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

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
Step-Growth Polymerization: Overview01:03

Step-Growth Polymerization: Overview

4.8K
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...
4.8K
Photochemical Electrocyclic Reactions: Stereochemistry01:26

Photochemical Electrocyclic Reactions: Stereochemistry

2.5K
The absorption of UV–visible light by conjugated systems causes the promotion of an electron from the ground state to the excited state. Consequently, photochemical electrocyclic reactions proceed via the excited-state HOMO rather than the ground-state HOMO. Since the ground- and excited-state HOMOs have different symmetries, the stereochemical outcome of electrocyclic reactions depends on the mode of activation; i.e., thermal or photochemical.
Selection Rules: Photochemical Activation
2.5K
Polymers02:34

Polymers

44.0K
The word polymer is derived from the Greek words “poly” which means “many” and “mer” which means “parts”. Polymers are long chains of molecules composed of repeating units of smaller molecules, known as monomers. They either occur naturally, such as DNA and proteins, or can be constructed synthetically, like plastics. They have varied structural characteristics, such as linear chains, branched chains, or complex networks, that contribute to the...
44.0K
Free-Radical Chain Reaction and Polymerization of Alkenes02:35

Free-Radical Chain Reaction and Polymerization of Alkenes

10.5K
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.
10.5K
Radical Chain-Growth Polymerization: Mechanism01:09

Radical Chain-Growth Polymerization: Mechanism

3.9K
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...
3.9K

You might also read

Related Articles

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

Sort by
Same author

Nanodroplet-Confined Electroplating Enables Submicron Printing of Metals and Oxide Ceramics.

ACS nano·2026
Same author

Light-Driven Topological Relaxation and Dynamic Scaling in Photoresponsive Polymer Films.

ACS photonics·2026
Same author

Multimode Single-Ring Photonic Molecule.

Physical review letters·2026
Same author

Magnetoactive soft elastomers-materials design, processing and applications.

Reports on progress in physics. Physical Society (Great Britain)·2026
Same author

Electrohydrodynamic redox printing vs. physical vapour deposition: a comparative study of nanoporous Ag morphology and SERS performance.

Discover nano·2025
Same author

Silica Meta-Optics: When High Performance Does Not Need a High Index.

Nano letters·2025

Related Experiment Video

Updated: Apr 20, 2026

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering
06:16

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering

Published on: December 21, 2017

6.1K

Instability-induced pattern formation of photoactivated functional polymers.

Henning Galinski1, Antonio Ambrosio2, Pasqualino Maddalena3

  • 1School of Engineering and Applied Science, Harvard University, Cambridge, MA 02138; Laboratory for Nanometallurgy and hgalinski@seas.harvard.edu antonio.ambrosio@spin.cnr.it.

Proceedings of the National Academy of Sciences of the United States of America
|November 19, 2014
PubMed
Summary

Photoactivated pattern formation in azobenzene polymer films is driven by phase separation. This process, influenced by light polarization, offers potential for advanced molecular electronics and photoresponsive systems.

Keywords:
azobenzenepattern formationphase separationphotoactivated functional polymersspinodal decomposition

More Related Videos

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
10:35

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Published on: May 29, 2018

9.3K
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

12.5K

Related Experiment Videos

Last Updated: Apr 20, 2026

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering
06:16

Monitoring the Effects of Illumination on the Structure of Conjugated Polymer Gels Using Neutron Scattering

Published on: December 21, 2017

6.1K
Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
10:35

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Published on: May 29, 2018

9.3K
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

12.5K

Area of Science:

  • Materials Science
  • Polymer Chemistry
  • Physics

Background:

  • Pattern formation is a fundamental concept observed across nature and physics, from animal coats to material self-assembly.
  • Photoactivated pattern formation in functional polymers is of significant interest for applications in molecular electronics and photoresponsive systems.

Purpose of the Study:

  • To demonstrate that photoactivated pattern formation in azobenzene-containing polymer films can be explained by phase separation.
  • To investigate the role of light polarization in this phenomenon.

Main Methods:

  • Experimental studies on azobenzene-containing polymer films.
  • Computer simulations to model the observed pattern formation.
  • Analysis of photoactivated transitions and their effect on polymer states.

Main Results:

  • Photoactivated pattern formation is driven by phase separation caused by light-induced transitions between immiscible polymer states.
  • Polarized light significantly enhances the phase separation process, leading to distinct pattern formation.
  • The findings align with theoretical predictions regarding phase transitions and light-matter interactions.

Conclusions:

  • Phase separation is the underlying physical mechanism for photoactivated pattern formation in azobenzene polymer films.
  • The study provides a physical explanation for these patterns, with implications for designing novel photoresponsive materials.
  • Controlled light polarization can be used to tune and enhance pattern formation for technological applications.