Biofilms of cellulose and hydroxyapatite composites: Alternative synthesis process

A new biofilm of cellulose coated with hydroxyapatite particles have been prepared using a simple, fast and low temperature process based on a microwave-assisted hydrothermal synthesis. The cellulose used as matrix of the biocomposite was extracted from banana stems residues. The hydroxyapatite coating was performed using calcium nitrate tetrahydrate, phosphoric acid, and 1,2-ethylenediamine dispersed in a cellulose/water solution, with posterior microwave-assisted hydrothermal synthesis, for 5 min at 140°C. The chemical, structural, thermal, and morphological properties of the composites were investigated by X-ray diffraction, infrared spectroscopy, thermogravimetry and field emission scanning electron microscopy. Results showed that the methodology was effective to produce high quality composites, with good thermal stability. Cell viability tests indicated that the cellulose/Hap films were not cytotoxic.

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Study of Nano-Hydroxyapatite Adsorption in Heavy Metals

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.777.15 ◽

2013 ◽

Vol 777 ◽

pp. 15-18 ◽

Cited By ~ 2

Author(s):

Jiu Xu Liu ◽

Feng Wang ◽

Jian Xing Shen ◽

Qi Hui Lai ◽

Ying Gai

Keyword(s):

Aqueous Solutions ◽

Inductively Coupled Plasma ◽

Raw Materials ◽

Calcium Nitrate ◽

Precipitation Method ◽

Calcium Nitrate Tetrahydrate ◽

X Ray Diffraction ◽

Absorption Function ◽

Inductively Coupled ◽

Nitrate Tetrahydrate

nanohydroxyapatite (nanoHA) powders were prepared by liquid phase precipitation method, using diammonium hydrogen phosphate and calcium nitrate tetrahydrate as raw materials. It was studied that the prepared nanoHA powders not sintered and sintered at 800°C to adsorption of Cu2+ and Pb2+ in aqueous solutions, respectively. The structure and size of nanoHA powders was investigated by X-ray diffraction (XRD) and the concentrations of Cu2+and Pb2+ in aqueous solutions were tested by inductively coupled plasma emission spectrometer. The results revealed that the nanoHA powders have obvious absorption function for Cu2+ and Pb2+ in aqueous solutions. In addition, the absorption ratio was affected by the size of nanoHA.

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Apatite Formation on PDMS-Modified SiO2-CaO-P2O5 Hybrids Prepared with Different P2O5 Content by Sol-Gel Method

Materials Science Forum ◽

10.4028/www.scientific.net/msf.449-452.1121 ◽

2004 ◽

Vol 449-452 ◽

pp. 1121-1124 ◽

Cited By ~ 2

Author(s):

Do Won Seo ◽

J.G. Kim ◽

Yun Hae Kim ◽

Chin Myung Whang

Keyword(s):

Sol Gel ◽

Calcium Nitrate ◽

Apatite Formation ◽

Calcium Nitrate Tetrahydrate ◽

X Ray Diffraction ◽

Phosphate Ions ◽

P2o5 Content ◽

Sol Gel Process ◽

Nitrate Tetrahydrate

Bioactive ORMOSILS (organically modified silicate), PDMS-CaO-SiO2-P2O5 with five different P2O5 content (0, 0.01, 0.03, 0.06, 0.09 mol%) have successfully been synthesized by sol-gel process. The hybrids have been prepared with polydimethylsiloxane (PDMS), tetraethoxysilane (TEOS), calcium nitrate tetrahydrate [Ca(NO3)2 4H2O] and triethyl phosphate (TEP) as starting materials and subsequently soaked into the simulated body fluid (SBF) for different period of time and the bioactivity of hybrids was determined by examining the apatite formation on the surface of the specimen by FT-IR, Thin-Film X-ray Diffraction, and Scanning Electron Microscopy (SEM). All of the prepared samples with different P2O5 content showed in vitro bioactivity. It was observed that the increase in P2O5 content up to 0.03 mole % increases the apatite formation compared to P2O5- free hybrids. However, further increase in P2O5 concentration slows down the formation of the apatite layer most probably due to the decrease of pH of SBF by dissolution of a large amount of phosphate ions.

