排除了对触角驱动的活性环聚合物的体积效应
1Istituto Applicazioni Calcolo, Consiglio Nazionale delle Ricerche (CNR), Via Amendola 122/D, 70126 Bari, Italy.
Physical review. E
|June 22, 2024
概括
活性环聚合物表现出大小和形状的变化受到驱动力的影响,并排除了体积相互作用. 它们的动力学范围从增强的扩散到弹道运动,旋转周期与施加的力相反.
科学领域:
- 软物质物理学 软物质物理学
- 聚合物物理 聚合物物理
- 计算物理 计算物理
背景情况:
- 了解活性聚合物的行为在生物物理学和材料科学等领域至关重要.
- 环聚合物,一个特定的拓,呈现独特的结构和动态挑战.
- 活性物质系统将储存或消耗的能量转化为机械工作,导致复杂的行为.
研究的目的:
- 研究被限制在两个维度中的活性环聚合物的结构和动态特性.
- 探索排除体积相互作用,曲刚性和驱动力对聚合物行为的影响.
- 描述内部和长时间动态,包括扩散和旋转运动.
主要方法:
- 使用聚合物珠弹链模型进行数值模拟.
- 布朗的多粒子碰撞动态来建模热浴和活跃的驱动力.
- 考虑具有不同曲刚度的幻象 (不排除体积) 和自我避开 (不包括体积) 链.
主要成果:
- 聚合物大小和形状在很大程度上取决于持久度,驱动力和排除体积效应.
- 灵活的幻环随着力量的增加而收缩,而自我避开的链条显示出适度的胀.
- 内部动力学揭示了灵活的幻环中的活动增强的扩散,以及自我避开的链中的硬性独立的弹道运动.
- 长时间动力学由旋转运动主导,周期与应用于的触力相成比例.
结论:
- 排除的体积相互作用在调节活性环聚合物对外部驱动力的反应方面发挥着至关重要的作用.
- 观察到的动态突出显示了幻象和自我避开的活跃环之间的独特行为,受刚性和活动的影响.
- 旋转周期与驱动力的普遍缩放表明了活性环动力学的基本方面.
相关概念视频
01:16Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)
2.6K
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...
2.6K
01:17Ziegler–Natta Chain-Growth Polymerization: Overview
3.3K
Ziegler–Natta polymerization is another form of addition or chain‐growth polymerization used for synthesizing linear polymers over branched polymers. The catalyst used for polymerization is the Ziegler–Natta catalyst, named after Karl Ziegler and Giulio Natta, who developed it in 1953. This catalyst is an organometallic complex of titanium tetrachloride and triethyl aluminum, with the active form of the catalyst being an alkyl titanium compound. Using the Ziegler–Natta...
3.3K
01:07Gravitational Potential Energy for Extended Objects
1.4K
Consider a system comprising several point masses. The coordinates of the center of mass for this system can be expressed as the summation of the product of each mass and its position vector divided by the total mass:
1.4K
01:14π Electron Effects on Chemical Shift: Aromatic and Antiaromatic Compounds
1.2K
In aromatic compounds, such as benzene, the circulation of (4n + 2) π-electrons sets up a diamagnetic or diatropic ring current around the perimeter of the molecule. This current induces a magnetic field that opposes the external field inside the ring and reinforces it on the outside. The protons in benzene are deshielded and exhibit high chemical shifts in the range 6.5–8.5 ppm. The shielding effect at the center of the ring is evident in complex aromatic molecules, such as...
1.2K
01:17Radical Chain-Growth Polymerization: Chain Branching
1.9K
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...
1.9K
01:08Molecular Weight of Step-Growth Polymers
2.2K
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
2.2K