In reversed-phase liquid chromatography, solute retention is primarily influenced by interactions between a nonpolar stationary phase and a moderately polar hydro-organic mobile phase, based on the ...solute lipophilicity. However, challenges regarding retention and peak tailing can arise due to ionic interactions between positively charged analytes and free silanols present on silica-based stationary phases. To address these challenges, incorporating surfactants and ionic liquids (ILs) into the mobile phase offers an effective solution. These additives synergistically enhance chromatographic performance through electrostatic and lipophilic interactions, which enable fine-tuning of selectivity and improved separation efficiency.
This study explores the chromatographic behaviour of several basic compounds in aqueous mixtures containing the anionic surfactant sodium dodecyl sulphate (SDS), above its critical micellar concentration, combined with various 1-alkyl-3-methylimidazolium-based ionic liquids (ILs) featuring chloride, tetrafluoroborate, and hexafluorophosphate anions, all without the addition of organic solvents. Specifically, this research investigates the influence of different anion types within the ILs and considers the impact of the IL cations. Analysis of solute peak profiles reveals narrow and symmetrical peaks. By introducing tetrafluoroborate and hexafluorophosphate IL anions into a mobile phase that contains an anionic surfactant, the study sheds light on the interactions occurring within the chromatographic column. This enhanced understanding of the combined effects of surfactants and ILs contributes to refining chromatographic methodologies.
This research highlights the importance of carefully selecting the appropriate IL when incorporating it into a micellar mobile phase alongside SDS. This combination results in practical retention times that surpass the performance achieved with either the surfactant or IL alone in the mobile phase. The study particularly emphasises the impact of the IL anion, especially in the absence of SDS and organic solvents. This unveils interactions that are otherwise obscured in micellar and hydro-organic media, providing new insights into chromatographic dynamics.
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•Combination of ionic liquid and anionic surfactant finely tunes chromatographic behaviour.•Retention is dominated by the electrostatic interaction of surfactant and ionic liquid.•Retention times are influenced by the length of the cation's alkyl chain.•Surfactant's adsorption masks the variations in adsorption among the ionic liquid anions.•Surfactant and ionic liquid cover the silanol groups resulting in symmetrical peaks.
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•Demonstration of simple in-situ synthesis of CsPbI3-xBrx using sodium dodecyl sulphate.•Dual-passivation of cationic and anionic vacancy by SDS is demonstrated.•Suppression of halide ...migration and segregation.
The phenomenal growth of metal halide perovskites over the last decade makes them intriguing for next-generation optoelectronic materials. Despite numerous advantages over the traditional light absorbing materials, mixed-halide perovskites suffer from defects which enhances halide migration and segregation, leading to shorter lifetime of charge carriers. Hear in, we employ a simple defect passivation technique using sodium dodecyl sulphate (SDS) to leading to significantly higher stability and higher photoluminescence efficiency. The uncoordinated lead sites or halide interacts and Schottky defects or cation vacancy are dual passivated by both anion and cation of SDS resulting in suppression of halide migration and thus segregation. The passivated samples exhibit their ability to have a longer carrier lifetime ∼65 ns and also retain the longer lifetime (∼56 ns) post prolonged illumination unlike the non-passivated samples which show complete reduction in lifetime with illumination time.
The Yamuna River, a tributary of the holy Ganga, is heavily polluted in the Delhi-NCR region, India and has been gaining attention due to the excessive foaming of the river over the past few years. ...This can be directly or indirectly related to the overuse of surfactants and the discharge of untreated domestic and textile wastewater into the river. To determine the surfactant load and investigate potential surfactant-degrading bacteria in the region, 96 water samples from four sites in the Okhla Barrage stretch of the river were collected and analysed. The results showed that the selected sites have surfactant concentrations more than the permissible limit (1.00 mgL
−1
). Also, at most of the sites, the concentration crossed the desirable limit of BIS (0.2 mgL
−1
) during the period of analysis. The concentration of anionic surfactant reported in the region was found in the range of 0.29 mgL
−1
and 2.83 mgL
−1
. A total of 38 different bacteria were isolated using selective media from the same water samples, out of which 7 bacterial isolates were screened for sodium dodecyl sulphate (SDS) tolerance activity. Based on 16S rRNA gene sequencing, 2 species, namely
Pseudomonas koreensis
YRW-02 and
Pseudomonas songnenensis
YRW-05 have been identified and their degradation potential was assessed at different SDS concentrations. The results showed that our strains YRW-02 and YRW-05 degraded 78.29 and 69.24% of SDS respectively. Growth optimization was also performed at different substrate concentrations, pH, and temperature to investigate optimum degradation conditions. This study plays a significant role in assessing the surfactant load and also gives a promising background for future use in in-situ bioremediation experiments.
