Manipulation of nanoneedle and nanosphere apatite/poly(acrylic acid) nanocomposites.
Colloidal apatitic nanosphere of 2-5 nm in diameter was synthesized in the presence of poly(acrylic acid), PAA. PAA, which has long been recognized as an inhibitor in the synthesis of hydroxyapatite, is used as a structure-directing agent for the synthesis of calcium-deficient apatite (CDHA) in this study. Experimental observation suggests a critical amount of the low-molecular-weight PAA, above which morphological evolution of CDHA nanoparticles from needle to sphere was observed. This reveals that the PAA acts as an inhibitor for the growth of CDHA crystals. Further incorporation of PAA of high molecular weight formed a highly optically transparent nanocomposite, even with the nanospherical apatite loading up to 35 wt %, suggesting no agglomeration. This was further justified through transmission electron microscopy (TEM), where the CDHA nanospheres were uniformly distributed in the PAA-CDHA nanocomposites. No interfacial crevices were visually observed, indicating a highly compatible interface between the inorganic CDHA and organic PAA phase.
Liou
Sz-Chian
SC
Department of Materials Science and Engineering, National Chiao Tung University, 1001 Ta-hsueh Road, Hsinchu, Taiwan 300, Republic of China.
Chen
San-Yuan
SY
Liu
Dean-Mo
DM
D000180:Acrylic Resins / Q000737:chemistry*; D000838:Anions; D001031:Apatites / Q000737:chemistry; D001672:Biocompatible Materials / Q000737:chemistry* / Q000494:pharmacology; D001709:Biotechnology / Q000379:methods*; D002118:Calcium / Q000737:chemistry; D003102:Colloids / Q000737:chemistry; D003460:Crystallization; D017886:Durapatite / Q000737:chemistry; D007477:Ions; D008422:Materials Testing; D046529:Microscopy, Electron, Transmission; D008863:Microspheres; D036103:Nanotechnology / Q000379:methods*; D043942:Nanotubes; D014961:X-Ray Diffraction
D000180:Acrylic Resins; D000838:Anions; D001031:Apatites; D001672:Biocompatible Materials; D003102:Colloids; D007477:Ions; C006903:carbopol 940; D017886:Durapatite; D002118:Calcium