An Influence of the Spatial Arrangement, Length of the Alkyl Chain and Temperature on Micellar Properties of N-Alkyl-N-{[2-(benzyloxy)cyclohexylmethyl]}-N,N-dimethylammonium Bromides in Aqueous Solutions

1997 ◽  
Vol 62 (12) ◽  
pp. 1853-1862 ◽  
Author(s):  
Jarmila Oremusová ◽  
Veronika Mislovičová
Keyword(s):  
Aqueous Solutions ◽  
Alkyl Chain ◽  
Spatial Arrangement ◽  
Critical Micellar Concentration ◽  
Small Decrease ◽  
Counterion Binding ◽  
Micellar Properties ◽  
Fold Reduction ◽  
Increasing Temperature ◽  
Methylene Group

In this work we study influence of the length of the alkyl chain and temperature on critical micellar concentration (CMC) for cis and trans diastereoisomers of the N-alkyl-N-{[2-(benzyloxy)cyclohexylmethyl]}-N,N-dimethylammonium bromides in aqueous solutions using conductometric and spectrophotometric techniques. From the measured dependences, the degree of the counterion binding (β) and thermodynamic parameters of micellization (∆Gm0, ∆Hm0, ∆Sm0) were calculated and compared with the literature data on similar compounds. The results show that lengthening of the alkyl chain by one methylene group causes approximately a two-fold reduction in CMC. The β values decrease with temperature and with increasing length of the alkyl chain. While only a small decrease in the ∆Gm0 values (ca 1 kJ mol-1) due to increasing temperature was found, the decrease in ∆Hm0 is much more pronounced.

Excess molar volumes of binary mixtures of acetic acid and propionic acid with some members of homologous series of alkanes

1991 ◽  
Vol 56 (4) ◽  
pp. 736-744 ◽  
Author(s):  
Ondřej Drábek ◽  
Ivan Cibulka
Keyword(s):  
Acetic Acid ◽  
Propionic Acid ◽  
Alkyl Chain ◽  
Excess Molar Volumes ◽  
Liquid Mixtures ◽  
Entire Concentration Range ◽  
Molar Volumes ◽  
Binary Liquid ◽  
Alkane Molecule ◽  
Increasing Temperature

Excess molar volumes of binary liquid mixtures of (acetic or propionic acid = hexane) at 25 and 35°C, and (acetic or propionic acid + heptane or octane) and (acetic acid + dodecane) at 25°C, measured with a tilting dilution dilatometer, are reported. The excess volumes are positive over the entire concentration range for all mixtures and increase with increasing length of an alkane molecule, decrease with increasing of the alkyl chain in a molecule of carboxylic acid, and increase with increasing temperature.

scholarly journals Litogenolitic and solubility properties of products obtained from common ivy extract (Hederae helicis e folium) and medium of diversified polarity (εM)

2019 ◽  
Vol 65 (1) ◽  
pp. 20-31 ◽  
Author(s):  
Elżbieta Nowak ◽  
Zbigniew Marczyński ◽  
Beata Skibska ◽  
Michał Jakub Nachajski ◽  
Jerzy Jambor ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Thermodynamic Potential ◽  
Micelle Formation ◽  
Critical Micellar Concentration ◽  
Herbal Drugs ◽  
Efficacy And Safety ◽  
Micellar Solubilization ◽  
Hedera Helix ◽  
Inflammatory Drugs ◽  
Preformulation Studies

