Sodium Dodecyl Benzyl Sulfonate Research Articles

Conductive Nanocomposite Cotton Thread Strands for Wire and Industrial Applications

This paper reports the synthesis of conducting cotton thread strands obtained by dip coating in sodium dodecyl-benzene sulfonate (SDBS) surfactant with dispersed single-walled carbon nanotubes (SWCNT), as a promising candidate for energy storage applications. The effect of the dispersion and SDBS in the dissolved SWCNT solution was detected using field emission scanning electron microscopy (FE-SEM) and x-ray diffraction (XRD). XRD confirms that there was good dispersion of SWCNTs on the cotton thread strands obtained by doping employing ethylene glycol (EG) which lowers the corrugation of the cotton thread. FE-SEM images obtained at different magnifications show micro-fibril structure. Energy dispersive x-ray (EDX) analysis confirms the presence of only C, Na and S, ruling out the presence of any elemental impurity. A strong decrease from 3.587Ω to 0.01257Ω in electrical resistance was observed when the concentration of SWCNTs was increased from 0.008049 wt.% to 1.07269 wt.%, indicating that the SWCNTs induced conductive properties in the cotton thread strands. The study shows that sodium dodecyl benzyl sulfonate (SDBS) has the best dispersion of single-walled carbon nanotubes in water when used along with ethylene glycol. The results show that the coated threads can have great industrial applications as conduction wire substitute.

New luminescent probe for the selective detection of dopamine based on in situ prepared Ru(II) complex-sodium dodecyl benzyl sulfonate assembly

Due to clinical importance, detection of dopamine by using easy and rapid method is still ongoing challenge. Here we present a simple and quite efficient method for dopamine (DA) detection in alkalescent medium using in situ prepared Ru(II) complex and sodium dodecyl benzyl sulfonate (SDBS) as highly luminescent luminophore. The luminescence enhancement in the Ru(II) complex (Ru-CIP) has been observed in the miceller medium formed by SDBS. The capability to successively quench the luminescence intensity has been tested for variety of molecules and only dopamine as analyte found to be able to quench luminescence effectively. Hence selective quenching of luminescence by dopamine was used as a tool to detect dopamine and two linear concentration ranges has been established from 0.1 μM to 1μM and from 2 μM to 10 μM with limit of detection (LOD) is 6.6 nM (S/N = 3). Spectral evidence showed that luminescence quenching mechanism arose via Forster resonance energy transfer (FRET) among oxidized DA (i.e. DA quinone) and in situ generated Ru-CIP and SDBS assembly. Due to ultra sensitivity and high selectivity of the prescribed (Ru-CIP-SDBS) luminescent probe has a strong potential for practical analytical application in clinical diagnosis.

Ratiometric Interactions of Anionic Surfactants with Calf Thymus DNA Bound Cationic Surfactants: Study II

AbstractCationic surfactant cetyltrimethylammonium bromide (CTAB) and cetylpyridinium bromide (CPB) bind to the calf thymus DNA (ct‐DNA) like anionic biopolymers electrostatically, and establish equilibrium in aqueous medium at pH 7. At low concentration, ct‐DNA does not interact with anionic surfactants, sodium dodecylsulfate (SDS) and sodium dodecylbenzylsulfonate (SDBS). However, in the ground state, anionic surfactant is found to clearly establish equilibrium with ct‐DNA‐bound cationic surfactant whereby the same surfactant–DNA isosbestic point reappears. We herein report a detail ratiometric binding of CPB with ct‐DNA, and interaction of anionic SDBS with DNA‐bound CPB in comparison with the combined ct‐DNA–CTAB–SDS system. Compaction of ct‐DNA in presence of CPB and its decompaction using anionic SDBS is also studied in comparison with CTAB–SDS combination. The techniques used are tensiometry, spectrophotometry, viscometry, cyclic voltammetry, circular dichroism, isothermal titration calorimetry, and density functional theory (DFT)‐based computational calculations. The size and surface charge density of the surfactant headgroups and the phosphate group in DNA have a contributing role in the DNA compaction–decompaction phenomenon.

