Cationic Cetyltrimethylammonium Bromide Research Articles

Exploring the role of aspartic acid in modulating micellization behavior of cationic cetyltrimethylammonium bromide

The study of the interaction between aspartic acid (Asp) and cetyltrimethylammonium bromide (CTAB) reveals important information about surfactant organization, surface tension, critical micelle concentration (CMC), and surface pressure. Because of enhanced surfactant solubility brought about by electrostatic interactions, Asp’s ionization lowers CTAB’s CMC. The maximal surface excess concentration falls with increasing Asp concentration, suggesting competition for surface adsorption. The minimum occupied area per surfactant molecule increases at the same time, indicating changed surfactant activity at the interface between air and water. Higher CTAB concentrations are associated with a decrease in surface tension, which suggests that when Asp concentration rises, micelle formation would be promoted. Saturation effects, on the other hand, happen at high Asp concentrations and interfere with micelle formation. These tendencies are supported by surface pressure measurements, highlighting the significance of ionic interactions in micelle behavior.Moreover, surfactant structuring is impacted by the packing parameter decreasing as Asp concentration increases. The changing balance between hydrophilic and hydrophobic interactions within the CTAB/Asp micellar complexes is further explained by variations in degree of counterion dissociation of micelles (α) values. The complex dynamics of ionic interactions and their impact on surfactant behavior in CTAB/Asp systems are highlighted by these studies.

Effects of surfactants on the wettability of sodium propionate aqueous deacidification agent

Abstract To address the challenges of difficulty and low penetration speed of aqueous deacidification agents in paper, we aimed to enhance the wetting performance of these agents by incorporating a surfactant. We selected four surfactants for our study: anionic sodium dodecyl benzene sulfonate (SDBS), cationic cetyltrimethylammonium bromide (CTAB), nonionic polysorbate-80 (TW80), and polyether-modified trisiloxane (TRSE). The wetting properties of these surfactants on sodium propionate aqueous deacidification agent, the alkali stability of the solution, and the effects of moist heat aging on paper durability were explored. The results demonstrated that TRSE exhibited superior performance compared to the other three surfactants, effectively reducing the surface tension of sodium propionate solution to 21.02 mN/m. In alkaline conditions with a pH range of 8.00–10.00, the surface tension of SDBS, CTAB, and TW80 solutions remained stable for 30 days. Similarly, under weakly alkaline conditions with a pH value below 9, the surface tension of TRSE solutions exhibited stability. It should be noted that SDBS accelerated the decline of paper tensile index and whiteness during the heat and humidity aging process; at the same time, CTAB, TW80, and TRSE had no noticeable adverse effects on paper aging resistance.

Effect of surfactants and implementation strategies for the pentachlorophenol degradation with Ni/Fe bimetallic nanoparticles in soil

Pentachlorophenol (PCP) removal was found to be dependent on many factors including soil surface charge, Ni/Fe nanoparticle (NP) dosage, pH, and types of surfactants. Desorption efficiencies of PCP from the contaminated soil treated with DI water, cetyltrimethylammonium bromide (CTAB), sodium dodecyl sulfate (SDS), and Triton X-100 (TX-100) were 88.2%, 1.35%, 103%, and 80.9%, respectively. PCP desorption was significantly enhanced by anionic SDS but reduced by cationic CTAB. PCP desorption efficiency was governed by van der Waals attraction and electrostatic interaction among surfactants, soil particles, and Ni/Fe nanoparticles. For SDS-modified Ni/Fe NPs, SDS bilayers form on the positively charged Ni/Fe surface to sterically and electrostatically stabilize Ni/Fe and enhance the PCP removal efficiency of Ni/Fe in soil. However, an opposite effect was observed in the CTAB-modified Ni/Fe. In the soil slurry, CTAB was readily detached from Ni/Fe and subsequently form a CTAB bilayer on the soil surface to adsorb PCP at the soil surface that significantly reduce PCP degradation by blocking PCP from accessing the Ni/Fe reactive sites although the Ni/Fe-CTAB exhibited extremely high reactivity for PCP in soil solutions. Based on the results, remediation strategies using a combination of surfactants and Ni/Fe bimetallic nanoparticles for ex-situ soil remediation were proposed.