Keeping the industrial viability in view, manganese incorporated zinc oxide nanocomposites (Mn-ZnO NCs) was synthesized as a reusable photocatalyst. The photocatalytic efficiency of Mn-ZnO NCs was ...compared with ZnO nanoparticles. Morphology and size of the samples were modulated using sodium dodecyl sulphate (SDS) as the cappant. The crystallite size and crystalline parameters were estimated through X-ray diffraction spectra, while the adsorption of SDS on the samples was assessed through Fourier transform infrared spectra. Since the efficiency of any photocatalyst fundamentally depends upon its photo-physical and surface properties, UV-Visible, Photoluminescence, and Electron paramagnetic resonance spectroscopic techniques were used to access the optical properties while Field emission scanning electron microscopy was employed to deduce the morphology of the samples. Energy dispersive X-ray spectra and X-ray photoelectron spectra confirmed the elemental composition of the samples. The photocatalytic degradation of dye solutions was monitored initially through UV-Vis spectra. In order to confirm that the final products of photocatalytic degradation were non-toxic, Mass spectrometry was employed to estimate the types of intermediates and final products formed during and after the course of photocatalytic reaction. The results of visible light assisted photocatalytic degradation studies indicated that Mn-ZnO NCs were highly reusable for degrading alternate solutions of dyes (rhodamine B and methylene blue) as well as their mixture within a span of only 20 min. The difference in the morphology of Mn-ZnO NCs before and after performing the photocatalytic activity was also assessed.
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•Room temperature assisted synthesis of SDS capped ZnO and Mn-ZnO nanocomposites.•Morphology of ZnO tuned upon Mn incorporation.•Photostability of Mn-ZnO photocatalyst for alternate dyes degradation.•Efficient degradation of mixed dye solutions by Mn-ZnO nanocomposites•Non-toxic end-products of photodegradation estimated using ESI-MS spectrometry
In this study, the conductivity of poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS) was greatly enhanced by using sodium dodecyl sulfate (SDS) without damaging the fabric ...substrates. We suggest that blending and dipping methods using SDS which is compatible with natural and synthetic fabrics dramatically increase the conductivity of PEDOT:PSS to as high as 1335 S cm −1 . Additionally, a highly stretchable fabric heater with high conductivity was successfully fabricated using SDS-modified PEDOT:PSS. The fabric heaters exhibited reversible electrical behaviour with cyclic loading of a tensile strain even larger than 80%. The increase in resistance with the tensile strain was significantly smaller than the calculated value for a rigid substrate because the fabrics with a weave structure exhibited interfibrillar contact effects with strain. For example, the resistance was increased by a factor of only 2.62 with 80% strain. The Joule heating behaviours of the fabric heaters were demonstrated at several different applied voltages and ambient temperatures, and the heat capacity and convective heat transfer coefficient were 2 J K −1 and 30 W m −2 K −1 , respectively. The results demonstrated that the method suggested in this work is not only efficient for greatly improving the conductivity but also simple and cost-effective for fabricating highly conductive and stretchable fabrics with various e-textile applications.
A facile and convenient method has been developed for the one-pot three-component synthesis of 2-amino-3-cyano substituted tetrahydrobenzo
b
pyran derivatives from the reactions of aromatic ...aldehydes, malononitrile and dimedone or 1,3-cyclohexanedione in the presence of a catalytic amount of sodium dodecyl sulphate as an efficient surfactant type catalyst in water at room temperature. Synthesis of 2-amino-3-cyano substituted spiropyrans was also achieved under the same reaction conditions starting from ninhydrin/isatins, malononitrile and dimedone or 1,3-cyclohexanedione. All the reactions were completed within 2.5 h and the desired products afforded in good to excellent yields. Gram scale production of the desired compound was also achieved. Use of water as green solvent, commercially available low cost surfactant type catalyst, high atom economy, excellent yields, energy efficiency, no column chromatographic purifications, reusability of the solvent media, multiple carbon–carbon and carbon-heteroatom bond formations are some of the major advantages of this newly developed protocol.
Graphical Abstract
Biology uses various cross‐linking mechanisms to tailor material properties, and this is inspiring technological efforts to couple independent cross‐linking mechanisms to create hydrogels with ...complex mechanical properties. Here, it is reported that a hydrogel formed from a single polysaccharide can be triggered to reversibly switch cross‐linking mechanisms and switch between elastic and viscoelastic properties. Specifically, the pH‐responsive self‐assembling aminopolysaccharide chitosan is used. Under acidic conditions, chitosan is polycationic and can be electrostatically cross‐linked by sodium dodecyl sulfate (SDS) micelles to confer viscoelastic and self‐healing properties. Under basic conditions, chitosan becomes neutral, the electrostatic SDS–chitosan interactions are no longer operative, and chitosan chains can self‐assemble to form crystalline network junctions that serve as strong physical cross‐links that confer elastic properties. Mechanical measurements performed in water demonstrate these different mechanical behaviors and the repeated pH‐induced switching between these behaviors. Printing of SDS micelles onto a neutral chitosan film allows the cross‐linking mechanisms to be spatially programed to confer anisotropic mechanical properties. The reversibility of these cross‐linking mechanisms allows the patterned films to be erased and reprogramed with reconfigured mechanical properties. Potentially, the ability to reversibly program hydrogel networks enables fabrication of the dynamically reconfigurable networks required for soft machines.
