Related Experiment Video
Updated: Apr 16, 2026

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal
Published on: October 31, 2019
Remarkable distinctions in the heat-induced phase transition processes of two poly(2-isopropyl-2-oxazoline)-based
Tianjiao Li1, Hui Tang, Peiyi Wu
1State Key Laboratory of Molecular Engineering of Polymers, Collaborative Innovation Center of Polymers and Polymer Composite Materials, Department of Macromolecular Science, Laboratory for Advanced Materials, Fudan University, Shanghai 200433, China. peiyiwu@fudan.edu.cn.
Abstract:
Detailed phase transition processes of poly(2-isopropyl-2-oxazoline) (PIPOZ)/poly(N-isopropylacrylamide) (PNIPAM) and PIPOZ/poly(N-vinylcaprolactam) (PVCL) mixtures in aqueous solution were investigated by DSC, temperature-variable (1)H-NMR, optical microscopy and FT-IR spectroscopy measurements accompanied with two-dimensional correlation spectroscopy (2Dcos) and perturbation correlation moving window (PCMW) analytical methods. Through the comparison of these two systems, it is revealed that PVCL chains can interact with PIPOZ chains directly through the polymer-water-polymer cross-linking hydrogen bonds (C[double bond, length as m-dash]OD-O-DO[double bond, length as m-dash]C), which induce their transition process as one. However, in the PIPOZ/PNIPAM mixture, the phase transition of the given component (PNIPAM or PIPOZ) is indirectly affected by the presence of the second component, because the strong hydrogen bonds C[double bond, length as m-dash]OD-N in PNIPAM components forbid the direct connection with PIPOZ, which induces two phase transition processes separately with no liquid-liquid phase separation (LLPS). Additionally, the formation of polymer-water-polymer hydrogen bonds (C[double bond, length as m-dash]OD-O-DO[double bond, length as m-dash]C) is highlighted as the key process in macroscopic LLPS.
More Related Videos
12:07Fabricating Degradable Thermoresponsive Hydrogels on Multiple Length Scales via Reactive Extrusion, Microfluidics, Self-assembly, and Electrospinning
Published on: April 16, 2018
06:26Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets
Published on: May 15, 2017
Related Concept Videos
Phase Transitions
Phase Transitions
Phase Transitions: Melting and Freezing
Phase Transitions: Vaporization and Condensation
Heating and Cooling Curves
For instance, the addition of heat raises the temperature of a solid; the amount of heat absorbed depends on the heat capacity of the solid (q = mcsolidΔT). According to thermochemistry, the relation between the amount of heat absorbed or released by a substance,...
States of Matter and Phase Changes