Tetrabutylammonium Dodecyl Sulfate Research Articles

Impact of Inulin on Self-Assembled Behavior of Anionic Surface Active Ionic Liquids: Conductometric, Spectroscopic and Antimicrobial Studies

The self-assembled behavior of greener anionic surface-active ionic liquids (SAILs), namely Tetrapropylammonium Dodecylsulfate (TPADS) and Tetrabutylammonium Dodecylsulfate (TBADS), in an aqueous solution of biocompatible saccharide inulin, has been extensively investigated using conductometric and fluorescence probe techniques at different temperatures. The critical micellar concentration (CMC) values have been determined by observing the breakage point in κ vs. [SAIL] plots. These values as obtained from fluorescence probe techniques have also been calculated. It has been found that the CMC values obtained through both conventional and spectroscopic techniques exhibited close agreement. Additionally, thermodynamic parameters of micellization, such as Gibbs free energy (ΔGmo), enthalpy (ΔHmo), and entropy (ΔSmo) were calculated using conductivity data as they play a crucial role in understanding the various interactions prevailing in the SAIL-inulin-water system. It was found that the micellization process for SAILs in the aqueous inulin solution occurs readily, as indicated by the Gibbs free energy of micellization. Furthermore, the antimicrobial properties of biocompatible SAILs in 0.2% w/w aqueous inulin solution were explored against bacterial strains, gram-positive i.e. B. cereus, S. aureus, and gram-negative namely P. aeruginosa. Molecular docking studies were also conducted to determine the binding energy and binding sites between TBADS and the proteins of the aforementioned bacteria. These investigations help to enhance the understanding of potential applications and interactions of SAILs in the presence of inulin.

Temperature dependent micellization behavior of as synthesized anionic SAILs in aqueous nonionic polymer solutions: conductivity, UV-visible probe and antimicrobial studies

As synthesized surface active ionic liquids (SAILs), Tetrapropylammonium Dodecylsulfate (TPADS), and Tetrabutylammonium Dodecylsulfate (TBADS) have been characterized by FTIR, 1H-NMR and 13C-NMR spectroscopic techniques. Conductometric and UV-Visible probe investigations have been attempted to study the aggregation behavior of these synthesized SAILs in aqueous solution of polymers Polyvinylpyrrolidone (PVP) and Polyethylene glycol (PEG) at different temperatures and concentrations. Two breaking points were identified from κ vs [SAILs] plots. First, the critical aggregation concentration (CAC) is recognized with the polymer-SAILs binding and the second being regarded as critical micellar concentration (CMC), suggested to represent saturation point for Polymer-SAIL aggregation. Thermodynamic parameters of micellization ( Δ G m o , Δ H m o and Δ S m o ) are rationalized in terms of interactions prevailing between hydrophobic and hydrophilic regions of SAIL-Polymer system. Micellization process for the blend of SAIL-PVP is found to be more favored than SAIL-PEG at all temperatures. Further, the effect of PVP on the antimicrobial activities of TPADS/TBADS has been tested by measuring zone of inhibition which accounts for higher effectiveness of PVP-SAILs system against gram positive bacteria (Bacillus cereus and Staphylococcus aureus) as compared to gram negative bacteria (Pseudomonas aeruginosa).

TETRABUTYLAMMONIUM DODECYL SULFATE: ION EXCHANGE SYNTHESIS, CHARACTERIZATION AND BIOLOGICAL ACTIVITY IN COMPARISON OF SODIUM DODECYL SULFATE

A surface-active ionic liquid, tetrabutylammonium dodecyl sulfate was obtained from tetrabutylammonium bromide by employing anion exchange technique, an alternative novel approach giving 87.72 % yield and about 99 % exchange. The infrared spectroscopy coupled with prescribed tests for detection of anions confirmed the success of anion exchange. Differential Scanning Calorimetry was used for thermal characterization of the compound. A comparative profile of the physicochemical properties of three compounds viz. tetrabutylammonium dodecyl sulfate, tetrabutylammonium bromide and sodium dodecyl sulfate was created. The sodium free ionic liquid reported in this paper shows superior activity against Candida albicans at concentrations above 100 μg.

