Related Experiment Video
Updated: Jun 16, 2026
11:52
Single Particle Cryo-Electron Microscopy: From Sample to Structure
Published on: May 29, 2021
Amorphous freezing in two dimensions: from soft coils to rigid particles.
A Maestro1, D Langevin, F Monroy
1Departamento de Química Física I, Universidad Complutense, Madrid, Spain.
The European Physical Journal. E, Soft Matter
|January 27, 2010
Summary
This study revisits the 2D gel transition using shear elasticity data from spherical object monolayers. Findings suggest amorphous freezing relates to structural percolation, differing from entropic network expectations.
Area of Science:
- Condensed Matter Physics
- Soft Matter Physics
- Materials Science
Background:
- The gel transition in two dimensions is a critical phenomenon observed in various soft matter systems.
- Understanding the mechanical properties, such as shear elasticity, provides insights into the underlying structural organization.
- Langmuir monolayers offer a model system to study 2D phase transitions and material behavior.
Purpose of the Study:
- To re-examine the gel transition in two dimensions.
- To investigate the shear elasticity of Langmuir monolayers composed of different spherical objects.
- To correlate mechanical properties with structural characteristics and theoretical models.
Main Methods:
- Measurement of shear elasticity of Langmuir monolayers.
- Analysis of data concerning the dependence of shear modulus on packing fraction.
- Comparison of experimental results with theoretical predictions for amorphous freezing and percolation.
Main Results:
- Amorphous freezing in these 2D systems can be linked to structural percolation.
- The shear modulus and its dependence on packing fraction are highly sensitive to the interaction potential details.
- Observed behavior deviates significantly from predictions for purely entropic networks.
Conclusions:
- The study provides a refined understanding of the 2D gel transition and amorphous freezing.
- Elaborated percolation theories, incorporating central and bond-bending forces, are necessary to explain the observed shear elasticity.
- The findings highlight the importance of inter-particle interactions in determining the mechanical response of 2D soft matter systems.
Related Concept Videos
02:39Phase Transitions: Melting and Freezing
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...
01:21Polymer Classification: Crystallinity
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...
01:23States of Water
Water exists in any one of the three classical states: solid (ice), liquid (water), and gas (steam or water vapor). The state of water depends on i) the intermolecular forces that draw molecules together and ii) the kinetic energy that leads to movements that pull them apart.
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
Water freezes when the intermolecular forces are greater than the kinetic energy. Unlike most other substances, water is less dense in its solid state than in its liquid state. This is because each water molecule can form...
01:28Cryo-electron Microscopy
Conventional electron microscopy (EM) involves dehydration, fixation, and staining of biological samples, which distorts the native state of biological molecules and results in several artifacts. Also, the high-energy electron beam damages the sample and makes it difficult to obtain high-resolution images. These issues can be addressed using cryo-EM, which uses frozen samples and gentler electron beams. The technique was developed by Jacques Dubochet, Joachim Frank, and Richard Henderson, for...
02:54Molecular 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...
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...
02:22Structures of Solids
Solids in which the atoms, ions, or molecules are arranged in a definite repeating pattern are known as crystalline solids. Metals and ionic compounds typically form ordered, crystalline solids. A crystalline solid has a precise melting temperature because each atom or molecule of the same type is held in place with the same forces or energy. Amorphous solids or non-crystalline solids (or, sometimes, glasses) which lack an ordered internal structure and are randomly arranged. Substances that...