Probing the carbon nanotube-surfactant interaction for the preparation of composites

Adsorption isotherms of four different surfactants, sodium dodecyl sulfate (SDS), sodium dodecyl benzyl sulfonate, benzethonium chloride and Triton X-100 were measured on multi-wall carbon nanotubes (MWCNT) in water. With the surfactant SDS, the isotherms were also measured on single-wall carbon nanotubes (SWCNT) as well as on MWCNT under various ionic strength and temperature conditions. The nature of the polar head had only little influence on adsorption which was mainly driven by hydrophobic interactions. However, the outcome of the dispersion experiment was dependent on the purity of the carbon nanotubes. Using these results, it was possible to prepare concentrated colloidaly stable dispersions of MWCNTs in water (c=32g/L). Conducting MWCNT/polymer composite films could then readily be prepared by simple formulation of the MWCNTs with a polymeric dispersion.

Formation of self-assembled nanofiber-like Ag@PPy core/shell structures induced by SDBS

Core-shell structured Ag@PPy nano-particles (NPs) were prepared by a facile method through a redox reaction, where silver nitrate and pyrrole were employed as reactants, sodium dodecyl benzyl sulfonate (SDBS) was used as a template to induce the formation of nanofiber-like Ag@PPy core-shell structure. Formation processes of this kind of structure were proposed. Firstly, sphere-like Ag@PPy structures were produced. Secondly, these sphere-like particles assembled to form nanofiber-like morphology. Effects of the concentration of SDBS on morphology of the sample were investigated. When the morphology of the samples changed from spherical to nanofibrous, the electrical conductivity of the sample increased from 11±2 to 165±5S/cm.

Synthesis of polyaniline nanofibers with high electrical conductivity from CTAB–SDBS mixed surfactants

Mixed surfactant solution, containing cetyltrimethyl ammonium bromide (CTAB) and sodium dodecylbenzyl sulfonate (SDBS), is used to prepare polyaniline (PANI) with soft 1D structure and high electrical conductivity. The mixed surfactants in the reaction play double roles of soft templates and dispersion reagents. The influence of CTAB–SDBS ratio on the morphology and conductive property of PANI is investigated. Through varying the proportion of surfactants, uniformly branched nanofibers with higher aspect ratio and good dispersion are obtained, which possess the highest conductivity (0.102 S·cm −1). Moreover, FT-IR spectra are measured to explain the change of structure and conductivity under assistance of mixed surfactants. As a result, the mixed surfactants have significant effect on the electron density of whole structure as well as the PANI molecular orientation.

Growth of Dendritic Silver Crystals in CTAB/SDBS Mixed-Surfactant Solutions

Novel dendritic silver crystals, which consist of several branches with lengths up to 10 μm, have been successfully synthesized by a simple wet chemical route using l-ascorbic acid as reductant in cetyltrimethylammonium bromide (CTAB) and sodium dodecyl benzyl sulfonate (SDBS) mixed surfactant solution at room temperature. Powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), and UV−vis absorption spectroscopy have been used to characterize the obtained silver products. It is found that the architecture of silver crystals is drastically influenced by the molar ratio, concentration of CTAB/SDBS, and the concentration of the precursors. It is revealed that the mixed-surfactant solution might play both capping reagent and dispersion reagent roles.

Directed Disassembly of an Interfacial Rubisco Protein Network

We present the first study of the directed disassembly of a protein network at the air-water interface by the synergistic action of a surfactant and an enzyme. We seek to understand the fundamentals of protein network disassembly by using rubisco adsorbed at the air-water interface as a model. We propose that rubisco adsorption at the air-water interface results in the formation of a fishnet-like network of interconnected protein molecules, capable of transmitting lateral force. The mechanical properties of the rubisco network during assembly and disassembly at the air-water interface were characterized by direct measurement of laterally transmitted force through the protein network using the Cambridge interfacial tensiometer. We have shown that, when used individually, either 2 ppm of the surfactant, sodium dodecyl benzyl sulfonate (SDOBS), or 2 ppm of the enzyme, subtilisin A (SA), were insufficient to completely disassemble the rubisco network within 1 h of treatment. However, a combination of 2 ppm SDOBS and 2 ppm SA led to almost complete disassembly within 1 h. Increasing the concentration of SA in the mixture from 2 to 10 ppm, while keeping the SDOBS concentration constant, significantly decreased the time required to completely disassemble the rubisco network. Furthermore, the initial rate of network disassembly using formulations containing SDOBS was surprisingly insensitive to this increase in SA concentration. This study gives insight into the role of lateral interactions between protein molecules at interfaces in stabilizing interfacial protein networks and shows that surfactant and enzyme working in combination proves more effective at disrupting and mobilizing the interfacial protein network than the action of either agent alone.