Effect of surfactants on the permeation rate and selectivity of polyamide composite membranes for organic solvent nanofiltration

Solvent-resistant membranes are pivotal in industrial separations. This study aims to develop thin-film composite polyamide (TFC-PA) membranes with enhanced organic solvent nanofiltration (OSN) capabilities. Polyallylamine hydrochloride (PAAH) was used as the aqueous amine and isophthaloyl chloride (IPC) as the crosslinker to form the polyamide active layer by interfacial polymerization (IP) on a polyacrylonitrile (PAN) support. The impact of using anionic sodium dodecyl sulfate (SDS) and cationic cetyltrimethylammonium bromide (CTAB) to act as phase transfer agents during IP was investigated to understand their potential for facilitating the transfer of PAAH to the organic phase for reaction with IPC. The SDS and CTAB were separately dissolved into the PAAH solutions before IP to evaluate their effects on membrane properties. Extensive characterization including SEM, EDX, AFM, Water Contact Angle, ATR-FTIR, and Solid (CP-MAS) 13C NMR revealed various chemical and structural features of the membrane. The membrane M2 (PAAH-IPC) (exhibited >98% rejection for various anionic and cationic dyes. The inclusion of SDS during interfacial polymerization led to a substantial 3-fold increase in methanol permeate flux from 31 L m−2 h−1 to 119 L m−2 h−1, at a pressure of 15 bar. Conversely, the addition of CTAB resulted in membranes with higher permeate flux but insufficient dye rejection. Moreover, after three weeks of static aging of the membranes no significant changes were detected in either permeability or solute rejection, substantiating the stability of membranes.

Oil-in-Water Emulsions Probed Using Fluorescence Multivariate-Curve-Resolution Spectroscopy.

Hydrophobic surfaces in contact with aqueous media are omnipresent in nature. A plethora of key biological and physiological processes occur at the interface of immiscible fluids. Besides its fundamental importance, probing such interfaces is rather challenging, especially when one medium is bathed in the other. Herein, we demonstrate a fluorescence-based method that probes the oil-water interface and interfacial processes through surface dielectric perturbations. The fluorescence response of Nile Red is measured in hexadecane in water nanoemulsions. Three major spectral components appear: two from the bulk liquid media (hexadecane and water) and a distinct band at around 640 nm due to the interfacial component. Such spectra are deconvoluted using the multivariate-curve-resolution algorithm, and interface-correlated fluorescence spectra are attained. The influence of anionic sodium dodecylbenzenesulfonate (SDBS) and cationic cetyltrimethylammonium bromide (CTAB) surfactants on the oil-water interface is elucidated with concentration-dependent measurements. A charge-dependent spectral shift is observed. The interface correlated band at 641 nm for bare hexadecane nanoemulsions red shifts in the presence of anionic surfactants, indicating an apparent dielectric increase. In contrast, the same band gradually blue shifts with increasing cationic surfactant concentration, indicating an apparent interface dielectric decrease. Such a method can be utilized to probe alterations at interfaces beyond the oil/water interface.

Cationic surfactant-assisted assembly of water-dispersible MnO2 onto indoor textiles for anti-bacterial and HCHO removal

Nowadays, the applications of nanoparticle-decorated textiles for environmental governmental governance have aroused great concerns, while the poor fastness and uncontrolled aggregation of the nanoparticles negatively influenced its practical use. Herein, an environmental-friendly synthesis strategy of water-dispersible MnO2 was demonstrated by using the reductant of 2-(N-morpholino) ethanesulfonic acid (MES) and template of cetyltrimethylammonium bromide (CTAB), and then the as-prepared MnO2 was further employed as a multifunctional textile coating. In all the procedures under room temperatures, three effects of cationic CTAB micelles were thoroughly explored, from optimizing MnO2 to uniform micro/nanoscale through template strategy, to bridging the gaps between electronegative particles and fabrics, and even providing stable antibacterial effect. Consequently, without any additional binding agents, multifunctional cotton textile was obtained by simply immersing cotton into a MnO2-CTAB aqueous solution, and appeared antibacterial rates (over 99 %) to both E. coli and S. aureus. Meanwhile, HCHO removal and ultraviolet blocking (UVA<0.1 %) properties as well as high durability of the nanoparticles are also introduced to the textiles. We believe as-presented cationic surfactant-templated strategy for regulating synthesis and deposition of functional particles onto cotton textiles has broad application prospects in green and sustainable functionalization of decoration textiles.

