Sodium N-dodecylbenzenesulfonate Research Articles

Synthesis and characterization of pH-sensitive superabsorbent hydrogels based on sodium alginate-g-poly(acrylic acid-co-acrylamide) obtained via an anionic surfactant micelle templating under microwave irradiation

A novel porous superabsorbent polymer based on poly(acrylic acid-co-acrylamide) grafted onto sodium alginate backbone was prepared under microwave irradiation. Anionic surfactant sodium n-dodecyl benzenesulfonate (SDBS) is used as a pore-forming micelle templating. FTIR spectroscopy confirmed the formation of the gel and removal of SDBS by washing. The swelling behaviors in distilled water and in solutions with different pH values are investigated. The results indicate that there is an optimized concentration of SDBS (1.92 mM) where the swelling rate (63.84 g g−1 min−1) and the swelling capacity (1078 g/g) are maximal. These results are also supported by scanning electron microscopy where the optimized hydrogel exhibits higher pore sizes and interconnected open cellular structure. The optimized hydrogel is used as adsorbent for metal ion Pb(II). Isotherm of adsorption and effect of pH, adsorption dosage and recyclability are discussed. The results show that maximum adsorption capacity of Pb(II) on the hydrogel is 480.77 mg.g−1 and adsorption is well described by Langmuir isotherm model. Adsorption capacity of the optimized hydrogel for other hazardous heavy metal ions Cd(II), Ni(II) and Cu(II) and their competitive adsorption are also investigated.

Effect of surfactant type on microbubble formation behavior using Shirasu porous glass (SPG) membranes

We have recently proposed a new method for generating monodispersed microbubbles from Shirasu porous glass (SPG) membranes with a narrow pore size distribution. In this study, to investigate the effects of surfactant type on microbubble formation behavior from SPG membranes, the microbubble formation experiments were performed using differently charged surfactants. Sodium n-dodecylbenzenesulfonate (SDBS), polyoxyethylene (20) sorbitan monolaurate (Tween 20) and cetyltrimethylammonium bromide (CTMA) were used as anionic, nonionic and cationic surfactants, respectively. Air was pressurized into a surfactant solution of 2.0 mol m −3 through an SPG membrane with a mean pore diameter of 5.1 μm at a transmembrane/bubble-point pressure ratio of 1.1. In systems containing SDBS and Tween 20, monodispersed microbubbles with mean bubble diameters of 35.6 and 43.0 μm were generated, respectively, from the membrane. The CTMA-containing system resulted in polydispersed bubble formation, due to the adsorption of CTMA molecules (cations) onto the negatively charged membrane surface, which lowered the hydrophilicity of the membrane surface. The microbubbles generated were smaller for SDBS than for Tween 20. This is probably because for the case of SDBS, the microbubbles detached from the pores as soon as they were formed, due to a strong electrostatic repulsion between the negatively charged bubble surface and the negatively charged membrane surface, which assists in microbubble detachment from the pore openings. The gaseous-phase flux was about 11–15 times larger for Tween 20 than for SDBS, but much smaller for CTMA, which is a consequence of the fact that the proportion of active pores is significantly lower for SDBS than for both Tween 20 and CTMA.

Temperature-Swing Solid-Phase Extraction of Heavy Metals on a Poly(N-isopropylacrylamide) Hydrogel

The feasibility of temperature-swing adsorption of heavy metals on a thermosensitive N-isopropylacrylamide (NIPA) hydrogel was examined. We have proposed a novel temperature-swing solid-phase extraction (TS-SPE) technique. First, a metal ion in an aqueous solution is complexed with an extractant. Subsequently, the metal-extractant complexes (or micelles) are adsorbed onto the NIPA hydrogel through a hydrophobic interaction above the lower critical solution temperature (LCST). Finally, the metal-extractant complexes are desorbed from the NIPA hydrogel after it is cooled below the LCST. In a model system consisting of Cu(II) ions, sodium n-dodecylbenzenesulfonate (SDBS), and NIPA hydrogel, the proposed TS-SPE technique has been successfully conducted. The following observations can be made: the amount of adsorbed Cu(II) ions increases with the increase in temperature, the maximum adsorption is attained at a temperature above the LCST, and the hydrogel adsorbs and desorbs Cu(II) ions reversibly due to the temperature-swing between 10 and 40 degrees C. The LCSTs of poly(NIPA) in aqueous SDBS solutions with/without CuCl2 and the surface tensions of their solutions suggest that the hydrophobicity of the complex Cu(DBS)2 is greater than the hydrophobicities of SDBS and DBS. In addition to the separation of heavy metals, TS-SPE is potentially applicable to cases such as the separation of biological molecules by means of metal-ion affinity.

Enrichment in axial direction of aqueous foam in continuous foam separation

Estimation of overhead production enrichment in continuous foam separation was conducted with a surfactant: sodium n-dodecylbenzenesulfonate (SDBS) and soluble proteins: ovalbumin (OA) and hemoglobin (HB). Axial profiles of the volumetric flow rate and the concentration of the collapsed foam liquid within the column were measured, and the enrichment ratio and the liquid holdup in axial direction were determined experimentally. The proposed model was fitted to the experimental results obtained with various experimental conditions (superficial gas velocity, feed concentration and pH) and was in reasonable agreement with the experimental data by using the least square regression. The present model makes it possible to estimate the foamate concentration at a desired foam height.

