Related Experiment Video
Updated: Jul 2, 2025
09:11
Alternating Magnetic Field-Responsive Hybrid Gelatin Microgels for Controlled Drug Release
Published on: February 13, 2016
9.8K
Nonionic Microgels Adapt to Ionic Guest Molecules: Superchaotropic Nanoions
Jasmin Simons1, Nabanita Hazra1, Alexander V Petrunin1
1Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, DE-52074 Aachen, Germany.
ACS Nano
|February 28, 2024
Summary
Superchaotropic polyoxometalates (POMs) induce tunable swelling and deswelling in poly(N-isopropylacrylamide) (pNiPAM) microgels by altering their charge and acting as cross-links. This reveals POMs as effective agents for modifying microgel properties.
Area of Science:
- Materials Science
- Polymer Chemistry
- Soft Matter Physics
Background:
- Microgels are versatile solute carriers whose properties depend on solute interactions.
- Polyoxometalates (POMs) are ionic solutes with unique properties relevant for material modification.
Purpose of the Study:
- To investigate the impact of superchaotropic Keggin POMs (PW and SiW) on the swelling and internal structure of nonionic poly(N-isopropylacrylamide) (pNiPAM) microgels.
- To understand the mechanisms behind POM-induced swelling and deswelling in microgels.
- To explore the potential of POMs for fine-tuning microgel properties.
Main Methods:
- Light scattering techniques.
- Small-angle X-ray scattering (SAXS).
Main Results:
- POM binding induces microgel swelling at low concentrations due to counterion osmotic pressure and deswelling at higher concentrations via physical cross-linking.
- The swelling/deswelling transition is sharper for PW than SiW, attributed to PW's lower charge density and stronger binding.
- Microgel network softness and topology significantly influence the swelling response to POM binding.
- POM/pNiPAM systems exhibit both temperature and pH-responsive swelling.
Conclusions:
- POMs offer a novel method for controlling microgel swelling and internal structure, distinct from traditional salts or surfactants.
- Microgel network architecture plays a crucial role in mediating responses to external stimuli like POMs.
- These findings open avenues for designing advanced functional microgels with tunable properties for various applications.
Keywords:
Hofmeister SeriesMicrogelsPolyoxometalateResponsive MaterialSuperchaotropicSwelling BehaviorMore Related Videos
10:01Thermal Scanning Conductometry TSC as a General Method for Studying and Controlling the Phase Behavior of Conductive Physical Gels
Published on: January 23, 2018
7.6K
11:34Controlled Synthesis and Fluorescence Tracking of Highly Uniform PolyN-isopropylacrylamide Microgels
Published on: September 8, 2016
10.3K
Related Concept Videos
01:19Complexation Equilibria: The Chelate Effect
514
In complexation reactions, metal atoms or cations interact with ligands to form donor-acceptor adducts called metal complexes. Ligands that bind through one donor site are monodentate, ligands with two donor sites are bidentate, and those with more than two donor sites are polydentate ligands. For example, ethylene diamine is a bidentate ligand that binds through two nitrogen donor atoms, forming a five-membered ring. EDTA is a polydentate ligand that binds through four oxygen and two nitrogen...
514
01:17Ion Exchange
592
Ion exchange chromatography separates charged molecules from a solution by reversibly exchanging them with mobile, or 'active', ions associated with the oppositely charged stationary phase. This method can be used to separate ions, soften and deionize water, and purify solutions. The polymers comprising the ion-exchange column are high-molecular-weight and chemically stable polymers, crosslinked to be porous and essentially insoluble. They are also functionalized with either acidic or...
592
03:13Intermolecular Forces
58.3K
Atoms and molecules interact through bonds (or forces): intramolecular and intermolecular. The forces are electrostatic as they arise from interactions (attractive or repulsive) between charged species (permanent, partial, or temporary charges) and exist with varying strengths between ions, polar, nonpolar, and neutral molecules. The different types of intermolecular forces are ion–dipole, dipole–dipole, hydrogen bonds, and dispersion; among these, dipole–dipole, hydrogen...
58.3K
01:17Pore Transport and Ion-Pair Transport
451
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct...
451
02:42Aqueous Solutions and Heats of Hydration
14.7K
Water and other polar molecules are attracted to ions. The electrostatic attraction between an ion and a molecule with a dipole is called an ion-dipole attraction. These attractions play an important role in the dissolution of ionic compounds in water.
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
When ionic compounds dissolve in water, the ions in the solid separate and disperse uniformly throughout the solution because water molecules surround and solvate the ions, reducing the strong electrostatic forces between them. This process...
14.7K
01:30Ligand-Gated Ion Channel Receptor: Gating Mechanism
2.2K
Ligand-gated ion channels are transmembrane proteins that play a vital role in intercellular communication and functions of the nervous system. They allow the influx of ions across the membrane once the neurotransmitter binds, allowing the subsequent transmission of electrical excitation across the neurons. Other ligand-gated ion channels, like the γ-aminobutyric acid (GABA) receptor, permit anions like chloride into the cells on the binding of the GABA molecule. Their entry into the cell...
2.2K