Анализ распространения фитоплазм почернения древесины и золотистого пожелтения на виноградниках Краснодарского края

The purpose of research is to study the spread of phytoplasma infection in the vineyards of the Krasnodar Region using the PCR method. The object of the study is grape plants of various varieties with external symptoms of phytoplasma infection. The material for total DNA extraction was symptomatic leaves (their veins and petioles) collected from plantings of Shiraz, Chardonnay, Cabernet Sauvignon, Saperavi, Mizar, Moldova, Augustine, Pinot Blanc, Riesling, and Aligote varieties. DNA extraction was carried out using a buffer based on the cationic detergent CTAB (cetyltrimethylammonium bromide), according to the protocol recommended by EPPO (European plant protection organization) for the isolation of phytoplasmas from grape plant material. Sampling was carried out in industrial vineyards of the Krasnodar Region in 9 different geographical locations of the Novorossiysk, Temryuk and Anapa Regions. DNA was isolated from symptomatic leaves according to the protocol recommended by EPPO (European plant protection organization). Determination of the presence of phytoplasma infection was carried out by real-time PCR on a Quant Studio 5 amplifier using a commercial kit designed to detect phytoplasmas – Candidatus Phytoplasma solani and Candidatus Phytoplasma vitis (Synthol) and a test system recommended by EPPO. Using a kit produced by Synthol, 239 samples were analyzed, including 12 rechecked with markers recommended by EPPO. As a result of the analysis, it was found that DNA of Candidatus Phytoplasma solani was present in 113 samples studied. DNA from the phytoplasma Candidatus Phytoplasma vitis, which causes golden yellowing of leaves, was not detected in any of the analyzed samples.

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.

Effect of glycerol on micellization of quasi-binary mixture of zwitterionic cocamidopropyl hydroxysultaine and cetyltrimethylammonium bromide in aqueous solution

The micellization behavior of quasi-binary mixture of zwitterionic cocamidopropyl hydroxysultaine (CAPHS) with cationic cetyltrimethylammonium bromide (CTAB) was investigated both in aqueous solution and in glycerol-water. Both the tensiometric and the conductive techniques were adopted to determine the critical micelle concentrations (cmc) of individual and mixed surfactants. In the framework of the regular solution theory and based on the pseudophase separation model, some micellization and thermodynamic parameters were estimated by the Rubingh’s and the Clint’s models. The results indicate that the nonideal mixing of CAPHS with CTAB and the synergistic interaction between them play vital roles on the reduction of mixed cmc, the amplitude of synergistic interaction depends on the composition of mixture and the presence of glycerol induces the increase in the individual and mixed cmc values and the change of the participation of CAPHS in mixed micelle with the composition in bulk solution. The electrostatic repulsion, the diversity of molecular conformation and the steric hindrance can account for the formation of mixed micelle and the difference in micellar composition. Thermodynamic parameters show that the entropy makes overwhelming contributions on the spontaneous process of micellization, the release of mixing heat makes the stable mixed micelle formed and the presence of glycerol makes for reducing the contribution of entropy and forming the more stable mixed micelle. These findings help with understanding the interaction behavior between two species and the effect of glycerol and further providing some information for the design of the related surfactant formulations.

Decolorization and mineralization of methylene blue by potassium permanganate

Methylene blue (MB)-permanganate redox reaction has been studied spectrophotometrically in absence and presence of cationic cetyltrimethylammonium bromide (CTAB). The UV–visible spectroscopy reveals the presence of intermediate reaction products (Azure B, Azure A, and thionine) during interaction confirming the real degradation of MB. The gas chromatography-mass spectrometry (GC-EIMS) was used to establish the formation of MB degradation products. The electron transfers lead to a rapid N-demethylation oxidative reaction to form colored intermediary compounds. The key factors ([MnO4−], [MB], [H2SO4], and temperature) that affect the degradation rate of MB solution are analyzed. The redox reaction proceeds through a complex formation between the MB and MnO4−. The position of absorption band of MB was shifted from 666 nm to 603 nm with increasing the reaction time. The degradation efficiency decreases drastically from 82.1 % to 41.8 % in presence of 1.0 mM H2SO4. The results show that the degradation rate in acidic solutions is lower than that in neutral reaction media. The MnO2 was not formed as the product with H2SO4. The degradation efficiency of MB decreases with increasing CTAB concentrations. Sub-micellar inhibitory role of CTAB indicates that the MnO4− interact with positive head group of CTAB, and inhibit the oxidation of MB.

