title: Catalysis, nanostructure and macroscopic property triangle in bioactive calcium-containing ceramic systems.
abstract: Calcium silicate ceramics are intended for application as long-term implant materials. In the present work, attention was paid to understand the correlations between the nanostructure (aggregate size, crystallinity, porosity) and the macroscopic properties (solubility in water and simulated body fluids, SBF; hardness) varying the chemical composition. Varying the catalyst (from a base to various acids) during the chemical synthesis was shown to significantly impact on the pore size, crystallinity and mechanical properties. The basic catalyst yields the ceramics with the highest mechanical strength. Ammonia used in 1.0 or 10.0 molar ratio results in bulk ceramics with parameters required for a biomedical application, good hardness (180-200 HV) and low solubility (1-3%) in water and in SBF. The fine porosity (~50 nm) and homogeneous amorphous structure induce good mechanical character.
authors.affiliation: Institute of Chemistry, L. Eötvös University, Budapest, H-1117, Hungary.
authors.forename: Anikó
authors.initials: A
authors.lastname: Meiszterics
authors.forename: Károly
authors.initials: K
authors.lastname: Havancsák
authors.forename: Katalin
authors.initials: K
authors.lastname: Sinkó
mesh_terms: D000641:Ammonia / Q000032:analysis; D001672:Biocompatible Materials / Q000737:chemistry*; D002118:Calcium / Q000737:chemistry*; D017610:Calcium Compounds / Q000737:chemistry; D002384:Catalysis; D002516:Ceramics / Q000737:chemistry*; D003460:Crystallization; D006244:Hardness; D008422:Materials Testing; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure; D010756:Phosphoric Acids / Q000737:chemistry; D017640:Silicates / Q000737:chemistry; D012995:Solubility; D013052:Spectrometry, X-Ray Emission; D017550:Spectroscopy, Fourier Transform Infrared; D013696:Temperature; D013997:Time Factors; D014961:X-Ray Diffraction
chemical_list: D001672:Biocompatible Materials; D017610:Calcium Compounds; D010756:Phosphoric Acids; D017640:Silicates; D000641:Ammonia; C030242:phosphoric acid; C031293:calcium silicate; D002118:Calcium
keywords: Bioceramic; Calcium silicate; Hardness; SEM; Solubility; Sol–gel process