相关实验视频
Updated: Jul 21, 2025

10:44
Isolating Free Carbenes, their Mixed Dimers and Organic Radicals
Published on: April 19, 2019
10.8K
碳纤维表面的修饰,由白银催化激素脱碳化促进
David J Hayne1, Bhagya Dharmasiri1, Filip Stojcevski2
1Institute for Frontier Materials, Deakin University, Waurn Ponds, Geelong, Victoria 3216, Australia. luke.henderson@deakin.edu.au.
概括
这项研究使用银催化工艺将聚合物植入碳纤维上,增强环氧树脂复合材料. 修改后的纤维提高了材料的柔性,并将故障从接口转移到矩阵.
科学领域:
- 材料科学 材料科学 材料科学
- 聚合物化学 聚合物化学
- 纳米技术纳米技术
背景情况:
- 碳纤维是复合材料中重要的增强剂.
- 改善碳纤维和聚合物矩阵之间的接口是提高复合材料性能的关键.
- 碳纤维的表面修改可以提高它们与矩阵的兼容性和结合性.
研究的目的:
- 用一种新的表面修饰技术将甲基烯酸酸/烯酸共聚物移植到短碳纤维上.
- 为了描述表面移植的碳纤维.
- 研究这些改性纤维对环氧树脂复合材料的机械性能和故障机制的影响.
主要方法:
- 用银催化激素脱碳化为共聚合物接种.
- 用X射线光电子光谱 (XPS),扫描电子显微镜 (SEM) 和热重力测量分析 (TGA) 来进行表面特征.
- 包含改性碳纤维的环氧树脂复合材料的制造和机械测试.
主要成果:
- 在XPS,SEM和TGA验证的短碳纤维上成功将4:1甲基酸/酸共聚物接种到短碳纤维上.
- 接种的聚合物约占修改纤维质量的10%.
- 带有改性纤维的环氧复合材料显示出增强的可塑性和故障模式的过渡,从粘合性 (在纤维-矩阵接口) 到凝聚性 (在矩阵内).
结论:
- 银催化接种是一种修改碳纤维表面的有效方法.
- 表面移植的共聚合物增强了碳纤维增强环氧复合材料的界面特性.
- 改进的界面粘附导致复合材料的延展性增强和更有利的凝聚力故障模式.
更多相关视频
相关概念视频
Radical Formation: Addition
1.7K
Radicals can be formed by adding a radical to a spin-paired molecule. This is typically observed with unsaturated species, where the addition of a radical across the π bond leads to the production of a new radical by dissolving the π bond. For example, the addition of a Br radical to an alkene yields a carbon-centered radical.
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
Similar to charge conservation in chemical reactions, spin conservation is implicit for radical reactions. Accordingly, the product formed must possess an...
1.7K
Radical Autoxidation
2.2K
The oxidation of an organic compound in the presence of air or oxygen is called autoxidation. For example, cumene reacts with oxygen to form hydroperoxide. Autoxidation involves initiation, propagation, and termination steps. Many organic compounds are susceptible to autoxidation—especially ethers in the presence of oxygen, which form hydroperoxides. Even though this reaction is slow, old ether bottles contain small amounts of peroxide, which leads to laboratory explosions during ether...
2.2K
Loss of Carboxy Group as CO2: Decarboxylation of β-Ketoacids
3.2K
Carboxylic acids, upon heating, undergo a decarboxylation reaction by releasing carbon dioxide gas. Monocarboxylic acids do not undergo decarboxylation easily. However, a silver salt of carboxylic acid reacts with bromine or iodine under high temperature to release carbon dioxide gas and forms halide with one less carbon. This reaction is called the Hunsdiecker reaction.
3.2K
Oxidations of Aldehydes and Ketones to Carboxylic Acids
4.0K
Oxidation of aldehydes and ketones results in the formation of carboxylic acids. Aldehydes, bearing hydrogen next to the carbonyl group, are easily oxidized compared to ketones. This is because an aldehydic proton can easily be abstracted during oxidation.
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...
Aldehydes readily undergo oxidation in strong oxidizing agents such as potassium permanganate and chromic acid. The oxidation can also be carried out using mild oxidizing agents such as silver oxide. In fact, aldehydes can be easily oxidized...
4.0K
Preparation of Carboxylic Acids: Carboxylation of Grignard Reagents
4.6K
Carboxylic acids can be prepared by the carboxylation of Grignard reagents (RMgX). This method is convenient for converting alkyl (primary, secondary or tertiary), vinyl, benzyl, and aryl halides to carboxylic acids with one additional carbon than the starting RMgX.
4.6K
Radical Formation: Elimination
1.7K
Another method of radical formation is the elimination process. It is the opposite of the addition route and is driven by the instability of the radical. For example, as depicted in Figure 1, dibenzoyl peroxide yields a pair of unstable radicals upon homolysis. Given its instability, this radical spontaneously undergoes elimination via a C–C bond cleavage to form a relatively more stable phenyl radical. The mechanism involves cleavage of the bond between the α and β positions...
1.7K