Spectroscopic insights for the enhanced partitioning and removal of Reactive Violet 5 by mixed micellar formulations under optimized conditions: An ionic-nonionic mechanistic approach

This study demonstrates MEUF (micellar enhanced ultrafiltration) as an effective method for the removal of Reactive Violet 5 (RV5) coming from the synthetic waste. MEUF technique is currently employed to decrease aqueous systems toxicity by employing cationic surfactants micellar media, specifically CPC (cetylpyridinium chloride) and CTAB (Cetyltrimethylammonium bromide). The study also examines the impact of nonionic surfactant on the addition of Triton X-100 (TX-100), on solubilizing capacity of the cationic surfactants. Our goal is to determine the optimal conditions for achieving maximum removal efficiency. RV5 partitioning constant, Kb as well as Gibbs energy of the partition ΔGp determines surfactant and dye molecules interaction. Dye molecules initially interact with ionic surfactants to form ion pairs. Subsequently, these ion pairs become incorporated into micelles and later on can subsequently be removed by MEUFThe maximum values of ΔGp (free energy of partition) were determined to be −42.30 kJmol−1 and −37.15 kJmol−1 using cationic surfactants, CPC and CTAB, respectively. Increase in pollutant size results in easy filtration. This study examines the impact of different factors, such as pH, transmembrane pressure, electrolyte (NaCl), surfactant concentration and revolutions per minute (RPM), on the removal of RV5 from an aqueous system. MEUF efficiency has been evaluated through the determination of permeate flux and rejection percentage values. It has been noticed that both surfactants had the potential to effectively encapsulate RV5. However, overall, the highest R% (rejection percentage) of 97.17% was attained.

Surfactants interaction with sulfathiazole: Spectroscopic, conductometric, and thermodynamic approach

Taking into the account the advantages of surfactant micelles as drug carrier, the interaction of sulfathiazole (STZ) with three types of surfactants, namely, cationic cetyltrimethylammonium bromide (CTAB), anionic sodium dodecyl sulfate (SDS), and non-ionic t-octylphenoxypolyethoxyethanol (TX-100) has been studied by using UV–visible spectroscope and conductivity measurements. The critical micelle concentration (CMC), degree of ionization (α), counter ion binding constant (β), free energy change of micellization (ΔG0m), relative solubility (St/S0), STZ-surfactant interaction constant (θ), approximate number (n) of STZ molecules incorporated per micelle, heat capacity (ΔC0m), and transfer of thermodynamic parameters were calculated and discussed for both the systems. The CMC values of CTAB and SDS were found to decrease in presence of increasing STZ concentrations. The values of counter ions dissociation were also found to be dependent of temperature. The ΔG0m values are obtained to be negative of both systems. A comparison of the binding constants (KC) calculated from the Kawamura equation indicated that the solubilization tendency of STZ with CTAB is much higher than that with SDS micelles. However, this interaction was weak since no significant change in the micellization phenomenon was observed with TX-100 under our experimental conditions.

Low‐Cost Multi‐Function Electrolyte Additive Enabling Highly Stable Interfacial Chemical Environment for Highly Reversible Aqueous Zinc Ion Batteries

AbstractThe practicality of aqueous zinc ion batteries (AZIBs) for large‐scale energy storage is hindered by challenges associated with zinc anodes. In this study, a low‐cost and multi‐function electrolyte additive, cetyltrimethyl ammonium bromide (CTAB), is presented to address these issues. CTAB adsorbs onto the zinc anode surface, regulating Zn2+ deposition orientation and inhibiting dendrite formation. It also modifies the solvation structure of Zn2+ to reduce water reactivity and minimize side reactions. Additionally, CTAB optimizes key physicochemical parameters of the electrolyte, enhancing the stability of the electrode/electrolyte interface and promoting reversibility in AZIBs. Theoretical simulations combined with operando synchrotron radiation‐based in situ Fourier transform infrared spectra and in situ electrochemical impedance spectra further confirm the modified Zn2+ coordination environment and the adsorption effect of CTAB cations at the anode/electrolyte interface. As a result, the assembled Zn‐MnO2 battery demonstrates a remarkable specific capacity of 126.56 mAh g−1 at a high current density of 4 A g−1 after 1000 cycles. This work highlights the potential of CTAB as a promising solution for improving the performance and practicality of AZIBs for large‐scale energy storage applications.

