Aluminum(III)-Citrate Complexes: a Potentiometric and 13C N.M.R.-Study

1986 ◽  
Vol 39 (11) ◽  
pp. 1851 ◽  
Author(s):  
JE Gregor ◽  
HKJ Powell
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Time Scale ◽  
Ligand Exchange ◽  
Equilibrium System ◽  
Equilibrium Reactions ◽  
Aluminium Citrate ◽  
Coordination Isomers ◽  
Broad Structure ◽  
Best Fit

The equilibrium reactions of citrate ion with protons and aluminium(III) have been studied by potentiometric titration in aqueous solution, I 0.10 M KCl, 25°C. The protonation constants for citrate, log Ki, corrected for K+-citrate ion pairing, were determined as 5.90�0.02, 4.35�0.01 and 2.91�0.02, i = 1-3 respectively. The model which gave the best fit to experimental data for the aluminium-citrate equilibrium system (TL/TM > 5.3) included AlHL + ( logβ 11.02�0.02), AlL (8.35�0.23), AlL23- (13.40�0.35), Al(HL)L2- (17.36�0.11), AlL2H-14-[ pK (AlL23-)6.07�0.24] and Al(LH-1)25- [ pK (AlL2H-14-) 7.09�0.08]. 13C n.m.r.data established that ligand exchange in the aluminium(III) complexes is slow on the n.m.r . time scale. The spectra were consistent with deprotonation of the coordinated C(2)-OH group commencing between pH 5 and 6, corresponding to formation of the species designated AlL2H-14- and Al(LH-1)25-. The broad structure of the- CH2-, -COOH (central) and -COOH (terminal) resonances for coordinated citrate was indicative of coordination isomers and/or the presence of both mono and bis complexes.

Kinetics of Glyphosate Adsorption on Composite Resin from Aqueous Solution

2013 ◽  
Vol 803 ◽  
pp. 157-160
Author(s):  
Zhen Zhen Kong ◽  
Dong Mei Jia ◽  
Su Wen Cui
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Composite Resin ◽  
Order Equation ◽  
Second Order ◽  
First Order ◽  
Basic Resin ◽  
Pseudo Second Order ◽  
Kinetics Of ◽  
Best Fit

The composite weakly basic resin (D301Fe) was prepared and examined using scanning electron microscopy and Fourier transform infrared spectroscopy. The adsorption kinetics of glyphosate from aqueous solution onto composite weakly basic resin (D301Fe) were investigated under different conditions. The experimental data was analyzed using various adsorption kinetic models like pseudo-first order, the pseudo-second order, the Elovich and the parabolic diffusion models to determine the best-fit equation for the adsorption of glyphosate onto D301Fe. The results show that the pseudo-second order equation fitted the experimental data well and its adsorption was chemisorption-controlled.

scholarly journals Recovery of Ga(III) by Raw and Alkali Treated Citrus limetta Peels

2014 ◽  
Vol 2014 ◽  
pp. 1-10
Author(s):  
Sachin C. Gondhalekar ◽  
Sanjeev R. Shukla
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Functional Groups ◽  
Langmuir Isotherm ◽  
Bayer Liquor ◽  
Pseudosecond Order ◽  
Best Fit ◽  
Citrus Limetta

Alkali treated Citrus limetta peels were used for recovery of Ga(III) from its aqueous solution. The raw and alkali treated peels were characterized for functional groups. The efficiency of adsorption increased from 47.62 mg/g for raw peels to 83.33 mg/g for alkali treated peels. Between pH 1 and 3, the adsorption increased and thereafter decreased drastically. The adsorption followed pseudosecond order kinetics and Langmuir isotherm gave the best fit for the experimental data. Desorption studies showed 95.28% desorption after 3 cycles for raw peels while it was 89.51% for alkali treated peels. Simulated Bayer liquor showed 39.57% adsorption for gallium ions on raw peels which was enhanced to 41.13% for alkali treated peels.

Utilization of Waste of Enzymes Biomass as Biosorbent for the Removal of Dyes from Aqueous Solution in Batch and Fluidized Bed Column

2020 ◽  
Vol 71 (1) ◽  
pp. 1-12
Author(s):  
Salman H. Abbas ◽  
Younis M. Younis ◽  
Mohammed K. Hussain ◽  
Firas Hashim Kamar ◽  
Gheorghe Nechifor ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Particle Size ◽  
Adsorption Capacity ◽  
Fluidized Bed ◽  
Flow Rate ◽  
Fungal Biomass ◽  
Solution Flow Rate ◽  
Maximum Adsorption Capacity ◽  
Solution Flow

The biosorption performance of both batch and liquid-solid fluidized bed operations of dead fungal biomass type (Agaricusbisporus ) for removal of methylene blue from aqueous solution was investigated. In batch system, the adsorption capacity and removal efficiency of dead fungal biomass were evaluated. In fluidized bed system, the experiments were conducted to study the effects of important parameters such as particle size (701-1400�m), initial dye concentration(10-100 mg/L), bed depth (5-15 cm) and solution flow rate (5-20 ml/min) on breakthrough curves. In batch method, the experimental data was modeled using several models (Langmuir,Freundlich, Temkin and Dubinin-Radushkviechmodels) to study equilibrium isotherms, the experimental data followed Langmuir model and the results showed that the maximum adsorption capacity obtained was (28.90, 24.15, 21.23 mg/g) at mean particle size (0.786, 0.935, 1.280 mm) respectively. In Fluidized-bed method, the results show that the total ion uptake and the overall capacity will be decreased with increasing flow rate and increased with increasing initial concentrations, bed depth and decreasing particle size.