The cloud point phenomenon of ionic surfactants: A view from molecular dynamics and metadynamics simulation

Molecular dynamics (MD) and metadynamics simulations were used to give an understanding on the cloud point phenomenon of ionic surfactants. Meanwhile, the differences between tetrabutylammonium interactions with dodecyl sulfate (DS−) and alkyl carboxylate (C12) micelles are discussed. Micelle ionization degree (α), binding patterns between the counterions and micelle, potential of mean force (PMF), and intermicellar interactions were characterized to present a reasonable explanation on the different behaviors of tetrabutylammonium alkyl carboxylate (TBAC) and tetrabutylammonium dodecyl sulfate (TBADS). Free energy profiles indicate that three bridging models exist between TBADS micelles. This will be the fundamental intermicellar model to interpret the cloud point phenomenon of TBADS ionic surfactants and other analogous systems.

Thermodynamic Parameters of Anionic Surfactant−Additive Systems at the Cloud Point

The thermodynamic parameters of an aqueous anionic surfactant, tetrabutylammonium dodecyl sulfate (TBADS), are calculated in the presence of various additives (viz., quaternary bromides, alcohols, and amines) at the cloud point (CP) of the TBADS−additive system. As the clouding components release their solvated water, they separate out from the solution. Therefore, the CP of an amphiphile can be considered the limit of its solubility. The standard Gibbs energy change of solubilization (ΔsG°) for all of the additives is found to be negative. The standard enthalpy change (ΔsH°) and the standard entropy change (TΔsS°) values are found to be negative as well as positive depending upon the type and nature of the additive. The results are explained on the basis of their nature, effect on the water structure, and solubilization of these additives either in the micellar or aqueous phase.

Interfacial and Solution Properties of Tetraalkylammonium Bromides and their Sodium Dodecyl Sulfate Interacted Products: A Detailed Physicochemical Study

The adsorption and solution behaviors of symmetrical tetramethyl-, tetraethyl-, tetrapropyl-, and tetrabutylammonium bromides (TMAB, TEAB, TPAB, and TBAB, respectively) were studied at the air/water interface and in the bulk aqueous environments. Their salts were prepared by reacting tetraalkylammonium bromide (TAAB) with sodium dodecyl sulfate (SDS) in a solution from which the products of the higher two homologues (tetrapropylammonium dodecyl sulfate (TPADS) and tetrabutylammonium dodecyl sulfate (TBADS)) could only be isolated as solids and for which detailed characterization has been performed. The interfacial behaviors of 1:1 molar mixtures of TAAB and SDS and the prepared TPADS and TBADS were examined. Micellization of the 1:1 mixtures along with the isolated species were studied in the presence and absence of NaBr salt. The energetics of the micellization process and the counterion binding of the micelles were evaluated. The interaction of the TAABs with SDS micelles was examined, and the results were evaluated in terms of single- and two-site binding interaction models. Of the formed tetraalkylammonium dodecyl sulfates (TAADSs), only TBADS evidenced clouding, which was investigated in detail along with 1:1 molar mixtures of TBAB and SDS in aqueous solution in the presence of additives such as NaBr, SDS, and TBAB. The solution behaviors of the TAADS and the clouding of TBADS have been rationalized in terms of a mixed micellar model.

Effect of the Nature of the Counterion on the Properties of Anionic Surfactants. 4. Characterizing Micelles of Tetraalkylammonium Dodecyl Sulfate as Reaction Media

Micelles formed in water from tetramethyl-, tetraethyl-, tetrapropyl- and tetrabutylammonium dodecyl sulfate (TMADS, TEADS, TPADS, and TBADS, respectively) are characterized as reaction media. All of the results are identical in the presence or absence of added salt, provided micelles of the same aggregation number, N, are compared. The microviscosity (eta) deduced from the rotational motion of the nitroxide group of a spin probe increases modestly as a function of N in TMADS and TEADS, decreases slightly in TPADS, and decreases slightly before increasing in TBADS. The activation energy for the viscosity is remarkably similar in all of the tetraalkylammonium dodecyl sulfate (TAADS) micelles and is similar to that in ethanol/water mixtures as well as other anionic and cationic micelles. The volume fraction occupied by water in the polar shell, H(t), decreases with N in TMADS, TEADS, and TPADS at 10, 25, and 45 degrees C whereas it decreases, goes through a minimum, and then increases in TBADS. H(t) also decreases with the size of the counterion. The bimolecular collision rate as deduced from fluorescence quenching of pyrene by dodecylpyridinium chloride conforms well to a hydrodynamic description, varying linearly with T/eta, where T is the absolute temperature and passing through the origin. Quenching probablities of 0.53, 0.51, 0.45, 0.39 for TMADS, TEADS, TPADS, and TBADS, respectively, are rationalized in terms of small shifts of the diffusion zones outside of the Stern layer by an average of 16% of the Stern layer thickness.

