Study of ionic surfactants binding to humic acid and fulvic acid by potentiometric titration and dynamic light scattering

2009 ◽  
Vol 347 (1-3) ◽  
pp. 128-132 ◽  
Author(s):  
Min Min Yee ◽  
Tohru Miyajima ◽  
Noboru Takisawa
Keyword(s):  
Light Scattering ◽  
Humic Acid ◽  
Dynamic Light Scattering ◽  
Fulvic Acid ◽  
Potentiometric Titration ◽  
Ionic Surfactants

scholarly journals Temperature Induced Aggregation and Clouding in Humic Acid Solutions

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Leah Shaffer ◽  
Ray von Wandruszka
Keyword(s):  
Aqueous Solution ◽  
Light Scattering ◽  
Humic Acid ◽  
Dynamic Light Scattering ◽  
Acid Solutions ◽  
Inverse Temperature ◽  
Mechanical Agitation ◽  
Coulombic Repulsion ◽  
Polarity Sensitive ◽  
Induced Aggregation

Humic acids in aqueous solution demonstrate inverse temperature-solubility relationships when solution conditions are manipulated to reduce coulombic repulsion among the humic polyanions. These effects were followed by dynamic light scattering (DLS) measurements of the resulting aggregates, as well as the addition of a polarity sensitive fluorescent probe (pyrene). The humic solutions could be primed for temperature induced clouding by carefully lowering the pH to a point where hydration effects became dominant. The exact value of the cloud point (CP) was a function of both pH and humate concentration. The CPs mostly lay in the range 50–90°C, but DLS showed that temperature induced aggregation proceeded from approximately 30°C onward. Similar effects could be achieved by adding multivalent cations at concentrations below those which cause spontaneous precipitation. The declouding of clouded humate solutions could be affected by lowering the temperature combined with mechanical agitation to disentangle the humic polymers.

Soil humic acid aggregation by dynamic light scattering and laser Doppler electrophoresis

2013 ◽  
Vol 176 (5) ◽  
pp. 674-679 ◽  
Author(s):  
Uroš D. Jovanović ◽  
Mirjana M. Marković ◽  
Svjetlana B. Cupać ◽  
Zorica P. Tomić
Keyword(s):  
Light Scattering ◽  
Humic Acid ◽  
Dynamic Light Scattering ◽  
Laser Doppler ◽  
Soil Humic Acid ◽  
Laser Doppler Electrophoresis

scholarly journals Improvement of econazole nitrate solubility by using surfactants and phospholipids according to optimized experimental design

2020 ◽  
Vol 11 (2) ◽  
pp. 1578-1584
Author(s):  
Ismail Bennani ◽  
Lamyae Yachi ◽  
Yassir El Alaoui ◽  
Aicha Fahry ◽  
Nawal Cherkaoui ◽  
...  
Keyword(s):  
Light Scattering ◽  
Experimental Design ◽  
Dynamic Light Scattering ◽  
Design Space ◽  
Mixture Design ◽  
Ionic Surfactants ◽  
Maximum Point ◽  
Optimal Composition ◽  
Size Of Particles ◽  
Econazole Nitrate

The main purpose of this study is to improve and boost the solubility of Econazole Nitrate in water using phospholipid and surfactants, until it becomes possible to evaluate the utility of a mixture design in order to determine the optimal composition of non-ionic surfactants and phospholipids needed to obtain a significant improvement in the solubility of Econazole Nitrate in water. The design of experiments approach was tested using a mixture design of Lipoïd 75® as phospholipid and Econazole Nitrate, Tween® 80 and Solutol®HS 15 as surfactants,. Solubility was determined by the analysis of samples absorbance at 225 nm. and the measurement size of particles conducted using a Dynamic Light Scattering at the maximum point of solubility. The final results displayed an improvement in solubility with a statistically significant increase in many tested mixtures. Analysis of the design space showed that, the solubility of Econazole Nitrate is importantly affected by the concentration of surfactants. The best obtained test encloses 1% Econazole Nitrate, 2% Tween® 80, 0.5% Lipoid 75®, 2% Solutol®HS 15 and water q. s. for 100% w / w. Our study has demonstrated that optimized experimental design determines the proportions and the effects of every component based on a limited number of experiments.

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