Capillary flows and self-assembly of porous hydrate structures

2012 ◽  
Vol 9 (1) ◽  
pp. 22-25
Author(s):  
S.V. Amel’kin ◽  
D.Ye. Igoshin
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Self Assembly ◽  
Capillary Flow ◽  
Secondary Crystallization ◽  
Assembly Model ◽  
Physical Processes ◽  
Good Correspondence ◽  
Solution Formation ◽  
Capillary Flows

A self-assembly model for porous hydrate structures is proposed, which takes into account the sequence of basic physical processes: hydrate growth on the surface of the aqueous solution, formation of islet structure, capillary flow, separation and transfer of secondary crystallization nuclei to the meniscus. The model was studied within the cellular automata method. A good correspondence between the results of the simulation and the experimental data is obtained.

Separation of phenylenediamine isomers by using decamethylcucurbit[5]uril

2021 ◽  
Author(s):  
Long Cao ◽  
Han-Ling Guo ◽  
Rui Lian Lin ◽  
Li-Fei Tian ◽  
Zhi-Hua Zhang ◽  
...  
Keyword(s):  
Experimental Data ◽  
Aqueous Solution ◽  
Solid State ◽  
Phenylenediamine Isomers

Using multiple techniques, this work studied the binding behaviors of decamethylcucurbit[5]uril (Me10Q[5]) with o-, m- and p-phenylenediamine (PDA) isomers both in solid state and in aqueous solution. Experimental data indicate...

scholarly journals Smart Design Nano-Hybrid Formulations by Machine Learning

Proceedings ◽  
2020 ◽  
Vol 78 (1) ◽  
pp. 5
Author(s):  
Raquel de Melo Barbosa ◽  
Fabio Fonseca de Oliveira ◽  
Gabriel Bezerra Motta Câmara ◽  
Tulio Flavio Accioly de Lima e Moura ◽  
Fernanda Nervo Raffin ◽  
...  
Keyword(s):  
Machine Learning ◽  
Experimental Data ◽  
Water Solubility ◽  
Inorganic Materials ◽  
Fine Tuning ◽  
Support Vector ◽  
Drug Solubility ◽  
Physical Behavior ◽  
Best Fit

Nano-hybrid formulations combine organic and inorganic materials in self-assembled platforms for drug delivery. Laponite is a synthetic clay, biocompatible, and a guest of compounds. Poloxamines are amphiphilic four-armed compounds and have pH-sensitive and thermosensitive properties. The association of Laponite and Poloxamine can be used to improve attachment to drugs and to increase the solubility of β-Lapachone (β-Lap). β-Lap has antiviral, antiparasitic, antitumor, and anti-inflammatory properties. However, the low water solubility of β-Lap limits its clinical and medical applications. All samples were prepared by mixing Tetronic 1304 and LAP in a range of 1–20% (w/w) and 0–3% (w/w), respectively. The β-Lap solubility was analyzed by UV-vis spectrophotometry, and physical behavior was evaluated across a range of temperatures. The analysis of data consisted of response surface methodology (RMS), and two kinds of machine learning (ML): multilayer perceptron (MLP) and support vector machine (SVM). The ML techniques, generated from a training process based on experimental data, obtained the best correlation coefficient adjustment for drug solubility and adequate physical classifications of the systems. The SVM method presented the best fit results of β-Lap solubilization. In silico tools promoted fine-tuning, and near-experimental data show β-Lap solubility and classification of physical behavior to be an excellent strategy for use in developing new nano-hybrid platforms.

scholarly journals Photoinduced Ligand Exchange Dynamics of a Polypyridyl Ruthenium Complex in Aqueous Solution

2021 ◽  
pp. 7278-7284
Author(s):  
Isabelle M. Dixon ◽  
Sylvestre Bonnet ◽  
Fabienne Alary ◽  
Jérôme Cuny
Keyword(s):  
Aqueous Solution ◽  
Ligand Exchange ◽  
Ruthenium Complex

scholarly journals Unbinding of Hyaluronan Accelerates the Enzymatic Activity of Bee Hyaluronidase

2011 ◽  
Vol 286 (41) ◽  
pp. 35699-35707 ◽  
Author(s):  
Attila Iliás ◽  
Károly Liliom ◽  
Brigitte Greiderer-Kleinlercher ◽  
Stephan Reitinger ◽  
Günter Lepperdinger
Keyword(s):  
Experimental Data ◽  
Quartz Crystal ◽  
Surface Loop ◽  
X Ray ◽  
Site Model ◽  
Substrate Interaction ◽  
Close Proximity ◽  
Binding Groove ◽  
The One ◽  
Best Fit

Hyaluronan (HA), a polymeric glycosaminoglycan ubiquitously present in higher animals, is hydrolyzed by hyaluronidases (HAases). Here, we used bee HAase as a model enzyme to study the HA-HAase interaction. Located in close proximity to the active center, a bulky surface loop, which appears to obstruct one end of the substrate binding groove, was found to be functionally involved in HA turnover. To better understand kinetic changes in substrate interaction, binding of high molecular weight HA to catalytically inactive HAase was monitored by means of quartz crystal microbalance technology. Replacement of the delimiting loop by a tetrapeptide interconnection increased the affinity for HA up to 100-fold, with a KD below 1 nm being the highest affinity among HA-binding proteins surveyed so far. The experimental data of HA-HAase interaction were further validated showing best fit to the theoretically proposed sequential two-site model. Besides the one, which had been shown previously in course of x-ray structure determination, a previously unrecognized binding site works in conjunction with an unbinding loop that facilitates liberation of hydrolyzed HA.

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