Improved performance of rechargeable alkaline batteries via surfactant-mediated electrosynthesis of MnO 2

An innovative application of surfactant-mediated modifications of electrolytic MnO 2 (EMD), proved to be a major step toward enhancement of the rechargeability in alkaline batteries. Presence of different surfactants in boiling acidic solutions of manganese sulfate, under atmospheric pressure, enhanced a variety of EMD products, with various structural and electrochemical properties. Surfactants employed consisted of: anionic sodium n-dodecylbenzenesulfonate (SDBS), cationic cetyltrimethylammonium bromide (CTAB) and non-ionic t-octyl phenoxy polyethoxyethanol (Triton X-100). Among them, EMDs produced in the presence of CTAB has a slight positive effect on the cycle performances, while SDBS inhibits it. Interestingly, the EMD powders prepared from the micellar solution, in the range of 0.3 wt.% of Triton X-100, exhibited much higher discharge capacities, as well as better cyclabilities in comparison with the commercial EMD sample known as TOSOH™. The superiority of the former EMD was further confirmed through electrochemical cyclic voltammetry and also electrochemical impedance spectroscopy (EIS). Modifications of electrolytic MnO 2, via mediations of different surfactants were perceived through changes in their compositions, crystal structures and morphologies. The characteristics of the produced materials were determined by thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and scanning electron microscopy (SEM). Enhancements of electrochemical properties, observed for Triton X-100 modified EMD, could be attributed to a homogeneous current distribution with unique crystalline structure, based on the modified electrode/solution interface, through adsorbed surfactant layers. Moreover, the observed improvements appear connected to the enhanced film growth, with different degrees of mesoscopic organizations. Higher cycle performances, mechanical stabilities and the ease of production make this method excellent for being employed in a number of industrial applications.

Toxicity of anionic detergents determined by Saccharomyces cerevisiae microarray analysis

Sodium n-dodecyl benzene sulfonate (LAS) and sodium dodecyl sulfate (SDS) are popular anionic detergents (surfactants) that are used worldwide and the toxicities of these chemicals have been characterized. We applied these chemicals in a DNA microarray bioassay and determined that the microarray data reflects previous findings and also provides some new information about anionic detergent toxicity. The mRNA expression profiles suggest that LAS and SDS cause damage to membranes and alterations in carbon metabolism, and induce the oxidative stress response. We also found that LAS and SDS induce the pleiotropic drug-resistance network, and that LAS and SDS may be pumped out of yeast cells by this network. Hierarchical clustering of the expression profiles showed that LAS and SDS cause similar features of toxicity and that the toxicity is similar to that of capsaicin but different from that of cadmium and mercury.

Simultaneous electrochemical formation of Al 2O 3/polypyrrole layers (I): effect of electrolyte anion in formation process

We studied the capability of various kinds of sulfonate-based electrolytes to form a bilayered Al 2O 3/polypyrrole (PPy) film on an aluminum substrate in aqueous solution. As electrolytes, we selected sodium p-toluenesulfonate (monovalent sulfonate), sodium naphthalene-trisulfonate (trivalent sulfonate), poly(sodium 4-styrenesulfonate), poly(sodium vinylsulfonate) (sulfonate polymer), sodium n-dodecylbenzenesulfonate (SDBS), sodium butylnaphthalenesulfonate(BNS), and sodium n-dodecylsulfate (SDS, surfactant sulfonate/sulfate). Among the sulfonates we investigated, SDBS, BNS and SDS appeared to form a barrier-type Al 2O 3 layer with high coulombic efficiency in the absence of pyrrole. In the presence of pyrrole, anodization of these electrolytes resulted in the formation of Al 2O 3 and PPy layers, simultaneously.

Interaction of surfactant with antistatic polymer thin layers

Thin layers made from three kinds of hydrophilic polymer were coated onto poly(ethylene terephthalate)(PET) fibers to study the interaction of an anionic surfactant, sodiumn-dodecyl benzenesulfonate, with the polymer layers. The coated layers include a) poly(vinyl alcohol) (PVA) crosslinked with glutaraldehyde [nonionic], b) crosslinked, sulfated PVA [anionic], and c) polyethyleneimine crosslinked with poly(ethyleneglycol diglycidylether) [cationic]. All of these coatings were found to reduce the electrostatic charging of the PET cloths, indicating that they were effectively coated with the hydrophilic polymers. The PET cloth coated with the thin layers was immersed in the aqueous solution of surfactant at 40°C for different durations and the electrostatic voltage as well as the weight change were determined after drying. When the cloth coated with the nonionic or the anionic layer was brought into contact with the surfactant, neither the electrostatic voltage nor the weight of PET changed. On the contrary, immersion in the surfactant solution brought about an increase in both the electrostatic voltage and the weight for the PET coated with the cationic layer. This suggested that the surfactant molecules were bound to the cationic layer, in contrast to the nonionic and the anionic layer. It was concluded that the binding was due to ion complexing between the cationic groups in the polymeric layer and the sulfate groups in the surfactant molecules.

