決定的反復合成による単分散グラフェンナノリボンのプログラム可能な製造
Jiangliang Yin1, Peter H Jacobse2,3, Daniel Pyle1
1Department of Chemistry, University of Chicago, Chicago, Illinois 60637, United States.
Journal of the American Chemical Society
|August 26, 2022
まとめ
研究者は,精密に制御されたグラフェンナノリボン (GNR) を作成するための新しい繰り返し合成方法を開発しました. このアプローチにより,長さやモノメア配列が事前に決定され,以前の製造上の課題を克服できます.
科学分野:
- 材料科学
- 有機化学
- ナノテクノロジー
背景:
- 原子精度の高いグラフェンナノリボン (GNR) の合成は著しく進歩した.
- GNRの長さとモノメア配列の正確な制御は依然として重要な課題です.
研究 の 目的:
- 構造的に多様で単一分散の"設計者"GNRの製造方法を開発する.
- GNR合成において,事前に決定された長さとモノメア配列を達成する.
主な方法:
- サイクルごとに1つのモノマーを組み込む,繰り返し合成戦略を使用した.
- ナノリボン形成のための表面補助サイクロデヒドロジネーションを使用しています.
- 結合解像度スキャントンネル顕微鏡を用いて合成されたGNRを特徴づけた.
主要な成果:
- 構造的に多様で単一分散の GNR を成功裏に製造した.
- GNRの長さとモノメア配列の制御が実証されている.
- 繰り返し合成と表面補助サイクロデヒドロゲネーションのアプローチを検証した.
結論:
- 開発された方法は,高い構造的精度で"設計者"GNRの合成を可能にします.
- この繰り返し戦略は,GNRの長さと配列を制御する際の制限を克服します.
- この発見は,GNRの高度な応用への道を開く.
関連する概念動画
Radical Chain-Growth Polymerization: Overview
Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...
Radical Chain-Growth Polymerization: Chain Branching
The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the...
Production of Formed Elements
Hemangioblasts are multipotent stem cells originating from the mesoderm. They give rise to hematopoietic stem cells (HSCs), which undergo hematopoiesis to produce all the formed elements of blood. This process is regulated by a complex network of hematopoietic growth factors, including transcription factors, growth factors, and cytokines. These factors stimulate the HSCs to divide and differentiate, though some HSCs remain undifferentiated to maintain a self-renewing pool.
Most HSCs commit to...
Most HSCs commit to...
Sequence Networks of Rotating Machines
A Y-connected synchronous generator, grounded through a neutral impedance, is designed to produce balanced internal phase voltages with only positive-sequence components. The generator's sequence networks include a source voltage that is exclusively in the positive-sequence network. The sequence components of line-to-ground voltages at the generator terminals illustrate this configuration.
Zero-sequence current induces a voltage drop across the generator's neutral impedance and other...
Zero-sequence current induces a voltage drop across the generator's neutral impedance and other...


