Surfactant Sodium Dodecyl Sulfate Research Articles

Enhanced hydrogen sequestration through hydrogen foam generation with SDS Co-Injection in subsurface formations

Inherent obstacles of hydrogen injection encompass preferential channeling through larger pathways, hampering microscopic sweep efficiency within porous media. This work pioneers hydrogen foam generation via co-injection with aqueous sodium dodecyl sulfate (SDS) to enhance subsurface hydrogen trapping capacity. SDS addition substantially reduces hydrogen-water interfacial tension and enhances viscoelasticity. In contrast to robust hydrogen foam stability, CO2 foams display compromised integrity, stemming from surfactant aggregation and ensuing infiltration channels that permit aqueous phase CO2 dissolution. Hydrogen foams conversely sustain uniform surfactant films, forestalling hydrogen ingress into water. Synergetic microfluidic and pore-scale simulations visualise mechanisms underlying intensified hydrogen capture and mobility reduction attributed to deformation and flow resistance when traversing constricted pores. Introducing the amphiphilic SDS surfactant considerably promotes hydrogen adsorption through its hydrophobic tail. Core flooding experiments quantify over 2 times hydrogen storage ratio amplification with SDS relative to sole hydrogen injection. The framework contributes pragmatic strategies to harness high-efficiency hydrogen foam for scalable clean energy storage.

Nanoporous gold with microporous structure prepared by sodium dodecyl sulfate-mediated electrochemical dealloying

Nanoporous gold (NPG) is a promising catalytic material for the oxidation of CO and methanol applications. However, NPGs are prone to extensive macroscopic cracking that often decrease mechanic properties of NPGs and depresses their catalytic action. To produce crack-free NPG with an ultra-finer porosity in room temperature, the anionic surfactant sodium dodecyl sulfate (SDS) was added in electrochemical dealloying process. SDS has the effect of reducing the surface diffusion of gold which hinder the initial coarsening of ligaments and prevents interior silver atoms from being exposed and dissolved. As a result, the pore and ligment size are finer, but higher residual silver of NPG samples. NPG with pore size down to 2 nm and the ligament 4.0 nm was successfully fabricated with 13.32 mM SDS in perchloric acid solution. The surface diffusion coefficient of Au atoms was 1.6 × 10−24 m2·s−1, nearly 3 orders of magnitude smaller than that of Au atoms in the absence of SDS (2.8 × 10−21 m2·s−1). Nanoindentation results demonstrated that high residual silver content made NPG samples harder and stiffer，the specific surface areas of NPG with 6.66 mM SDS was 190 m2 g−1 by BET. This work provided very important clues on how to control the crack free ultrafine nanoporous structure of other materials.

Effect of surfactants on the interfacial viscoelasticity and stability of silk fibroin at different oil-water interfaces.

The biocompatible amphiphilic silk fibroin, extracted from domesticated silkworms, can adsorb at the oil-water interface and form elastic interfacial layers. In this study, three surfactants (cationic cetyltrimethylammonium bromide, the nonionic polyoxyethylene sorbitan monolaurate, and the anionic sodium dodecyl sulfate) were selected to investigate, through interfacial shear rheology, the influences of surfactants on the interfacial viscoelasticity and stability of silk fibroin at the interfaces between water and two different oils. The presence of surfactant prolongs the equilibration time and enhances the interfacial elastic modulus and toughness of the interfacial silk fibroin layers, especially at the nonpolar dodecane-water interface. However, when the surfactant exceeds a critical concentration, the shear modulus and stability of interfacial silk fibroin layers begin to decrease due to the competitive adsorption of surfactant molecules and the weakening of the protein network. Owing to electrostatic interactions, the ionic surfactants cetyltrimethylammonium bromide and sodium dodecyl sulfate can form more hydrophobic complexes with silk fibroin, which results in higher shear moduli than for silk fibroin and silk fibroin-polyoxyethylene sorbitan monolaurate mixture. Both the surfactant type and oil polarity play important roles in the adsorption, shear viscoelasticity, and stability of silk fibroin at the oil-water interface. Enhanced interactions between a silk fibroin-surfactant mixture and the oil phase delay the equilibration of the adsorption layers but strengthen the stability of interfacial layers. © 2023 Society of Chemical Industry.

