Sol-Gel Preparation of HAp-Coated Silica Macrospheres from Water Glass and their Protein Adsorption

2012 ◽  
Vol 529-530 ◽  
pp. 637-640
Author(s):  
Jie Li ◽  
Yuki Shirosaki ◽  
Satoshi Hayakawa ◽  
Artemis Stamboulis ◽  
Akiyoshi Osaka
Keyword(s):  
Water Glass ◽  
Electrostatic Interactions ◽  
Coating Layer ◽  
Sol Gel ◽  
Adsorption Model ◽  
Silica Source ◽  
Layer Adsorption ◽  
Protein Molecules ◽  
Gel Preparation ◽  
Ca Alginate

Silica gel macrospheres of 2~4 mm in size, and wrapped with Ca-alginate chelate film were prepared as the substrate for hydroxyapatite coating layer, using water glass as the silica source. Those Ca-SiO2 macrospheres were soaked in a 1:1 (volume) mixture of ethanol and 0.1 M Na2HPO4 to deposit hydroxyapatite layer (HAp-SiO2 macrospheres). Adsorption of bovine serum albumin and egg lysozyme on those Ca-SiO2 and HAp-SiO2 macrospheres under physiological pH (7.2) was well correlated to the Langmuir-type adsorption equation. The electrostatic interactions between the protein molecules and those macrospheres well interpret the adsorption isotherms, while the mesopores in the Ca-SiO2 contributed to some extent. A multi-layer adsorption model was proposed.

scholarly journals L-Arginine-Modified Silica for Adsorption of Gold(III)

2015 ◽  
Vol 15 (2) ◽  
pp. 108-115 ◽  
Author(s):  
Sri Hastuti ◽  
Nuryono Nuryono ◽  
Agus Kuncaka
Keyword(s):  
Sol Gel ◽  
Tetraethyl Orthosilicate ◽  
Modified Silica ◽  
Experimental Conditions ◽  
Silica Source ◽  
Batch System ◽  
Sol Gel Process ◽  
Pseudo Second Order ◽  
Prospective Application ◽  
Gel Preparation

In this research, L-arginine-modified silica (SiO2-Arg) with 3-glycidoxypropyl-trimethoxysilane (GPTMS) as the linking agent has been synthesized through sol gel process for adsorption of Au(III) in aqueous solution. Tetraethyl orthosilicate (TEOS) as the silica source precursor, L-arginine solution 0.9 M with various volume ratios and the linking agent were mixed together to form a gel. SiO2-Arg was characterized using Fourier transform infrared (FTIR) spectrophotometer, thermogravimetric analysis (TGA), and an elemental analysis. Adsorption was carried out in a batch system under various experimental conditions including contact time and initial concentration of metal Au(III). The selectivity of adsorbent toward Au(III) was examined in the presence of Cu(II), Fe(III), and Zn(II) ion at various pHs. Results of characterization showed that silica has been successfully modified with L-arginine. The optimum adsorption of Au(III) on SiO2-Arg was obtained at pH of 3.0 and the adsorption isotherm of Au(III) on SiO2-Arg gives the adsorption capacity of 52.79 mg/g. The kinetic study demonstrates that the adsorption of Au(III) ion follows pseudo-second order with the rate constant of 53197 g mol–1 min–1. The selectivity order of Au-Zn = Au-Cu > Au-Fe. This sol-gel preparation is simple and provides prospective application of SiO2-Arg material as an effective adsorbent for metal ions particularly gold(III).

Electrical and Physical Property of TiO2 Films Prepared at Different Deposition Time

2015 ◽  
Vol 1109 ◽  
pp. 524-528
Author(s):  
Irma Hidayanti Halim Affendi ◽  
Najwa Ezira Ahmed Azhar ◽  
Puteri Sarah Mohamad Saad ◽  
Salman A.H. Alrokayan ◽  
Haseeb A. Khan ◽  
...  
Keyword(s):  
Deposition Time ◽  
Coating Layer ◽  
Sol Gel ◽  
Physical Property ◽  
Section Technique ◽  
Current Voltage ◽  
Gel Preparation ◽  
Deposited Films ◽  
Dioxide Film ◽  
Easy Operation

