title: Synthesis of CaO-SiO2-P2O5 mesoporous bioactive glasses with high P2O5 content by evaporation induced self assembly process.
abstract: Mesoporous bioactive glasses (MBGs) of the CaO-SiO(2)-P(2)O(5) system containing relatively high P(2)O(5) contents (10-30 mol%) were prepared from a sol-gel. An evaporation-induced self-assembly (EISA) technique was used with poly(ethylene oxide)-block-poly(propylene oxide)-block-poly(ethylene oxide) (EO(20)-PO(70)-EO(20), P123) acting as a template. The structural, morphological and textural properties of MBGs were investigated by small-angle X-ray diffraction (SAXRD), transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy and a N(2) sorption/desorption technique. SAXRD and TEM results display the reduced long-range ordering of mesopores with increasing P(2)O(5) content. N(2) sorption/desorption analysis shows that all three samples exhibit a type IV isotherm with type H1 hysteresis loops, characteristic of independent cylindrical slim pore channels and this material has a Barret-Joyner-Halenda (BJH) model pore size of ~4 nm and BET specific surface area ~430 m(2)/g. NMR results indicate a more condensed framework for samples with 30 mol% P(2)O(5) than samples with 10 mol% P(2)O(5). For in vitro bioactivity tests where samples were soaked in simulated body fluid (SBF), samples with 30 mol% P(2)O(5) showed higher crystallinity than those with lower P(2)O(5) contents Silicon concentration increased in SBF solution during the soaking period, which indicates MBGs can be degradable in SBF solution.
authors.affiliation: State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing University of Technology, Nanjing, 210009, People's Republic of China.
authors.forename: Shan
authors.initials: S
authors.lastname: Zhao
authors.forename: Yanbao
authors.initials: Y
authors.lastname: Li
authors.forename: Dongxu
authors.initials: D
authors.lastname: Li
mesh_terms: D001672:Biocompatible Materials / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry*; D003460:Crystallization; D005898:Glass / Q000737:chemistry*; D006801:Humans; D008422:Materials Testing; D008855:Microscopy, Electron, Scanning / Q000379:methods; D046529:Microscopy, Electron, Transmission / Q000379:methods; D009584:Nitrogen / Q000737:chemistry; D010087:Oxides / Q000737:chemistry*; D017553:Phosphorus Compounds / Q000737:chemistry*; D010949:Plasma / Q000378:metabolism; D011092:Polyethylene Glycols / Q000737:chemistry; D011126:Polypropylenes / Q000737:chemistry; D012822:Silicon Dioxide / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000379:methods; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D010087:Oxides; D017553:Phosphorus Compounds; D011126:Polypropylenes; D011092:Polyethylene Glycols; C012500:phosphorus pentoxide; D012822:Silicon Dioxide; D009584:Nitrogen; D002118:Calcium