Investigated the effects of surfactant concentration on cobalt ferrite nanoparticles synthesized in reverse micelles

The use of reverse micelles as nanoscale hydrophilic voids of microemulsions in the manufacture of ferrites has been recognized since the 1960s, but there has been very little attention on the structural and magnetic properties with respect to surfactant concentration. This paper investigates the influence of surfactant sodium dodecyl sulphate (SDS) concentrations on cobalt ferrite (CoFe2O4) nanoparticles prepared by reverse micelles at annealing temperatures 250°C and 500°C. Samples with varied cobalt to SDS ratios (Co: SDS = 1: 0.33, 1: 0.5, 1: 0.66) were subjected to XRD, TGA, TEM, FTIR and VSM Studies. All the samples exhibited single-phase spinel structures with crystalline diameters ranging from 10 to 18 nm. As the SDS concentration increased the crystallite size decreased. The TEM images showed the particle size in the range of 7.6 -17.7 nm. VSM investigations show the ferromagnetic behavior of the sample. The observed increase in coercivity with respect to annealing temperature for the same concentration reflects the single-domain nature of the nano particles. This underscores the crucial role of annealing conditions in customizing cobalt ferrite nanoparticles as a suitable application in longitudinal magnetic recording media.

A SANS investigation of silk-stabilized aqueous poly(3-hexylthiophene): phenyl-C61-butyric acid methyl ester nanoparticle dispersions

Regenerated silk fibroin (RSF) protein comprising both hydrophilic and hydrophobic chain segments offer great potential for interfacial interaction and stabilization of organic nanoparticles (NPs) in aqueous medium. In this work, aqueous dispersion of poly(3-hexylthiophene):phenyl-C61-butyric acid methyl ester (P3HT:PCBM) NPs of 1:1 weight ratio were prepared using RSF as surfactant for the first time via the mini-emulsion method. The size, morphology, internal structure, interface and hierarchical organization of RSF-stabilized P3HT:PCBM NPs was investigated using UV–visible spectroscopy, contrast-variation small-angle neutron scattering (CV-SANS) and ultra-small-angle neutron scattering (CV-USANS). The P3HT:PCBM NPs were established to be stabilized in the matrix of RSF colloidal microparticles in water. Unlike the commonly used surfactant sodium dodecyl sulfate which produces core–shell (PCBM–P3HT) NPs, the RSF molecules generated P3HT:PCBM NPs with internal structure that resemble phase-separated solvent-cast films. The as-prepared dispersion has good film-forming ability and has been demonstrated for fabrication of composite films comprising graphene oxide.

Quick and Green Procedure for the Quantification of Chromium in an Anionic Surfactant System

This study aims to establish a facile, user-friendly, accurate, and repeatable spectrophotometric detection method for Cr(III) ions in trace quantities. The method utilises reagent 1-nitroso-2-naphthol (NNPh) in a sodium dodecyl sulphate (SDS) 1.0 % micellar solution, replacing the old, time-consuming, and expensive solvent extraction method that employs hazardous solvents such as carbon tetrachloride and chloroform. SDS surfactant is used to solubilise indissoluble chelates, making the proposed technique easy, rapid, and environmentally friendly. The established method exhibits an improved linear calibration range, sensitivity, limit of detection, and selectivity compared to earlier spectrophotometric methods employing different complexing agents. The stoichiometric ratio between Cr and NNP was observed to be 1 : 3. The molar absorption coefficient (<i>ε</i>) was determined to be 2.05 ∙ 104 l mol<sup>–1</sup> cm<sup>–1</sup> at <i>λ</i><sub>max</sub> 579 nm. The limits of detection for Cr(III) was measured as 3.49 ng l<sup>–1</sup>. A calibration linear curve was achieved in the concentration range of 0.5–5.0 μg ml<sup>–1</sup>. Results obtained showed good comparison with the results obtained by atomic absorption spectrometry. The developed method has been adapted for the analysis of Cr(III) in various alloys, pharmaceutical, environmental, and biological samples.

