Hydroxy propyl cellulose capped silver nanoparticles produced by simple dialysis process

Silver (Ag) nanoparticles (∼6 nm) were synthesized using a novel dialysis process. Silver nitrate was used as a starting precursor, ethylene glycol as solvent and hydroxy propyl cellulose (HPC) introduced as a capping agent. Different batches of reaction mixtures were prepared with different concentrations of silver nitrate (AgNO3). After the reduction and aging, these solutions were subjected to ultra-violet visible spectroscopy (UVS). Optimized solution, containing 250 mg AgNO3 revealed strong plasmon resonance peak at ∼410 nm in the spectrum indicating good colloidal state of Ag nanoparticles in the diluted solution. The optimized solution was subjected to dialysis process to remove any unreacted solvent. UVS of the optimized solution after dialysis showed the plasmon resonance peak shifting to ∼440 nm indicating the reduction of Ag ions into zero-valent Ag. This solutionwas dried at 80 8C and the resultant HPC capped Ag (HPC/Ag) nanoparticles were studied using transmission electron microscopy (TEM) for their particle size and morphology. The particle size distribution (PSD) analysis of these nanoparticles showed skewed distribution plot with particle size ranging from 3 to 18 nm. The nanoparticles were characterized for phase composition using X-ray diffractrometry (XRD) and Fourier transform infrared spectroscopy (FT-IR). © 2010 Elsevier Ltd. All rights reserved

Sol-gel synthesis of forsterite nanopowders with narrow particle size distribution

Forsterite (FS) nanopowders (∼27 nm) were synthesized using a sol-gel route with magnesium nitrate hexahydrate and tetra ethyl ortho-silicate as magnesium and silicon precursors, respectively. Nitric acid was used as a catalyst. After aging, the FS gel was calcined at 800 °C for 30 min. The calcined powders were characterized for phase composition using X-ray diffractrometry and fourier transform-infrared spectroscopy. The particle size and morphology was studied using transmission electron microscopy. The particle size distribution analysis of FS powders showed skewed distribution plot with particle size ranging from 5-90 nm. This study showed that high phase purity and narrowly distributed FS nanoparticles could be obtained using this simple sol-gel technique. © 2010 Elsevier B.V. All rights reserved

Synthesis of nano hydroxyapatite powder that simulate teeth particle morphology and composition

A simple sol-gel precipitation technique to synthesize nano hydroxyapatite (HA) particles (∼30 nm) that show similar morphology, size and crystallinity to HA crystals of human teeth is reported. Calcium nitrate tetrahydrate and potassium dihydrogenphosphate were used as calcium and phosphorus precursors, respectively. Double distilled water was used as a diluting media for HA sol preparation and ammonia was used to adjust the pH to 11. After aging, the HA gel was dried at 40 °C and calcined to different temperatures ranging from 200 to 600 °C. The dried and calcined powders were characterized for phase composition using X-ray diffractrometry, and Fourier transform infra-red spectroscopy. The particle size and morphology was studied using Transmission electron microscopy. The particle size distribution analysis of HA powders showed skewed distribution plot. The phase and particle characterization studied above showed that HA calcined at 600 °C simulate HA crystals of teeth. © 2009 Elsevier B.V. All rights reserved

Synthesis and characterization of porous silicon as hydroxyapatite host matrix of biomedical applications

In this work, porous-silicon samples were prepared by electrochemical etching on p-type (Bdoped) Silicon (Si) wafers. Hydrofluoric acid (HF)-ethanol (C2H5OH) [HF:Et] and Hydrofluoric acid (HF)-dimethylformamide (DMF-C3H7NO) [HF:DMF] solution concentrations were varied between [1:2]-[1:3] and [1:7]-[1:9], respectively. Effects of synthesis parameters, like current density, solution concentrations, reaction time, on morphological properties were studied by scanning electron microscopy (SEM) and atomic force microscopy (AFM) measurements. Pore sizes varying from 20 nm to micrometers were obtained for long reaction times and [HF:Et] [1:2] concentrations; while pore sizes in the same order were observed for [HF:DMF] [1:7], but for shorter reaction time. Greater surface uniformity and pore distribution was obtained for a current density of around 8 mA/cm2 using solutions with DMF. A correlation between reflectance measurements and pore size is presented. The porous-silicon samples were used as substrate for hydroxyapatite growth by sol-gel method. X-ray diffraction (XRD) and SEM were used to characterize the layers grown. It was found that the layer topography obtained on PS samples was characterized by the evidence of Hydroxyapatite in the inter-pore regions and over the surface. © 2017 Dussan et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited