Effects of solvents and Sb sources on the morphologies of LaFe3CoSb12 nanopowders made by the hydro/solvo thermal method

2009 ◽  
Vol 24 (9) ◽  
pp. 2873-2879 ◽  
Author(s):  
Pengxian Lu ◽  
Zigang Shen ◽  
Xing Hu
Keyword(s):  
Aqueous Solution ◽  
Ethylene Glycol ◽  
Cetyltrimethylammonium Bromide ◽  
Disodium Salt ◽  
The Other ◽  
Thermal Method ◽  
Water As Solvent

The thermoelectric LaFe3CoSb12 nanopowders were synthesized by the hydro/solvo thermal method. The effects of different solvents were investigated by using only the potassium antimony tartrate as Sb source. Also, the effects of the different Sb sources were investigated by using only water as solvent on the morphologies of the resulting nanopowders. The results show that a mixture of nanoparticles and nanorods can be obtained in aqueous solution of cetyltrimethylammonium bromide or ethylenediamine-tetra-acetic disodium salt. In ethylenediamine only nanorods can be obtained, and in ethylene glycol only nanoparticles can be obtained. The other morphologies of the LaFe3CoSb12, such as particle-like, nest-shaped, branch-shaped, or feather-like crystalline, can be synthesized in water by selecting a suitable Sb source.

scholarly journals Effect of Micellar Aggregate on the Kinetics and Mechanism of the Reaction between Ethylene Glycol and Periodate

2014 ◽  
Vol 2014 ◽  
pp. 1-3
Author(s):  
Olaseni Segun Esan
Keyword(s):  
Ethylene Glycol ◽  
Cetyltrimethylammonium Bromide ◽  
Reaction Rate ◽  
The Other ◽  
Bulk Solution ◽  
Kinetic Behavior ◽  
Pseudophase Model ◽  
Micellar Aggregates ◽  
Vis Spectroscopy ◽  
Mechanism Of The Reaction

The oxidation of ethylene glycol by periodate (IO4-) was studied in different micellar aggregates of cetyltrimethylammonium bromide (CTABr) and dodecylamine (DA) by means of UV/Vis spectroscopy. The observed constant Ko was obtained by monitoring the disappearing of ethylene glycol with time at a suitable wavelength under pseudofirst condition. Addition of CTABr and DA inhibits the reaction rate while the kinetic behavior was explained on the association of one of the reactants with the micelles leaving the other reactant in the bulk solution (pseudophase model).

Immuno-compatibility of desaminotyrosine and desaminotyrosyl tyrosine functionalized star-shaped oligo(ethylene glycol)s with different molecular weights

2015 ◽  
Vol 1718 ◽  
pp. 97-102 ◽  
Author(s):  
Toralf Roch ◽  
Konstanze K. Julich-Gruner ◽  
Axel T. Neffe ◽  
Nan Ma ◽  
Andreas Lendlein
Keyword(s):  
Aqueous Solution ◽  
Ethylene Glycol ◽  
Average Molecular Weight ◽  
Molecular Weights ◽  
Immunological Effects ◽  
Microbial Products ◽  
Low Levels ◽  
Chain Lengths ◽  
Immunological Evaluation

ABSTRACTPolymer-based therapeutic strategies require biomaterials with properties and functions tailored to the demands of specific applications leading to an increasing number of newly designed polymers. For the evaluation of those new materials, comprehensive biocompatibility studies including cyto-, tissue-, and immunocompatibility are essential. Recently, it could be demonstrated that star-shaped amino oligo(ethylene glycol)s (sOEG) with a number average molecular weight of 5 kDa and functionalized with the phenol-derived moieties desaminotyrosine (DAT) or desaminotyrosyl tyrosine (DATT) behave in aqueous solution like surfactants without inducing a substantial cytotoxicity, which may qualify them as solubilizer for hydrophobic drugs in aqueous solution. However, for biomedical applications the polymer solutions need to be free of immunogenic contaminations, which could result from inadequate laboratory environment or contaminated starting material. Furthermore, the materials should not induce uncontrolled or undesired immunological effects arising from material intrinsic properties. Therefore, a comprehensive immunological evaluation as perquisite for application of each biomaterial batch is required. This study investigated the immunological properties of sOEG-DAT(T) solutions, which were prepared using sOEG with number average molecular weights of 5 kDa, 10 kDa, and 20 kDa allowing analyzing the influence of the sOEG chain lengths on innate immune mechanisms. A macrophage-based assay was used to first demonstrate that all DAT(T)-sOEG solutions are free of endotoxins and other microbial contaminations such as fungal products. In the next step, the capacity of the different DAT(T)-functionalized sOEG solutions to induce cytokine secretion and generation of reactive oxygen species (ROS) was investigated using whole human blood. It was observed that low levels of the pro-inflammatory cytokines interleukin(IL)-1β and IL-6 were detected for all sOEG solutions but only when used at concentrations above 250 µg·mL-1. Furthermore, only the 20 kDa sOEG-DAT induced low amounts of ROS-producing monocytes. Conclusively, the data indicate that the materials were not contaminated with microbial products and do not induce substantial immunological adverse effectsin vitro,which is a prerequisite for future biological applications.