Effect of counterions on the structure and dynamics of water near a negatively charged surfactant: a theoretical vibrational sum frequency generation study.

Charged aqueous interfaces are of paramount importance in electrochemical, biological and environmental sciences. The properties of aqueous interfaces with ionic surfactants can be influenced by the presence of counterions. Earlier experiments involving vibrational sum frequency generation (VSFG) spectroscopy of aqueous interfaces with negatively charged sodium dodecyl sulfate (Na+DS- or SDS) surfactants revealed that the hydrogen bonding strength of the interfacial water molecules follows a certain order when salts of monovalent and divalent cations are added. It is known that cations do not directly participate in hydrogen bonding with water molecules, rather they only influence the hydrogen bonded network through their electrostatic fields. In the current work, we have simulated the aqueous interfacial systems of sodium dodecyl sulfate in the presence of chloride salts of mono and divalent countercations. The electronic polarization effects on the ions are considered at a mean-field level within the electronic continuum correction model. Our calculations of the VSFG spectra show a blue shift in the presence of added countercations whose origin is traced to different relative contributions of water molecules from the solvation shells of the surfactant headgroups and the remaining water molecules in the presence of countercations. Furthermore, the cations shield the electric fields of the surfactant headgroups, which in turn influences the contributions of water molecules to the total VSFG spectrum. This shielding effect becomes more significant when divalent countercations are present. The dynamics of water molecules is found to be slower at the interface in comparison to the bulk. The interfacial depth dependence of various dynamical quantities shows that the interface is structurally and dynamically more heterogeneous at the microscopic level.

Green Extraction of Carotenoids from Tomato By-products Using Sodium Dodecyl Sulphate

AbstractTomato peel by-products contain high levels of lycopene, which has traditionally been extracted using organic solvents. This research focuses on the optimisation of a sustainable method to obtain a lycopene-rich extract using the biodegradable anionic surfactant sodium dodecyl sulphate (SDS). A Plackett–Burman experimental design was used to investigate the effect of seven factors on the extraction of carotenoids from tomato peels using sodium dodecyl sulphate (SDS volume and concentration, homogenisation intensity and time, sonication phase, extraction time and ultracentrifugation intensity). Based on the responses of total carotenoid extraction, the SDS volume, the use of ultrasound and the extraction time significantly influenced the extraction yield and were selected for optimisation using a Box–Wilson experimental design. The final green extraction protocol (1 g sample + 11.9 ml SDS 0.3%, homogenisation at 13,500 rpm for 2 min, ultrasound phase, agitation for 8.2 h and ultracentrifugation) was selected after quantification of total carotenoids by UV–VIS and HPLC-DAD. Finally, we used nuclear magnetic resonance to demonstrate a high lycopene purity in the carotenoid extract obtained. Furthermore, using transmission electron microscopy, we observed the presence of intact chromoplasts in the extract, protecting the carotenoids from the exposure to external agents. Thus, this work reports an optimised method for the sustainable extraction of carotenoids and demonstrates the viability of the degradable solvent SDS for the extraction of liposoluble bioactive compounds, like carotenoids and mainly lycopene. The lycopene extract could be used for the technological and nutritional enrichment of new foods and/or the design of nutraceuticals.

