In the present study, ZrB2 nano powders were synthesized using sol-gel method. Zirconium alkoxide was used as the source of zirconium and boric acid as the source of boron. The size of precursor nanoparticle was controlled using the pH parameter inside the sol, and the More
In the present study, ZrB2 nano powders were synthesized using sol-gel method. Zirconium alkoxide was used as the source of zirconium and boric acid as the source of boron. The size of precursor nanoparticle was controlled using the pH parameter inside the sol, and the formation of primary nuclei of ZrB2 phase and their crystallized amount were investigated using the temperature parameter. To evaluate the mechanism of product formation during the sol-gel process, DLS analysis showed that the size of precursor particle inside the sol at pH less than 5 was below 10 nm. Mixing of precursor particles at molecular level inside the sol was one of the important reasons in reducing the synthesis temperature of ZrB2 particles. FTIR analysis on chemical bonds showed that Zr-O-B bond was formed inside the gel powder.DTA analysis showed that the primary nuclei of ZrB2 particles were formed at a temperature of about 1400 °C. XRD observations proved that the primary nuclei of the ZrB2 phase crystallized and grew at a temperature of about 1500°C. Surface research revealed that the specific surface area of the synthesized ZrB2 particles is equivalent to 115 m2/g, and also the surfaces of these particles are porous, and the size of these porosities is in meso range. SEM analysis showed that the particle size of ZrB2 having homogeneous morphology is about 50 nm. TEM microstructural analysis revealed that ZrB2 particles were formed uniformly and orderly in very fine dimensions.
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In this paper, nano-composite powder of TiO2 and multi-walled carbon nanotubes (CNTs) was synthesized by in-situ sol-gel method. The effect of processing parameters of benzyl alcohol, H2O and CNT content (1 and 10 wt.%) on the prepared powder morphology was investigated More
In this paper, nano-composite powder of TiO2 and multi-walled carbon nanotubes (CNTs) was synthesized by in-situ sol-gel method. The effect of processing parameters of benzyl alcohol, H2O and CNT content (1 and 10 wt.%) on the prepared powder morphology was investigated. The samples were characterized via field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD) analysis. Firstly, the influence of calcination stage on the powders structure was evaluated. XRD results showed amorphous structures for the composite powders before calcination and the dominant structure of anatase TiO2 after calcination treatment. FESEM results showed a non-uniform and agglomerated morphology without benzyl alcohol. Furthermore, addition of Tetrabutyl-orthotitanate solution to the initial solution containing H2O as the hydrolysis agent resulted in finer powder microstructure with uniform coating of TiO2 on CNTs due to slower hydrolysis reaction. The effect of CNTs on the morphology depends on percent of CNTs. Also, composite powder with higher particle size was formed with the decrease of CNT content from 10 to 1 percent which is attributed to the decreased and less accessible surface area to TiO2 particles formation.
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The major aim of this study was to evaluate the effect of CaO content on in vitro hydroxyapatite formation, MC3T3cells cytotoxicity and proliferation as well as antibacterial efficiency of sol-gel derived SiO2–CaO–P2O5 ternary system. For this purpose, first More
The major aim of this study was to evaluate the effect of CaO content on in vitro hydroxyapatite formation, MC3T3cells cytotoxicity and proliferation as well as antibacterial efficiency of sol-gel derived SiO2–CaO–P2O5 ternary system. For this purpose, first two grades of bioactive glass (BG); BG-58s (mol%: 60%SiO2–36%CaO–4%P2O5) and BG-68s (mol%: 70%SiO2–26%CaO–4%P2O5)) with the fixed P2O5 content were synthesized by sol-gel method. Second, the effect of CaO content in their composition on in vitro bioactivity was investigated by soaking the BG-58s and BG-68s powders in simulated body fluid (SBF) for time periods up to 14 days. The evolution of the SBF composition was monitored by inductively coupled plasma atomic emission spectrometry (ICP-AES) analyses. Additionally, Fourier transform infrared (FTIR), X-ray diffraction (XRD) and scanning electron microscopy (SEM) were performed to characterize formed hydroxyapatite on BG's surface. On the other hand, Live/dead staining, 3-(4,5dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and alkaline phosphatase (ALP) activity assays were conducted respectively, as qualitatively and quantitatively assess for cell viability, proliferation and differentiations of MC3T3cells in presence of 58s and 68s BGs. Eventually, BG-58s with enhanced MC3T3 cells proliferation and ALP activity, acceptable bioactivity and significant high antibacterial effect against MRSA bacteria is suggested as a suitable candidate in comparison to BG-68S in order to further functionalizing for delivery of therapeutic ions and growth factors in bone tissue engineering.
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