Dielectric Relaxation of Aqueous Solution with Low-molecular-weight Nonelectrolytes and Its Relationship with Solution Structure

1997 ◽  
Vol 61 (11) ◽  
pp. 1831-1835 ◽  
Author(s):  
Akiko Saito ◽  
Osato Miyawaki ◽  
Kozo Nakamura
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Dielectric Relaxation ◽  
Solution Structure ◽  
Low Molecular Weight

scholarly journals Low Molecular Weight Gelators Based on Functionalized l-Dopa Promote Organogels Formation

Gels ◽  
2019 ◽  
Vol 5 (2) ◽  
pp. 27 ◽  
Author(s):  
Demetra Giuri ◽  
Nicola Zanna ◽  
Claudia Tomasini
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Rheological Properties ◽  
Rhodamine B ◽  
Lauric Acid ◽  
Water Solution ◽  
Preliminary Test ◽  
Low Molecular Weight ◽  
Coupling Reactions ◽  
Low Molecular Weight Gelators

We prepared the small pseudopeptide Lau-l-Dopa(OBn)2-d-Oxd-OBn (Lau = lauric acid; l-Dopa = l-3,4-dihydroxyphenylalanine; d-Oxd = (4R,5S)-4-methyl-5-carboxyl-oxazolidin-2-one; Bn = benzyl) through a number of coupling reactions between lauric acid, protected l-Dopa and d-Oxd with an excellent overall yield. The ability of the product to form supramolecular organogels has been tested with different organic solvents of increasing polarity and compared with the results obtained with the small pseudopeptide Fmoc-l-Dopa(OBn)2-d-Oxd-OBn. The mechanical and rheological properties of the organogels demonstrated solvent-dependent properties, with a storage modulus of 82 kPa for the ethanol organogel. Finally, to have a preliminary test of the organogels’ ability to adsorb pollutants, we treated a sample of the ethanol organogel with an aqueous solution of Rhodamine B (RhB) for 24 h. The water solution slowly lost its pink color, which became trapped in the organogel.

Dynamical studies on low molecular weight polyacrylamide aqueous solution

Polymer ◽  
1985 ◽  
Vol 26 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Michel Duval ◽  
Jeanne François ◽  
Dominique Sarazin
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Low Molecular Weight

Weak alkali and alkaline earth metal complexes of low molecular weight ligands in aqueous solution

2008 ◽  
Vol 252 (10-11) ◽  
pp. 1093-1107 ◽  
Author(s):  
Pier G. Daniele ◽  
Claudia Foti ◽  
Antonio Gianguzza ◽  
Enrico Prenesti ◽  
Silvio Sammartano
Keyword(s):  
Aqueous Solution ◽  
Molecular Weight ◽  
Metal Complexes ◽  
Alkaline Earth ◽  
Earth Metal ◽  
Alkaline Earth Metal ◽  
Low Molecular Weight

Effect of Hydrogen Peroxide on the Extraction of Components of Cedar Powder with Tetrabutylphosphonium Hydroxide Aqueous Solution at 60°C

2017 ◽  
Vol 70 (3) ◽  
pp. 322 ◽  
Author(s):  
Sachiko Yamanaka ◽  
Koichi Yoshioka ◽  
Hisashi Miyafuji ◽  
Hiroyuki Ohno
Keyword(s):  
Aqueous Solution ◽  
Hydrogen Peroxide ◽  
Molecular Weight ◽  
Woody Biomass ◽  
Low Molecular Weight ◽  
Hydroxymethyl Furfural ◽  
Mild Conditions ◽  
Initial Stage ◽  
Aqueous Mixture ◽  
Molecular Weight Fractions

We successfully dissolved cedar powder with tetrabutylphosphonium hydroxide ([P4 4 4 4]OH) aqueous solution at 60°C. The dissolution was accelerated by the addition of H2O2. At the initial stage, cellulose was more soluble than hemicellulose and lignin. Both hemicellulose and lignin were gradually dissolved in this solution containing H2O2. Cellulose chains were revealed to be cut into shorter chains in this solution. The lignin network was also found to be partly broken at 60°C. These steps induced components with higher-molecular-weight fractions that cannot be extracted with polar ionic liquids to dissolve. Also, low-molecular-weight fractions such as vanillin and 5-(hydroxymethyl)furfural were found in the resulting solution. Breakage of ether bonds of polysaccharides and lignin and further oxidation were attributed to the active oxygens generated from H2O2. The aqueous mixture reported here is a protocol that can be used to dissolve woody biomass under mild conditions.

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