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

23.9K
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...
23.9K
Phase Transitions01:21

Phase Transitions

70
A phase transition is the process in which a substance changes from one state of matter to another, like from a solid to a liquid, liquid to gas, or vice versa, at a specific temperature and under given pressure conditions. This change is spontaneous and is affected by alterations in temperature and pressure. These parameters impact the strength of the forces between molecules (intermolecular forces) in the substance.During a phase transition, both the initial and final phases of the substance...
70
Phase Transitions: Melting and Freezing02:39

Phase Transitions: Melting and Freezing

15.7K
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...
15.7K
Phase Diagram01:19

Phase Diagram

7.3K
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).
7.3K
Phase Diagram01:24

Phase Diagram

131
A phase diagram is a graphical representation of the physical states of a substance under different conditions of temperature and pressure. It shows the boundaries between solid, liquid, and gas phases and the conditions at which these phases coexist in equilibrium. An area in a phase diagram represents a single phase, whereas lines or phase boundaries represent the equilibrium between two phases.In the phase diagram of water, the boundary line between the solid and liquid states illustrates...
131
Phase Transitions: Sublimation and Deposition02:33

Phase Transitions: Sublimation and Deposition

21.0K
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...
21.0K

You might also read

Related Articles

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

Sort by
Same author

Radio-clinical Aspects of Infertility in Bangladeshi Women: A Cross-sectional Study.

Mymensingh medical journal : MMJ·2026
Same author

Search for Light Pseudoscalar Bosons, Pair-Produced in Higgs Boson Decays in the Four-Electron Final State in Proton-Proton Collisions at sqrt[s]=13  TeV.

Physical review letters·2026
Same author

First Evidence for Mixing-Induced CP Violation in B_{s}^{0}→J/ψϕ(1020) Decays in pp Collisions at sqrt[s]=13  TeV.

Physical review letters·2026
Same author

Observation of Suppressed Charged-Particle Production in Ultrarelativistic Oxygen-Oxygen Collisions.

Physical review letters·2026
Same author

Measurement of D^{0} Meson Photoproduction in Ultraperipheral Heavy Ion Collisions.

Physical review letters·2026
Same author

Observation of tWZ Production at the CMS Experiment.

Physical review letters·2026

Related Experiment Video

Updated: Apr 4, 2026

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

7.7K

Non-equilibrium phase transitions in a liquid crystal.

K Dan1, M Roy1, A Datta1

  • 1Surface Physics and Material Science Division, Saha Institute of Nuclear Physics, 1/AF Bidhannagar, Kolkata 700064, West Bengal, India.

The Journal of Chemical Physics
|September 7, 2015
PubMed
Summary

This study investigates the glass transition and Nematic-Isotropic phase transition in liquid crystals using various spectroscopy methods. Findings reveal non-equilibrium behavior influenced by heating rate and initial temperature, impacting molecular ordering.

More Related Videos

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

7.0K
Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
10:35

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Published on: May 29, 2018

9.3K

Related Experiment Videos

Last Updated: Apr 4, 2026

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

7.7K
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

7.0K
Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals
10:35

Novel Techniques for Observing Structural Dynamics of Photoresponsive Liquid Crystals

Published on: May 29, 2018

9.3K

Area of Science:

  • Condensed Matter Physics
  • Materials Science
  • Physical Chemistry

Background:

  • Liquid crystals exhibit complex phase transitions, including glass transitions and Nematic-Isotropic (N-I) transitions.
  • Understanding the kinetic behavior and non-equilibrium features of these transitions is crucial for materials science applications.
  • Previous studies have explored these transitions, but a comprehensive kinetic analysis considering heating rate and initial temperature effects is needed.

Purpose of the Study:

  • To elucidate the kinetic behavior of the glass transition and the non-equilibrium aspects of the Nematic-Isotropic phase transition in N-(4-methoxybenzylidene)-4-butylaniline.
  • To investigate the influence of heating rate and initial temperature on these transitions using multiple spectroscopic techniques.
  • To provide experimental evidence for the non-equilibrium nature of the N-I transition and its underlying mechanisms.

Main Methods:

  • Differential Scanning Calorimetry (DSC) to analyze heat flow and transition enthalpies.
  • Fourier Transform Infrared (FTIR) spectroscopy to probe molecular vibrations and structural changes.
  • Fluorescence anisotropy measurements to quantify molecular ordering and the order parameter.

Main Results:

  • Glass transition exhibits a baseline shift at higher heating rates (> 5 K min⁻¹) and a distinct peak at lower rates (≤ 5 K min⁻¹), indicating a transition from ergodic to non-ergodic behavior.
  • FTIR spectroscopy reveals freezing of out-of-plane vibrations and enhanced coplanarity of benzene rings near the glass transition, signifying increased molecular ordering.
  • The Nematic-Isotropic transition temperature (TNI) and enthalpy change (ΔH) are dependent on the initial temperature, providing direct evidence of non-equilibrium behavior, consistent with Mesquita's extension of Landau-deGennes theory.

Conclusions:

  • The study confirms the non-equilibrium nature of both the glass transition and the Nematic-Isotropic phase transition in the studied liquid crystal.
  • Heating rate and initial temperature significantly influence the observed transition behaviors and molecular ordering.
  • The findings contribute to a deeper understanding of liquid crystal phase transitions and their kinetic dependencies.