Related Experiment Video
Updated: Jun 27, 2026
06:55
Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
Published on: September 26, 2016
On the relationship between two popular lattice models for polymer melts
Gopinath Subramanian1, Sachin Shanbhag
1Department of Scientific Computing, Florida State University, Tallahassee, Florida 32306-4120, USA. gsub@scs.fsu.edu
The Journal of Chemical Physics
|December 3, 2008
Summary
Comparing polymer models reveals relationships between molecular weight, length, and time. While a perfect mapping remains elusive, this study offers a practical guide for converting between models, aiding polymer simulations.
Area of Science:
- Polymer physics
- Computational materials science
Background:
- Lattice bond-fluctuation models are crucial for simulating polymer behavior.
- Understanding the relationship between different models aids simulation accuracy and comparability.
Purpose of the Study:
- To investigate a mapping between two prominent lattice bond-fluctuation models for polymers.
- To establish relationships between molecular weight, lengthscale, and timescale for polymer simulations.
- To provide a practical guide for converting between the investigated polymer models.
Main Methods:
- Primitive path analysis was employed to determine the average number of monomers per entanglement.
- Simulations were conducted using both polymer models.
- Published data and simulation results were compared to establish model relationships.
Main Results:
- Excellent agreement was found for the self-diffusion coefficient between the two models and with experimental data for polystyrene, polybutadiene, and polydimethylsiloxane.
- Relationships between molecular weight, lengthscale, and timescale were established.
- A definitive, true mapping between the two models was found to be elusive.
Conclusions:
- While a perfect mapping between the two lattice bond-fluctuation models is not achieved, practical conversion guidelines are provided.
- The study validates the use of these models for predicting polymer self-diffusion coefficients.
- Further research is needed to fully reconcile the differences between the models.
Related Concept Videos
02:54Trends in Lattice Energy: Ion Size and Charge
An ionic compound is stable because of the electrostatic attraction between its positive and negative ions. The lattice energy of a compound is a measure of the strength of this attraction. The lattice energy (ΔHlattice) of an ionic compound is defined as the energy required to separate one mole of the solid into its component gaseous ions. For the ionic solid sodium chloride, the lattice energy is the enthalpy change of the process:
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...
01:27Lattice Energies of Ionic Crystals
Lattice energy represents the energy released when gaseous cations and anions combine to form an ionic solid, reflecting the strength of electrostatic interactions within the crystal. This process is fundamentally governed by Coulombic attraction between oppositely charged ions, where the potential energy varies inversely with the interionic distance and directly with the product of ionic charges. As ions approach one another, the electrostatic energy becomes increasingly negative, indicating a...
01:34Fluid Mosaic Model
The fluid mosaic model was first proposed as a visual representation of research observations. The model comprises the composition and dynamics of membranes and serves as a foundation for future membrane-related studies. The model depicts the structure of the plasma membrane with a variety of components, which include phospholipids, proteins, and carbohydrates. These integral molecules are loosely bound, defining the cell’s border and providing fluidity for optimal function.LipidsThe most...
02:00Molecular Models
Physical models representing molecular architectures of chemical compounds play essential roles in understanding chemistry. The use of molecular models makes it easier to visualize the structures and shapes of atoms and molecules.
02:34Comparing Intermolecular Forces: Melting Point, Boiling Point, and Miscibility
Intermolecular forces are attractive forces that exist between molecules. They dictate several bulk properties, such as melting points, boiling points, and solubilities (miscibilities) of substances. Molar mass, molecular shape, and polarity affect the strength of different intermolecular forces, which influence the magnitude of physical properties across a family of molecules.
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...
Temporary attractive forces like dispersion are present in all molecules, whether they are polar or nonpolar. They...