Influence of Surface Roughness on Cetyltrimethylammonium Bromide Adsorption from Aqueous Solution

Langmuir ◽  
2011 ◽  
Vol 27 (10) ◽  
pp. 6091-6098 ◽  
Author(s):  
Shuqing Wu ◽  
Liu Shi ◽  
Lucas B. Garfield ◽  
Rico F. Tabor ◽  
Alberto Striolo ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Surface Roughness ◽  
Cetyltrimethylammonium Bromide

scholarly journals Clicked and long spaced galactosyl- and lactosylcalix[4]arenes: new multivalent galectin-3 ligands

2014 ◽  
Vol 10 ◽  
pp. 1672-1680 ◽  
Author(s):  
Silvia Bernardi ◽  
Paola Fezzardi ◽  
Gabriele Rispoli ◽  
Stefania E Sestito ◽  
Francesco Peri ◽  
...  
Keyword(s):  
Surface Plasmon Resonance ◽  
Ethylene Glycol ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Lectin Binding ◽  
The Other ◽  
Isomeric Form ◽  
Synthetic Pathway ◽  
Cuaac Reaction ◽  
Galectin 3

Four novel calix[4]arene-based glycoclusters were synthesized by conjugating the saccharide units to the macrocyclic scaffold using the CuAAC reaction and using long and hydrophilic ethylene glycol spacers. Initially, two galactosylcalix[4]arenes were prepared starting from saccharide units and calixarene cores which differ in the relative dispositions of the alkyne and azido groups. Once the most convenient synthetic pathway was selected, two further lactosylcalix[4]arenes were obtained, one in the cone, the other one in the 1,3-alternate structure. Preliminary studies of the interactions of these novel glycocalixarenes with galectin-3 were carried out by using a lectin-functionalized chip and surface plasmon resonance. These studies indicate a higher affinity of lactosyl- over galactosylcalixarenes. Furthermore, we confirmed that in case of this specific lectin binding the presentation of lactose units on a cone calixarene is highly preferred with respect to its isomeric form in the 1,3-alternate structure.

Micellar catalysis of organic reactions. VIII. Kinetic studies of the hydrolysis of 2-acetyloxybenzoic acid (aspirin) in the presence of micelles

1982 ◽  
Vol 35 (7) ◽  
pp. 1357 ◽  
Author(s):  
TJ Broxton
Keyword(s):  
Aqueous Solution ◽  
Cetyltrimethylammonium Bromide ◽  
Cetylpyridinium Chloride ◽  
Kinetic Studies ◽  
Base Catalysis ◽  
Plateau Region ◽  
General Base ◽  
Mechanism Of Hydrolysis ◽  
Ph Range ◽  
Hydrolysis Of

The hydrolysis of 2-acetyloxybenzoic acid in the pH range 6-12 has been studied in the presence of micelles of cetyltrimethylammonium bromide (ctab) and cetylpyridinium chloride (cpc). In the plateau region (pH 6-8) the hydrolysis is inhibited by the presence of micelles, while in the region where the normal BAC2 hydrolysis (pH > 9) occurs the reaction is catalysed by micelles of ctab and cpc. The mechanism of hydrolysis in the plateau region is shown to involve general base catalysis by the adjacent ionized carboxy group both in the presence and absence of micelles. This reaction is inhibited in the presence of micelles because the substrate molecules are solubilized into the micelle and water is less available in this environment than in normal aqueous solution.

scholarly journals Comparative Study of Ag Nanostructures: Molecular Simulations, Electrochemical Behavior, and Antibacterial Effect

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Álvaro de Jesús Ruíz-Baltazar ◽  
Simón Yobanny Reyes-López ◽  
D. Larrañaga ◽  
R. Pérez
Keyword(s):  
Cyclic Voltammetry ◽  
Ethylene Glycol ◽  
Comparative Study ◽  
Sodium Borohydride ◽  
Electrochemical Behavior ◽  
Antibacterial Effect ◽  
Chemical Reduction ◽  
Molecular Simulations ◽  
The Other ◽  
E Coli

Nanoparticles of Ag with different sizes and structures were obtained and studied. Two methods for reductions of Ag ions were employed, chemical reduction by sodium borohydride and ethylene glycol. Cuboctahedral and icosahedral structures were obtained. Molecular simulations were carried out in order to evaluate the reactivity of both structures. On the other hand, the electrochemical activity and antibacterial effect (E. coli) of the cuboctahedral and icosahedral structures were measured experimentally. The results obtained by molecular simulation, cyclic voltammetry, and antibacterial effect were compared and discussed in this work.