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Synthesis of Strontium Substituted Hydroxyapatite through Different Precipitation Routes

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.674.3 ◽

2016 ◽

Vol 674 ◽

pp. 3-8 ◽

Cited By ~ 4

Author(s):

Liga Stipniece ◽

Kristine Salma-Ancane ◽

Dagnija Loca ◽

Sintija Pastare

Keyword(s):

Significant Proportion ◽

Calcium Nitrate ◽

Absorption Spectrometry ◽

Calcium Nitrate Tetrahydrate ◽

Strontium Nitrate ◽

X Ray Diffraction ◽

Spectrometry Analysis ◽

Nitrate Tetrahydrate ◽

Strontium Hydroxide ◽

Materials Used

The aim of this work was to evaluate the effect of precursor materials used in the synthesis on the Sr incorporation levels into the hydroxyapatite (HAp) lattice and to characterize the synthesis products. HAp powders containing various amounts of Sr were synthesized through three different precipitation routes. In all cases, the as-synthesized products were found to be pure HAp. However, atomic absorption spectrometry analysis showed that by reacting orthophosphoric acid with calcium hydroxide and strontium hydroxide, as well as by reacting diammonium hydrogen phosphate with calcium nitrate tetrahydrate and strontium nitrate a significant proportion of the Sr added, did not substitute into the HAp lattice. X-ray diffraction analysis revealed that the effect of substituting relatively high amounts (up to 3.69 ± 0.37 wt.%) of Sr into the HAp lattice was to decrease the cristallinity. Brunauer-Emmett-Teller (nitrogen absorption) analysis showed that the incorporation of Sr reduced particle sizes of the precipitated HAp products. Contrary, scanning electron microscopy revealed that the incorporation of Sr increased length of the precipitated needle-like particles.

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A Novel Mixed Hydroxide Method for Hydroxyapatite Preparation

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.152-153.1399 ◽

2010 ◽

Vol 152-153 ◽

pp. 1399-1403 ◽

Cited By ~ 1

Author(s):

Mei Mei Zhang ◽

Hong Shi Zhao ◽

Hong Liu ◽

Jian An Liu ◽

Xiu Xiu Han ◽

...

Keyword(s):

Raw Materials ◽

Calcium Nitrate ◽

Nano Particles ◽

Calcium Nitrate Tetrahydrate ◽

X Ray Diffraction ◽

Transmission Electron ◽

Nitrate Tetrahydrate ◽

Pure Phase ◽

Temperature Time ◽

Nano Size

Hydroxyapatite(HAP) nanoparticles were synthesized by a mixed hydroxide method using calcium nitrate tetrahydrate[Ca(NO3)24H2O] and phosphoric pentoxide(P2O5) as raw materials. The synthesized nanoparticles were analyzed by x-ray diffraction (XRD), infrared spectroscopy (IR) and transmission electron microscopy (TEM) methods. The effects of reaction temperature, time and concentration of reactants on the microstructure of the nano-particles have been discussed. The results show that the hydroxyapatite particles synthesized have features of uniform morphology, pure phase and well crystallized nano size. The particle size is in the range of 30-200 nm.

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Sodium-Doped Hydroxyapatite Nanopowder through Sol-Gel Method: Synthesis and Characterization

Materials Science Forum ◽

10.4028/www.scientific.net/msf.694.128 ◽

2011 ◽

Vol 694 ◽

pp. 128-132 ◽

Cited By ~ 2

Author(s):

Erlani Pusparini ◽

Iis Sopyan ◽

Mohd. Hamdi ◽

Singh Ramesh

Keyword(s):

