Melamine -formaldehyde microcapsules: micro - and nanostructural characterization with electron microscopy

RIVERO GUADALUPE; HEIDARI, HAMED; IDRISSI, HOSNI; RAMACHANDRAN, DHANYA; CAKIR SEDA; EGOAVIL, RICARDO; KURTTEPELI, MERT; CRABBÉ, AMANDINE; HAUFFMAN, TOM; TERRYN, HERMAN; DU PREZ FILIP E.; SCHRYVERS, DOMINIQUE

MICROSCOPY & MICROANALYSIS

CAMBRIDGE UNIV PRESS

Lugar: Cambridge; Año: 2016 vol. 22 p. 1222 - 1232

1431-9276

A systematic study has been carried out to compare the surface morphology, shell thickness, mechanical properties and binding behavior of melamine formaldehyde icrocapsules of 5 to 30 µm diameter size with various amounts of core content by using scanning and transmission electron microscopy including electron tomography, in-situ nanomechanical tensile testing and electron energy-loss spectroscopy. It is found that porosities are present at the outside surface of the capsule shell but not at the inner surface of the shell. Nano-mechanical tensile tests on the capsule shells reveal that the Young?s modulus of the shell material is higher than that of bulk melamine formaldehyde and that the shells exhibit a larger fracture strain compared to the bulk. Core-loss elemental analysis of microcapsules embedded in epoxy indicates that during the curing process, the microcapsule-matrix interface remains uniform and the epoxy matrix penetrates into the surface microporosities of the capsule shells. Nota: H. Heidari y G. Rivero contribuyeron igualmente y son ambos 1er autor de la publicación.