Nano-stabilized foam for enhanced oil recovery using green nanocomposites and anionic surfactants: An experimental study

With the decline in hydrocarbon resources around the world, the use of different enhanced oil recovery (EOR) methods became more attractive. Recently, gas foams have been considered by researchers as one of the most effective ways to increase oil recovery. Despite its functions, the conventional foams have low stability. Recently, nanomaterials, as appropriate agents, are used to increase the stability of foams in enhances oil recovery. In this study, the synthesized nanocomposites (NCs), SiO2/KCl/Xanthan NCs was used to stabilize the foams obtained from sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) surfactants. Thus, the synergic effect of the surfactant and NCs was investigated along with the salinity, foam quality, alkalinity and oil properties. The experimental measurements of conductivity, pH, surface tension (ST), interfacial tension (IFT), contact angle (CA) and oil displacement were performed. The obtaining results showed that the SDS and CTAB surfactants have the critical micelle concentration (CMC) of 2000 and 300 ppm, respectively. In terms of the foam stability, both surfactants demonstrated the same behavior of equal stability, while it is improved under the influence of NaCl and NaOH at different concentrations with reducing the ST, IFT and foam generation time (tg). In addition, the optimal NCs concentrations for SDS and CTAB surfactants which improved the foam stability significantly, reduced the CA by 73.27 and improved the oil recovery by 20 % original oil in place (OOIP) were 1000 ppm and 500 ppm, respectively. This was also confirmed by macroscopic analysis of the formulated nano-surfactant systems. On the other hand, the viscosity, density and the gas rate had the inverse influence on the foam stability.

Experimental Study on the Influence of Surfactants on Ore Surface Wettability.

To reveal the evolution law of ore surface wettability under the condition of adding surfactant and chemical reaction, the test experiments of ore surface morphology, roughness, and chemical element distribution were carried out. The results show that the contour of the ore surface morphology was relatively flat in the early stage of leaching and the roughness factor increased slowly, while the contour fluctuated significantly in the late stage of leaching and the roughness factor increased sharply. With the leaching reaction, the roughness factor and spreading coefficient of the ore with a 0.008 mol/L surfactant (sodium dodecyl sulfate) concentration were always higher than those without surfactant and the surfactant enhanced the erosion effect of the solution on the ore surface. During the leaching process, the chemical elements Cu, Al, and K were dissolved on the ore surface, and the content of Cu decreased significantly from 2.01 to 0.86%; the leaching rate of copper was about 57.2%. According to the morphology characteristics of the ore surface during leaching and the distribution law of chemical elements on the ore surface before and after leaching, the leaching process was divided into four stages of "contact-penetration-reaction-disintegration". The surfactant had the most obvious effect on the ore surface morphology in the two stages of "reaction" and "disintegration".

A novel amidine-based fluorescent probe TPE-4+ for rapid detection of anionic surfactant sodium dodecyl sulfate

An accurate, fast, and simple surfactant detection method is of great significance for monitoring surfactants pollution. Sodium dodecyl sulfate (SDS) is one of the most commonly used anionic surfactants and has been listed as an important monitoring pollutant for surfactant residues. Herein, a novel fluorescent probe named TPE-4+ with four amidines as the recognition functional group and tetraphenylethene as the fluorophore was fabricated. Due to the special intramolecular environment, the probe showed selectively identification towards SDS which made an aggregation induced fluorescence enhencement. Under the optimum conditions, the fluorescence enhencement of TPE-4+ is linearly related to the concentration of SDS in the range of 5.0–60.0 μM with limit of detection (LOD) of 0.010 μM and limit of quantification (LOQ) of 0.034 μM. Relative to the reported methods, the probe in our work showed better selectivity and sensitivity. The proposed method was successfully applied for the SDS determination of disinfecting bowls.