Effect of polymer–surfactant interactions on elongational viscosity and atomization of peo solutions

The elongational viscosities of aqueous solutions of polyethylene oxide (PEO) containing either sodium dodecyl sulfate (SDS) or sodium dodecyl benzyl sulfonate (SDBS) are measured by an opposing jet elongational rheometer. The elongational viscosities of these solutions are greatly enhanced by interactions between the polymer chain and surfactant micelles, and the behavior of the elongational viscosity–strain rate curves is complex, and strongly dependent on surfactant concentration. In the case of PEO–SDS solutions, abrupt rises in elongational viscosity are observed at critical values of strain rate, which vary with the SDS concentration. Data from these measurements are also employed to estimate elongational viscosities prevailing at the nozzle atomization stress in previous atomization experiments performed on PEO–SDS and PEO–SDBS solutions. Strong similarities are found between the variation of elongational viscosity and the variation of atomization droplet size with surfactant concentration.

Electron Injection into the Surface States of ZrO2 Nanoparticles from Photoexcited Quinizarin and Its Derivatives: Effect of Surface Modification

The effect of surface modification on interfacial electron transfer (IET) dynamics into the surface states of ZrO(2) nanoparticles sensitized by quinizarin (Qz) and its derivatives has been carried out using time-resolved emission spectroscopy. The surface of ZrO(2) nanoparticles has been modified by sodium dodecyl benzyl sulfonate . We have observed that Qz's can form a strong charge-transfer (CT) complex with both unmodified and surface-modified (SM) ZrO(2) nanoparticles. We have confirmed electron injection into the surface states of ZrO(2) nanoparticles from the photoexcited Qz molecule in our earlier work (J. Phys. Chem. B 2004, 108, 4775; Langmuir 2004, 20, 7342). In the present investigation, we have observed electron injection from photoexcited Qz derivatives into the surface states of both unmodified and SM ZrO(2) nanoparticles and also detected CT emission. Monitoring CT emission, we have determined back electron transfer (BET) dynamics of the dye-nanoparticle systems. We have found that the BET rate for the QZs/ZrO(2) systems decreases as the relative driving force increases following Marcus inverted region kinetic behavior for an IET process. BET dynamics was found to be faster on SM ZrO(2) nanoparticles as compared to that of the unmodified (bare) one. Our time-resolved emission data indicates that upon surface modification the majority of the deeper trap states of ZrO(2) nanoparticles can be removed with the formation of some new shallower trap states in the band gap region.

Particle Size in Emmulsion Polymerization of Octamethyltetrasiloxane

In view of interest in the emulsion polymerization of octamethylcyclosiloxane, (D4), the stability of droplets of monomer D4 against Ostwald ripening was studied and shown to obey the LSW theory at room temperature. The emulsifier was sodium dodecyl benzylsulfonate and the mixture was initially sonicated for a few minutes. Upon polymerization, initiated with dibenzylsulfonic acid, the particle size, measured by dynamic light scattering (DLS), first increases, then rapidly decreases probably through some secondary nucleation process to become stable when the particles contain enough polymer, that can act as a stabilizer against the Ostwald ripening.

Different effects of alkyl sulfate and alkylbenzene sulfonate surfactants on the synthesis and properties of CuPc/TiO 2 composite films by the liquid-phase deposition (LPD) method

The insoluble copper phthalocyanine (CuPc)/TiO 2 composite thin film has been successfully prepared in an aqueous solution by liquid-phase deposition (LPD) method, applying two surfactants as the solubilizing agents. The two surfactants are sodium dodecyl benzylsulfonate (SDBS) and sodium lauryl sulfate (SDS), selected as the representative of their groups. The deposited films were characterized by UV–vis, SEM, FT-IR, XRD and ICP–AES. Comparing the two composite thin films, it revealed a series of interesting facts. The films showed excellent adherence to the substrate with particle diameter ranging from 20–50 nm in, and 90 and 280 nm in thickness. It is identified that CuPc is coexisting of dimers and monomers form, mainly in dimeric form for both the composite thin films by UV–vis spectroscopy, illustrating that the CuPc is not further aggregated by LPD process. The dependences of deposited amount of Ti and Cu with the reaction time suggested the growing of the films can be easily controlled, the SDBS seems to be hindrance to the growing of the films. After heat treatment at 250 °C for 2 h, the SDS–CuPc/TiO 2 thin film becomes crystallized, but no obvious XRD peak is observed in the SDBS–CuPc/TiO 2 composite thin film.