Surfactant-modified hydrous titanium oxide gels

In a previous paper [H. Z. Chen and E. Ruckenstein, J. Colloid Interface Sci. 145, 581 (1991)] it was demonstrated that a hydrous oxide gel containing a surfactant can have increased adsorption power compared with one free of surfactant. In addition, it was observed that an optimum surfactant concentration exists for which the adsorption power is maximum. To explain these observations and to characterize the material, the effect of the addition of sodium n-dodecylbenzene sulfonate (SDBS) on the crystallographic structure, morphology, surface chemistry, and mechanical strength of air dried hydrous titanium oxide gels is investigated. The changes with increasing amount of surfactant in the crystallographic structure were followed by X-ray powder diffraction analysis, and the ratios of surface atoms have been determined by X-ray energy-dispersive spectroscopic analysis measurements. Compressive strength measurements provided information on the mechanical strength, and scanning electron microscopy observations provided information on the morphology of the material. Finally, Fourier transform-infrared spectral analysis has allowed identification of the adsorption active sites of the gel. The experiments have shown that there exists an optimum surfactant concentration for which the size of the particles that constitute the gel is the smallest and the surface area and the mechanical strength are the largest. A possible explanation for the existence of an optimum surfactant concentration is suggested.

Electrodes coated with polystyrene films containing surface-active agents: Attachment of screening capabilities for electrode reactions of electroactive ionic species

Glassy carbon (GC) electrodes coated with polystyrene (PSt) films containing surface-active agents have been studied. GC electrodes coated with PSt films containing sodium n-dodecylbenzenesulfonate (DBS) as an anionic surface-active agent bind Ru(bpy) 2+ 3 in high surface concentrations in aqueous solutions. Rotating disc electrode measurements have clarified that the incorporated Ru(bpy) 2+ 3 in the coated layer mediates the electron transfer reaction of Ru(bpy) 2+ 3 in solution at the electrodes, and the rate constant of the electron transfer is influenced by the quantity of the coated polystyrene. If lauryltrimethylammonium chloride (LMA) or laurylpyridinium chloride (LPy) as a cationic surface-active agent is blended in the coated PSt layers, the resulting electrodes bind Fe(CN) 3− 6. The electrodes coated with PSt films containing surface-active agents do not show any electrochemical reactivities for electroactive species having the same polar charges as the surface-active agents used because of electrostatic repulsions between them.

ChemInform Abstract: A NEW METHOD FOR THE PREPARATION OF ZEOLITE ZSM‐5 BY USING SODIUM N‐DODECYLBENZENE SULFONATE

Zeolite ZSM-5 was easily synthesized by using sodium n-dodecylbenzene sulfonate (SDBS) in place of organic ammonium and/or phosphonium ions. A well-crystallized ZSM-5 was obtained by the mild hydrothermal treatment of a reaction mixture composed of SDBS and alumina-silica gel at about 180 °C and PH2O ≈10 kg/cm2 for 4 h.

A NEW METHOD FOR THE PREPARATION OF ZEOLITE ZSM-5 BY USING SODIUM n-DODECYLBENZENE SULFONATE

Abstract Zeolite ZSM-5 was easily synthesized by using sodium n-dodecylbenzene sulfonate (SDBS) in place of organic ammonium and/or phosphonium ions. A well-crystallized ZSM-5 was obtained by the mild hydrothermal treatment of a reaction mixture composed of SDBS and alumina-silica gel at about 180 °C and PH2O ≈10 kg/cm2 for 4 h.

Studies on Sodium Linear Alkylbenzenesulfonate (LAS). I. Distribution of LAS in the Sediments of Sagami River Estuary

The distribution of contents of sodium n-alkylbenzenesulfonate (LAS) was investigated in the sediments of the Sagami River Estuary and its adjacent sea areas to discuss the relationship between the null points of sediment and the points where LAS was detected. Further the compositions of homologous series of LAS, sodium n-decylbenzenesulfonate (C10-LAS), sodium n-undecylbenzenesulfonate (C11-LAS), sodium n-dodecylbenzenesulfonate (C12-LAS) and sodium n-tridecylbenzenesulfonate (C18-LAS), in the sediments and in the river waters were compared. The contents of LAS were determined by combined methylene blue colorimetry and infrared spectrometry, and then homologous series of LAS were determined by high-performance liquid chromatography. LAS was contained over the range of dry weight 5.5 to 17μg/g at 3 points among 10 points in the estuary, but not detected in the sea areas. The null points of sediment which were presumed from particle size distribution and from ignition loss in the estuary nearly agreed with the points where LAS was detected. In the sediments C12-LAS was the most abundant among homologous series of LAS and its average percentage was 59, and C10-LAS was absent. On the other hand, in the river waters C11-LAS was 50% and C13-LAS was not detected. These facts were considerably different from the percentage of compositions of LAS in the commercial detergent.