Adsorption, association and precipitation in hexadecyltrimethylammonium bromide/sodium dodecyl sulfate mixtures

Tomašić, Vlasta; Štefanić, Igor; Filipović-Vinceković, Nada

doi:10.1007/s003960050380

Cited by 88 publications

(62 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…independence of the CMC of CTAB upon SDS addition [25]. Above 0.1 mM total surfactant, the magnitude of the reversed EOF is independent of surfactant concentration, as previously observed for CTAB alone [7,15,38].…”

Section: Effect Of Surfactant Concentration On Eofmentioning

confidence: 59%

“…For instance, phase separation and precipitation can be minimized by using one surfactant with a long alkyl chain and another with a short alkyl chain [36,37]. Fortunately, the CTAB/SDS system has recently been characterized [25]. Mixtures of near-equimolar concentrations of CTAB and SDS yield turbid solutions containing predominantly large vesicles (,600 nm) and some crystallites of CTA 1 DS…”

Section: Resultsmentioning

confidence: 99%

“…Addition of SDS to CTAB reduces the headgroup area (a 0 ) from 6.7610 219 m 2 /mol for pure CTAB to 5.9610 219 m 2 /mol for equimolar CTAB-SDS [25]. This in turn causes a transition from spherical micelles to vesicular structures [26].…”

Section: Theorymentioning

confidence: 97%

See 2 more Smart Citations

Mixed cationic/anionic surfactants for semipermanent wall coatings in capillary electrophoresis

Wang

Lucy

2004

Electrophoresis

View full text Add to dashboard Cite

Mixtures of the cationic surfactant cetyltrimethylammonium bromide (CTAB) with the anionic surfactant sodium dodecyl sulfate (SDS) form more stable coatings in fused-silica capillaries than CTAB alone. The reversed electroosmotic flow (EOF) generated by CTAB/SDS mixtures remains stable for over 80 min after removal of the surfactants from the buffer. Enhanced stability (relative to CTAB alone) was found even when the ratio of SDS to CTAB was as low as 1%. This greater coating stability is attributed to the structural transition from adsorbed micelle to bilayer, which is induced by addition of SDS. Separation of a mixture of basic proteins yielded efficiencies of 364 000-562 000 plates/m and recoveries ranging from 85% to 98%. Migration time reproducibility was less than 0.9% relative standard deviation (RSD) from run to run and less than 2.6% RSD from day to day.

show abstract

Section: Effect Of Surfactant Concentration On Eofmentioning

confidence: 59%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Mixed cationic/anionic surfactants for semipermanent wall coatings in capillary electrophoresis

Wang

Lucy

2004

Electrophoresis

View full text Add to dashboard Cite

show abstract

“…[14] It has been documented that in mixed CTAB/SDS solutions, relatively larger catanionic vesicles and surfactant salts rather than mixed micelles tend to form at the equimolar mixing ratio (CTAB/SDS = 1:1). [15] Therefore, in the equimolar CTAB/SDS solution, a wide variety of microstructures possibly coexist, especially at the early stage of the reaction when the solution is heated to 80°C. Consequently, irregularly shaped nuclei are formed, possibly due to the influence of the various microstructures, resulting in the final formation of irregular plate-like PbS crystals.…”

mentioning

confidence: 99%

Low‐Temperature Synthesis of Star‐Shaped PbS Nanocrystals in Aqueous Solutions of Mixed Cationic/Anionic Surfactants