3D electro-Fenton augmented with iron-biochar particle electrodes derived from waste iron bottle caps and sugarcane bagasse for the remediation of sodium dodecyl sulphate

The present work demonstrates a novel strategy of synthesizing iron-biochar (Fe@BCSB) composite made with the waste iron bottle cap and sugar cane bagasse for implementation in the three-dimensional electro-Fenton (3DEF) process. The catalytic ability of the Fe@BCSB composite was explored to remediate the sodium dodecyl sulphate (SDS) surfactant from wastewater at neutral pH. At the optimum operating condition of Fe@BCSB dose of 1.0 g L−1, current density of 4.66 mA cm−2, and Na2SO4 dose of 50 mM, nearly 92.7 ± 3.1% of 20 mg L−1 of SDS abatement was attained during 120 min of electrolysis time. Moreover, the Fe@BCSB showed significant recyclability up to six cycles. Besides, other organics were successfully treated with more than 85% abatement efficiency in the proposed Fe@BCSB-supported 3DEF process. The total operating cost obtained during SDS treatment was around 0.31 US$ m−3 of wastewater. The phytotoxicity test revealed the positive impact of the 3DEF−treated effluent on the germination of the Vigna radiata. The electron paramagnetic resonance conveyed •OH as the prevailing reactive species for the oxidation of SDS in the 3DEF process. Further, about 81.3 ± 3.8% of SDS and 53.7 ± 4.1% of mineralization efficacy were acquired from the real institutional sewage.

Molecular interactions of cationic/anionic surfactants in presence of anionic antibiotic drug cloxacillin sodium at different temperatures: Micellization and thermodynamic studies

The physicochemical properties and interactions of surfactant–drug aggregates are regarded as essential features to achieve optimum therapeutic action of the drug. In this article, the effect of various concentrations of anionic antibiotic drug cloxacillin sodium (ClxNa) on the micellization of cationic surfactants such as cetyltrimethylammonium bromide (CTAB), tetradecyltrimethylammonium bromide (TTAB) and anionic surfactant sodium dodecyl sulphate (SDS) have been investigated using electrical conductance measurement at different temperatures (288.15 K, 293.15 K, 298.15 K, 303.15 K, 308.15 K, and 313.15 K). The results suggest an increase in critical micelles concentration (CMC) values for cationic surfactants (CTAB/TTAB) with a rise in drug concentration (0 mM up to 10 mM) whereas anionic surfactant SDS shows a decrease in CMC at higher drug concentrations (from 2.5 mM up to 10 mM) at all the studied temperatures. The degree of counterion dissociation (α) values for TTAB aggregates show a slight increase with [ClxNa], except at a few lower temperature ranges whereas such a regular trend was not obtained for CTAB and SDS aggregates. Temperature-dependent CMC values show a nonlinear nature with a rise in temperatures and follow a U-shaped curve for all studied pure surfactant and surfactant–ClxNa systems. Micellization for all surfactant-drug systems is found to be spontaneous. Investigation of other temperature-dependent thermodynamic parameters such as change in standard enthalpy (ΔHm0), and entropy (ΔSm0) of micellization suggest that surfactant–drug interactions are both endothermic (ΔHm0 < 0, particularly at lower temperatures) and exothermic (ΔHm0 < 0, at higher temperatures), whereas micellization is largely entropically driven (ΔSm0 > ΔHm0).

A smartphone-intergrated dual-emission fluorescent nanoprobe for visual and ratiometric detection of anthrax biomarkers

A novel dual-emission fluorescent nanoprobe based on rare-earth nanosheets was fabricated to detect 2,6-pyridine dicarboxylic acid (DPA), which is the biomarker of Bacillus anthracis. 2-amino terephthalic acid (BDC-NH2) and surfactant sodium dodecyl sulfate (SDS) were co-intercalated into layered europium hydroxide (LEuH) to prepare the organic/inorganic composite, which was delaminated to obtain the rare-earth nanosheets. The ratio detection of DPA is possible due to the antenna effect between DPA and Eu3+. The nanoprobe shows high accuracy and sensitivity due to the large specific surface area of the rare-earth nanosheets. The limit of detection (LOD) is 4.4 nM for DPA in the range of 0–20 μM. In addition, a more convenient and faster smartphone-based visual detection platform was established based on the obvious color change. This work offers an effective way for developing visual sensing platforms, which opens a new path for designing fluorescent probes with superior sensing capabilities.