The Formation Analysis of Ca (II), Mg (II), Zn (II) and 5-Hydroxysalicylic Acid Binary Complexes in Cetyltrimethylammonium Bromide Cationic Micelles

The Formation Analysis of Ca (II), Mg (II), Zn (II) and 5-Hydroxysalicylic Acid Binary Complexes in Cetyltrimethylammonium Bromide Cationic Micelles

Enabling high rate capability and stability all-solid-state batteries via cationic surfactant modification of composite electrolyte

The garnet-type solid electrolyte Li6.4La3Zr1.4Ta0.6O12 (LLZTO) was modified with a cationic surfactant Cetyltrimethylammonium Bromide (CTAB) to improve the dispersion of LLZTO inorganic particles in Poly (ethylene oxide) (PEO) electrolyte (PEO-LLZTO@CTAB) by a liquid phase casting method. During fabrication, the cationic modifier CTAB is uniformly adsorbed on the surface of LLZTO particles, which can effectively reduce their surface energy and lead to a thin CTAB surface coating layer. This fabricated PEO-LLZTO@CTAB can avoid the aggregation of LLZTO particles in the composite solid-state electrolyte (CSSE) and improve the interfacial contact at the PEO/LLZTO interface, thus reducing the overall resistance of PEO-LLZTO@CTAB/Li half-cell and inhibiting the dendrite growth during cycling. The all-solid-state batteries (ASSBs) with LiFePO4 (LFP) as the cathode, PEO-LLZTO@CTAB as the electrolyte and Li as the anode exhibit a high initial discharge capacity of 146.6 mAh-g−1, excellent rate performance and high-capacity retention of 91.0 % after 300 cycles at 0.2 C multiplier and 60 °C within the voltage range of 2.7–4.0 V.

Exploring the pH-Responsive Interaction of β-Blocker Drug Propranolol with Biomimetic Micellar Media: Fluorescence and Electronic Absorption Studies.

Interaction of neutral and charged lipophilic beta-blocker drug, propranolol (PPL) with biomimicking nanocavities formed by micelles bearing same and opposite charges namely, cationic cetyltrimethylammonium bromide (CTAB), a surface-active ionic liquid 1-hexadecyl-3-methylimidazolium chloride (HDMIC) and anionic sodium dodecyl sulphate (SDS) have been investigated using fluorescence and absorption spectroscopic techniques. Binding of PPL to SDS at pH < pKa is characterised by biphasic interactions with decrease in fluorescence intensity at lower concentrations and subsequent increase post micellization. All the surfactants show significant interactions with the neutral drug molecule at pH > pKa, which is evident from the strongest binding constant ( ) values at pH 10.4. Results of quenching studies indicate that the location of drug molecule is determined by its charge, which is influenced by both pH and charge on micelle surface. For PPL-CTAB and PPL-HDMIC systems, quenching was strongest at pH 10.4, moderate at pH 7.4 and was absent at pH 3.5. However, the PPL-SDS system displayed similar values at all pH conditions, suggesting that the probe is at the same position regardless of pH. Non-covalent interactions, which play crucial role in biological systems, are similarly the primary driving force governing the interaction between PPL and surfactant micelles.

Thermodynamics of modulation of interaction of α-helix inducer 2, 2, 2-trifluoroethanol with lysozyme in presence of cationic, anionic and non-ionic surfactants

The interactions of anionic sodium dodecyl sulphate (SDS), cationic cetyltrimethylammonium bromide (CTAB) and nonionic triton X-100 (TX-100) surfactants with lysozyme at pH = 2.4 have been studied individually as well as in combination with 2,2,2-trifluoroetanol (TFE). Urea has also been used in combination with surfactants. By using these combinations, efforts have been made to obtain partially folded conformations of the protein in the presence of surfactants and effect of α-helix inducer 2,2,2-trifluoroethanol on these intermediate states. Thermodynamic analysis of all these interactions has been done employing a combination of UV-visible, fluorescence and circular dichroism spectroscopies. The results have been correlated with each other and characterized qualitatively as well as quantitatively. At lower concentration of surfactant, the thermodynamic parameters indicated the destabilizing effect of SDS, stabilizing effect of CTAB and unappreciable destabilizing impact of TX-100 on lysozyme. The enhancement in destabilization effect or reduction in stabilization effect of surfactants on lysozyme in the presence of TFE and urea has also been indicated. Communicated by Ramaswamy H. Sarma

Transport of polystyrene nanoplastics in porous media: Combined effects of two co-existing substances

