permeation Chromatography ◽

Synthetic Polymers ◽

Young’S Moduli ◽

Structural Rigidity ◽

Assembly Mechanism ◽

Low Dimensionality ◽

Harsh Conditions

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 (>103), 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 CF3CO2H 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.

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Photopolymerization-assisted self-assembly as a strategy to obtain a dispersion of very high aspect ratio nanostructures in a polystyrene matrix

European Polymer Journal ◽

10.1016/j.eurpolymj.2018.10.037 ◽

2019 ◽

Vol 112 ◽

pp. 704-713 ◽

Cited By ~ 1

Author(s):

Ú.M. Montoya Rojo ◽

C.C. Riccardi ◽

M.D. Ninago ◽

A.E. Ciolino ◽

M.A. Villar ◽

...

Keyword(s):

Aspect Ratio ◽

High Aspect Ratio ◽

Self Assembly ◽

Polystyrene Matrix ◽

Very High

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Laser in-situ synthesis of high aspect ratio TiB fiber bundle reinforced titanium matrix composite coating

Optics & Laser Technology ◽

10.1016/j.optlastec.2019.02.047 ◽

2019 ◽

Vol 115 ◽

pp. 364-373 ◽

Cited By ~ 2

Author(s):

Yinghua Lin ◽

Changchun Jiang ◽

Zhenheng Lin ◽

Qingtang Chen ◽

Yongping Lei ◽

...

Keyword(s):

Aspect Ratio ◽

Composite Coating ◽

Matrix Composite ◽

High Aspect Ratio ◽

Fiber Bundle ◽

In Situ Synthesis ◽

Titanium Matrix ◽

Titanium Matrix Composite

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High-aspect-ratio mushroom-like silica nanopillars immersed in air: epsilon-near-zero metamaterials mediated by a phonon-polaritonic anisotropy

RSC Advances ◽

10.1039/c9ra02494h ◽

2019 ◽

Vol 9 (29) ◽

pp. 16431-16438

Author(s):

Kota Ito ◽

Yuri Yamada ◽

Atsushi Miura ◽

Hideo Iizuka

Keyword(s):

Block Copolymers ◽

Aspect Ratio ◽

High Aspect Ratio ◽

Self Assembly ◽

Infrared Range ◽

Mid Infrared ◽

Zero Response ◽

Epsilon Near Zero

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.

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Solidification Processing Routes to High Aspect Ratio Reinforcements in γ-TiAl

MRS Proceedings ◽

10.1557/proc-194-89 ◽

1990 ◽

Vol 194 ◽

Cited By ~ 3

Author(s):

J. J. Valencia ◽

J. P. A. Löfvander ◽

J. Rösler ◽

C. G. Levi ◽

R. Mehrabian

Keyword(s):

Solid Solution ◽

Aspect Ratio ◽

Creep Strength ◽

High Aspect Ratio ◽

Anisotropic Growth ◽

Solidification Processing ◽

Aspect Ratios ◽

The Matrix ◽

Solute Strengthening

AbstractAdditions of ∼5%B1 and ∼9%Ta to binary γ-TiAl result in the formation of a monoboride isomorphous with TiB but containing Ta in solid solution. This boride exhibits strongly anisotropic growth from the melt, producing rod-like primary phases which are of potential interest for creep strengthening of the γ matrix. Fibrous borides with aspect ratios larger than ∼20 and volume fractions of ∼0.12 have been produced in arc-melted Ti-48AI-9Ta-4.3B alloys. Creep testing at 1255 K indicates that these “in-situ” composites have much higher creep strength than γ-TiAl, but the contribution of the reinforcements is relatively small compared with the solute-strengthening of the matrix.

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Synthesis and Photoelectrocatalytic Property of Two-Nonmetal-Codoped TiO2 Nanotube Arrays with High Aspect Ratio

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.412.219 ◽

2011 ◽

Vol 412 ◽

pp. 219-222 ◽

Cited By ~ 2

Author(s):

Hai Da Liao ◽

Wei Ping Zhang ◽

Xiao Ming Sun ◽

Liang Shi ◽

Ming Feng Qin

Keyword(s):

Methyl Orange ◽

Aspect Ratio ◽

High Aspect Ratio ◽

Mixed Crystal ◽

Nanotube Arrays ◽

Xenon Lamp ◽

Metallic Elements ◽

Nanotube Array ◽

Natural Lighting

Electrolyte containing F–was employed to conduct two-step anodic oxidation. Through adjustment of the composition of electrolyte, TiO2nanotube array with high aspect ratio was grown in situ on Ti matrix, and meanwhile the binary doping with non-metallic elements, namely, F and S, was achieved. Using FSEM, XRD and EDS, the characterization on the topography, structure and doped elements of TiO2nanotubes were performed. Taking methyl orange as the target degradation substance and using xenon lamp to simulate natural lighting, the comparison between the doped non-high-aspect-ratio nanotube and the doped high-aspect-ratio nanotube was made to investigate the related photoelectrocatalytic property. The results showed that the photoelectrocatalytic property of doped nanotube with high aspect ratio was significantly superior to that with non-high aspect ratio. The mixed crystal ratio of anatase and rutile obtained after calcination for 2h at 500°C enabled higher photoelectrocatalytic activity of TiO2nanotube array.

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