Chitosan can be electrostatically cross‐linked by sodium dodecyl sulfate micelles to confer viscoelastic properties under acidic conditions, but self‐assembles into crystalline network junctions to confer elastic properties under basic conditions. These two cross‐linking mechanisms can be spatially programed by printing technologies. The reversibility of these cross‐linking mechanisms allows the patterned films to be erased and reprogramed with reconfigured mechanical properties.
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•The quercetin-βCD (1:2) complex is demonstrated and its equilibrium constant was calculated.•Cyclodextrin and SDS act as quercetin fluorescence promoters and confer photostability to ...quercetin.•The value of critical micellar concentration increases with the concentration of βCD.•The formation of a ternary complex (quercetin, βCD and Sodium dodecyl sulfate) does not take place.
The global formation constants of two inclusion complexes formed from quercetin (QH5) and beta-cyclodextrin (βCD) in ClO4- 0.1 M pH 4.7 were calculated with the support of Stability Quotients from Absorbance Data (SQUAD), in addition, the effect of sodium dodecyl sulphate (SDS) on these complexes was studied. The molar ratios of the inclusion complexes formed QH5-βCD were 1:1 and 1:2 with log β values of 2.06 ± 0.22 and 3.69 ± 0.13 M−1 respectively. With measurements of surface tension and fluorescence, the critical micellar concentration (CMC) value of the SDS was calculated in the absence and presence of βCD resulting in an increase with the concentration of βCD, as a consequence of the formation of an inclusion complex βCD-SDS with log K of 3.589 ± 0.059 M−1. From the fluorescence results, the breakdown of the complex Q-βCD is inferred due to the interaction with the SDS causing its inclusion in the βCD cavity and displacement of the QH5. Finally, with the UV–vis spectrophotometric data it is shown that the formation of a ternary complex does not take place, as stated in some studies.
Although controversial, the amyloid cascade hypothesis remains central to the Alzheimer's disease (AD) field and posits amyloid‐beta (Aβ) as the central factor initiating disease onset. In recent ...years, there has been an increase in emphasis on studying the role of low molecular weight aggregates, such as oligomers, which are suggested to be more neurotoxic than fibrillary Aβ. Other Aβ isoforms, such as truncated Aβ, have also been implicated in disease. However, developing a clear understanding of AD pathogenesis has been hampered by the complexity of Aβ biochemistry in vitro and in vivo. This review explores factors contributing to the lack of consistency in experimental approaches taken to model Aβ aggregation and toxicity and provides an overview of the different techniques available to analyse Aβ, such as electron and atomic force microscopy, nuclear magnetic resonance spectroscopy, dye‐based assays, size exclusion chromatography, mass spectrometry and SDS‐PAGE. The review also explores how different types of Aβ can influence Aβ aggregation and toxicity, leading to variation in experimental outcomes, further highlighting the need for standardisation in Aβ preparations and methods used in current research.
Amyloid‐beta (Aβ) hypothesis drives the notion that Aβ peptide is a central player in Alzheimer's disease (AD) onset and/ or progression. However, it remains difficult to investigate Aβ in vitro due to differences in published protocols describing varying methods of peptide preparations. This is especially true as protocols may vary depending on whether toxic Aβ oligomers (as well as associated isoforms) or plaque‐ forming Aβ fibrils are investigated. Due to the biochemical and structural differences in both peptide species, the methods of peptide characterisation also vary, further complicating the field of Aβ biochemistry in the context of AD pathology.
A cost-effective and sustainable Calligonum polygonoides biomass based activated carbon (AC) was synthesized. The prepared AC was utilized in the fabrication of carbon-alginate beads for the ...adsorption of methylene blue (MB) textile dye from aqueous solution. The surface morphology, surface functional groups, elemental analysis and thermal behavior of the prepared beads were investigated using different analytical techniques. Batch adsorption experiments were performed to investigate the adsorption capacity of the beads. Effect of different parameters such as initial pH of MB solution, dose of adsorbent, contact time, initial concentration of MB and temperature were evaluated. The kinetic studies identified pseudo-second order model. Langmuir and Freundlich isotherm models were applied and fitted to the experimental equilibrium data. The beads showed a maximum adsorption capacity of 769 mg/g in basic pH at 30 °C while using 400 mg·L−1 of MB solution. The adsorption process was found to be endothermic and spontaneous as confirmed by the thermodynamic data. The fabricated beads were subjected to recycling which exhibited same adsorption efficiency after six regeneration cycles. The results showed that the AC-alginate beads impregnated with SDS have high adsorption capability and would be used for the efficient removal of cationic dyes from wastewater.
•Activated carbon-alginate-SDS composite beads were prepared.•Beads were characterized using FTIR, TGA, EDX and SEM techniques.•Process variables were optimized for the efficient removal of MB dye.•Kinetics, isotherms, and thermodynamics study were performed for MB adsorption.•Developed beads showed maximum removal efficiency of 769.23 mg/g for MB.
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