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

Molecular Weight of Step-Growth Polymers01:08

Molecular 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...
Polymers: Molecular Weight Distribution01:10

Polymers: Molecular Weight Distribution

For any given polymer, the weight average molecular weight (Mw) is higher than, if not equal to, the number average molecular weight (Mn). The only situation in which the weight average molecular weight and the number average molecular weight are equal is when a polymer consists only of chains with equal molecular weight. However, this never happens in a synthetic polymer, since it is difficult to control the polymerization process up to a molecular level with accuracy to a hundred percent.
Polymers: Defining Molecular Weight01:01

Polymers: Defining Molecular Weight

Unlike small molecules with definite molecular weights, polymers are a mixture of individual polymer chains of varying lengths, each with a unique molecular weight. So, the molecular weight of a polymer is expressed as an average value based on the average size of the polymer chains. The two most common forms of averages used for polymers are the number average molecular weight and weight average molecular weight.
The number average molecular weight (Mn) is the summation of the number...
Radical Chain-Growth Polymerization: Mechanism01:09

Radical Chain-Growth Polymerization: Mechanism

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 species into the...
Radical Chain-Growth Polymerization: Overview01:10

Radical Chain-Growth Polymerization: Overview

Chain-growth or addition polymerization is successive addition reactions of monomers with a polymer chain. In radical chain-growth polymerization, the reaction proceeds via a free-radical intermediate. The free radical is formed from radical initiators, which spontaneously generate free radicals by homolytic fission. Organic peroxides (such as dibenzoyl peroxide, as shown in Figure 1) or azo compounds are popular radical initiators. A low concentration ratio of radical initiator to monomer is...
Step-Growth Polymerization: Overview01:03

Step-Growth Polymerization: Overview

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...

You might also read

Related Articles

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

Sort by
Same author

Field-induced phase transitions in ferro-antiferromagnetic diblock copolymers.

The Journal of chemical physics·2026
Same author

Variational autoencoders understand knot topology.

Physical review. E·2025
Same author

Fluctuations of driven probes reveal nonequilibrium transitions in complex fluids.

The Journal of chemical physics·2025
Same author

xEEGNet: towards explainable AI in EEG dementia classification.

Journal of neural engineering·2025
Same author

Equilibrium phases and phase transitions in multicritical magnetic polymers.

Soft matter·2025
Same author

Upsurge of Spontaneous Knotting in Polar Diblock Active Polymers.

Physical review letters·2025

Related Experiment Video

Updated: Jun 12, 2026

Molecular Entanglement and Electrospinnability of Biopolymers
07:59

Molecular Entanglement and Electrospinnability of Biopolymers

Published on: September 3, 2014

Interplay between writhe and knotting for swollen and compact polymers.

Marco Baiesi1, Enzo Orlandini, Stuart G Whittington

  • 1Instituut voor Theoretische Fysica, K. U. Leuven, Celestijnenlaan 200D 3001, Belgium.

The Journal of Chemical Physics
|June 24, 2010
PubMed
Summary

The study reveals that a ring polymer's knot type influences its writhe, independent of length or solvent. Geometric factors increase writhe with length, but complex knots dominate in compact chains.

More Related Videos

DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers
08:00

DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers

Published on: October 25, 2017

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
16:24

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Published on: August 2, 2012

Related Experiment Videos

Last Updated: Jun 12, 2026

Molecular Entanglement and Electrospinnability of Biopolymers
07:59

Molecular Entanglement and Electrospinnability of Biopolymers

Published on: September 3, 2014

DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers
08:00

DNA Nanotubes as a Versatile Tool to Study Semiflexible Polymers

Published on: October 25, 2017

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water
16:24

Controlling the Size, Shape and Stability of Supramolecular Polymers in Water

Published on: August 2, 2012

Area of Science:

  • Polymer Physics
  • Computational Chemistry
  • Statistical Mechanics

Background:

  • Understanding the relationship between topology and geometry in biopolymers is crucial.
  • Physical conditions significantly affect polymer behavior.

Purpose of the Study:

  • To investigate the interplay between polymer writhe and knotting in good and poor solvents.
  • To model interacting self-avoiding polygons on a cubic lattice.

Main Methods:

  • Monte Carlo simulations were employed.
  • Analysis of polygons with fixed knot types and fixed writhe.

Main Results:

  • Writhe distribution's average depends on knot type, not length or solvent.
  • Standard deviation of writhe scales with N^0.5 (geometric) or N^0.6 (compact chains).
  • Knot distribution depends on writhe; achiral knots are suppressed at high writhe.

Conclusions:

  • A 'topological contribution' to writhe is identified, consistent with ideal knots.
  • Complex knots dominate compact chains, influencing scaling.
  • Knot occurrence depends on writhe, chain length, and solvent conditions.