Related Experiment Video
Updated: Jun 24, 2026
11:42
Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers
Published on: June 20, 2019
Defect evolution and hydrodynamic effects in lamellar ordering process of two-dimensional quenched block copolymers
Kai-Xu Song1, Zhao-Yan Sun, Li-Jia An
1State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, People's Republic of China.
The Journal of Chemical Physics
|April 2, 2009
Summary
Hydrodynamic interactions accelerate domain growth and reduce defect density in block copolymer ordering. The Flory-Huggins parameter (chiN) significantly influences defect evolution, impacting material morphology.
Area of Science:
- Polymer Science
- Materials Science
- Computational Physics
Background:
- Block copolymers exhibit complex self-assembly into ordered structures.
- Understanding defect evolution is crucial for controlling material properties.
- Hydrodynamic effects can significantly influence polymer dynamics.
Purpose of the Study:
- To investigate the impact of hydrodynamic interactions on lamellar ordering in 2D block copolymers.
- To analyze the evolution of topological defects during the ordering process.
- To explore the relationship between polymer parameters and defect dynamics.
Main Methods:
- Numerical simulations using a model combining lattice Boltzmann method and self-consistent field theory.
- Analysis of domain growth kinetics by tracking average domain size.
- Quantification of defect evolution using a defined defect density parameter.
Main Results:
- Stronger hydrodynamic effects lead to faster domain growth and altered morphologies.
- Hydrodynamic interactions were found to reduce the overall defect density.
- The product of the Flory-Huggins interaction parameter and polymer chain length (chiN) was identified as a key factor in defect evolution.
Conclusions:
- Hydrodynamic interactions play a critical role in dictating the kinetics and defect landscape of block copolymer ordering.
- The interplay between hydrodynamic forces and thermodynamic parameters (chiN) governs the final morphology and defect structure.
- This study provides insights into controlling self-assembly processes for tailored material design.
Related Concept Videos
01:24Characteristics and Nomenclature of Copolymers
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...
00:57Cationic Chain-Growth Polymerization: Mechanism
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 generated carbocation,...
01:21Polymer Classification: Crystallinity
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...
01:25Imperfections in Crystal Structure: Point, Line and Plane Defects
A perfect crystal, in theory, has a uniform structure with the same unit cell and lattice points throughout. However, any deviation from this periodic arrangement is known as an imperfection or defect. These defects can be categorized into three types: point, line, and plane defects.Point defects occur when there is a deviation from the ideal due to missing atoms, displaced atoms, or additional atoms. These imperfections might occur due to imperfect packing during crystallization or because of...
01:17Ziegler–Natta Chain-Growth Polymerization: Overview
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 catalyst, high molecular...
01:08Molecular Weight of Step-Growth Polymers
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...