Both surfactants and natural organic matters (NOMs) are substances commonly found in aqueous environments, and their effects on the transport of nanoplastics that is gradually gaining widespread attention in porous media are currently in their infancy, while their combined effects are absent. We investigated innovatively the combined effect of surfactants and NOMs on the transport of polystyrene nanoplastics (PS-NPs) in saturated porous media. Adsorption tests of surfactants and NOMs onto PS-NPs, adsorption tests of PS-NPs onto quartz sand, and transport tests of PS-NPs in saturated quartz sand were conducted. Hydrophobicity and Derjaguin-Landau-Verwey-Overbeek (DLVO) interaction energy were measured and calculated. A mathematical model was employed to fit the transport of PS-NPs in porous media. It was found that the effects and action mechanisms of cationic cetyl trimethylammonium bromide (CTAB) and anionic sodium dodecylbenzene sulfonate (SDBS) on the transport of PS-NPs in porous media were distinct. In the presence of CTAB, 1 mg/L humic acid (HA) and 10 mg/L sodium alginate (SA) could promote aggregation of PS-NPs by decreasing the absolute zeta potential of PS-NPs, and reducing the energy barrier between PS-NPs and porous media and increasing the blocking and straining, thus inhibiting the transport of PS-NPs. In the presence of SDBS, SA and HA could improve the adsorption of SDBS onto PS-NPs by bridging and increasing adsorption sites, thus increasing the hydrophilicity of PS-NPs and improving the transport of PS-NPs. Whether or not NOMs were present, the transport of PS-NPs in porous media was mainly governed by the DLVO interaction energy in the presence of cationic surfactants and by hydrophobicity in the presence of anionic surfactants. This innovative observation has led to an understanding on the environmental behaviour of nanoplastics in porous media under complex environments.

Enhanced electronic absorption and solubility of Mammeigin in aqueous micelles and protein aggregate solutions compared to water

The physicochemical properties of plant polyphenol Mammeigin (MMG) from Mesua ferrea, upon interactions with carrier molecules like surfactants and Hen Egg-White Lysozyme (HEWL) aggregates were investigated using UV–Vis and Fluorescence spectroscopy; and Zeta potential (ZP) measurements in aqueous solutions. The role of surfactant charge on the interactions of MMG was studied using anionic Sodium Dodecyl Sulfate (SDS), cationic Cetyltrimethylammonium Bromide (CTAB), and neutral Tween 20 (T20). It was observed that ionic surfactants offered more stability to the system, which was enhanced in the presence of salt at physiological concentration and lower amounts of surfactant. The environment of MMG in these micelles was proposed to be partially semi-polar in nature based on solvent studies in organic and binary solvent systems. A similar favorable environment was found in early and partially exposed aggregates of HEWL at pH 2 and pH 9 respectively, which significantly diminished at later stages of aggregation and fibrillation at pH 2. With growing interest in plant polyphenols as bioactive, a major challenge for their utility in biological systems is the aqueous insolubility and thus, research in the field of drug/compound delivery is expanding. Our study could provide insights for developing better molecular carriers and formulations of MMG at physiological conditions for therapeutic applications with improved efficacy.

Effects of anionic and cationic surfactants on the surface Plasmon resonance intensity of biogenic silver nanoparticles: Stability, and position of optical band

Fabrication of noble metal nanoparticles by using green plant extract as reducing agent have been the subject of various investigators due to their enhanced plasmonic properties for various applications. This paper describes the effects of cetyltrimethylammonium bromide (CTAB) and sodium dodecylsulfate (SDS) on the nucleation of silver sols formation by using coriander seeds extract and silver nitrate redox reaction. The wavelength maxima (λmax) were blue shifted from 433 nm to 425, 423, and 420 nm, respectively, with 0.0, 0.4, 1.0, and 1.6 mM CTAB. The blue and red shifts were also observed from 433 nm to 421, 421, 418, and 438 with 0.0, 0.4, 1.0, 1.6 and 2.0 mM SDS, respectively. The pre-micellar inhibition, and post-micellar catalytic effects were observed on the formation of silver sols with cationic CTAB surfactant. SDS exhibits inhibitory effect on the nucleation rate for an entire range of concentration. Additionally, antioxidant activity in vitro revealed that the percentage scavenging with 2,2-diphenyl-1-picrylhydrazyl (DPPH•) were depended on the dose of AgNPs.