Advanced Nano-Bio-Materials and Devices – AdvNanoBioMD 2022; Vol 6; Issue 4 is now being populated. Thank you for all the contributors and reviewers!
Advanced Nano-Bio-Materals and Devices – AdvNanoBioMD 2022; Vol 6; Issue 4 (December 30)
Nanohydroxyapatites are at the forefront of biomaterials due to their biocompatible and bioactive properties, as well as promoting osseointegration due to their size. However, the weak mechanical properties of hydroxyapatites limit their use in areas that will be exposed to load transfer. In this study, the mechanical, structural and bioactivity properties of nanohydroxyapatite were investigated by doping nano zinc oxide. 90% nano hydroxyapatite with 10 wt % nano ZnO and 90 wt. % nano hydroxyapatite with 10 wt. % nano CIG by weight were subjected to mechanical alloying process separately for 4 hours. Afterwards, the mixtures were sintered at 760°C for 30 minutes by hot press method. Density value of hydroxyapatite composite with zinc oxide added after sintering is 2.94 g/cm3, Vickers hardness value is 380 HV, compression strength value is 127 MPa. The density of the commercial inert glass added hydroxyapatite composite was 2.76 g/cm3, the Vickers hardness value was 290 HV, and the compression strength value was 82 MPa.
In the present work powder morphology and kinetics of adsorption-desorption of water vapor on magnetite nanopowder prepared by chemical precipitation method from iron chlorides in the presence of hydrazine as well as its specific surface area and skeleton density have been investigated. It was established that synthesized magnetite nanopowder has a quite uniform particles size distribution and particles (33-84 nm) with a regular close to spherical shape. According to BET results synthesized magnetite (skeleton density 3.42±0.02 g/cm3) can be characterized as a microporous material with specific surface area, pore volume and average pore diameter equal to 28 m2/g, 0.01 cm3/g and 2 nm, respectively. The study of adsorption-desorption kinetics of water vapors on magnetite nanopowder showed that adsorption rate depends on humidity. At 100 % humidity adsorption rate stabilizes during 0.5-4.5 h and after maintaining powder at 100 % humidity for 24 hours the reduced adsorbed weight reached the value 0.42. It was shown that desorption process depends on the rate of temperature increasing. Thus, the desorption of adsorbed water ends after 24 min and 1 h at the rate of temperature increasing 5 °C/min and 1 °C/min, respectively. The most intensive desorption process take place in the range of 35–55 °C at 55 % humidity. Obtained results could be useful for magnetite nanopowder storage after synthesis and predicting the adsorption properties of composite based on it.