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).

THE KINETICS OF THE DECOMPOSITION REACTIONS OF THE LOWER PARAFFINS: I. n-BUTANE

1938 ◽  
Vol 16b (5) ◽  
pp. 176-193 ◽  
Author(s):  
E. W. R. Steacie ◽  
I. E. Puddington
Keyword(s):  
Reaction Rate ◽  
High Pressures ◽  
The Other ◽  
First Order ◽  
Decomposition Reactions ◽  
Temperature And Pressure ◽  
Products Of Reaction ◽  
Kinetics Of ◽  
Good Agreement ◽  
Mechanism Of The Reaction

The kinetics of the thermal decomposition of n-butane has been investigated at pressures from 5 to 60 cm. and temperatures from 513 to 572 °C. The initial first order rate constants at high pressures are given by[Formula: see text]The results are in good agreement with the work of Frey and Hepp, but differ greatly from that of Paul and Marek. The reaction rate falls off strongly with diminishing pressure; this is rather surprising for a molecule as complex as butane. The first order constants in a given run fall rapidly as the reaction progresses. The last two facts suggest that chain processes may be involved.A large number of analyses of the products of reaction have been made at various pressures, temperatures, and stages of the reaction, the method being that of low-temperature fractional distillation. The products are virtually independent of temperature and pressure over the range investigated. The initial products, obtained by extrapolation to zero decomposition, are:—H2, 2.9; CH4, 33.9; C3H6, 33.9; C2H4, 15.2; C2H6, 14.1%. The mechanism of the reaction is discussed, and the results are compared with those of the other paraffin decompositions.

Application of a Novel Initiator on Acrylic Emulsion Polymerization

2011 ◽  
Vol 233-235 ◽  
pp. 1415-1418
Author(s):  
Shao Guo Wen ◽  
Shi Gao Song ◽  
Hong Bo Liu ◽  
Ji Hu Wang ◽  
Qian Xu ◽  
...  
Keyword(s):  
Emulsion Polymerization ◽  
Reaction Rate ◽  
The Other ◽  
Polymerization Reaction ◽  
Polymerization Temperature ◽  
Acrylic Emulsion ◽  
Polymerization Mechanism ◽  
Lower Temperature ◽  
Classical Mechanism ◽  
Mechanism Of The Reaction

New initiator of FFM6 is used to initiate the acrylic emulsion polymerization. The influences of concentration of FFM6 (c[I]) and polymerization temperature (T) on polymerization reaction rate (Rp) were discussed. Rp is proportional to (c[I])1.4 which is different with classical emulsion polymerization whose Rp is proportion to (c[I])0.4, that indicate polymerization mechanism of the reaction in the study is different with classical mechanism. The value of Ea, 56.4 kJ/mol, is lower than the value of general radical polymerization’s Ea (80.0-96.0 kJ/mol), which indicates the FFM6 can initiate acrylic emulsion polymerization at a lower temperature compared with the other kinds of initiator.

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.

Understanding the risks and rewards of using 50% vs. 10% strength peroxide in pulp bleach plants

TAPPI Journal ◽  
2018 ◽  
Vol 17 (11) ◽  
pp. 601-607
Author(s):  
Alan Rudie ◽  
Peter Hart
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Rate ◽  
The Other ◽  
Mechanical Pulp ◽  
Engineering Controls ◽  
Point Of Use ◽  
Process Failure

The use of 50% concentration and 10% concentration hydrogen peroxide were evaluated for chemical and mechanical pulp bleach plants at storage and at point of use. Several dangerous occurrences have been documented when the supply of 50% peroxide going into the pulping process was not stopped during a process failure. Startup conditions and leaking block valves during maintenance outages have also contributed to explosions. Although hazardous events have occurred, 50% peroxide can be stored safely with proper precautions and engineering controls. For point of use in a chemical bleach plant, it is recommended to dilute the peroxide to 10% prior to application, because risk does not outweigh the benefit. For point of use in a mechanical bleach plant, it is recommended to use 50% peroxide going into a bleach liquor mixing system that includes the other chemicals used to maintain the brightening reaction rate. When 50% peroxide is used, it is critical that proper engineering controls are used to mitigate any risks.

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.

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.

