Video Experimental Relacionado
Updated: Oct 26, 2025
11:42
Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers
Published on: June 20, 2019
8.0K
Eventos de nucleación primaria y secundaria estereoselectivos en la polimerización supramolecular con semilla
Souvik Sarkar1, Aritra Sarkar1, Arka Som1
1New Chemistry Unit and School of Advanced Materials (SAMat), Jawaharlal Nehru Centre for Advanced Scientific Research (JNCASR), Jakkur, Bangalore 560064, India.
Journal of the American Chemical Society
|July 26, 2021
Resumen
Este estudio demuestra el control de la quiralidad molecular sobre la nucleación primaria y secundaria en la polimerización supramolecular. Esto avanza en la organización jerárquica de polímeros dinámicos para propiedades de materiales novedosos.
Área de la Ciencia:
- Química de polímeros supramoleculares
- Autoensamblaje de polímeros
- Ciencia de los materiales quirales
Sus antecedentes:
- El crecimiento de semillas controlado cinéticamente ofrece control sobre la estructura polimérica supramolecular primaria.
- El control de estructuras de orden superior en polímeros supramoleculares sigue siendo un desafío.
- Las vías de nucleación secundarias, vistas en los sistemas biológicos, ofrecen potencial para el control topológico.
Objetivo del estudio:
- Investigar el control de la quiralidad molecular sobre los eventos de nucleación primaria y secundaria en la polimerización supramolecular inducida por semillas.
- Elucidar las ideas mecanicistas sobre la nucleación secundaria en sistemas supramoleculares sintéticos.
- Para explorar el impacto de la nucleación estereoselectiva en la arquitectura del polímero supramolecular.
Principales métodos:
- Se utilizó la polimerización supramolecular inducida por semillas.
- Se emplearon experimentos cinéticos completos con sondas espectroscópicas in situ.
- Realizó análisis cinéticos detallados y varios estudios microscópicos.
Principales resultados:
- Se ha demostrado un control sin precedentes de la quiralidad molecular sobre los eventos de nucleación primaria y secundaria.
- Eventos de nucleación primaria y secundaria caracterizados en la polimerización supramolecular.
- Se reveló el efecto significativo de la nucleación y la siembra estereoselectivas en los aspectos (micro) estructurales de los polímeros supramoleculares multicomponentes.
Conclusiones:
- La quiralidad molecular es un determinante clave para controlar las vías de nucleación en la polimerización supramolecular.
- Este trabajo proporciona una base para el diseño de materiales supramoleculares complejos y organizados jerárquicamente.
- Los hallazgos abren nuevas vías para el control de topología en sistemas macromoleculares sintéticos.
Videos de Conceptos Relacionados
00:57Cationic Chain-Growth Polymerization: Mechanism
2.5K
The cationic polymerization mechanism consists of three steps: initiation, propagation, and termination. In the initiation step of the polymerization process, the π bond of a monomer gets protonated by the Lewis acid catalyst, which is formed from boron trifluoride and water. The protonation of the π bond generates a carbocation stabilized by the electron‐donating group. In the propagation step, the π bond of the second monomer acts as a nucleophile and attacks the...
2.5K
01:17Ziegler–Natta Chain-Growth Polymerization: Overview
3.5K
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...
3.5K
01:03Step-Growth Polymerization: Overview
3.9K
Step-growth or condensation polymerization is a stepwise reaction of bi or multifunctional monomers to form long-chain polymers. As all the monomers are reactive, most of the monomers are consumed at the early stages of the reaction to form small chains of reactive oligomers, which then combine to form long polymer chains in the late stages. Hence, the reaction has to proceed for a long time to achieve high molecular weight polymers.
Many natural and synthetic polymers are produced by...
Many natural and synthetic polymers are produced by...
3.9K
01:04Anionic Chain-Growth Polymerization: Mechanism
2.2K
The mechanism for anionic chain-growth polymerization involves initiation, propagation, and termination steps. In the initiation step, a nucleophilic anion, such as butyl lithium, initiates the polymerization process by attacking the π bond of the vinylic monomer. As a result, a carbanion, stabilized by the electron‐withdrawing group, is generated. The resulting carbanion acts as a Michael donor in the propagation step and attacks the second vinylic monomer, which acts as a Michael...
2.2K
01:09Radical Chain-Growth Polymerization: Mechanism
2.9K
The radical chain-growth polymerization mechanism consists of three steps: initiation, propagation, and termination of polymerization. The polymerization initiates when a free radical generated from the radical initiator adds to the unsaturated bond in the monomer. The unpaired electron of the free radical and one π electron in the unsaturated bond creates a σ bond between the free radical and the monomer. As a result, the other π electron in the unsaturated bond converts this...
2.9K
02:14SN2 Reaction: Kinetics
9.1K
Kinetic Studies and Significance
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
In a chemical reaction, a relationship exists between the concentration of reactants and the rate at which the reaction proceeds. The study to measure this relationship is known as the kinetics of a chemical reaction. Kinetic studies are used to deduce the rate law of a chemical reaction, which provides information about the species involved during the transition state of the rate-determining step. Thus, kinetic studies help to derive the mechanism of a...
9.1K