Premium
Melamine Formaldehyde Core Decomposition as the Key Step Controlling Capsule Integrity: Optimizing the Polyelectrolyte Capsule Fabrication
Author(s) -
Gao Changyou,
Moya Sergio,
Donath Edwin,
Möhwald Helmuth
Publication year - 2002
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/1521-3935(20020401)203:7<953::aid-macp953>3.0.co;2-k
Subject(s) - permeation , polyelectrolyte , capsule , acrylic acid , chemical engineering , melamine resin , materials science , polymer chemistry , decomposition , formaldehyde , chemistry , nanotechnology , copolymer , composite material , membrane , polymer , organic chemistry , coating , biochemistry , botany , engineering , biology
Capsule integrity as a function of the acid concentration, the acid‐adding sequence, the outermost layer of the deposited multilayers, and the capsule wall thickness was investigated using confocal laser scanning microscopy. Optimal conditions for fabricating good quality polyelectrolyte capsules templated on melamine formaldehyde (MF) particles are elaborated. Intact capsules in a yield of higher than 90% can be normally obtained by injecting a small amount of MF particles coated with 10 polyelectrolyte layers (with positively charged species as the outermost layer) into a large amount of acid solution at pH 1.1. The capsule integrity depends on the interplay between the rate of the core decomposition and the permeation of the degraded products through the capsule walls. A larger permeability and an appropriate core‐decomposition speed would be favorable for releasing the tension, thus facilitating the permeation of intact capsules.