Titanium Dioxide film will be deposited on a glass slide substrate by spin coating technique which is the frequently used technique because of its easy operation and cheap due to the sol gel preparation. The deposited films were then characterized by cross section technique using Field Emission Scanning Electron Microscopy (FESEM) to investigate the thickness based on the number of coatings. Then by the same FESEM, the surface morphology was studied to see the grain size and the porosity of each film based on the number of coatings. AFM was used to see the uniformity of the thin film's surface. Then by using current voltage (IV) measurement, the electrical property of the film can be studied, from IV characterization the resistivity of the film will be calculated. In this investigation, it is found that by increasing the coating layer, the resistivity values were decreasing whereas the conductivity of the film is increasing since conductivity is the inverse of resistivity. The porosity of the film also increases with the coating layers.

Efficient Micromixing for Continuous Biodiesel Production from Jatropha Oil

2018 ◽  
Vol 9 (1) ◽  
pp. 133-139
Author(s):  
Waleed S. Mohammed ◽  
Ahmed H. El-Shazly ◽  
Marwa F. Elkady ◽  
Masahiro Ohshima
Keyword(s):  
Methyl Esters ◽  
Continuous Process ◽  
Sol Gel ◽  
Average Diameter ◽  
Biodiesel Production ◽  
High Mass ◽  
Molar Ratio ◽  
Jatropha Oil ◽  
Energy Deficiency ◽  
Gel Preparation

Introduction: The utilization of biodiesel as an alternative fuel is turning out to be progressively famous these days because of worldwide energy deficiency. The enthusiasm for utilizing Jatropha as a non-edible oil feedstock is quickly developing. The performance of the base catalyzed methanolysis reaction could be improved by a continuous process through a microreactor in view of the high mass transfer coefficient of this technique. Materials & Methods: Nanozirconium tungstovanadate, which was synthetized using sol-gel preparation method, was utilized in a complementary step for biodiesel production process. The prepared material has an average diameter of 0.066 &µm. Results: First, the NaOH catalyzed methanolysis of Jatropha oil was investigated in a continuous microreactor, and the efficient mixing over different mixers and its impact on the biodiesel yield were studied under varied conditions. Second, the effect of adding the nanocatalyst as a second stage was investigated. Conclusion: The maximum percentage of produced methyl esters from Jatropha oil was 98.1% using a methanol/Jatropha oil molar ratio of 11 within 94 s using 1% NaOH at 60 &°C. The same maximum conversion ratio was recorded with the nanocatalyst via only 0.3% NaOH.

scholarly journals Chemical and Structural Characterization of Amorphous and Crystalline Alumina Obtained by Alternative Sol–Gel Preparation Routes

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1761
Author(s):  
Izabela Rutkowska ◽  
Jakub Marchewka ◽  
Piotr Jeleń ◽  
Mateusz Odziomek ◽  
Mateusz Korpyś ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Aluminum Oxide ◽  
Physicochemical Properties ◽  
Sol Gel ◽  
Magic Angle Spinning ◽  
Magic Angle ◽  
Bet Method ◽  
Gel Preparation ◽  
Angle Spinning ◽  
Middle Infrared

Aluminum oxide is one of the most commonly used materials in the industry. It is used in the field of catalysis, refractories, and optics. Despite the fact that there are many techniques available, there is still a great challenge in obtaining a material with desired and designed properties. Nevertheless, there is a great flexibility in making customized alumina materials with desired physicochemical properties synthesized by sol–gel methods. This work consists in characterizing the physicochemical properties of sol–gel synthesized aluminum oxide using different sol–gel preparation routes. Three different sols were obtained by using organic precursors and underwent thermal treatment. The structure (Middle Infrared Spectroscopy, Diffused Reflectance Infrared Spectroscopy, X-ray Diffraction, Magic Angle Spinning Nuclear Magnetic Resonance) and microstructure (Scanning Electron Microscopy with Electron Dispersive Spectroscopy) tests of the materials were carried out. The specific surface area was determined by using the Brunauer–Emmett–Teller (BET) method. Thermal analysis was performed for all the powders, in order to analyze the specific temperature of materials transformation.

