Macroscopic ordering of helical pores for arraying guest molecules noncentrosymmetrically

Abstract Helical nanostructures have attracted continuous attention, not only as media for chiral recognition and synthesis, but also as motifs for studying intriguing physical phenomena that never occur in centrosymmetric systems. To improve the quality of signals from these phenomena, which is a key issue for their further exploration, the most straightforward is the macroscopic orientation of helices. Here as a versatile scaffold to rationally construct this hardly accessible structure, we report a polymer framework with helical pores that unidirectionally orient over a large area (∼10 cm2). The framework, prepared by crosslinking a supramolecular liquid crystal preorganized in a magnetic field, is chemically robust, functionalized with carboxyl groups and capable of incorporating various basic or cationic guest molecules. When a nonlinear optical chromophore is incorporated in the framework, the resultant complex displays a markedly efficient nonlinear optical output, owing to the coherence of signals ensured by the macroscopically oriented helical structure.

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Convergent Beam Electron Diffraction

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100070072 ◽

1978 ◽

Vol 36 (3) ◽

pp. 304-315

Author(s):

G. Lehmpfuhl

Keyword(s):

Electron Diffraction ◽

Diffraction Pattern ◽

Crystal Surface ◽

Diffraction Spot ◽

Crystal Thickness ◽

Large Area ◽

Electron Microscopic ◽

Additional Information ◽

Microscopic Investigations

Introduction In electron microscopic investigations of crystalline specimens the direct observation of the electron diffraction pattern gives additional information about the specimen. The quality of this information depends on the quality of the crystals or the crystal area contributing to the diffraction pattern. By selected area diffraction in a conventional electron microscope, specimen areas as small as 1 µ in diameter can be investigated. It is well known that crystal areas of that size which must be thin enough (in the order of 1000 Å) for electron microscopic investigations are normally somewhat distorted by bending, or they are not homogeneous. Furthermore, the crystal surface is not well defined over such a large area. These are facts which cause reduction of information in the diffraction pattern. The intensity of a diffraction spot, for example, depends on the crystal thickness. If the thickness is not uniform over the investigated area, one observes an averaged intensity, so that the intensity distribution in the diffraction pattern cannot be used for an analysis unless additional information is available.

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Chlorosulfuric acid-assisted production of functional 2D materials

npj 2D Materials and Applications ◽

10.1038/s41699-021-00215-2 ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Mohsen Moazzami Gudarzi ◽

Maryana Asaad ◽

Boyang Mao ◽

Gergo Pinter ◽

Jianqiang Guo ◽

...

Keyword(s):

Hexagonal Boron Nitride ◽

2D Materials ◽

Real Life ◽

Large Area ◽

Polar Solvents ◽

Aspect Ratios ◽

Two Dimensional Materials ◽

Liquid Phase Exfoliation

AbstractThe use of two-dimensional materials in bulk functional applications requires the ability to fabricate defect-free 2D sheets with large aspect ratios. Despite huge research efforts, current bulk exfoliation methods require a compromise between the quality of the final flakes and their lateral size, restricting the effectiveness of the product. In this work, we describe an intercalation-assisted exfoliation route, which allows the production of high-quality graphene, hexagonal boron nitride, and molybdenum disulfide 2D sheets with average aspect ratios 30 times larger than that obtained via conventional liquid-phase exfoliation. The combination of chlorosulfuric acid intercalation with in situ pyrene sulfonate functionalisation produces a suspension of thin large-area flakes, which are stable in various polar solvents. The described method is simple and requires no special laboratory conditions. We demonstrate that these suspensions can be used for fabrication of laminates and coatings with electrical properties suitable for a number of real-life applications.

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One dimensional polymeric photonic crystal doped with second-order nonlinear optical chromophore

10.1117/12.809268 ◽

2009 ◽

Cited By ~ 1

Author(s):

Azusa Inoue ◽

Shin-ichiro Inoue ◽

Shiyoshi Yokoyama ◽

Keisuke Kojima ◽

Kei Yasui ◽

...

