Triton X-100 System Research Articles

Solubilization of aqueous-insoluble phenothiazine drug in TX-100 micellar solution and interactions of cationic/anionic surfactants with phenothiazine–TX-100 system

This article discusses the interaction of surfactants such as tetradecyltrimethylammonium bromide (TTAB), hexadecyltrimethylammonium bromide (CTAB), cetylpyridinium chloride (CPC), cetylpyridinium bromide (CPB) and sodium dodecylsulphate (SDS) in presence of poorly soluble drug phenothiazine (PTZ) in triton X-100 (TX-100) micellar aqueous media through the investigation of different physicochemical parameters. The interaction of surfactants in PTZ–TX-100 media has been studied using conductometric technique at pH 7.4 (SP buffer) and at three temperatures. The conductometric results reveal the sequence of critical micelle concentration (CMC) values of surfactants as SDS > TTAB > CPC > CPB > CTAB. UV–vis spectroscopy studies were used to learn the interactions of surfactants with the drug PTZ in TX-100 aqueous media (at 303.15 K and pH 7.4) which suggest the interactions are highly feasible (change of Gibbs energy; ΔGb < 0) and greatly improve beyond the CMC values of corresponding surfactants. The estimated parameters using the Benesi–Hildebrand equation indicate higher binding constant (Kb) for cetylpyridinium surfactants and least for SDS and the drug–surfactant complex formations are found to be in 1:2 stoichiometric ratios. Fluorescence technique has also been employed to study the aggregation number (Nagg), Stern-Volmer constant (KSV) and micro-polarity of TTAB/CTAB/SDS in PTZ–TX-100 systems at 303.15 K. The evaluated thermodynamic parameters such as change in Gibbs energy (ΔGm0), enthalpy (ΔHm0) and entropy (ΔSm0) of micellization show the process of micellization of all studied surfactants in PTZ–TX-100 aqueous media are spontaneous and exothermic.

Fouling behavior of silica nanoparticle-surfactant mixtures during constant flux dead-end ultrafiltration

The increasing use of engineered nanoparticles in customer products results in their accumulation in water sources. In this experimental study, we investigated the role of surfactant type (cationic, anionic and non-ionic) and concentration on fouling development, nanoparticle rejection and fouling irreversibility during dead-end ultrafiltration of model silica nanoparticles. Our work demonstrates that the type of surfactant influences the nanoparticle stability, which in turn is responsible for differences in fouling behavior of the nanoparticles. Moreover, the surfactant itself interacts with the PES-PVP membrane and contributes to the fouling as well. We have shown that anionic SDS (sodium dodecylsulfate) does not interact extensively with the negatively charged silica nanoparticles and does not change significantly the surface charge and size of these nanoparticles. Adsorption of the cationic CTAB (cetyltrimethylammonium bromide) onto the silica nanoparticles causes charge transition and nanoparticle aggregation, whereas non-ionic TX-100 (Triton X-100) neutralizes the surface charge of the nanoparticles but does not change significantly the nanoparticle size. The most severe fouling development was observed for the silica nanoparticle – TX-100 system, where nanoparticles in the filtration cake formed exhibited the lowest repulsive interactions. Rejection of the nanoparticles was also highest for the mixture containing silica nanoparticles and TX-100.

Microstructure of Triton X-100/poly (ethylene glycol) complex investigated by fluorescence resonance energy transfer

The microstructure of Triton X-100 (TX-100)/poly (ethylene glycol) (PEG) complex has been investigated by fluorescence resonance energy transfer (FRET), dynamic light scatter (DLS), freeze-fractured transmission electron microscopy (FF-TEM) and 1H NMR technology. The nonionic surfactant TX-100 and pyrene are employed as energy donor and acceptor respectively, and the average distance between them is calculated quantitatively in the systems of TX-100/PEG with different molecular weights (MW). The results of FRET study indicate that the presence of PEG leads to the separation of donor and acceptor in TX-100 micelle, suggesting that PEG chains insert into TX-100 micelles making the microstructure of PEG-bound TX-100 aggregates looser than that of free micelles, which is independent of the MW of PEG. However, FF-TEM, DLS and 1H NMR studies show that the morphology of TX-100/PEG complex depends on the MW of the polymer: PEG with shorter chain (MW < 2000 Da) insert into and wrap around TX-100 micelles and form sphere-like complex, while that with longer chain (MW > 2000 Da) would interact with numbers of TX-100 micelles and form coral-shaped clusters. In addition, the effects of temperature and alcohol on the microstructure of TX-100/PEG complex are studied.

