温度和聚合物度对纳米颗粒块共聚物系统中反入相互作用演变的竞争影响
Sugam Kumar1,2, Joachim Kohlbrecher3, Vinod K Aswal1,2
1Solid State Physics Division, Bhabha Atomic Research Centre, Mumbai 400 085, India.
Langmuir : the ACS journal of surfaces and colloids
|July 8, 2024
概括
无离子二氧化纳米颗粒块共聚物分散显示了从排斥性到吸引性,然后回到排斥性状态的重新进入过渡. 这种行为是由影响纳米粒子相互作用的温度和聚合物度变化驱动的.
科学领域:
- 材料科学 材料科学 材料科学
- 合体和表面化学
- 聚合物科学 聚合物科学
背景情况:
- 了解纳米粒子-聚合物相互作用对于设计先进材料至关重要.
- 像P85这样的区块共聚合物可以修改纳米粒子分散稳定性.
- 复杂流体中的回入过渡提供了可调节的特性.
研究的目的:
- 为了研究离子二氧化纳米粒子-块共聚合物 (P85) 分散中的回入相互作用演变.
- 阐明温度和聚合物度对系统相互作用的影响.
- 探索开发刺激响应纳米粒子聚合物复合材料的潜力.
主要方法:
- 使用对比变化小角度中子散射 (SANS) 来探测相互作用.
- 研究了系统行为在一系列的温度和聚合物度.
- 分析的重点是控制相互作用的温度/度依赖的修改.
主要成果:
- 在固定的温度下,随着聚合物度的增加,观察到一个反入转变 (排斥-吸引-排斥).
- 随着温度的升高,由于增强的共聚合物疏水性,最初的吸引力增加了.
- 较高的聚合物度导致固态排斥,减少吸引力,但高温 (>75°C) 重新诱导吸引力和聚合.
结论:
- 这项研究证明了纳米粒子聚合物系统中可调节的重新进入过渡.
- 温度和聚合物度是控制纳米粒子相互作用和聚合的关键因素.
- 这些发现支持开发能够响应外部刺激的智能复合材料.
相关概念视频
Polymer Classification: Stereospecificity
2.4K
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
2.4K
Characteristics and Nomenclature of Copolymers
2.5K
Copolymers are the products obtained from the polymerization of multiple monomer species. So, in a polymer chain itself, there can be multiple repeating units that come from different monomers. The process of synthesizing a polymer from different monomer species is called copolymerization. When two monomers are involved, the polymer is known as a bipolymer. Polymers with three and four monomers are termed terpolymers and quaterpolymers, respectively. Figure 1 depicts the copolymerization of...
2.5K
Polymer Classification: Crystallinity
2.8K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.8K
Effect of Temperature Change on Reaction Rate
4.0K
The Arrhenius equation,
4.0K
Temperature Dependence on Reaction Rate
81.5K
The Collision Theory
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
Atoms, molecules, or ions must collide before they can react with each other. Atoms must be close together to form chemical bonds. This premise is the basis for a theory that explains many observations regarding chemical kinetics, including factors affecting reaction rates.
The collision theory is based on the postulates that (i) the reaction rate is proportional to the rate of reactant collisions, (ii) the reacting species collide in an orientation allowing contact between...
81.5K
Polymer Classification: Architecture
2.7K
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
2.7K


