Synthesis,Characterization and Evaluation of the Surface Active Properties of Novel Cationic Imidazolium Gemini Surfactants

New imidazolium gemini surfactants were synthesized by reaction of epichlorohydrin with long chain fatty alcohols furnishing products 2-(alkoxymethyl)oxirane followed by their subsequent treatment with imidazole resulting in the formation of 1-(1H-imidazol-1-yl-3 alkoxy)propane-2-ol which on subsequent treatment with 1,2-dibromoethane and 1,3-dibromopropane resulted in the formation of title gemini surfactants:1,2-bis(1(3-alkoxy-2-hydroxypropyl)-1H-imidazol-3-ium)ethane bromide (7), 1,3-bis(1(3-alkoxy-2-hydroxypropyl)-1H-imidazol-3-ium)propane bromide (8), 1,2-bis(1(3-alkoxy-2-hydroxypropyl)-1H-imidazol-3-ium)ethane bromide (9), 1,3-bis(1(3-alkoxy-2-hydroxypropyl)-1H-imidazol-3-ium)propane bromide (10), 1,2-bis (1(3-alkoxy-2-hydroxypropyl)-1H-imidazol-3-ium)ethane bromide (11) and 1,3-bis (1(3-alkoxy-2-hydroxypropyl)-1H-imidazol-3-ium)propane bromide (12). Their identification was based on IR, ¹H-, ¹³C-NMR, DEPT, COSY and mass spectral studies. Their surface active properties were also evaluated on the basis of surface tension and conductivity measurements.     

Physicochemical investigations of Pd2+ substituted ZnO nanoflowers for liquefied petroleum gas sensing

Journal of Materials Science: Materials in Electronics - Present study portrays, physicochemical investigations of pristine and Pd2+ modified ZnO nanoflowers (NFs) compositional series...     

Synthesis of Ester Based Cationic Pyridinium Gemini Surfactants and Appraisal of Their Surface Active Properties

New pyridinium gemini surfactants have been synthesized by esterification of halogenated carboxylic acids with long chain fatty alcohols furnishing respective esters (dodecyl-2-chloroacetate, tetradecyl-2-chloroacetate, hexadecyl-2-chloroacetate, dodecyl-2-bromoacetate, tetradecyl-2-bromoacetate and hexadecyl-2-bromoacetate) followed by their subsequent treatment with 4,4′-trimethylene dipyridine resulting in the formation of title Gemini surfactants: 4,4′-(propane-1,3-diyl)bis1-{2-(dodecyloxy)-2-oxoethyl}; 4,4′-(propane-1,3-diyl)bis{1-(2-(tetradecyloxy)-2-oxoethyl}; 4,4′-(propane-1,3-diyl)bis{1-(2-(hexadecyloxy)-2-oxoethyl} dipyridinium chlorides; 4,4′-(propane-1,3-diyl)bis{1-(2-(dodecyloxy)-2-oxoethyl}; 4,4′-(propane-1,3-diyl)bis{1-(2-(tetradecyloxy)-2-oxoethyl} and 4,4′-(propane-1,3-diyl)bis{1-(2-(hexadecyloxy)-2-oxoethyl} dipyridinium bromides. Their identifications are based on IR, ¹H-NMR, ¹³C-NMR, DEPT, COSY and Mass spectral studies. Their surface active properties were also evaluated on the basis of surface tension and conductivity measurements.     

On I–V measurements and high field conduction of (Se80Te20)94−xGe6Bix (0 ≤ x ≤ 12) chalcogenide alloys

Journal of Materials Science: Materials in Electronics - (Se80Te20)94?xGe6Bix (0?≤?x?≤?12) chalcogenide alloys were prepared by melt quenching technique....     