Effect of Surfactants on In-Plane and Out-of-Plane Rotational Dynamics of Octadecylrhodamine B at Toluene−Water Interface

We measured the time-resolved fluorescence anisotropy of N-octadecylrhodamine B (C18RB) at a toluene−water interface under the total internal reflection conditions (an incident angle of 70°), in the absence and presence of surfactants (Triton X-100 (TX-100), sodium dodecyl sulfate (SDS), or dihexadecyl hydrogen phosphate (DHP, pKa ≈ 2)). Without surfactants, the in-plane fluorescence anisotropy, rΦ, was almost 0 independent of time, and this implied that C18RB molecules rotated very fast (rotational correlation time, τΦ ≤ 1 ns) at the interface. In the nonionic TX-100 system, C18RB molecules rotated fast (τΦ ≤ 1 ns), but their rotational regions were restricted by the surfactant molecules. In the cases of SDS and deprotonated DHP systems, the interfacial concentration of the protonated C18RB, C18RBH+, increased with an increase in the surfactant concentration (1.0 × 10-10 − 5.0 × 10-8 M) by electrostatic attractive force. In these anionic surfactant systems, rΦ decreased exponentially with time and τΦ cou...

Fluorescence quenching mechanisms in micelles: the effect of high quencher concentration

In this investigation the fluorescence quenching of fluorescent probe molecules situated within surfactant micelles was examined. The hydrophobic polyaromatic hydrocarbon benzo(a)pyrene (B(a)P) and the more polar 6-propionyl-2-(dimethylamino)-naphthalene (PRODAN) were used to assess the effect of high quencher concentration on the quenching process in micelles. Using the surfactant systems sodium dodecyl sulfate (SDS) and Triton X-100 (TX-100), three distinct modalities of quenching were observed. For the TX-100 system, both I − and H 2O 2 quenching of probe fluorescence reached saturation in efficiency. These data are modeled quite well by assuming a limited number of quenching sites per micelle in conjunction with standard Stern–Volmer quenching dynamics. For the SDS system, similar quenching saturation effects are observed, but the saturation model worked less well. It is suggested that a bimodal distribution of micelle sizes could be responsible. The B(a)P/SDS/I − system is singular in that the quenching does not saturate. The efficiency of quenching here varies approximately with the third power of I − concentration. A resonance energy transfer mechanism is proposed in which B(a)P is quenched by I 3 −.

The interaction of sodium dodecyl sulfonate and petroleum sulfonate with nonionic surfactants (Triton X-100, Triton X-114)

We have investigated the synergistic interaction between sodium dodecyl sulfonate (AS) and two nonionic surfactants [Triton X-100 (TX-100), Triton X-114 (TX-114)] in 0.1 M NaCl. Surface tension results show that a synergism exists in mixed micelle formation and surface excess concentration increases as at the specific α 1 values (the net mole fraction of component 1) for these binary systems as compared with the single surfactant system. The strength of the interaction of AS with the nonionic surfactant in two systems obeys the following order: AS–TX-100>As–TX-114. As a practical consideration, we try to apply RST (regular solution theory) to treating sodium petroleum sulfonate (SPS)–TX-100 systems. The experimental results indicate that the interaction of SPS with nonionic surfactants is much stronger than that of AS with nonionic surfactants. In addition, electron spin resonance (ESR) results are very consistent with predictions made by RST, and reveal the formation of mixed micelles in As–TX-100 and As–TX-114 systems.

Comparative Phase Behavior About the L2 Phase of Ternary and Quaternary Systems of Triton X-100 and Its Separated p-tert-OPEn (n = 5, 7, and 9) Components in Cyclohexane

The nonionic surfactant Triton X-100 (TX-100) is separated by preparative column chromatography into its poly(oxyethylene tert-octylphenyl ether) (OPEn) components. The phase behavior in the neighborhood of the L2 phase is investigated for ternary (cyclohexane/H2O) and quaternary (cyclohexane/H2O/n-hexanol) systems of TX-100 and OPEn (n = 5, 7 and 9). The extent of the L2 domain and the maximum amount of water wo,max that can be solubilized by isotropic solutions strongly depend on the concentration and the length (n) of the polar chain of the surfactant, temperature, and the amount of n-hexanol present. Depending on these variables, with increasing wo (molar ratio of water to surfactant) some of the following phase transitions occur: L2 → LC → L → liquid/gel → gel. Except for the liquid crystalline LC phase, all phases involved are optically isotropic, and the liquid L phase is most likely bicontinuous. Since n-hexanol is a better solvent than cyclohexane for both the surfactant and water, it destabiliz...