Effect of different micelles on charging and discharging behavior of phase change material

Phase change material (PCM) offers high-density thermal energy storage, making it attractive for thermal management applications of electronic circuitry and thermal energy storage. However, PCM, like paraffin wax, ideal for such low-temperature applications, has very low thermal conductivity. The present study focused on the improvement of the thermal conductivity of paraffin wax using surfactants. The surfactants used as thermal conductivity enhancers (TCE) are cetyltrimethyl ammonium bromide (CTAB), Dioctyl sodium sulfosuccinate (known as AOT) and sodium dodecyl sulfate (SDS). The surfactant self-aggregation called a micelle, acts as conducting medium inside the paraffin wax, providing better thermal conductivity. The highest heat transfer rate with a peak temperature of 71 °C was observed in the case of AOT micelle paraffin wax. Adding SDS, CTAB, and AOT surfactants increased the highest temperatures by 4%, 8.4%, and 18.33% compared to pure PCM.

Mechanical and Corrosion resistance behavior of Ultrasonication-assisted Electrodeposited Ni–SiC Nanocomposite coatings

Pure Ni/Ni–SiC composite coatings were electrodeposited onto stainless-steel substrate using ultrasonic-assisted electroco-deposition techniques by varying the deposition times. The investigations mainly focus on the structural, microstructural, mechanical, and corrosion properties of the composites coating deposited by varying deposition times in the presence of sodium dodecyl sulphate surfactant and Silicon carbide (SiC) nanoparticles (∼50 nm) reinforcement. The incorporation of filler and increasing deposition time decreases the surface roughness of the coating, making the composite Ni–SiC 2 h deposition smoother as (0.087 ± 0.005) μm compared to other coatings. X-Ray Diffraction results indicated that the coating exhibited an FCC Ni-type structure with the primary orientation along the (200) direction. Microstructural studies conducted with a scanning electron microscope revealed irregular shaped granules within the composite, along with fine grains, and their compaction increased with longer deposition times. Energy dispersive X-ray spectroscopy and elemental mapping confirmed that SiC was uniformly distributed in the 2 h composite coatings. This resulted in a considerable enhancement of the composite's mechanical properties, with a nano hardness of (3.12 ± 0.13) GPa and bulk microhardness of (213 ± 5) HV on both the top surface and cross-sectional surface of the composites, respectively. The corrosion study indicated that the Ni–SiC composite films deposited for 2 h provided better corrosion resistance when compared to pure Ni coating.

Characterization of Nanoprecipitated PET Nanoplastics by 1H NMR and Impact of Residual Ionic Surfactant on Viability of Human Primary Mononuclear Cells and Hemolysis of Erythrocytes.

Manufactured nanoplastic particles (NPs) are indispensable for in vitro and in vivo testing and a health risk assessment of this emerging environmental contaminant is needed. The high surface area and inherent hydrophobicity of plastic materials makes the production of NPs devoid of any contaminants very challenging. In this study, we produced nanoprecipitated polyethylene terephthalate (PET) NPs (300 nm hydrodynamic diameter) with an overall yield of 0.76%. The presence of the ionic surfactant sodium dodecyl sulfate (SDS) was characterized by 1H NMR, where the relative ratio of NP/surfactant was monitored on the basis of the chemical shifts characteristic of PET and SDS. For a wide range of surfactant/NP ratios (17:100 to 1.2:100), the measured zeta potential changed from -42.10 to -34.93 mV, but with an NP concentration up to 100 μg/mL, no clear differences were observed in the cellular assays performed in protein-rich media on primary human cells. The remaining impurities contributed to the outcome of the biological assays applied in protein-free buffers, such as human red blood cell hemolysis. The presence of SDS increased the NP-induced hemolysis by 1.5% in protein-rich buffer and by 7.5% in protein-free buffer. As the size, shape, zeta potential, and contaminants of NPs may all be relevant parameters for the biological effects of NPs, the relative quantification of impurities exemplified in our work by the application of 1H NMR for PET NPs and the ionic surfactant SDS could be a valuable auxiliary method in the quality control of manufactured NPs.

