APATITE ORGANIC POLYMER COMPOSITES PREPARED BY A BIOMIMETIC PROCESS -IMPROVEMENT IN ADHESION OF THE APATITE LAYER TO THE SUBSTRATE BY ULTRAVIOLET-IRRADIATION

Citation
Gj. Liu et al., APATITE ORGANIC POLYMER COMPOSITES PREPARED BY A BIOMIMETIC PROCESS -IMPROVEMENT IN ADHESION OF THE APATITE LAYER TO THE SUBSTRATE BY ULTRAVIOLET-IRRADIATION, Journal of materials science. Materials in medicine, 9(5), 1998, pp. 285-290
Citations number
21
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Engineering, Biomedical","Materials Science, Biomaterials
ISSN journal
0957-4530
Volume
9
Issue
5
Year of publication
1998
Pages
285 - 290
Database
ISI
SICI code
0957-4530(1998)9:5<285:AOPCPB>2.0.ZU;2-H
Abstract
A dense and uniform layer of highly bioactive apatite can be formed in arbitrary thickness on any kind and shape of organ ic polymer substra tes by the following biomimetic process. The substrate is first placed in contact with granular particles of CaO, SiO2-based glass soaked in a simulated body fluid with ion concentrations nearly equal to those of human blood plasma for forming apatite nuclei, and then soaked in a nother fluid highly supersaturated with respect to the apatite for mak ing the apatite nuclei grow. In the present study, the polymer substra tes were pretreated with ultraviolet (UV) light, and then subjected to the biomimetic process described above. By UV irradiation, the induct ion period for the apatite nucleation of poly(ethylene terephthalate) (PET), poly-ether sulphone (PESF), polyethylene (PE), poly(methyl meth acrylate) (PMMA) and polyamide 6 (N6) substrates were reduced form 24 h to 10 h. The adhesive strengths of the apatite layer to the substrat es increased from 2.5-3.2 MPa to 4.5-6.0 MPa for PET, PESF and PMMA, a nd from about 1.0 MPa to 4.0-6.5 MPa for PE and N6 substrates. These r esults have been explained by assuming that silicate ions, which induc e apatite nucleation, are easily adsorbed on the substrates due to the formation of polar groups, with an improved hydrophilic nature, on th e polymer surfaces by UV irradiation. (C) 1998 Chapman & Hall.