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

Phase Transitions02:31

Phase Transitions

19.4K
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...
19.4K
Phase Transitions: Melting and Freezing02:39

Phase 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
Phase Transitions: Vaporization and Condensation02:39

Phase Transitions: Vaporization and Condensation

17.8K
The physical form of a substance changes on changing its temperature. For example, raising the temperature of a liquid causes the liquid to vaporize (convert into vapor). The process is called vaporization—a surface phenomenon. Vaporization occurs when the thermal motion of the molecules overcome the intermolecular forces, and the molecules (at the surface) escape into the gaseous state. When a liquid vaporizes in a closed container, gas molecules cannot escape. As these gas phase...
17.8K
Thermal Sigmatropic Reactions: Overview01:16

Thermal Sigmatropic Reactions: Overview

2.1K
Sigmatropic rearrangements are a class of pericyclic reactions in which a σ bond migrates from one part of a π system to another. These are intramolecular rearrangements where the total number of σ and π bonds remain unchanged.
Sigmatropic shifts are classified based on an order term [i, j ], where i and j indicate the number of atoms across which each end of the σ bond migrates. Below are examples of a [3,3] sigmatropic shift in...
2.1K
Woodward–Hoffmann Selection Rules and Microscopic Reversibility01:34

Woodward–Hoffmann Selection Rules and Microscopic Reversibility

3.2K
Electrocyclic reactions, cycloadditions, and sigmatropic rearrangements are concerted pericyclic reactions that proceed via a cyclic transition state. These reactions are stereospecific and regioselective. The stereochemistry of the products depends on the symmetry characteristics of the interacting orbitals and the reaction conditions. Accordingly, pericyclic reactions are classified as either symmetry-allowed or symmetry-forbidden. Woodward and Hoffmann presented the selection criteria for...
3.2K
Phase Transitions: Sublimation and Deposition02:33

Phase Transitions: Sublimation and Deposition

17.3K
Some solids can transition directly into the gaseous state, bypassing the liquid state, via a process known as sublimation. At room temperature and standard pressure, a piece of dry ice (solid CO2) sublimes, appearing to gradually disappear without ever forming any liquid. Snow and ice sublimate at temperatures below the melting point of water, a slow process that may be accelerated by winds and the reduced atmospheric pressures at high altitudes. When solid iodine is warmed, the solid sublimes...
17.3K

You might also read

Related Articles

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

Sort by
Same author

Unlocking Hidden Topological Multistability via Biphasic Correlated Order Evolution.

Physical review letters·2026
Same author

Stress-induced and anchoring-programmed smectic layer architectures.

Soft matter·2025
Same author

Linggui Zhugan decoction ameliorating mitochondrial damage of doxorubicin-induced cardiotoxicity by modulating the AMPK-FOXO3a pathway targeting BTG2.

Phytomedicine : international journal of phytotherapy and phytopharmacology·2025
Same author

The biological macromolecules constructed Matrigel for cultured organoids in biomedical and tissue engineering.

Colloids and surfaces. B, Biointerfaces·2024
Same author

A Na<sup>+</sup> channel receptor of FMRFamide in the cephalopod Sepiella japonica: Identification, characterisation, and expression profiling during different stages of gonadal development.

Neuropeptides·2024
Same author

Electrical tuning of branched flow of light.

Nature communications·2024

Related Experiment Video

Updated: Aug 8, 2025

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
06:24

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal

Published on: October 31, 2019

6.5K

Topological Defect Guided Order Evolution across the Nematic-Smectic Phase Transition.

Sai-Bo Wu1, Jin-Bing Wu1, Hui-Min Cao1

  • 1National Laboratory of Solid State Microstructures, Key Laboratory of Intelligent Optical Sensing and Manipulation, College of Engineering and Applied Sciences, Nanjing University, Nanjing 210023, China.

Physical Review Letters
|March 3, 2023
PubMed
Summary

Topological defects guide order evolution in liquid crystals during phase transitions. Different defect types emerge based on thermodynamic processes, influencing the final ordered state.

More Related Videos

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
06:26

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

Published on: May 15, 2017

7.2K
Forming, Confining, and Observing Microtubule-Based Active Nematics
08:37

Forming, Confining, and Observing Microtubule-Based Active Nematics

Published on: January 13, 2023

2.7K

Related Experiment Videos

Last Updated: Aug 8, 2025

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
06:24

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal

Published on: October 31, 2019

6.5K
Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
06:26

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

Published on: May 15, 2017

7.2K
Forming, Confining, and Observing Microtubule-Based Active Nematics
08:37

Forming, Confining, and Observing Microtubule-Based Active Nematics

Published on: January 13, 2023

2.7K

Area of Science:

  • Condensed Matter Physics
  • Soft Matter Physics
  • Materials Science

Background:

  • Topological defects are crucial in phase transitions of ordered systems.
  • Their role in thermodynamic order evolution is a key research area.
  • Liquid crystals (LCs) provide a model system for studying these phenomena.

Purpose of the Study:

  • To investigate the generation of topological defects during liquid crystal phase transitions.
  • To understand how these defects guide the evolution of order.
  • To explore the influence of photopatterned alignment on defect formation and subsequent phase behavior.

Main Methods:

  • Utilized photopatterned alignment to control liquid crystal director fields.
  • Studied the Nematic-Smectic (N-S) phase transition.
  • Analyzed defect structures (toric focal conic domains, frustrated arrays) and their transformations.
  • Employed free energy diagrams and texture analysis to describe phase transitions.

Main Results:

  • Two distinct topological defect types were generated based on thermodynamic pathways.
  • A memory effect in the LC director field led to stable or frustrated arrays of toric focal conic domains (TFCDs).
  • Frustrated defects evolved into metastable TFCD arrays and subsequently into a crossed-walls nematic state, demonstrating order inheritance.

Conclusions:

  • Topological defects play a significant role in guiding order evolution across phase transitions.
  • The study reveals mechanisms of defect behavior and their impact on material properties.
  • This work provides a foundation for exploring defect-guided order evolution in various ordered systems.