Preparation and characterization of alkyl sulfate and alkylbenzene sulfonate surfactants/TiO 2 hybrid thin films by the liquid phase deposition (LPD) method

Hybrid titanium oxide thin films containing surfactants, sodium dodecyl benzylsulfonate and sodium dodecyl sulfate, have been prepared by a novel liquid-phase deposition method. It is a new attempt to prepare organic–inorganic hybrid thin film by this method which usually be applied in preparing metal oxide thin film before. The two kinds of surfactants/TiO 2 hybrid thin films were characterized by means of FT-IR, SEM, XRD, fluorescence X-ray, ICP–AES and Raman spectroscopy, and showed noticeable differences in surface top view and particle diameter, cross-section image and thickness, deposited amount of Ti, XRD patterns and Raman shift. The reasons giving rise to above differences of the two kinds composite thin films has been discussed. The deposition mechanism of organic–inorganic hybrid thin film has been also presumed. The use of this processing parameter may open up a new way to the preparing of the organic–inorganic hybrid thin film.

Interaction between spontaneously formed SDBS/CTAB vesicles and polymer studied by fluorescence method

The interaction between the mixture of sodium dodecyl benzyl sulfonate (SDBS)/hexadecyltrimethylammonium bromide (CTAB) and polymer has been studied by using a fluorescence method, pyrene as a probe. The polarity change of pyrene environment is accompanied with the change of the value of I 1/ I 3, which indirectly reflects the relative position of the polymer and vesicle/micelle. A complex is formed between the polyvinylpyrrolidone (PVP) and SDBS micelle or SDBS rich vesicles due to the electric attraction. But the mechanism of the interaction is different since their sizes are quite different.

Slow Back Electron Transfer in Surface-Modified TiO2 Nanoparticles Sensitized by Alizarin

Interfacial electron transfer dynamics of alizarin-sensitized surface-modified and unmodified TiO 2 nanoparticles has been studied using femtosecond transient absorption spectroscopy. The surface of TiO 2 nanoparticles has been modified by sodium dodecyl benzyl sulfonate (DBS). Electron injection has been confirmed by direct detection of the electron in the conduction band, cation radical of the adsorbed dye and by a bleach of the dye as monitored by transient absorption spectroscopy in the visible and near-IR region. The dynamics of back electron transfer (BET) of the injected electron from TiO 2 to the parent cation has been measured by monitoring the decay kinetics of the cation radical of the adsorbed dye, and it is found to be multiexponential. We have compared the BET dynamics of alizarin-sensitized unmodified and surface-modified nanoparticles, and it is found to be slow on the modified surface. Solvent polarity did not have much impact on the BET dynamics. As the molecule forms a strong charge-transfer (CT) complex with the TiO 2 nanoparticle, significant change in the electronic coupling is not expected. As the other parameters that govern the ET are not changed as a result of surface modification, the reduction in the BET on the surface-modified nanoparticles has been explained by the fact that on surface modification the Fermi level of the modified nanoparticles is pushed up in energy, increasing the overall free energy of reaction (-ΔG 0 ) for the BET reaction. The high exoergic BET reaction in dye-sensitized TiO 2 nanoparticles surfaces falls in the Marcus inverted regime. As a result, with increasing free energy of reaction the BET rate is decreased on the modified surface.

The Microstructure and Rheology of Mixed Cationic/Anionic Wormlike Micelles

The rheology, flow birefringence, and small-angle neutron scattering of mixed cationic/anionic wormlike micellar solutions composed of cetyl trimethylammonium tosylate (CTAT) and sodium dodecyl benzyl sulfonate (SDBS) are studied over a broad range of solution compositions. This combination of experimental techniques enables independent determination of the microstructural length scales (persistence, entanglement, interaction, and contour) that govern the rheological properties. Comparison and contrast of the effect of a hydrotropic salt (NaTosylate) with that of a screening electrolyte (NaCl) demonstrates the influence of micellar charge on the persistence length and, hence, the microstructure and rheology. Surfactant concentration and composition and electrolyte concentration and composition systematically affect the self-assembled microstructure such that a transition in rheological behavior from nonionic wormlike micelles to polyelectrolytes can be spanned.