Hydrophobically Associated Hydrogel for High Sensitivity and Resolution of an Interdigital Electrode Pressure Sensor.

Hydrogel-based flexible strain sensors have been known for their excellent ability to convert different motions of humans into electrical signals, thus enabling real-time monitoring of various human health parameters. In this work, a composite hydrogel with hydrophobic association and hybrid cross-linking was fabricated by using polyacrylamide (PAm), surfactant sodium dodecyl sulfate (SDS), lauryl methacrylate (LMA), and polypyrrole (PPy). The dynamic dissociation-conjugation among LMA, SDS, and PPy could dissipate energy to improve the toughness of hydrogels. The SDS/PPy/LMPAm composite hydrogel with a toughness of 1.44 MJ/m3, tensile fracture stress of 345 kPa, tensile strain of 1021%, and electrical conductivity of 0.57 S/m was obtained. Furthermore, an interdigital electrode flexible pressure sensor was designed to replace the bipolar electrode flexible pressure sensor, which greatly improved the sensitivity and resolution of the pressure sensor. The SDS/PPy/LMPAm composite hydrogel-based interdigital electrode flexible pressure sensor showed extraordinary stability and identified different hand gestures as well as monitored the pulse signal of humans. Moreover, the characteristic systolic and diastolic peaks were clearly observed. The pulse frequency (65 times/min) and the radial artery augmentation index (0.57) were calculated, which are very important in evaluating the arterial vessel wall and function of human arteries.

Exploring the Fluorescence Quenching of Sodium Dodecyl Sulfate Doped Polyaniline by Energetic Nitrocompounds

AbstractThe fluorescence quenching studies using conducting polymers (CPs) have greatly contributed in the trace detection of high energy materials (HEMs) with nitro functional groups. Polyaniline doped with the anion surfactant sodium dodecyl sulfate (SDS) acts as a fluorophore and is used in fluorescence quenching studies to detect HEMs at trace levels. A mechanistic approach to understanding electron transfer during the interaction of fluorophore with HEMs were studied by using spectroscopic and electrochemical techniques. The presence of conjugation in conducting polymer shows a molecular wire effect during fluorescence quenching by trace level of HEMs by quenching several emissions in polymer chains. The Stern‐Volmer(S‐V) and limit of detection(LOD) plots give quenching mechanism and the efficiency of quenching. These values indicate that TNT had good sensitivity compared to other HEMs such as RDX, PETN, CL‐20 and CRCC. The FTIR and Raman studies were used to understand the interaction between nitro groups of HEMs with the benzenoid, polaronic and semi‐quinoid units of doped polyaniline. The cyclic voltammetry studies revealed shift in potential and current during the interaction of the fluorophore with HEMs, and these results were combined with fluorescence studies for better understanding of the possible mechanism of quenching.

Revealing the Formation Dynamics of Janus Polymer Particles: Insights from Experiments and Molecular Dynamics.

Seeded emulsion polymerization is one of the best-known methods for preparing polymer particles with a controlled size, composition, and shape. It first requires the preparation of seed particles, which are then swollen with additional monomer (the same as the one used for the seed or a different one), to either increase the seed's size or change its morphology. The use of surfactants plays a central role in guaranteeing the required colloidal stability and contributing to the final shape and structure of the particles by lowering the interfacial energy between the polymer of the seed and the added monomer. We here study the polymerization of methyl methacrylate in the presence of polystyrene seed particles at various surfactant concentrations in the presence and absence of a surfactant (sodium dodecyl sulfate). We first show experimentally that the morphology of the colloidal particles can be tuned from Janus to core-shell, depending on the presence or absence of surfactant on the seeds particles' surface. Furthermore, using classical molecular dynamics simulations, we investigate the mechanism and behavior of the surfactants during the first stages of the polymerization process. We use a newly developed approach based on contact statistical analysis to confirm the critical role played by the organization of surfactant molecules on the surface of the seed particles in dictating the final particle morphology.