Related Experiment Video
Updated: Jul 3, 2026

Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers
Published on: June 20, 2019
Self-assembly of poly(ethylene oxide)-block-poly(acrylic acid) induced by CaCl2: mechanistic study
H Ronny Sondjaja1, T Alan Hatton, K C Tam
1Singapore-MIT Alliance, National University of Singapore, Singapore, Singapore.
Abstract:
The interaction between CaCl 2 and double hydrophilic block copolymer, poly(ethylene oxide) 45- block-poly(acrylic acid) 70, PEO 45- b-PAA 70, was investigated. At a stoichiometric ratio of Ca2+:COO (-) = 0.5, Ca2+ ions were bound to COO (-) groups on PAA segments via electrostatic interaction. Small particles of 4-8 nm in diameter were observed, suggesting the formation of coil-like polymeric globule induced by charge neutralization. At Ca2+:COO (-) >or= 2.5, monodispersed aggregates of average hydrodynamic diameter of 52.0 +/- 7.4 nm were produced. The ISE, ITC, surface tension and fluorescence spectroscopic data confirmed that the formation of these aggregates is not the result of interaction between excess Ca2+ ions and the polymer, but rather it is due to changes in the water activity that triggers the structural rearrangement of Ca2+/PEO 45- b-PAA 70 complex.
More Related Videos
09:02Using Polystyrene-block-poly(acrylic acid)-coated Metal Nanoparticles as Monomers for Their Homo- and Co-polymerization
Published on: July 9, 2015
10:53Anionic Polymerization of an Amphiphilic Copolymer for Preparation of Block Copolymer Micelles Stabilized by π-π Stacking Interactions
Published on: October 10, 2016
Related Concept Videos
Cationic Chain-Growth Polymerization: Mechanism
Anionic Chain-Growth Polymerization: Overview
Anionic Chain-Growth Polymerization: Mechanism