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 Experiment Videos

Closed-loop phase behaviour in block copolymers.

Du Yeol Ryu1, Unyong Jeong, Jin Kon Kim

  • 1Department of Chemical Engineering and Polymer Research Institute, Pohang University of Science and Technology, Kyungbuk 790-784, Korea.

Nature Materials
|March 6, 2003
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

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

Sort by
Same author

Rapid and Stereoselective Ring-Opening Polymerization of rac-Lactide Enabled by a Chiral Cyclopropenimine-Thiourea Catalyst.

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

Electron-conductive binder for silicon negative electrode enabling low-pressure all-solid-state batteries.

Nature communications·2025
Same author

One-Pot and Closed-Loop Recycling of Biomass-Derived Soft Electronics Toward Zero e-waste.

Small (Weinheim an der Bergstrasse, Germany)·2025
Same author

Revisiting the role of oxidation in stable and high-performance lead-free perovskite-IGZO junction field-effect transistors.

Nature communications·2025
Same author

Adapting Single-Atom Catalysts to Li-O<sub>2</sub> Batteries: Enhancing Energy Storage.

Small (Weinheim an der Bergstrasse, Germany)·2025
Same author

Manipulating the Crystalline Morphology in the Nonfullerene Acceptor Mixture to Improve the Carrier Transport and Suppress the Energetic Disorder.

Small science·2025
Same journal

Publisher Correction: Ultralow-voltage electrochemical organic light-emitting transistors with pinned and wide lateral recombination.

Nature materials·2026
Same journal

High-Chern-number orbital magnetism in twisted rhombohedral graphene.

Nature materials·2026
Same journal

Programming local confinements in crystalline frameworks through reticular chemistry.

Nature materials·2026
Same journal

Single-crystal-like polymer semiconductors via self-templated gradient assembly for ultrahigh charge carrier mobility.

Nature materials·2026
Same journal

Fractional quantum anomalous Hall effect in moiré fractional Chern insulators.

Nature materials·2026
Same journal

Excitons in van der Waals magnetic materials.

Nature materials·2026
See all related articles

Weakly interacting diblock copolymers, polystyrene-poly(n-pentylmethacrylate) (P(S-b-nPMA)), exhibit unique closed-loop phase behavior. This behavior, driven by entropy, shows temperature-dependent transitions and is sensitive to molecular weight.

Area of Science:

  • Polymer Science
  • Materials Science
  • Physical Chemistry

Background:

  • Closed-loop phase diagrams are established for strongly interacting systems.
  • Such behavior was previously unobserved in weakly interacting polymer systems.
  • Understanding phase transitions in these systems is crucial for materials design.

Purpose of the Study:

  • To investigate the possibility of closed-loop phase behavior in weakly interacting diblock copolymers.
  • To characterize the thermodynamic and morphological changes associated with these transitions.
  • To elucidate the role of molecular weight and intermolecular interactions.

Main Methods:

  • Synthesis of polystyrene-poly(n-pentylmethacrylate) (P(S-b-nPMA)) diblock copolymers.
  • Differential Scanning Calorimetry (DSC) to identify phase transitions.

Related Experiment Videos

  • Rheological measurements to probe material properties.
  • Small-angle X-ray scattering (SAXS) for morphological analysis.

    • Main Results:

    • P(S-b-nPMA) diblock copolymers exhibit closed-loop phase behavior within a specific molecular weight range.
    • Transitions from disordered to ordered and back to disordered states are endothermic and primarily entropic.
    • Disorder-to-order transition temperature increases with decreasing molecular weight, while order-to-disorder transition temperature decreases.
    • Morphology and rheological properties change significantly at the transition points.
    • The closed-loop behavior vanishes at a limiting molecular weight.

    Conclusions:

    • Weakly interacting diblock copolymers can display closed-loop phase diagrams, challenging previous assumptions.
    • The observed transitions are governed by entropic forces and are highly sensitive to molecular weight.
    • This study provides critical insights into phase behavior in complex polymer systems.