AI Article Synopsis
- Charged colloids undergo thermoreversible crystallization as ionic surfactants adsorb onto their surfaces, causing them to crystallize when cooled and melt when heated.
- The study used polystyrene particles in mixtures of ethylene glycol and water, allowing for modulation of surfactant adsorption by adjusting the ethylene glycol concentration.
- Changes in ionic strength due to the temperature-dependent concentration of non-adsorbed surfactants were found to drive this crystallization and melting behavior, with implications for controlling colloidal materials in lower permittivity environments.
Article Abstract
We report that charged colloids exhibit thermoreversible crystallization via the adsorption of ionic surfactants onto particle surfaces. Due to the temperature dependence of the adsorption quantity, the colloids crystallized upon cooling and melted upon heating. To clarify the influences of surfactant adsorption on the crystallization, polystyrene (PS) particles dispersed in ethylene glycol (EG)/water mixtures were employed, enabling continuous tuning of the adsorption quantity by changing the EG concentration. The thermoreversible crystallization/melting behavior was found to be mainly attributable to changes in the ionic strength of the medium resulting from variation in the concentration of the non-adsorbed ionic surfactant molecules with temperature. We expect that the present findings will be useful for fine control of colloidal crystallization and the further study of colloidal crystallization in low permittivity media.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.jcis.2015.11.064 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Effect of Micellar Morphology on the Temperature-Induced Structural Evolution of ABC Polypeptoid Triblock Terpolymers into Two-Compartment Hydrogel Network.
Macromolecules
July 2024
Department of Chemistry and Macromolecular Studies Group, Louisiana State University, Baton Rouge, Louisiana 70803, United States.
Article Synopsis
- Scientists studied how a special type of gel, made from three different building blocks, changes when heated.
- At normal temperatures, these gels form tiny ball-like structures in water.
- When heated, the gel changes shape, forming a network that can look different based on the lengths of the building blocks used to make it.
A Spatially Stable Crystal-Particle Gel to Trap Patchouli Oil for Efficient Colonic Drug Delivery.
ACS Appl Mater Interfaces
June 2024
School of Pharmacy, Shanghai University of Traditional Chinese Medicine, Shanghai 201203, China.
Patchouli oil has exhibited remarkable efficacy in the treatment of colitis. However, its volatility and potential irritancy are often drawbacks when extensively used in clinical applications. Oil gel is a semisolid and thermoreversible system that has received extensive interest for its solubility enhancement, inhibition of bioactive component recrystallization, and the facilitation of controlled bioactive release.
View Article and Find Full Text PDFPoly(vinylidene fluoride) Aerogels with α, β, and γ Crystalline Forms: Correlating Physicochemical Properties with Polymorphic Structures.
ACS Polym Au
April 2024
Materials Science and Technology Division CSIR-National Institute for Interdisciplinary Science and Technology, Trivandrum 695 019 Kerala, India.
Strategic customization of crystalline forms of poly(vinylidene fluoride) (PVDF) aerogels is of great importance for a variety of applications, from energy harvesters to thermal and acoustic insulation. Here, we report sustainable strategies to prepare crystalline pure α, β, and γ forms of PVDF aerogels from their respective gels using a solvent exchange strategy with green solvents, followed by a freeze-drying technique. The crucial aspect of this process was the meticulous choice of appropriate solvents to enable the formation of thermoreversible gels of PVDF by crystallization-induced gelation.
View Article and Find Full Text PDFHybrid Polymer Salogels for Reversible Entrapment of Salt-Hydrate-Based Thermal Energy Storage Materials.
ACS Appl Eng Mater
March 2024
Department of Materials Science & Engineering, Texas A&M University, College Station, Texas 77843, United States.
One of the challenges preventing wide use of inorganic salt hydrate phase change materials (PCMs) is their low viscosity above their melting point, leading to leakage, phase segregation, and separation from heat exchanger surfaces in thermal management applications. The development of a broad strategy for using polymers that provide tunable, temperature-reversible shape stabilization of a variety of salt hydrates by using the lowest possible polymer concentrations is hindered by differences in solubility and gelation behavior of polymers with change in the type of ion. This work addressed the challenge of creating robust, temperature-responsive shape-stabilizing polymer gels (i.
View Article and Find Full Text PDFThermoreversible Gel-Dispersed Liquid Crystals.
Gels
December 2023
Department of Physics and Information Technology, Faculty of Computer Science and Systems Engineering, Kyushu Institute of Technology, Kawazu 680-4, Iizuka 820-8502, Fukuoka, Japan.
A simple model is introduced to describe phase behaviours of binary mixtures of a thermoreversible gel and a low-molecular-weight liquid crystal (LC). We predict novel phase diagrams on the temperature-concentration plane, including sol-gel transition, nematic-isotropic phase transition, and phase separation. At high temperatures, the phase separation between the isotropic sol and gel phases appears.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!