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

Radical Chain-Growth Polymerization: Mechanism01:09

Radical Chain-Growth Polymerization: Mechanism

3.4K
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...
3.4K
Radical Chain-Growth Polymerization: Overview01:10

Radical Chain-Growth Polymerization: Overview

3.2K
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...
3.2K
Free-Radical Chain Reaction and Polymerization of Alkenes02:35

Free-Radical Chain Reaction and Polymerization of Alkenes

9.4K
The conversion of alkenes to macromolecules called polymers is a reaction of high commercial importance. The structure of the polymer is defined by a repeating unit, while the terminal groups are considered insignificant. The average degree of polymerization represents the number of repeating units in the polymer molecule and is denoted by the subscript n.
9.4K
Radical Chain-Growth Polymerization: Chain Branching01:17

Radical Chain-Growth Polymerization: Chain Branching

2.4K
The skeletal structure of polymers synthesized via radical polymerization is always branched. For example, the polymerization of ethylene by radical polymerization results in a low-density grade of polyethylene with a heavily branched skeletal structure. Here, the radical site abstracts hydrogen from the growing chain, and the radical site shifts from the end (a primary carbon center) to anywhere within the growing chain (a secondary carbon center). Consequently, the part of the chain from the...
2.4K
Anionic Chain-Growth Polymerization: Mechanism01:04

Anionic Chain-Growth Polymerization: Mechanism

2.5K
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...
2.5K
Cationic Chain-Growth Polymerization: Mechanism00:57

Cationic Chain-Growth Polymerization: Mechanism

2.8K
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...
2.8K

You might also read

Related Articles

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

Sort by
Same author

Pulmonary neuroendocrine cell-derived exosomes regulate iron homeostasis and oxidative stress in lung neurons.

Science advances·2026
Same author

Mechanochemical H-Bonding Organocatalysis Enabled Controlled Synthesis and Recycling of High-Molecular-Weight Poly(ɛ-Caprolactone).

Angewandte Chemie (International ed. in English)·2026
Same author

Probing Cellular Activity Via Charge-Sensitive Quantum Nanoprobes.

Advanced materials (Deerfield Beach, Fla.)·2026
Same author

Mechanochemical upcycling of poly (vinyl chloride) for alcohol halogenation.

Nature communications·2026
Same author

Programmable material via thiol-ene polymerization initiated by electric-field induced thiyl radical on piezoelectric ZnO.

Nature communications·2025
Same author

A fluorescent-protein spin qubit.

Nature·2025

Related Experiment Video

Updated: Jan 22, 2026

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
14:22

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

Published on: April 15, 2013

20.7K

Mechanically Initiated Bulk-Scale Free-Radical Polymerization.

Zhao Wang1, Jorge Ayarza1, Aaron P Esser-Kahn1

  • 1Institute of Molecular Engineering, University of Chicago, Chicago, IL, 60637, USA.

Angewandte Chemie (International Ed. in English)
|July 4, 2019
PubMed
Summary

Piezoelectric zinc oxide nanoparticles initiate polymerization and crosslinking using ultrasound. This method harnesses mechanical energy for creating high-molecular-weight polymers and gels, enabling bulk-scale reactions.

Keywords:
mechanochemistrynanoparticlespolymersradicalsultrasound

More Related Videos

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
06:49

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

Published on: April 22, 2016

12.4K
Preparation of Hollow Polystyrene Particles and Microcapsules by Radical Polymerization of Janus Droplets Consisting of Hydrocarbon and Fluorocarbon Oils
07:01

Preparation of Hollow Polystyrene Particles and Microcapsules by Radical Polymerization of Janus Droplets Consisting of Hydrocarbon and Fluorocarbon Oils

Published on: January 25, 2018

10.4K

Related Experiment Videos

Last Updated: Jan 22, 2026

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development
14:22

Free Radicals in Chemical Biology: from Chemical Behavior to Biomarker Development

Published on: April 15, 2013

20.7K
Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst
06:49

Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst

Published on: April 22, 2016

12.4K
Preparation of Hollow Polystyrene Particles and Microcapsules by Radical Polymerization of Janus Droplets Consisting of Hydrocarbon and Fluorocarbon Oils
07:01

Preparation of Hollow Polystyrene Particles and Microcapsules by Radical Polymerization of Janus Droplets Consisting of Hydrocarbon and Fluorocarbon Oils

Published on: January 25, 2018

10.4K

Area of Science:

  • Materials Science
  • Polymer Chemistry
  • Nanotechnology

Background:

  • Mechanical initiation of polymerization is an emerging field with unique applications.
  • Ultrasound-induced controlled radical polymerization has gained recent attention.
  • Other mechanically activated polymerizations, especially for high-molecular-weight polymers, are less common.

Purpose of the Study:

  • To demonstrate a novel method for mechanical polymerization using piezoelectric nanoparticles.
  • To explore the use of ultrasound to initiate polymerization and crosslinking.
  • To generate high-molecular-weight polymers and gels through mechanical activation.

Main Methods:

  • Utilizing piezoelectric zinc oxide (ZnO) nanoparticles as initiators.
  • Employing ultrasound to activate the ZnO nanoparticles and generate free radicals.
  • Initiating chain-growth polymerization and polymer crosslinking via mechanically generated radicals.

Main Results:

  • Successfully generated free-radical species from ZnO nanoparticles via ultrasound.
  • Achieved chain-growth polymerization and polymer crosslinking.
  • Formed polymer/gel structures rapidly due to high radical generation.

Conclusions:

  • Piezoelectric ZnO nanoparticles can effectively initiate polymerization and crosslinking under mechanical (ultrasound) activation.
  • This approach offers a new pathway to harness mechanical energy for polymer synthesis.
  • The developed chemistry is suitable for controlled polymerizations and bulk-scale reactions.