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 Kinetics and Mechanistic Study of Cetyltrimethylammonium Bromide Catalyzed Oxidation of Tetraethylene Glycol byN-Chlorosaccharin in Acidic Medium

2008 ◽  
Vol 5 (3) ◽  
pp. 598-606
Author(s):  
Vandana Sharma ◽  
K. V. Sharma ◽  
V. W. Bhagwat
Keyword(s):  
Cetyltrimethylammonium Bromide ◽  
Reaction Rate ◽  
Activation Parameters ◽  
Mechanistic Study ◽  
Tetraethylene Glycol ◽  
Aqueous Acetic Acid ◽  
Acetic Acid Medium ◽  
First Order ◽  
Dielectric Effect ◽  
Catalyzed Oxidation

The kinetics and mechanism of cetyltrimethylammonium bromide catalyzed oxidation of tetraethylene glycol [2,2'-(oxibis(ethylenoxy)diethanol)] byN-chlorosaccharin in aqueous acetic acid medium in presence of perchloric acid have been investigated at 323K. The reaction is first order dependence on Nchlorosaccharin. The reaction rate follows first order kinetics with respect to [tetraethylene glycol] with excess concentration of other reactants. The miceller effect due to cetyltrimethylammonium bromide, a cationic surfactant has been studied. The change in ionic strength shows negligible salt effect. The dielectric effect is found to be positive. Addition of one of the products (saccharin) retards the reaction rate. Activation parameters are calculated from the Arrhenious plot. A possible mechanism consistent with the experimental results has been proposed.

scholarly journals End group functionalization of poly(ethylene glycol) with phenolphthalein: towards star-shaped polymers based on supramolecular interactions

2014 ◽  
Vol 10 ◽  
pp. 2263-2269 ◽  
Author(s):  
Carolin Fleischmann ◽  
Hendrik Wöhlk ◽  
Helmut Ritter
Keyword(s):  
Ethylene Glycol ◽  
Cycloaddition Reaction ◽  
Supramolecular Interactions ◽  
Poly Ethylene Glycol ◽  
Naked Eye ◽  
Vis Spectroscopy ◽  
End Group Functionalization ◽  
Interesting Approach ◽  
Poly Ethylene ◽  
End Group

The synthesis of a new phenolphthalein azide derivative, which can be easily utilized in polymer analogous reactions, is presented. The subsequent cycloaddition reaction with propargyl-functionalized methoxypoly(ethylene glycol) yielded polymers bearing phenolphthalein as the covalently attached end group. In presence of per-β-cyclodextrin-dipentaerythritol, the formation of stable inclusion complexes was observed, representing an interesting approach towards the formation of star shaped polymers. The decolorization of a basic polymer solution caused by the complexation was of great advantage since this behavior enabled following the complex formation by UV–vis spectroscopy and even the naked eye.

The Effect of Glycidyl Silane as Coupling Agent in Intumescent Flame Retardant System

2013 ◽  
Vol 664 ◽  
pp. 677-682
Author(s):  
Hambali Raden Siti Amirah ◽  
Ahmad Faiza Mohd ◽  
Mohd Firdaus Yhaya ◽  
Rahmah Mohamed ◽  
Mohamed Nur Raihan
Keyword(s):  
Fourier Transform ◽  
Thermogravimetric Analysis ◽  
Thermal Degradation ◽  
Ethylene Glycol ◽  
Burning Rate ◽  
Chemical Bonding ◽  
Coupling Agent ◽  
The Other ◽  
Silane Treatment ◽  
Char Formation

The effect of different carbonizing agents; ethylene glycol, glycerol, and pentaerythritol to the char formation were studied in this research. After burning process, formulation with ethylene glycol, glycerol, and pentaerythritol showed chars thickness of 10 mm, 32 mm, and 45 mm. The chars’ strength at peak force was recorded at 3.20 N, 7.75 N, and 9.48 N while the burning rate of each sample were 5.23 x 10-4 mm/s, 4.20 x10-4 mm/s, and 6.24 x10-4 mm/s respectively. Formulation with glycerol as carbonizing agent showed the lowest burning rate as compared to the other formulations. Additional formulation with glycidyl silane as coupling agent in glycerol formulation was also studied. The formation of chemical bonding between silane, glycerol, and epoxy glycerol was confirmed by Fourier Transform Infrared (FTIR) absorption peak at 767.25 cm-1. The burning rate was 1.44 x 10-5 mm/s after silane treatment. Thermal degradation of the silane-treated resin started at 220°C as measured by thermogravimetric analysis (TGA).

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