Effect of the Nature of the Counterion on the Properties of Anionic Surfactants. 3. Self-Association Behavior of Tetrabutylammonium Dodecyl Sulfate and Tetradecyl Sulfate: Clouding and Micellar Growth

The surfactants tetrabutylammonium dodecyl sulfate (TBADS) and tetradecyl sulfate (TBATS) have been synthesized by ion-exchange, and their self-association behavior has been investigated. The solutions of these surfactants show clouding and phase separation as the temperature is increased. The clouding temperature TC of TBADS solutions has been found to be about 4−5 °C higher than for TBATS solutions in the whole range of composition up to a surfactant content of 64 wt %. The critical micellization concentration (cmc) of TBATS has been determined using the electrical conductivity method. The micelle aggregation numbers (N) have been determined using the time-resolved fluorescence quenching (TRFQ) method, with pyrene/dodecylpyridinium chloride as fluorescent probe/quencher pair. For the two surfactants, N increases with the surfactant concentration and above a threshold concentration with the temperature. This latter increase as well as the phase separation observed for TBADS and TBATS are very unusual fea...

Effect of the Nature of the Counterion on the Properties of Anionic Surfactants. 2. Aggregation Number-Based Micelle Ionization Degrees for Micelles of Tetraalkylammonium Dodecylsulfates

Tetramethyl-, tetraethyl-, tetrapropyl-, and tetrabutylammonium dodecylsulfate micelles in aqueous solution grow as either the surfactant or added electrolyte concentrations are increased. The variation in the aggregation number, N, of the first three surfactants is described as follows: N = N0(Caq/cmc0)γ where N0 is the aggregation number at the critical micelle concentration in the absence of added electrolyte, cmc0, Caq is the concentration of counterions in the aqueous phase, and γ is a constant. The values of N0 are rather small, in the range 54 to 64 at 25°; 61 to 74 at 10°; and 51 to 56 at 40 °C. The values of γ are insensitive to temperature and are rather small; 0.05 to 0.1. In contrast, tetrabutylammonium dodecylsulfate grows nearly linearly with Caq. The ionization degrees (α) of these micelles are studied by applying the hypothesis recently introduced (J. Phys. Chem. B 2001, 105, 6798) that the aggregation number at a given temperature is determined solely by Caq, whether these counterions ar...

Cloud Point of Aqueous Solutions of Tetrabutylammonium Dodecyl Sulfate Is a Function of the Concentration of Counterions in the Aqueous Phase

The cloud point of the surfactant tetrabutylammonium dodecyl sulfate is shown to be a function of the tetrabutylammonium counterion concentration in the aqueous phase whether the counterions are provided by the surfactant or both the surfactant and added tetrabutylammonium bromide. The micellized surfactant dissociates 17% of its counterions to aqueous phase.

Structure and Electrochemical Properties of Electrically Conductive Composites

Abstract Conducting composites of polypyrrole(PPy) and poly(N-methylpyrrole) (PNMP) were prepared by electrochemical polymerization of the corresponding monomers at a platinum electrode surface in 0.036M tetrabutylammoniumdodecyl-sulfate(TBADS) / acetonitrile(ACN) electrolyte solution system. Two types of composites were prepared; PPy/PNMP bilayer composite films and monomer mixture conducting polymer composites of pyrrole and N-methylpyrrole. The composites were characterized by TGA, SEM and 4-probe meter. The composites exhibited different electric resistances and thermal stabilities depending on the preparation method of the conducting polymer composites. The PPy/PNMP bilayer composite films showed lower electric resistance (i.e. better electric conductivity) and higher thermal stability than any other composite films obtained in this work.

