不同寻常的可光调的亚博烯终结型亚利法性聚碳酸盐的机械转化
Chaoxian Chen1, Yufan Ji1, Haomin Li1
1School of Materials Science and Engineering, and Key Laboratory of Polymer Chemistry and Physics of Ministry of Education, Peking University, Beijing, China.
Nature communications
|March 18, 2025
概括
研究人员开发了新型光响应性弹性体,在紫外线下改变机械性能. 这种能量驱动的材料表现出可调节的弹性和可塑性,为智能伤口带等先进应用提供了潜力.
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:
- 智能响应材料对于先进的应用至关重要,提供独特的响应能力和机械可变性.
- 开发具有这些特性的光响应性,能量驱动型弹性体具有重大挑战.
- 含有亚博的聚合物以光触发的机械变化而闻名,但寻求独特的行为.
研究的目的:
- 制造物理交叉连接的弹性体,其基础是酸性聚碳酸盐,其末端覆盖着亚博烯.
- 研究这些弹性体在紫外线照射后的光诱导机械转化.
- 探索这些材料作为具有可切换机械性能的能量驱动弹性体的潜力.
主要方法:
- 用一种亚博烯衍生物终结的亚利法性聚碳酸盐的合成.
- 用紫外线照射辐射来诱导亚博的光异构化.
- 机械测试用于评估弹性和可塑性的变化.
- 对超分子相互作用和交联密度的分析.
主要成果:
- 在紫外线暴露时,亚利法性聚碳酸呈现出不寻常的机械转变,从弹性转变为可塑性.
- 这种转化归因于cis-azobenzene和聚合物侧链之间更强的相互作用,增加了交联密度.
- 该材料表现出可光调的机械性能,cis-azobenzene半衰期为16.9小时.
- 光诱导的机械变化发生在室温下,使得非可热切换的粘附.
结论:
- 亚二终结的阿利法性聚碳酸盐作为能量驱动的弹性体,具有可光切换的超分子相互作用.
- 该材料显示可调节的机械性能和室温光感应的机械变化.
- 这为智能粘合剂和先进的伤口愈合带的应用提供了潜力.
相关概念视频
01:26Photochemical Electrocyclic Reactions: Stereochemistry
1.8K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
Selection Rules: Photochemical Activation
1.8K
01:26Thermal and Photochemical Electrocyclic Reactions: Overview
2.3K
Electrocyclic reactions are reversible reactions. They involve an intramolecular cyclization or ring-opening of a conjugated polyene. Shown below are two examples of electrocyclic reactions. In the first reaction, the formation of the cyclic product is favored. In contrast, in the second reaction, ring-opening is favored due to the high ring strain associated with cyclobutene formation.
2.3K
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
2.5K
Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...
2.5K
02:35Free-Radical Chain Reaction and Polymerization of Alkenes
7.6K
The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.
7.6K
01:12Cycloaddition Reactions: MO Requirements for Photochemical Activation
2.0K
Some cycloaddition reactions are activated by heat, while others are initiated by light. For example, a [2 + 2] cycloaddition between two ethylene molecules occurs only in the presence of light. It is photochemically allowed but thermally forbidden.
2.0K
00:53Olefin Metathesis Polymerization: Acyclic Diene Metathesis (ADMET)
1.9K
Acyclic diene metathesis polymerization or ADMET polymerization involves cross-metathesis of terminal dienes, such as 1,8-nonadiene, to give linear unsaturated polymer and ethylene. As ADMET is a reversible process, the formed ethylene gas must be removed from the reaction mixture to complete the polymerization process.
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
Similar to cross-metathesis, ADMET also involves the formation of metallacyclobutane intermediate by [2+2] cycloaddition of one of the double bonds of a terminal diene with...
1.9K