2006

View full text Add to dashboard Cite

Obtaining control over the morphology of colloidal nanocrystals with well-defined shapes remains an important goal of modern materials chemistry, since shape-controlled nanocrystals are promising candidates as active components in a wide range of technological applications, and are model systems for the study of nanoscale shape-dependent properties. [1] In particular, the shape-controlled synthesis of colloidal nanocrystals of metal chalcogenide semiconductors, such as cadmium chalcogenides, [1a,b,2] lead chalcogenides, [3] Ag 2 S, [4] and MnS, [3b,5] has attracted intensive interest; in this regard, synthetic methods based on high-temperature (typically 120-360°C) reactions in organic solutions involving capping agents have most often been employed. Although this hightemperature organic solution approach has been demonstrated to be a promising method for achieving morphological control of semiconductor nanocrystals, low-temperature synthesis in aqueous solutions is highly desirable because it represents an environmentally benign and user-friendly approach, which may be considered to be a relatively green chemical alternative of practical significance. [6] However, the development of a facile, low-temperature synthesis of shape-controlled semiconductor nanocrystals in aqueous solutions remains a great challenge. It is to be noted that mixtures of various surfactants, including alkyl amines, alkyl acids, alkylphosphonic acids, and trioctyl phosphine oxide (TOPO), are frequently used as capping agents to tailor the crystal shape in high-temperature solution-phase syntheses. Recently, we have demonstrated that the low-temperature synthesis of morphologycontrolled one-dimensional (1D) BaXO 4 (where X = Cr, Mo, W) nanostructures and their hierarchical architectures can be readily achieved in reverse-micelle solutions of mixed cationic/anionic surfactants. [7] These results have inspired us to explore the low-temperature synthesis of semiconductor nanocrystals with tailored shapes in aqueous solutions of mixed cationic/anionic surfactants.As a p-p semiconductor with a narrow bandgap (0.41 eV) and a large exciton Bohr radius (18 nm), PbS shows extensive quantum-size effects in nanocrystalline form and has wideranging potential applications, such as in near-IR (NIR) communication, optical switches, thermal and biological imaging, photovoltaics, and solar cells. [3a,8] While much effort has been devoted to the size-controlled synthesis of PbS quantum dots with tunable optical properties, [9] there are only a few reports on the shape-controlled synthesis of high-quality colloidal PbS nanocrystals. [3a,b] Notably, PbS nanocrystals with a variety of novel shapes, including rod-based multipods, truncated octahedrons, cubes, and stars with six symmetric horns, were successfully produced by the thermal decomposition of a molecular precursor in hot phenyl ether solvent at temperatures varying from 140 to 250°C.[3a] The obtained star-shaped PbS nanocrystals (50-60 nm in size) represent novel nanoscale structures, but the...

show abstract

“…From the pioneering studies by Kaler on oppositely charged single tailed surfactants [29][30][31][32][33][34] numerous contributions have been reported on the spontaneous vesicle formation and micelle-vesicle transitions produced as a function of the surfactant ratio in the mixture [35][36][37][38][39][40][41]. Similar vesicle formation should be expected when a cationic surfactant is mixed with an ionic liquid displaying anionic surfactant-like behavior.…”

Section: Introductionmentioning

confidence: 80%

Catanionic surfactant formation from the interaction of the cationic surfactant hexadecyltrimethylammonium bromide (CTAB) and the ionic liquid 1-butyl-3-methylimidazolium octyl sulfate (bmim-octyl SO4) in aqueous solution

Comelles

Ribosa

González

et al. 2015

Colloids and Surfaces A: Physicochemical and Engineering Aspect

View full text Add to dashboard Cite

The interaction between the cationic surfactant Hexadecyltrimethylammonium bromide (CTAB) and the ionic liquid 1-butyl-3-methylimidazolium octyl sulfate (bmim-octylSO 4 ) in aqueous solution has been investigated at two total concentrations (0.5 and 10 mM) and different CTAB mole fractions ( CTAB ).Samples of different physical appearance were obtained depending on  CTAB suggesting different kind of aggregates. Bluish solutions ( CTAB from 0.1 to 0.6) were assigned to vesicles of the catanionic surfactant formed (CTA-octylSO 4 ), whereas clear and isotropic solutions ( CTAB  0.6) corresponded to mixed micelles. Surface tension, electrical conductivity, absorbance and dynamic light scattering (DLS) measurements were performed with the aim of correlating properties changes with the aggregation structures. The critical aggregation concentration (cac) and the surface tension value at the cac ( cac ) were much lower for the mixtures than for the individual components. Thiis finding reveals the 3 exceptional surface activity of these mixtures, attributable to the formation of the CTA-octylSO 4 catanionic surfactant. Once the catanionic surfactant is formed it makes no sense to consider anymore the initial CTAB / bmim-octylSO 4 binary system but a new one composed by CTA-octylSO 4 and the excess of bmimoctylSO 4 or CTAB. On the basis of this consideration the surface activity parameters have been recalculated.

show abstract

Adsorption, association and precipitation in hexadecyltrimethylammonium bromide/sodium dodecyl sulfate mixtures

Cited by 88 publications

References 10 publications

Mixed cationic/anionic surfactants for semipermanent wall coatings in capillary electrophoresis

Mixed cationic/anionic surfactants for semipermanent wall coatings in capillary electrophoresis

Low‐Temperature Synthesis of Star‐Shaped PbS Nanocrystals in Aqueous Solutions of Mixed Cationic/Anionic Surfactants

Catanionic surfactant formation from the interaction of the cationic surfactant hexadecyltrimethylammonium bromide (CTAB) and the ionic liquid 1-butyl-3-methylimidazolium octyl sulfate (bmim-octyl SO4) in aqueous solution

Contact Info

Product

Resources

About