Application of cationic-nonionic surfactant based nanostructured dye carriers: Mixed micellar solubilization

Mixed bio-based surfactant-templated mesoporous silica for supporting palladium catalyst

The study aimed on the synthesis of bio-based surfactant-templated mesoporous silica for supporting palladium catalyst using mixed bio-based templating agents namely cashew nut shell liquid (CNSL) and castor oil for pore direction purposes. The materials prepared through co-condensation of 3-aminopropyltriethoxysilane (APTS) and tetraethyl orthosilicate (TEOS) in a 1:4 M ratio using 1:1, 4:1 and 9:1 ratio of CNSL and castor oil. The resulting porous materials were utilized to support the palladium(II) chloride catalyst, resulting in a heterogeneous catalyst-a better and more environmentally friendly catalyst than a homogeneous one. Different instruments were used to characterize the prepared materials such as nitrogen porosimeter, Powder X-ray Diffraction, Diffuse Reflectance Infrared Fourier Transform Spectroscopy and Inductively coupled plasma optical emission spectroscopy. Physisorption studies of the prepared materials indicated that the largest pore diameter of 43.84 nm could be obtained by using a 1:1 M ratio of CNSL and castor oil. On the other hand, the largest surface area of 209 m2/g was obtained from a 9:1 whereas the largest pore volume was 1.55 cm3/g from a 4:1. Diffuse Reflectance Infrared Fourier Transform Spectroscopy analysis confirmed the presence of N-H group, the bending vibration bands at around 1640 and 1543 cm-1 indicating that the reaction of organoaminesilanes and tetraethyl orthosilicate had occurred. The palladium content of the supported catalyst was determined by ICP-OES which confirmed the attachment of palladium to the synthesized materials. The highest palladium loading was obtained from the adsorbent prepared by using 1:1 ratio of surfactants mixture which gave the adsorption value of 2.16 mmol/g. Powder X-ray Diffraction indicated that the synthesized organosilica materials are amorphous with improved crystallinity upon attachment of palladium catalyst. The incorporation of palladium in the synthesized materials using the mixed bio-based surfactant was successful.

Unveiling the Role of Nonionic Surfactants in Enhancing Cefotaxime Drug Solubility: A UV-Visible Spectroscopic Investigation in Single and Mixed Micellar Formulations

This study reports the interfacial phenomenon of cefotaxime in combination with nonionic surfactants, Triton X-100 (TX-100) and Tween-80 (TW-80), and their mixed micellar formulations. Cefotaxime was enclosed in a micellar system to improve its solubility and effectiveness. TX-100 and TW-80 were used in an amphiphilic self-assembly process to create the micellar formulation. The effect of the addition of TX-100, a nonionic surfactant, on the ability of TW-80 to solubilize the drug was examined. The values of the critical micelle concentration (CMC) were determined via UV-Visible spectroscopy. Gibbs free energies (ΔGp and ΔGb), the partition coefficient (Kx), and the binding constant (Kb) were also computed. In a single micellar system, the partition coefficient (Kx) was found to be 33.78 × 106 and 2.78 × 106 in the presence of TX-100 and TW-80, respectively. In a mixed micellar system, the value of the partition coefficient for the CEF/TW-80 system is maximum (5.48 × 106) in the presence of 0.0019 mM of TX-100, which shows that TX-100 significantly enhances the solubilizing power of micelles. It has been demonstrated that these surfactants are effective in enhancing the solubility and bioavailability of therapeutic compounds. This study elaborates on the physicochemical characteristics and solubilization of reactive drugs in single and mixed micellar media. This investigation, conducted in the presence of surfactants, shows a large contribution to the binding process via both hydrogen bonding and hydrophobic interactions.

