モノディスパースナノ結晶の形成のための基本的な成長チャネルの定量的な識別
Jiongzhao Li1, Huifeng Wang1, Long Lin1
1Center for Chemistry of Novel & High-Performance Materials, and Department of Chemistry , Zhejiang University , Hangzhou 310027 , P. R. China.
Journal of the American Chemical Society
|April 12, 2018
まとめ
新しいモデルでは ナノ結晶の形成は 一つの成長経路ではなく 全ての成長経路を考慮して説明しています 実験により,複数の成長チャネルが共存し,単分散ナノ結晶合成の理解を進めていることが確認されました.
科学分野:
- 材料科学
- 化学工学
- 物理化学
背景:
- モノディスパースナノ結晶形成の既存のモデルは,限られた実験的観測のみをしばしば説明する.
- 複雑な成長メカニズムを記述するには 統一されたモデルが必要です
研究 の 目的:
- 質量保存に基づくナノ結晶形成の一般的なモデルを開発し,すべての成長チャネルを網羅する.
- 合成された硫化カドミウム (CdS) ナノ結晶を用いてモデルを実験的に検証する.
- 成長チャネルの貢献を決定するための定量的な方法を提供すること.
主な方法:
- ナノ結晶の成長のための一般的な質量保存モデルの開発.
- 自動化されたマイクロリアクタシステムを用いた単分散CdSナノ結晶の合成.
- 液相フーリエ変換赤外線 (FTIR) と紫外線光譜を用いて,先駆体変換とナノ結晶のサイズ/濃度のインサイトモニタリング.
主要な成果:
- 開発されたモデルは,3つの成長チャネルを成功裏に記述しています:直接のモノメアの組み込み,ナノ結晶の溶解-再結晶化,およびクラスターの溶解.
- CdSナノ結晶による実験結果は,3つの成長チャネルの共存を示し,広く受け入れられている"フォーカシング"モデルと矛盾しています.
- 実験合成とモニタリングでは,高い再現性 (< 1%) と時間解像度 (< 1s) が達成されました.
結論:
- 質量保存に基づいた包括的なモデルは,以前に受け入れられた理論よりもナノ結晶形成のより完全なイメージを提供します.
- 多数の成長チャネルの共存は,単分散ナノ結晶の形成を理解するために重要です.
- 開発された理論的および実験的アプローチは,より広い範囲のコロイドナノ結晶合成に適用できます.
関連する概念動画
02:27Energy Basics
47.9K
Chemical reactions, such as those that occur when you light a match, involve changes in energy as well as matter.
47.9K
01:19Ion Channels
91.5K
The movement of ions like sodium, potassium, and calcium into and out of the cell is essential to maintain the electrochemical gradient in living cells. The ion channels—a class of membrane transport proteins—help maintain this ionic gradient for the smooth functioning of physiological activities such as maintaining cell size and volume, conducting nerve impulses, and gas and nutrient exchange.
Ion channels are specialized integral membrane proteins on the plasma membrane that allow...
Ion channels are specialized integral membrane proteins on the plasma membrane that allow...
91.5K
01:21Basicity of Aliphatic Amines
6.9K
Amines can behave as Brønsted–Lowry bases by accepting a proton from the acid to form corresponding conjugate acids. Due to a lone pair of nonbonding electrons, aliphatic amines can also act as Lewis bases by forming a covalent bond with an electrophile.
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...
To measure the basicity of amines, two conventions are generally used. The first defines Kb as the basicity constant for the deprotonation reaction of water by the amine, as presented in Figure 1. Conventionally, lower Kb indicates higher...
6.9K
01:22Basic Operations on Signals
1.1K
Basic signal operations include time reversal, time scaling, time shifting, and amplitude transformations. These operations are fundamental in signal processing and analysis.
Time Reversal mirrors a continuous-time signal about the vertical axis at t=0. This is achieved by substituting t with −t. For example, if a signal x(t) is considered, the time-reversed signal is x(−t). This operation can be graphically represented, showing the mirrored signal.
Time Reversal mirrors a continuous-time signal about the vertical axis at t=0. This is achieved by substituting t with −t. For example, if a signal x(t) is considered, the time-reversed signal is x(−t). This operation can be graphically represented, showing the mirrored signal.
1.1K
02:52VSEPR Theory and the Basic Shapes
85.4K
Overview of VSEPR Theory
85.4K
01:28Basic Concept
6.2K
Engineering mechanics is a branch of engineering that studies motion and the forces acting on objects. It is a fundamental subject and forms the basis of many other engineering disciplines. Length, time, mass, and force are some basic concepts in engineering mechanics.
Length, which measures the distance traveled by an object, is a fundamental concept in engineering mechanics. We use coordinates relative to a reference point to describe the distance. Length not only helps to describe the...
Length, which measures the distance traveled by an object, is a fundamental concept in engineering mechanics. We use coordinates relative to a reference point to describe the distance. Length not only helps to describe the...
6.2K