Keyword(s):

Photonic Crystal ◽

Nonlinear Optical ◽

Second Order ◽

One Dimensional ◽

Nonlinear Optical Chromophore

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New smart materials: molecular simulation of nonlinear optical chromophore-containing polypeptides and liquid crystalline siloxanes

10.1117/12.148462 ◽

1993 ◽

Cited By ~ 1

Author(s):

Ruth Pachter ◽

Soumya S. Patnaik ◽

Robert L. Crane ◽

W. Wade Adams

Keyword(s):

Molecular Simulation ◽

Smart Materials ◽

Liquid Crystalline ◽

Nonlinear Optical ◽

Nonlinear Optical Chromophore

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a-Si TFT Technologies for AM-LCDS

MRS Proceedings ◽

10.1557/proc-345-3 ◽

1994 ◽

Vol 345 ◽

Cited By ~ 7

Author(s):

Nobuki Ibaraki

Keyword(s):

Implantation Technique ◽

Picture Quality ◽

Large Area ◽

Aperture Ratio ◽

Large Size ◽

Ion Doping ◽

Doping Technique ◽

Future Technologies ◽

Improved Characteristics

AbstractA technical trend for a-Si TFTs is their application to large-size, high-pixel density AMLCDs such as XGA, EWS, and HDTV. In order to realize these LCDs, the TFT device characteristics must be improved. Future technologies, which will be necessary to fabricate TFTs with improved characteristics are as follows,(1) Fully self-aligned TFT technology: A SA-TFT structure reduces the feedthrough voltage caused by parasitic capacitance due to gate/source overlap. This results in an improved picture quality and a higher aperture ratio. Fabrication of such a structure would require ion doping technology.(2) Ion doping technology: This non-mass-separated implantation technique has large area doping capability and much higher doping speed compared to conventional ion implantation technique. The major problems with the ion doping technique is the implantation of unwanted species which deteriorate the quality of source/drain and channel regions of TFTs.

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Design and Demonstration of Large Scale Cu2O Photocathodes with Metal Grid Structure for Photoelectrochemical Water Splitting

Energies ◽

10.3390/en14217422 ◽

2021 ◽

Vol 14 (21) ◽

pp. 7422

Author(s):

Min-Kyu Son

Keyword(s):

Water Splitting ◽

Large Scale ◽

Grid Structure ◽

Large Area ◽

Intrinsic Conductivity ◽

Metal Grid ◽

Splitting System ◽

Insight Into ◽

Better Than

Upscaling of photoelectrode for a practical photoelectrochemical (PEC) water splitting system is still challenging because the PEC performance of large-scale photoelectrode is significantly low, compared to the lab scale photoelectrode. In an effort to overcome this challenge, sputtered gold (Au) and copper (Cu) grid lines were introduced to improve the PEC performance of large-scale cuprous oxide (Cu2O) photocathode in this work. It was demonstrated that Cu grid lines are more effective than Au grid lines to improve the PEC performance of large-scale Cu2O photocathode because its intrinsic conductivity and quality of grid lines are better than ones containing Au grid lines. As a result, the PEC performance of a 25-cm2 scaled Cu2O photocathode with Cu grid lines was almost double than one without grid lines, resulting in an improved charge transport in the large area substrate by Cu grid lines. Finally, a 50-cm2 scaled Cu2O photocathode with Cu grid lines was tested in an outdoor condition under natural sun. This is the first outdoor PEC demonstration of large-scale Cu2O photocathode with Cu grid lines, which gives insight into the development of efficient upscaled PEC photoelectrode.

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Detailed Investigation of Detached-Eddy Simulation for the Flow Past a Circular Cylinder at Re=3900

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.232.471 ◽

2012 ◽

Vol 232 ◽

pp. 471-476 ◽

Cited By ~ 3

Author(s):

Rui Zhao ◽

Chao Yan

Keyword(s):

Reynolds Number ◽

Circular Cylinder ◽

Flow Structures ◽

Detached Eddy Simulation ◽

Eddy Simulation ◽

Flow Past ◽

Large Eddy ◽

Mesh Resolution ◽

Physical Phenomena

The flow past a circular cylinder at a subcritical Reynolds number 3900 was simulated by the method of detached-eddy simulation (DES). The objective of this present work is not to investigate the physical phenomena of the flow but to study modeling as well as numerical aspects which influence the quality of DES solutions in detail. Firstly, four typical spanwise lengths are chosen and the results are systematically compared. The trend of DES results along the span increment is different from previous large-eddy simulation (LES) investigation. A wider spanwise length does not necessary improve the results. Then, the influence of mesh resolution is studied and found that both too coarse and over refined grids will deteriorate the performance of DES. Finally, different orders of numerical schemes are applied in the inviscid fluxes and the viscous terms. The discrepancies among different schemes are found tiny. However, the instantaneous flow structures produced by 5th order WENO with 4th order central differencing scheme are more abundant than the others. That is, for the time-averaged quantities, the second-order accurate schemes are effective enough, whereas the higher-order accurate methods are needed to resolve the transient characteristics of the flow.

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