Summary Introduction: Common ivy (Hedera helix) is a plant used successfully in the treatment of various ailments. This is possible owing to the unique set of substances contained in it such as large amount of saponins, flavonoids, phenolic acids and phytosterols as well as polyacetylenes and coumarins. All these substances have been used in the production of cosmetic and medicinal preparations. Clinical trials on the efficacy and safety of dry ivy leaf extract have shown its high efficacy, comparable to synthetic medications, and better tolerance of herbal drugs. Objective: Investigations were performed on model ivy leaf (Hedera helix) extracts which were created using a medium of diversified polarity ( εM). Measurements of viscosity and surface activity on phase boundary were performed. During preformulation studies attention was drawn to the possibility of micellar solubilization of cholesterol and selected structures of nonsteroidal anti-inflammatory drugs (NSAIDs) – ketoprofen. Methods: Viscosity measurements of Extractum Hederae helicis e folium aqueous solutions and in 0.1 mol HCl were performed according to the Polish Standard with Ubbelohde dilution viscometer. The surface tension of aqueous solutions $- \Delta \gamma _{{\rm{sol}}}^{25}$ of Hederae helicis e folium extracts was determined according to the Polish Standard with stalagmometric method. Critical micellar concentration (cmc) was calculated. This enabled to evaluate the dependence $\Delta {\rm{G}}_{\rm{m}}^0 = 2.303$ RT×log cmc of the thermodynamic potential of micelle formation ( $\Delta {\rm{G}}_{\rm{m}}^0$ ). Results: It has been confirmed in the conducted comparative studies that aqueous solutions of Extr. Hederae helicis e folium created with maltodextrin as well as with SiO2 – maltodextrin result in micellar solubilization. The increase of granulometric size of cholesterol particle to Ø 1.60 mm decreased the amount of solubilized cholesterol but solubility preferences of the extracts were maintained. Conclusions: Model extracts produced from Hederae helicis e folium with diversified polarity of the extraction medium (water – ethanol) are characterized by appropriate solubility of the components which results not only from the presence of chlorophyll and its derivatives in the extract but also from the technique used for spray drying of the extract.

Effect of alkyl and halide moieties on the absorption and stratification of SO2 in tetrabutylammonium halide aqueous solutions

RSC Advances ◽  
2016 ◽  
Vol 6 (60) ◽  
pp. 55401-55405 ◽  
Author(s):  
Erhong Duan ◽  
Peng Zhang ◽  
Kun Yang ◽  
Weizhao Liang ◽  
Meiting Yu ◽  
...  
Keyword(s):  
Aqueous Solutions ◽  
Alkyl Chain ◽  
Halide Anion ◽  
Tetraalkylammonium Halide ◽  
Effects Of Temperature

To explore the interactions between SO2 and tetraalkylammonium halide, the effects of temperature, concentration, length of alkyl chain, and halide anion on the solubility of SO2 in tetraalkylammonium halide aqueous solutions were investigated.

THE DISSOCIATION OF α- AND β-LIPOVITELLIN IN AQUEOUS SOLUTION: PART I. EFFECT OF pH, TEMPERATURE, AND OTHER FACTORS

1962 ◽  
Vol 40 (3) ◽  
pp. 363-372 ◽  
Author(s):  
R. W. Burley ◽  
W. H. Cook
Keyword(s):  
Aqueous Solution ◽  
Ionic Strength ◽  
Aqueous Solutions ◽  
Thermodynamic Data ◽  
Equilibrium Constants ◽  
Effect Of Ph ◽  
Reversible Dissociation ◽  
Lipoprotein Concentration ◽  
Irreversible Aggregation ◽  
Increasing Temperature

The effect of pH, temperature, ionic strength, and lipoprotein concentration on the reversible dissociation of α- and β-lipovitellin in aqueous solutions above pH 6 has been examined by ultracentrifugal measurements. Under otherwise similar conditions α- and β-lipovitellin are 50% dissociated at pH 10.5 and 7.8, respectively. Both lipovitellins undergo an irreversible aggregation above about pH 11; β-lipovitellin is sometimes converted to a non-dissociable form upon aging. Dissociation of both lipovitellins decreases with increasing ionic strength and increasing temperature. Although the ultracentrifugal method has limitations, provisional equilibrium constants and thermodynamic data were obtained from it that are comparable with those obtained for certain protein systems.

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