Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Polymers: Defining Molecular Weight

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...

Polymers: Molecular Weight Distribution

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.

Molecular Weight of Step-Growth Polymers

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

Polymers

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...

Molecular and Ionic Solids

Molecular and Ionic Solids

Crystalline solids are divided into four types: molecular, ionic, metallic, and covalent network based on the type of constituent units and their interparticle interactions.
Molecular Solids
Molecular crystalline solids, such as ice, sucrose (table sugar), and iodine, are solids that are composed of neutral molecules as their constituent units. These molecules are held together by weak intermolecular forces such as London dispersion forces, dipole-dipole interactions, or hydrogen bonds, which...

Conjugated Proteins

Conjugated Proteins

Simple proteins and protein complexes contain only amino acids. In contrast, many other proteins, called conjugated proteins, covalently bond with non-protein moieties.
Nucleoproteins are protein complexes that contain nucleic acids, categorized as deoxyribonucleoproteins (DNPs) or ribonucleoproteins (RNPs) respectively. The nucleosome is a typical example of a DNP where nuclear DNA is associated with histone proteins. The major antigen for the Covid-19 virus SARS-CoV is an RNP that is critical...

You might also read

Related Articles

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

Sort by

Same author

Higher-order lattice anharmonicity reshaping non-equilibrium carrier dynamics in wide-phonon-gap semiconductors.

National science review·2026

Same author

Encapsulated droplet array for intensified micromole-scale high-throughput reaction screening.

Nature communications·2026

Same author

Suppressing thermal transport in nonporous polymer hybrids by limiting thermally accessible vibrational modes.

Materials horizons·2026

Same author

Local Coordination Environment Engineering of Na3 Sites in Na<sub>4</sub>Mn<sub>1.5</sub>Fe<sub>1.5</sub>(PO<sub>4</sub>)<sub>2</sub>P<sub>2</sub>O<sub>7</sub> Cathode.

Journal of the American Chemical Society·2026

Same author

Atomistic characterization of the maturation mechanisms in the HIV-1 capsid domain.

Nature communications·2026

Same author

Bistable origami thermal switch with high switching ratios.

Nature communications·2026

Search research articles

Related Experiment Video

Updated: Feb 11, 2026

Author Spotlight: Advancing Energy Solutions Using Nanocomposites as Processed Thermoelectric Materials

Author Spotlight: Advancing Energy Solutions Using Nanocomposites as Processed Thermoelectric Materials

Published on: May 17, 2024

Molecular engineered conjugated polymer with high thermal conductivity.

Yanfei Xu¹, Xiaoxue Wang², Jiawei Zhou¹

¹Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.

Science Advances

|April 20, 2018

Summary

Researchers developed high thermal conductivity conjugated polymer films using oxidative chemical vapor deposition (oCVD). This breakthrough enhances phonon transport via covalent and π-π stacking interactions, enabling advanced heat management in electronics.

More Related Videos

Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

Published on: January 17, 2018

Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes

Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes

Published on: January 10, 2017

Related Experiment Videos

Last Updated: Feb 11, 2026

Author Spotlight: Advancing Energy Solutions Using Nanocomposites as Processed Thermoelectric Materials

Author Spotlight: Advancing Energy Solutions Using Nanocomposites as Processed Thermoelectric Materials

Published on: May 17, 2024

Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

Reactive Vapor Deposition of Conjugated Polymer Films on Arbitrary Substrates

Published on: January 17, 2018

Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes

Engineering Molecular Recognition with Bio-mimetic Polymers on Single Walled Carbon Nanotubes

Published on: January 10, 2017

Area of Science:

Materials Science
Polymer Chemistry
Nanotechnology

Background:

Traditional polymers are electrical and thermal insulators, limiting their use in advanced devices.
Electrically conductive polymers have enabled applications like flexible displays and biosensors.
Developing polymers with high thermal conductivity is crucial for next-generation electronics and energy devices.

Purpose of the Study:

To engineer polymers with simultaneously enhanced intramolecular and intermolecular interactions for high thermal conductivity.
To achieve high thermal conductivity in conjugated polymer thin films for advanced thermal management applications.

Main Methods:

Utilized bottom-up oxidative chemical vapor deposition (oCVD) to synthesize poly(3-hexylthiophene) thin films.
Leveraged strong C=C covalent bonding along polymer chains and π-π stacking between chains.
Employed systematic structural characterization to confirm the presence of both interaction types.

Main Results:

Achieved a near-room temperature thermal conductivity of 2.2 W/m·K, a tenfold increase over conventional polymers.
Demonstrated the ability to engineer both strong intramolecular and intermolecular interactions simultaneously.
Developed a solvent-free oCVD technique for conformal film growth on diverse substrates.

Conclusions:

The developed conjugated polymer films offer lightweight, flexible heat conductors with high thermal conductivity.
These films are electrically insulating and corrosion-resistant, suitable for demanding electronic applications.
This work opens new avenues for designing advanced polymer-based thermal management solutions.