Related Experiment Video
Updated: Jul 26, 2025
12:37
Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers
Published on: September 4, 2015
12.4K
Chimney-Shaped Phase Diagram in a Polymer Blend Electrolyte
Neel J Shah1,2, Marwan Shalaby3, Lilin He4
1Department of Chemical and Biomolecular Engineering, University of California, Berkeley, Berkeley, California 94720, United States.
ACS Macro Letters
|June 21, 2023
Summary
The phase behavior of poly(ethylene oxide) (PEO)/poly(methyl methacrylate) (PMMA)/lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) polymer electrolytes was mapped. Immiscibility occurs in salt-added PEO-lean blends, forming a chimney-like phase diagram.
Area of Science:
- Materials Science
- Polymer Chemistry
- Electrochemistry
Background:
- Polymer electrolytes are crucial for advanced battery technologies.
- Understanding phase behavior is key to optimizing electrolyte performance and stability.
- Poly(ethylene oxide) (PEO) and poly(methyl methacrylate) (PMMA) are common polymer hosts.
Purpose of the Study:
- To investigate the phase behavior of PEO/PMMA/LiTFSI polymer blend electrolytes.
- To map the phase diagram as a function of polymer and salt concentrations.
- To compare experimental results with theoretical predictions.
Main Methods:
- Light scattering and small-angle neutron scattering (SANS) were employed.
- Phase diagrams were constructed at a fixed temperature (110 °C).
- Flory-Huggins theory and self-consistent field theory were used for comparison.
Main Results:
- Blends are miscible at all PEO concentrations without salt.
- A chimney-like immiscibility region appears in PEO-lean electrolytes with added LiTFSI.
- PEO-rich blends remain miscible across a wide range of salt concentrations.
Conclusions:
- The phase diagram exhibits a unique chimney-like morphology.
- Experimental data align with extensions of Flory-Huggins theory.
- Further research is needed to reconcile theoretical models with experimental findings on interaction parameters.
Related Concept Videos
01:19Phase Diagram
5.9K
The phase of a given substance depends on the pressure and temperature. Thus, plots of pressure versus temperature showing the phase in each region provide considerable insights into the thermal properties of substances. Such plots are known as phase diagrams. For instance, in the phase diagram for water (Figure 1), the solid curve boundaries between the phases indicate phase transitions (i.e., temperatures and pressures at which the phases coexist).
5.9K
02:39Phase Diagrams
41.9K
A phase diagram combines plots of pressure versus temperature for the liquid-gas, solid-liquid, and solid-gas phase-transition equilibria of a substance. These diagrams indicate the physical states that exist under specific conditions of pressure and temperature and also provide the pressure dependence of the phase-transition temperatures (melting points, sublimation points, boiling points). Regions or areas labeled solid, liquid, and gas represent single phases, while lines or curves represent...
41.9K
02:39Phase Transitions: Melting and Freezing
12.5K
Heating a crystalline solid increases the average energy of its atoms, molecules, or ions, and the solid gets hotter. At some point, the added energy becomes large enough to partially overcome the forces holding the molecules or ions of the solid in their fixed positions, and the solid begins the process of transitioning to the liquid state or melting. At this point, the temperature of the solid stops rising, despite the continual input of heat, and it remains constant until all of the solid is...
12.5K
01:19Phase Changes
4.4K
Phase transitions play an important theoretical and practical role in the study of heat flow. In melting or fusion, a solid turns into a liquid; the opposite process is freezing. In evaporation, a liquid turns into a gas; the opposite process is condensation.
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
A substance melts or freezes at a temperature called its melting point and boils or condenses at its boiling point. These temperatures depend on pressure. High pressure favors the denser form of the substance, so typically, high pressure...
4.4K
02:31Phase Transitions
19.2K
Whether solid, liquid, or gas, a substance's state depends on the order and arrangement of its particles (atoms, molecules, or ions). Particles in the solid pack closely together, generally in a pattern. The particles vibrate about their fixed positions but do not move or squeeze past their neighbors. In liquids, although the particles are closely spaced, they are randomly arranged. The position of the particles are not fixed—that is, they are free to move past their neighbors to...
19.2K
01:21Polymer Classification: Crystallinity
2.9K
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
2.9K