A new three-dimensional anionic cadmium(II) dicyanamide network

2014 ◽  
Vol 70 (11) ◽  
pp. 1054-1056 ◽  
Author(s):  
Qiang Li ◽  
Hui-Ting Wang
Keyword(s):  
Crystal Structure ◽  
Aqueous Solution ◽  
Unit Cell Volume ◽  
Three Dimensional ◽  
Building Blocks ◽  
The Other ◽  
Dimensional Structure ◽  
Cadmium Nitrate ◽  
Nitrate Tetrahydrate ◽  
Anionic Framework

A new cadmium dicyanamide complex, poly[tetramethylphosphonium [μ-chlorido-di-μ-dicyanamido-κ4N1:N5-cadmium(II)]], [(CH3)4P][Cd(NCNCN)2Cl], was synthesized by the reaction of tetramethylphosphonium chloride, cadmium nitrate tetrahydrate and sodium dicyanamide in aqueous solution. In the crystal structure, each CdIIatom is octahedrally coordinated by four terminal N atoms from four anionic dicyanamide (dca) ligands and by two chloride ligands. The dicyanamide ligands play two different roles in the building up of the structure; one role results in the formation of [Cd(dca)Cl]2building blocks, while the other links the building blocks into a three-dimensional structure. The anionic framework exhibits a solvent-accessible void of 673.8 Å3, amounting to 47.44% of the total unit-cell volume. The cavities in the network are occupied by pairs of tetramethylphosphonium cations.

Cetyltrimethylammonium bromide- and ethylene glycol-assisted preparation of mono-dispersed indium oxide nanoparticles using hydrothermal method

2014 ◽  
Vol 68 (8) ◽  
Author(s):  
Selvakumar Dhanasingh ◽  
Dharmaraj Nallasamy ◽  
Saravanan Padmanapan ◽  
Vinod Padaki
Keyword(s):  
Ethylene Glycol ◽  
Hydrothermal Method ◽  
Indium Oxide ◽  
Cetyltrimethylammonium Bromide ◽  
Oxide Nanoparticles ◽  
X Ray Diffraction ◽  
Hydrothermal Conditions ◽  
X Ray ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractThe influence of cetyltrimethylammonium bromide and ethylene glycol on the size and dispersion of indium oxide nanoparticles prepared under hydrothermal conditions was investigated. The precursor compound, indium hydroxide, obtained by the hydrothermal method in the absence as well as the presence of cetyltrimethylammonium bromide, was converted to indium oxide by sintering at 400°C. The formation of nanoscale indium oxide upon sintering was ascertained by the characteristic infrared adsorption bands and X-ray diffraction patterns of indium oxide. Transmission electron microscopy and band gap values confirmed that the cetyltrimethylammonium bromide facilitated the formation of indium oxide nanoparticles smaller in size and narrower in distribution than those prepared without the assistance of cetyltrimethylammonium bromide.

scholarly journals Removal of Chromium from Aqueous Solution Using Modified Pomegranate Peel:Mechanistic and Thermodynamic Studies

2009 ◽  
Vol 6 (s1) ◽  
pp. S153-S158 ◽  
Author(s):  
Tariq S. Najim ◽  
Suhad A. Yassin
Keyword(s):  
Activation Energy ◽  
Solid Solution ◽  
Aqueous Solution ◽  
Adsorption Process ◽  
Batch Process ◽  
The Other ◽  
Water Molecules ◽  
Pomegranate Peel ◽  
Solution Interface ◽  
Adsorbent Surface

Modified pomegranate peel (MPGP) and formaldehyde modified pomegranate peel (FMPGP) were prepared and used as adsorbent for removal of Cr(VI) ions from aqueous solution using batch process. The temperature variation study of adsorption on both adsorbents revealed that the adsorption process is endothermic, from the positive values of ∆H˚. These values lie in the range of physisorption. The negative values of ∆G˚ show the adsorption is favorable and spontaneous. On the other hand, these negative values increases with increase in temperature on both adsorbents, which indicate that the adsorption is preferable at higher temperatures. ∆S˚ values showed that the process is accompanied by increase in disorder and randomness at the solid solution interface due to the reorientation of water molecules and Cr(VI) ions around the adsorbent surface. The endothermic nature of the adsorption was also confirmed from the positive values of activation energy, Ea, the low values of Ea confirm the physisorption mechanism of adsorption. The sticking probability, S*, of Cr(VI) ion on surface of both adsorbents showed that the adsorption is preferable due to low values of S*(0< S*< 1 ), but S*values are lower for FMPGP indicating that the adsorption on FMPGP is more preferable .

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