Tuneable Functionalization of Glass Fibre Membranes with ZnO/SnO2 Heterostructures for Photocatalytic Water Treatment: Effect of SnO2 Coverage Rate on the Photocatalytic Degradation of Organics

The construction of a ZnO/SnO2 heterostructure is considered in the literature as an efficient strategy to improve photocatalytic properties of ZnO due to an electron/hole delocalisation process. This study is dedicated to an investigation of the photocatalytic performance of ZnO/SnO2 heterostructures directly synthesized in macroporous glass fibres membranes. Hydrothermal ZnO nanorods have been functionalized with SnO2 using an atomic layer deposition (ALD) process. The coverage rate of SnO2 on ZnO nanorods was precisely tailored by controlling the number of ALD cycles. We highlight here the tight control of the photocatalytic properties of the ZnO/SnO2 structure according to the coverage rate of SnO2 on the ZnO nanorods. We show that the highest degradation of methylene blue is obtained when a 40% coverage rate of SnO2 is reached. Interestingly, we also demonstrate that a higher coverage rate leads to a full passivation of the photocatalyst. In addition, we highlight that 40% coverage rate of SnO2 onto ZnO is sufficient for getting a protective layer, leading to a more stable photocatalyst in reuse.

In vitro antibacterial capacity and cytocompatibility of SiO2–CaO–P2O5 meso-macroporous glass scaffolds enriched with ZnO

The biocompatibility and the antibacterial capability of meso-macroporous bioactive glass scaffolds in the SiO2–CaO–P2O5–ZnO system were investigated. Zn2+ ions release greatly influenced the osteoblast cell development and provides antibacterial capability against S. aureus.

Glass-Ceramic Scaffolds and Shock Waves Effect on Cells Migration

Glass-ceramic scaffolds for bone grafting have been prepared using the sponge replication method and a highly bioactive silica based glass belonging to the system SiO2-P2O5- CaO-MgO-Na2O-K2O (CEL2). The parameters for the sponge impregnation were optimized in order to obtain a continuous coating of the polymeric skeleton which will lead, after the polymeric phase removal, to a resistant macroporous glass-ceramic template. A complete characterization was carried out on the obtained scaffold in order to assess its morphology and specifically its porosity and the degree of pores interconnection. A human osteoblasts cells line (MG-63) was cultured onto the scaffold and the effect of stimulation with shock waves on the cell ability of colonizing the scaffold was investigated.

Preparation of Macroporous Glass-Ceramic Composites Containing β-TCP

A macroporous phosphate invert glass ceramic (PIGC) was prepared by dipping polymer sponges in the powder-slurry of the mother glass with a composition of 60CaO-30P2O-3TiO2- 7Na2O in mol%, and subsequent burning off the sponge at 850°C for 1 hr. The macroporous PIGC consists predominantly of ß-tricalcium phosphate (β-TCP) and ß-calcium pyrophosphate, and it has macropores of 500 μm in diameter and porosity of 83 %. Its compressive strength was estimated to be 160 kPa. The PIGC composite containing a large amount of β-TCP was also prepared by heating the mixture of Ca(OH)2 with the mother glass powders of the PIGC. Solubility of the composite was higher than PIGC. The macroporous PIGC and PIGC composite were expected to be applicable in high resorbable scaffolds for bone tissue engineering.