Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Step-Growth Polymerization: Overview01:03

Step-Growth Polymerization: Overview

4.7K
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...
4.7K
Cationic Chain-Growth Polymerization: Mechanism00:57

Cationic Chain-Growth Polymerization: Mechanism

3.0K
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...
3.0K
Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model01:09

Theories of Dissolution: The Danckwerts' Model and Interfacial Barrier Model

898
Various dissolution theories provide insight into the factors that influence the dissolution rate. Danckwerts' Model suggests that turbulence, rather than a stagnant layer, characterizes the dissolution medium at the solid-liquid interface. In this model, the agitated solvent contains macroscopic packets that move to the interface via eddy currents, facilitating the absorption and delivery of the drug to the bulk solution. The regular replenishment of solvent packets maintains the...
898
Anionic Chain-Growth Polymerization: Mechanism01:04

Anionic Chain-Growth Polymerization: Mechanism

2.6K
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...
2.6K
Phase Transitions: Vaporization and Condensation02:39

Phase Transitions: Vaporization and Condensation

22.0K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase molecules...
22.0K
Molecular Weight of Step-Growth Polymers01:08

Molecular Weight of Step-Growth Polymers

3.0K
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...
3.0K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Beyond confinement: conformational memory and the continuing legacy of Reiter and de Gennes in polymer films.

The European physical journal. E, Soft matter·2026
Same author

Finite size scaling of spinodal suppression in confined blends of strongly segregating polymers.

Soft matter·2026
Same author

The European Physical Journal E: Soft Matter and Biological Physics-the past and the future.

The European physical journal. E, Soft matter·2026
Same author

Temperature dependence of crystal melt coexistence for supported polyethylene filaments.

Nature communications·2025
Same author

Nanotetrapods promote polymer flow through confinement induced packing frustration.

Nature communications·2025
Same author

Crystallization and melting of polyethylene strongly cross-linked in the molten state.

Soft matter·2025

Related Experiment Video

Updated: Mar 24, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
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

8.5K

Transient Cooperative Processes in Dewetting Polymer Melts.

Sivasurender Chandran1, Günter Reiter1

  • 1Institute of Physics, Albert Ludwig University of Freiburg, 79104 Freiburg, Germany.

Physical Review Letters
|March 12, 2016
PubMed
Summary
This summary is machine-generated.

High-velocity dewetting of polystyrene films reveals distinct behaviors. Isotactic polystyrene (iPS) films show increased apparent viscosity, unlike atactic polystyrene (aPS) films which exhibit shear thinning.

More Related Videos

Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface
07:06

Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface

Published on: April 7, 2017

6.5K
Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst
07:39

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Published on: June 8, 2016

10.1K

Related Experiment Videos

Last Updated: Mar 24, 2026

Synthesis of Cyclic Polymers and Characterization of Their Diffusive Motion in the Melt State at the Single Molecule Level
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

8.5K
Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface
07:06

Methods for the Self-integration of Megamolecular Biopolymers on the Drying Air-LC Interface

Published on: April 7, 2017

6.5K
Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst
07:39

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Published on: June 8, 2016

10.1K

Area of Science:

  • Polymer Physics
  • Materials Science
  • Rheology

Background:

  • Polystyrene exists in atactic (aPS) and isotactic (iPS) forms with differing properties.
  • Understanding film dewetting is crucial for thin-film applications and material processing.

Purpose of the Study:

  • To compare the high-velocity dewetting behavior of aPS and iPS films at elevated temperatures.
  • To investigate the relationship between film viscosity and bulk viscosity during dewetting.

Main Methods:

  • High-velocity dewetting experiments on aPS and iPS films.
  • Measurement of zero shear bulk viscosity (η_bulk) and apparent film viscosity (η_f).
  • Analysis of viscosity ratios (η_f/η_bulk) and temperature dependence.

Main Results:

  • aPS films displayed shear thinning, with η_f < η_bulk.
  • iPS films unexpectedly showed η_f > η_bulk, even above the melting point.
  • The viscosity ratio for iPS films followed an Arrhenius behavior with a high activation energy (~160 kJ/mol).

Conclusions:

  • The contrasting dewetting behaviors of aPS and iPS are attributed to differences in their molecular structure and chain dynamics.
  • The observed behavior in iPS suggests cooperative segment motion induced by rapid dewetting.
  • These findings provide insights into the rheological properties of polymer films under dynamic conditions.