Sol Gel ◽

Calcium Nitrate ◽

Xrd Analysis ◽

Sodium Concentration ◽

Calcium Nitrate Tetrahydrate ◽

X Ray Diffraction ◽

Gel Method ◽

Sol Gel Method ◽

Transmission Electron ◽

Nitrate Tetrahydrate

The nanocrystalline HA powders were produced through sol-gel method which employed calcium nitrate tetrahydrate [Ca(NO3)2.4H2O] and diammonium hydrogen phosphate [(NH4)2HPO4] as calcium and phosphorous precursors. Sodium ion (Na+) is one of the trace elements found in biological apatite and believed to have important effect in its performance. The concentrations of sodium dopant were varied from 0 mol% until 15 mol% by using sodium nitrate (NaNO3) as the source of dopant. Characterization of nanopowders was investigated by using X-ray diffraction (XRD), Fourier transform infra red (FTIR) and Transmission Electron Microscope (TEM). XRD analysis revealed that there are no other phases exist in the synthesized powder, evinced single phase of HA and a trend shows an increase of cristallinity with increase of sodium dopant concentration. While the TEM images showed evidence that the particle sizes were bigger with the increasing sodium concentration, showing the effect of sodium dopant on the densification of the powder.

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Effect of Stirring and Aging Time on the Formation of β-Tricalcium Phosphate (β-TCP) Powder

Materials Science Forum ◽

10.4028/www.scientific.net/msf.840.156 ◽

2016 ◽

Vol 840 ◽

pp. 156-159

Author(s):

Shah Rizal Kasim ◽

Siti Noor Fazliah Mohd Noor ◽

Zainal Arifin Ahmad

Keyword(s):

Electron Microscopy ◽

Aging Time ◽

Tricalcium Phosphate ◽

Calcium Nitrate ◽

Xrd Analysis ◽

Precipitation Method ◽

Calcium Nitrate Tetrahydrate ◽

X Ray Diffraction ◽

Transmission Electron ◽

Nitrate Tetrahydrate

In this research, the effect of stirring and aging time on the formation of β-tricalcium phosphate (β-TCP) powder was studied. β-TCP powder was synthesized using calcium nitrate tetrahydrate (Ca(NO3)2.4H2O) (0.6M) and diammonium hydrogen phosphate (NH4)2HPO4) (0.4M) via wet precipitation method. The mixture was stirred with different duration (1, 3, 5 and 7 hours) then centrifuged before washed with distilled water (twice) and ethanol followed by drying in oven (80°C, 24 hours). The cake was ground to form powder. The as prepared powder was analyzed using thermo-gravimetric (TGA) to determine the suitable calcinations temperature. TGA results show that the proper calcinations temperature was 800°C. The formation of β-TCP was characterized using X-ray Diffraction (XRD) analysis. Sample with optimum formation of β-TCP phase will choose for further study on the effect of aging time (0.5, 1, 20 and 24 hours). XRD analysis confirmed that sample stirred for 7 hours and aging for 24 hours produced β-TCP as major phase. Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) proved that β-TCP powder form as agglomerated particles

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PREPARATION AND CHARACTERIZATION OF HYDROXYAPATITE-SILICA COMPOSITE NANOPOWDERS

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194512002565 ◽

2012 ◽

Vol 05 ◽

pp. 630-637 ◽

Cited By ~ 2

Author(s):

S.M. LATIFI ◽

M.H. FATHI ◽

M.A. GOLOZAR

Keyword(s):

Sol Gel ◽

Calcium Nitrate ◽

Bone Substitutes ◽

Calcium Nitrate Tetrahydrate ◽

X Ray Diffraction ◽

X Ray ◽

Silica Composite ◽

Biological Responses ◽

Nanocrystalline Hydroxyapatite ◽

Nitrate Tetrahydrate

One of the most important objectives in the field of biomaterials science and engineering is development of new materials as bone substitutes. Silica ( SiO 2) has an important role in the biomineralization and biological responses. The aim of this research was to prepare and characterize hydroxyapatite-silica ( HA - SiO 2) composite nanopowder with different content of silica. Hydroxyapatite-silica composite nanopowders with 20 and 40 wt% silica were prepared using a sol–gel method at 600°C with phosphoric pentoxide and calcium nitrate tetrahydrate as a source of hydroxyapatite; also, tetraethylorthosilicate and methyltriethoxisilane as a source of silica. Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis (EDX) techniques were used for characterization and evaluation of the products. The results indicated the presence of nanocrystalline hydroxyapatite phase beside amorphous silica phase in prepared composite nanopowders. Moreover, by increasing the content of silica in composite nanopowders, the crystallinity will be decreased,and the ability of the product as a bone substitute material might be controlled by changing the content of the ingredients and subsequently its structure.

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