On the Dielectric Study of Se<Subscript>80−<Emphasis Type="Italic">x</Emphasis></Subscript>Te<Subscript>20</Subscript>Pb<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> (<Emphasis Type="Italic">x</Emphasis> = 0, 1 and 2) Glasses

In the present paper, the dielectric parameters such as the dielectric constant ε′(ω), dielectric loss ε″(ω) and alternating current (ac) conductivity have been investigated for bulk amorphous chalcogenide Se_80?x Te₂₀Pb _x (x = 0, 1 and 2) glasses in the frequency range 10 Hz to 500 kHz and within the temperature range from 300 K to 320 K. Dielectric constant ε′(ω) and dielectric loss ε″(ω) are found to be highly frequency (ω) and temperature dependent, and this behavior is interpreted on the basis of Guintini’s theory of dielectric dispersion. The ac conductivity (σ _ac) is found to be temperature independent and obey the power law ω ^s , where s < 1 and decreases as temperature rises. The obtained results are discussed in terms of the correlation barrier hopping model proposed by Elliot. The composition dependence of the dielectric constant, dielectric loss and ac conductivity are also discussed and reported here.     

Cationic Imidazolium Monomeric Surfactants: Their Synthesis and Surface Active Properties

A series of long-chain ester-based water-soluble cationics have been synthesized by using renewable raw materials like fatty acids and halogenated alcohols. The surface activity of the molecules has been determined by measurement of their conductance and surface tension in aqueous solution. The dynamics of surface activity of these surfactants have also been investigated in the presence of sodium halides (NaCl and NaBr) by surface tension measurement. A series of useful parameters like critical micelle concentration (CMC), surface tension at the CMC (γ_CMC), adsorption efficiency (pC₂₀), effectiveness of surface tension reduction (Π_CMC), Gibbs free energy of the micellization (ΔG _0mic) and Gibbs free energy of adsorption (ΔG _0ads) have been determined from the measurements obtained by surface tension and conductivity methods. Further with the application of the Gibbs adsorption isotherm, maximum surface excess concentration (Γ_max) and minimum surface area/molecule (A_min) at the air–water interface were also estimated. Thermal stability of these long chain cationics have been measured by thermal gravimetric analysis under a nitrogen atmosphere. Analysis of thermal stability measurement indicated that the thermal stability of these long chain imidazoliums increases with an increase in chain length.     

Gemini Pyridinium Surfactants: Synthesis and Their Surface Active Properties

New pyridinium Gemini surfactants have been synthesized by esterification of renewable fatty acids with halogenated alcohols furnishing respective esters (2‐chloroethyl hexadecanoate, 2‐chloroethyl tetradecanoate, 2‐chloroethyl dodecanoate, 2‐bromoethyl hexadecanoate, 2‐bromoethyl tetradecanoate and 2‐bromoethyl dodecanoate) followed by their subsequent treatment with 4,4′‐trimethylenedipyridine resulting into the formation of title Gemini surfactants: (4,4′‐(propane‐1,3‐diyl)bis(1‐(2‐(hexadecanoyl oxy) ethyl) dipyridinium chloride(7), (4,4′‐(propane‐1,3‐diyl)bis(1‐(2‐(tetradecanoyl oxy) ethyl) dipyridinium chloride (8), 4,4′‐(propane‐1,3‐diyl)bis(1‐(2‐(dodecanoyl oxy) ethyl) dipyridinium chloride (9), (4,4′‐(propane‐1,3‐diyl)bis(1‐(2‐(hexadecanoyl oxy) ethyl) dipyridinium bromide (10), (4,4′‐(propane‐1,3‐diyl)bis(1‐(2‐(tetradecanoyl oxy) ethyl) dipyridinium bromide (11), 4,4′‐(propane‐1,3‐diyl)bis(1‐(2‐(dodecanoyl oxy) ethyl) dipyridinium bromide (12). Their identifications are based on IR, ¹H‐, ¹³C‐NMR, DEPT, COSY and mass spectral studies. Their surface active properties are also evaluated on the basis of surface tension and conductivity measurements and thermal stability of these long chain cationics Gemini surfactants have been measured by thermal gravimetric analysis under nitrogen atmosphere.