Sol-gel preparation and characterization of transparent GdTaO 4 : Eu3+thick films

2008 ◽  
Author(s):  
Kun Han ◽  
Mu Gu ◽  
Xiaolin Liu ◽  
Chen Ni ◽  
Shiming Huang ◽  
...  
Keyword(s):  
Thick Films ◽  
Sol Gel ◽  
Gel Preparation

THE EFFECTS OF CARBON NANO-COATING ON Li(Ni0.8Co0.15Al0.05)O2 CATHODE MATERIAL USING ORGANIC CARBON FOR Li-ION BATTERY

2010 ◽  
Vol 17 (01) ◽  
pp. 51-58 ◽  
Author(s):  
JEONG-HUN JU ◽  
YOUNG-MIN CHUNG ◽  
YU-RIM BAK ◽  
MOON-JIN HWANG ◽  
KWANG-SUN RYU
Keyword(s):  
Cathode Material ◽  
Coating Layer ◽  
Sol Gel ◽  
Electronic Conductivity ◽  
Lithium Ion ◽  
Cyclic Voltammogram ◽  
Active Materials ◽  
Nano Coating ◽  
Primary Particles ◽  
Li Ion

Carbon nano-coated LiNi 0.8 Co 0.15 Al 0.05 O 2/ C (LNCAO/C) cathode-active materials were prepared by a sol–gel method and investigated as the cathode material for lithium ion batteries. Electrochemical properties including the galvanostatic charge–discharge ability and cyclic voltammogram behavior were measured. Cyclic voltammetry (2.7–4.8 V) showed that the carbon nano-coating improved the "formation" of the LNCAO electrode, which was related to the increased electronic conductivity between the primary particles. The carbon nano-coated LNCAO/C exhibited good electrochemical performance at high C -rate. Also, the thermal stability at a highly oxidized state of the carbon nano-coated LNCAO was remarkably enhanced. The carbon nano-coating layer can serve as a physical and/or (electro-)chemical protection shell for the underlying LNCAO, which is attributed to an increase of the grain connectivity (physical part) and also to the protection of metal oxide from chemical reactions (chemical part).

Sol-gel preparation and transport properties of a tin oxide

1990 ◽  
Vol 9 (12) ◽  
pp. 1383-1388 ◽  
Author(s):  
J. C. Giuntini ◽  
W. Granier ◽  
J. V. Zanchetta ◽  
A. Taha
Keyword(s):  
Transport Properties ◽  
Tin Oxide ◽  
Sol Gel ◽  
Gel Preparation

scholarly journals Sol-gel preparation and electrical behaviour of Ln: YAG (Ln = Ce, Nd, Ho, Er)

2003 ◽  
Vol 68 (8-9) ◽  
pp. 677-684 ◽  
Author(s):  
Edita Garskaite ◽  
Darizus Jasaitis ◽  
Aivaras Kareiva
Keyword(s):  
Rare Earth ◽  
Yttrium Aluminum Garnet ◽  
Sol Gel ◽  
Structural Features ◽  
Dielectric Behavior ◽  
Homogeneous Distribution ◽  
Metallic Behavior ◽  
Gel Preparation ◽  
Xrd Patterns ◽  
Increasing Temperature

A sol-gel method has been developed to prepare pure yttrium aluminum garnet Y3Al5O12 (YAG), and rare-earth substituted (Ce-Y3Al5O12, Nd-Y3Al5O12 Ho-Y3Al5O12, and Er-Y3Al5O12) samples. The XRD patterns of the polycrystalline powders sintered at 1000 ?C showed the formation of monophasic garnet materials. The micro-structural features in the polycristalline samples were studied by scanning electron microscopy. A homogeneous distribution of rare-earth do pants in the YAG lattice was achieved in all of the cases. Electrical conductivity measurements were also performed on the compacts of sol-gel derived Ln-YAG samples. In contrast to the expected dielectric behavior, the conducting properties of the examined specimens indicate metallic behavior with the resistivity increasing gradually with increasing temperature.

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