A Polypyrrole Solution in Chloroform

Abstract Polypyrrole(PPy) soluble in chloroform and m-cresol was chemically synthesized by using ammonium persulfate as an oxidant and dodecylbenzene sulfonic acid as a dopant source. Electrical conductivity of resulting PPy becomes higher when polymerized with higher concentration of the oxidant and at lower polymerization temperature. The surface of PPy film cast from the solution is so smooth to give little scattering but total reflection and the film shows electrical conductivity of 4.5 S/cm. PPy solution in chloroform shows much greater absorption in the free carrier-tail region than that in m-cresol does, indicating that chloroform is a better solvent. The cast film sustains the cyclic redox reactivity for more than 100 cycles in the system of tetrabutylammonium dodecylsulfate in acetonitrile.

Electrochemical properties of poly(N-substituted pyrrole)s obtained in TBADS/ACN electrolyte system

The electrochemical properties of polu(N-substituted pyrrole)s were studied. Polypyrrole(PPy) and poly(N-substituted pyrrole)s were prepared via electrochemical methods using tetrabutylammonium dodecyl sulfate(TBADS)/Acetonitrile(ACN) electrolyte system. The electropolymerized films were characterized by potentiostat, SEM and 4-probe conductivity meter. Structural characteristics of the films were discussed using conductivity and morphology as well as spectroscopy. It was found out that the N-substituted pyrroles having larger substituted groups are more hampered when oxidation, resulting in lower conductivity.

Redox Behavior of Polypyrrole Films in Different Solvents

Abstract The redox behavior of polypyrrole (PPy) films has been examined by means of cyclic voltammetry and SEM/EDS. PPy was galvanostatically prepared in acetonitrile (AN) containing tetrabutylammonium dodecylsulfate (TBADS) as an electrolyte. Charge compensation mechanism of PPy films which incorporate dodecylsulfate (DS) ions was greatly influenced by the solvents or electrolyte used in the redox reaction. When the PPy was switched between -0.8 V and 0.5 V in the TBADS/AN solution, bulky DS ions were participated in the redox reaction of the swollen PPy film. In the aqueous solution containing NaDS, on the other hand, Na cations worked as main charge-compensating ions because DS anions with long alkyl chains were trapped in the contracted PPy and difficult to move during the switching process. However, DS ions in the TBADS/water solution should be the compensating ions to show higher oxidation potentials. When the free-standing films were reduced for 24 hours at -0.8 V against an Ag/AgCl reference elec...

Interactions of anionic surfactants with nonionic polymers. Comparison of guanidinium, tetraalkylammonium, and alkali metal ions as counterions

Abstract The interactions of anionic surfactants with nonionic polymers such as polyvinyl pyrrolidone (PVP), polyvinyl alcohol-acetate copolymers (PVA-Ac), and polyvinyl alcohol (PVA) in aqueous solution were studied with respect to guanidinium, four tetraalkylammoniums, sodium, and potassium as the counterions by means of electrical conductivity, dye solubilization, viscosity, and cloud point measurements. With sodium salts as the reference, guanidinium, a strongly water structure-breaking cation, lowers the critical micelle concentration (emc) of the long-chain alkylsulfates, and in the presence of PVP and PVA-Ac it promotes the binding of the anions to them and enforces the attraction between the bound anions by ion-pairing, exhibiting such phenomena as shrinking of the polymer chains or depression of the cloud points. Similar phenomena have been observed and discussed previously in the interactions of these polymers and long-chain alkylammonium or symmetrical tetraalkylammonium ions with thiocyanate or iodide as counterions, both also strongly water structure-breaking anions. Sodium and potassium dodecylsulfates interact with PVP and polyvinyl acetate to a similar extent because both counterions are of weak effect on water. On the other hand, for the quaternary ions, which promote the water structure, as the counterions to dodecylsulfate, the cmc lowers with increase in size of the quaternaries but the polymer interactions weaken, and tetrabutylammonium dodecylsulfate in particular barely interacts with PVP and PVA in the presence of the micelles, and only weakly with PVA-Ac. Thus, in comparison with the sodium salts, only the strongly water structure-breaking counterions enhance the binding of the long-chain anions to the polymers. The role of the quaternary counterions has been discussed in terms of the effect on the equilibria between micelle formation and complex formation with the polymer.