Determination of Ultra-Trace of Herbicides Using Smart Nanoparticles

2013 ◽  
Vol 699 ◽  
pp. 144-149 ◽  
Author(s):  
Nezar H. Khdary
Keyword(s):  
Sol Gel ◽  
Spherical Particles ◽  
Sol Gel Process ◽  
Ultra Trace ◽  
Solvent Modification

18- Smart Nanoparticles was synthesized using sol-gel process. The spherical particles were obtained using appropriate parameters such as solvent. Modification of C18-Smart Nanoparticles was carried out using trichloro and trimethoxy octadecylsilane. The modified particles were designed for extraction and preconcentration of herbicides as illustrated in figure 1. Herbicides molecules were easily recognized by C18- Smart Nanoparticles and the recoveries were varied from 59-82%.

Spherical particles from tetraorthosilicate (TEOS) sol–gel process with dimethyldiethoxysilane (DDS) and diphenyldiethoxysilane (DPDS) addition

2008 ◽  
Vol 354 (45-46) ◽  
pp. 5047-5052 ◽  
Author(s):  
Fang Wang ◽  
Jianhong Liu ◽  
Hui Yang ◽  
Zhongkuan Luo ◽  
Weizhong Lv ◽  
...  
Keyword(s):  
Sol Gel ◽  
Spherical Particles ◽  
Sol Gel Process

Some Comments on the Production of Medium Sized Spherical Particles by Anion and Water Extraction Variant of Sol-Gel Process

1994 ◽  
Vol 372 ◽  
Author(s):  
A. Deptula ◽  
W. Łstoke;ada ◽  
T. Olczak ◽  
A. Chmielewski
Keyword(s):  
Particle Size ◽  
Sol Gel ◽  
Ceramic Materials ◽  
Extraction Process ◽  
Spherical Particles ◽  
Drastic Reduction ◽  
Sol Gel Process ◽  
Emulsion Drops ◽  
Clustering Effect ◽  
Non Destructive

AbstractMedium sized spherical particles (with diameters below 100 μm) of ceramic materials (Al203 and Al203 +8%TiO2) were produced in the following steps: (1) preparation of concentrated hydroxide sols of cations by extraction of anions using Primene JMT, (2) formation of sol emulsion in 2-ethylhexanol-1 containing various amounts of surfactants (EH), (3) gelation of emulsion drops by extraction of water with partially dehydrated EH, (4) non-destructive thermal treatment. Principal properties of the sol depend on the temperature of the extraction process. For preparation of lowanionic sols a two step extraction process, separated by digestion of the aqueous phase at boiling point, was necessary. It was found that the parameters of emulsion formation as well as the properties of the sols significantly influence the particle size distribution. It was concluded that lowering of the sol- EH interracial tension by the surfactant does not influence the process. On the contrary the “anti-clustering” effect of surfactants is essential for preparation of perfect spherical powders. The thermal decomposition of gels to oxides is determinant for densities, specific surface area and carbon content. Medium sized spherical powders are free flowing. The compactibility and sinterability of those powders are poor. However drastic reduction of particle size by milling (connected with their transformation to irregular shape) significantly improves the sinterability.

Voltammetric determination of aluminum(III) using a reagentless sensor fabricated by sol–gel process

2004 ◽  
Vol 99 (2-3) ◽  
pp. 468-473 ◽  
Author(s):  
Junwei Di ◽  
Shuping Bi ◽  
Tianyu Yang ◽  
Ming Zhang
Keyword(s):  
Sol Gel ◽  
Voltammetric Determination ◽  
Sol Gel Process

Preparation of Superconducting YBa2Cu3O7−x Compounds By Water Extraction Variant Of Sol-Gel Process

1990 ◽  
Vol 180 ◽  
Author(s):  
A. Deptula ◽  
W. Lada ◽  
T. Olczak ◽  
T. zoltowski ◽  
A. Di Bartolomeo
Keyword(s):  
Thermal Treatment ◽  
Sol Gel ◽  
Ammonium Hydroxide ◽  
Water Extraction ◽  
Spherical Particles ◽  
Acidic Solutions ◽  
Sol Gel Process

ABSTRACTThe starting sols were prepared by addition of ammonium hydroxide to acidic solutions of Y-Ba-Cu acetates or by dissolving solid Ba9CO9 or CuCO9.CuCOH)2H2O in acetates of the remaining components. The sols were then gelled to spherical particles with diameter below 50μm by extracting water with 2-ethyl-l-hexanol or to shard by evaporation of water. After thermal treatment of both powders amorphous and then crystalline YBa2Cu,9O7−x were obtained. Formation of these compounds is strongly improved by aging the gel at 200°C. Green and sintered pellets exhibit excellent superconductivity properties.

Sol-Gel Syntheses and Characterization of BaTi4O9 and BaTiO3-Powders

1988 ◽  
Vol 121 ◽  
Author(s):  
Pradeep P. Phule ◽  
Subhash H. Rkbud
Keyword(s):  
High Purity ◽  
Sol Gel ◽  
Spherical Particles ◽  
Barium Acetate ◽  
Amorphous Precursor ◽  
Sol Gel Process ◽  
Alkoxide Precursor ◽  
Precursor Powders ◽  
Hydrolysis Of

ABSTRACTSol-gel processes for the synthesis of high purity, ultrafine BaTi4O9 and BaTiO3 powders are described. Hydrolysis of an alkoxide precursor derived from barium metal and titanium (IV) isopropoxide resulted in formation of powders consisting of ultrafine (0.2 to 1.0 μm) spherical particles. These amorphous precursor powders were converted to crystalline BaTi4O9 powders (particle size 2–3 μm) by heat treatment at 1100 C. The sol-gel process for the synthesis of BaTiOj powders utilized chemical polymerization between moisture insensitive and relatively inexpensive barium acetate and titanium (IV) isopropoxide in the presence of acetic acid. The gel to ceramic conversion was achieved by firing the gels at 1000 °C to obtain high purity, stoichiometric BaTiO3 powders. The powders were sintered to obtain relatively dense (90 % relative density) ceramic bodies.

