Effect of Sol-Gel Ageing Time on Three Dimensionally Ordered Macroporous Structure of 80SiO2-15CaO-5P2O5 Bioactive Glasses

Abstract

Three dimensionally ordered macroporous bioactive glasses (3D0M-BGs), namely 80SiO2-15CaO-5P2O5, were synthesized by sol-gel method. PMMA colloidal crystals and non-ionic block copolymers P123 were used as cotemplates. The amorphous 3D0M-BGs had skeletal walls enclosing macropores. Such structure resulted from octahedral and tetrahedral holes of the face-centered cubic {fee) closest packed PMMA templates and windows interconnecting through macropores network. The thicknesses of the walls were around 50 nm-80 nm and the windows were 90 nm-110 nm in diameter. These wall thickness is increased by with an increase in ageing time up to 24 h and then gradually reduced with further increase in aging time. Vibration bands of Si-O-Si and P-O were evident in infrared spectra which are in agreement with EDS spectra indicating Si, P and Ca compositions. After in vitro bioactivity testing by soaking 3D0M-BGs in simulated body fluid at 37 °C, the crystallization of amorphous calcium phosphate layers compatible to the bone component of hydroxyl carbonate apatite were rapidly formed within 3 h. These results indicated that these 3D0M-BGs resembled ideal bone implant materials.

Synchrotron X-ray Absorption and In Vitro Bioactivity of Magnetic Macro/Mesoporous Bioactive Glasses

“…To examine the magnetic properties at room temperature, the magnetizations of the bioactive glass scaffolds in response to the varying magnetic fields between −10 kOe and 10 kOe were measured by means of vibrating sample magnetometry (VSM). In the in vitro bioactivity test at body temperature (37° C) using the Kokubo method [19], the samples 65S15Fe and 60S20Fe were immersed in the stimulated body fluid (SBF), whose composition and ionic concentration similar to human blood plasma was detailed in the previous report [20]. The formation of the apatite phase was monitored by FESEM after a half, one, three and five days.…”

A high energy output and low onset temperature nanothermite based on three-dimensional ordered macroporous nano-NiFe2O4

“…However, the poor dispersion is the common disadvantage of this kind. Three-dimensionally ordered macroporous (3DOM) structure with pores sized in the sub-micrometer range is a viable alternative to solve dispersion problem because of the stable porous structures and uniform pore size 15,16 .…”