Ammonium ionic liquid as modulator of the critical micelle concentration of ammonium surfactant at aqueous solution: Conductimetric and dynamic light scattering (DLS) studies

2007 ◽  
Vol 314 (2) ◽  
pp. 643-650 ◽  
Author(s):  
Hocine Sifaoui ◽  
Katarzyna Ługowska ◽  
Urszula Domańska ◽  
Ali Modaressi ◽  
Marek Rogalski
Keyword(s):  
Aqueous Solution ◽  
Ionic Liquid ◽  
Light Scattering ◽  
Critical Micelle Concentration ◽  
Dynamic Light Scattering

Synthesis and properties of multiheaded and multitailed surfactants based on tripentaerythritol

2015 ◽  
Vol 93 (5) ◽  
pp. 502-508 ◽  
Author(s):  
Nawal K. Paul ◽  
Tyler Mercer ◽  
Hussein Al-Mughaid ◽  
D. Gerrard Marangoni ◽  
Michael J. McAlduff ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Aqueous Solution ◽  
Surface Tension ◽  
Light Scattering ◽  
Dynamic Light Scattering ◽  
Self Assembly ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Aggregation Behaviour ◽  
Aggregate Structures

The surface and self-assembly properties of a family of multiheaded, multitailed surfactants based on a tripentaerythritol backbone are described. Critical aggregation concentrations of these unusual surfactant systems have been determined from surface tension measurements; aggregate sizes in the presence and absence of a small amount of added electrolyte have been obtained via dynamic light scattering, and the morphologies of the aggregates were examined from electron microscopy measurements. In general, when compared to conventional ionic and two-headed surfactants (and other recently synthesized pentaerythritol derived surfactants from this group), these multiheaded surfactants exhibited some unusual trends in their aggregation behaviour and interesting aggregate structures in aqueous solution, as a function of alkyl chain length.

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.

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