Related Experiment Video
Updated: Jun 7, 2026

Preparation of Thermoresponsive Nanostructured Surfaces for Tissue Engineering
Published on: March 1, 2016
Steric stabilization of thermally responsive N-isopropylacrylamide particles by poly(vinyl alcohol)
1Department of Chemical Engineering, University of Rochester, Rochester, New York 14627, United States.
Abstract:
Poly(vinyl alcohol) (PVA) was used as a steric stabilizer for the dispersion polymerization of cross-linked poly(N-isopropylacrylamide) (PNIPAM) in water. A series of reactions were carried out using PVA of varying molecular weight and degree of hydrolysis. Under appropriate conditions, PNIPAM particles of uniform and controllable size were produced using PVA as the stabilizer. The colloidal stability was investigated by measuring changes in particle size with temperature in aqueous suspensions of varying ionic strength. For comparison, parallel colloidal stability measurements were conducted on PNIPAM particles synthesized with low-molecular-weight ionic surfactants. PVA provides colloidal stability over a wide range of temperature and ionic strength, whereas particles produced with ionic surfactants flocculate in moderate ionic strength solutions upon collapse of the hydrogel as the temperature is increased. Experimental results and theoretical consideration indicate that sterically stabilized PNIPAM particles resulted from the grafting of PVA to the PNIPAM particle surface. The enhanced colloidal stability afforded by PVA allows the temperature-responsive PNIPAM particles to be used under physiological conditions where electrostatic stability is ineffective.
More Related Videos
09:09Synthesis of Poly(N-isopropylacrylamide) Janus Microhydrogels for Anisotropic Thermo-responsiveness and Organophilic/Hydrophilic Loading Capability
Published on: February 27, 2016
08:39Magnetic and Thermal-sensitive Poly(N-isopropylacrylamide)-based Microgels for Magnetically Triggered Controlled Release
Published on: July 4, 2017
Related Concept Videos
Polymer Classification: Stereospecificity
Anionic Chain-Growth Polymerization: Overview
Radical Reactivity: Steric Effects
Along with electronic factors, steric factors also account...
Anionic Chain-Growth Polymerization: Mechanism
Cationic Chain-Growth Polymerization: Mechanism