EFFECT OF ANNEALING TEMPERATURE ON THE OPTICAL AND STRUCTURAL PROPERTIES OF DIP-COATED Al2O3 THIN FILMS PREPARED BY SOL–GEL ROUTE

2005 ◽  
Vol 12 (05n06) ◽  
pp. 793-797 ◽  
Author(s):  
F. E. GHODSI ◽  
M. MAFAKHERI ◽  
A. NOVINROOZ
Keyword(s):  
Thin Films ◽  
Structural Properties ◽  
Annealing Temperature ◽  
Sol Gel ◽  
Dip Coating ◽  
X Ray Diffraction ◽  
Glass Substrates ◽  
Sol Gel Process ◽  
Dip Coating Technique

Thin films of Al 2 O 3 were prepared by the sol–gel process. Dip-coating technique was used for deposition of the Al 2 O 3 thin films onto glass substrates. Optical and structural properties of the films were investigated with respect to the annealing temperature (100–500°C). The structure of these films was determined by X-ray diffraction (XRD). Scanning electron microscopy (SEM) was performed for the analysis of surface morphology. For determination of the optical constants of Al 2 O 3 thin films, UV-Visible spectrophotometry measurements were carried out. Annealing temperature affects the structural and optical properties of the Al 2 O 3 thin films. The refractive index and extinction coefficient of the films at 550 nm wavelength increase from 1.56 to 1.66, and from 3.41 × 10-5 to 5.54 × 10-5, respectively while optical band gap and thickness of the films decrease from 4.15 eV to 4.11 eV, and 360 nm to 260 nm, respectively, by increasing annealing temperature from 100°C to 500°C.

scholarly journals Multinuclear Magnetic Resonance Study on Aluminium Sec-butoxide Chelated with Ethyl Acetoacetate in Various Amounts

2019 ◽  
Vol 92 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Stanislav Kurajica ◽  
Gregor Mali ◽  
Vilko Mandić ◽  
Iva Minga
Keyword(s):  
Ethyl Acetoacetate ◽  
Sol Gel ◽  
Gain Control ◽  
Spectroscopic Techniques ◽  
27Al Nmr ◽  
One Dimensional ◽  
Sol Gel Process ◽  
Rapid Hydrolysis ◽  
First Time

Reactive aluminum alkoxide (ASB, aluminium sec-butoxide) was chelated using β-diketone (EAA, ethyl acetoacetate) in order to gain control over rapid hydrolysis in the course of the sol-gel process. Derived chelates were analysed using several NMR spectroscopic techniques: one-dimensional 1H, 13C, 27Al NMR and two-dimensional COSY, HSQC and DOSY. The NMR analysis enabled identification of the formed chelate species, as well as determination of their quantitative relationships. Several complexation products were observed: tris-chelated monomer, Al(EAA)3, bis-chelated dimmer, Al2(OnBu)4(EAA) 2, tris-chelated dimmer, Al2(OnBu)3(EAA)3, tetra-chelated dimmer, Al2(OnBu)2(EAA)4, and monochelated trimer, Al3(OnBu)8(EAA). Of the formed oligomer compounds, this is the first evidence of Al2(OR)3L3 in any alkoxide and β-ketoester or β-diketone combination. Aluminium sec-butoxide and ethyl acetoacetate complexes Al2(OnBu)4(EAA) 2 and Al2(OnBu)2(EAA)4 were also observed for the first time. With the increase of the EAA/ASB ratio the coordination of aluminium shifts towards six, whereas above the EAA/ASB ratio of 2.5 solely six-coordinated aluminium exists.

Effects of Heat Treatment on Apatite Formation of CaO-SiO2-PEEK Composites

2012 ◽  
Vol 529-530 ◽  
pp. 436-440 ◽  
Author(s):  
S.B. Cho ◽  
E.M. An ◽  
Sujeong Lee ◽  
H.D. Jang ◽  
Ill Yong Kim ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Simulated Body Fluid ◽  
Body Fluid ◽  
Sol Gel ◽  
Spherical Particles ◽  
Organic Polymer ◽  
Apatite Formation ◽  
Ceramic Filler ◽  
Induction Periods ◽  
Sol Gel Process

Osteoconductive bone-repairing materials with mechanical properties analogous to those of human bone can be prepared through the combination of an osteoconductive ceramic filler with an organic polymer. Osteoconduction is archived from apatite formation on substrates. Previously, we reported that novel osteoconductive spherical particles in a binary CaO-SiO2 system were produced through a sol-gel process as ceramic filler for the fabrication of composites. In this study, we fabricated the composites consisting of polyetheretherketone (PEEK) and 30CaO·70SiO2 (CS) spherical particles and evaluated the effects of heat treatment in the range of 320-360 °C on apatite formation of the composites in a simulated body fluid. The prepared composites of PEEK and CS particles form hydroxyapatite on their surfaces in the simulated body fluid. The induction periods of hydroxyapatite on the composites decreased with increasing the amount of CS particles and decreasing the temperature for heat treatment. The apatite formation was affected by exposure of ceramic filler on the polymer matrix.

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