Biosynthesis of Silver Nanoparticles Using Salvia pratensis L. Aerial Part and Root Extracts: Bioactivity, Biocompatibility, and Catalytic Potential

The aim of this research was the synthesis of silver nanoparticles (SPA- and SPR-AgNPs) using the aqueous extracts of the aerial (SPA) and the root (SPR) parts of the plant Salvia pratensis L., their characterization, reaction condition optimization, and evaluation of their biological and catalytic activity. UV-Vis spectroscopy, X-ray powder diffraction (XRPD), scanning electron microscopy with EDS analysis (SEM/EDS), and dynamic light scattering (DLS) analysis were utilized to characterize the nanoparticles, while Fourier transform infrared (FTIR) spectroscopy was used to detect some functional groups of compounds present in the plant extracts and nanoparticles. The phenolic and flavonoid contents, as well as the antioxidant activity of the extracts, were determined spectrophotometrically. The synthesized nanoparticles showed twice-higher activity in neutralizing 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS⁺) compared with the respective extracts. SPR-AgNPs exhibited strong antimicrobial activity against almost all of the tested bacteria (<0.0039 mg/mL) and fungal strains, especially against the genus Penicillium (<0.0391 mg/mL). Moreover, they were fully biocompatible on all the tested eukaryotic cells, while the hemolysis of erythrocytes was not observed at the highest tested concentration of 150 µg/mL. The catalytic activity of nanoparticles toward Congo Red and 4-nitrophenol was also demonstrated. The obtained results confirm the possibility of the safe application of the synthesized nanoparticles in medicine and as a catalyst in various processes.

Mixed micellar solubilization for procion blue MxR entrapment and optimization of necessary parameters for micellar enhanced ultrafiltration

In this study, micellar enhanced ultrafiltration, MEUF, being an active methodology, has been employed to remove Procion Blue MxR (PBM) from synthetic effluent. MEUF is being applied to reduce the toxicity level of aqueous system using the micellar media of cationic surfactants i.e. Cetyl trimethylammonium bromide (CTAB) and cetylpyridinium chloride (CPC). Subsequently, the effect of addition of nonionic surfactant, Triton X-100 (TX-100), on solubilizing power of cationic surfactants is investigated. The values of partition coefficient and free energy of partition reflect the extent of interaction of the dye with the surfactants. Initially molecules of pollutants i.e. dye form ion pairs with ionic surfactants and, later on, the same is incorporated within micelle. Maximum value of free energy of partition ΔG_p has been found to be -55.49 kJmol^-1 and -50.43 kJmol in the presence of CPC and CTAB, respectively. The size of pollutant, thus, increases and, consequently, can be easily filtered. The effect of various factors i.e. concentration of surfactant, concentration of electrolyte (NaCl), transmembrane pressure, revolutions per minute (RPM) and pH, have been investigated to find the optimum conditions for maximum removal of PBM from aqueous system. The efficiency of MEUF has been assessed by calculating the values of rejection percentage and permeate flux. Both the surfactants were observed as strong candidates for PBM encapsulation but overall, maximum rejection percentage (R%) of 96.90% was attained by CPC.

Synthesis and dilute aqueous solution properties of cationic antistatic surfactant functionalized with hydroxyl and ether groups

Polyester fibers tend to generate and accumulate electrical charges under friction and induction. This significantly affects the production and use process and even poses the risk of electric shocks and fire. Quaternary ammonium salt surfactants with a positive charge can be adsorbed on negatively charged polyester fibers and have excellent antistatic properties. Therefore, we have synthesised a cationic antistatic surfactant functionalised with hydroxyl and ether groups: N-hexadecyl-N,N-dimethyl-N-butanoxy glycerol ether ammonium chloride (HDBGA). The structure was characterized by 1H NMR, FTIR and ESI/MS. The excellent properties of HDBGA in aqueous solution were investigated by measuring the Krafft point (TK), surface tension, conductivity, and steady-state fluorescence. Also antistatic tests were carried out. The results show that the TK of HDBGA is below 0 °C indicating that it can still be applied in cold water. The new quaternary ammonium compound could effectively decrease the surface tension of aqueous solution to 31.28 mN m−1, where the critical micelle concentration (CMC) at 298.15 K was 3.83 × 10−4 mol L−1. In addition, the static electricity and static half-life values of the polyester cloths treated with the HDBGA solutions were also measured, as well as the effects on the fabric properties. The product exhibited excellent antistatic properties and satisfactory wash resistance, and the fabric fibers were not damaged.

Highly Selective Methodology for Entrapment and Subsequent Removal of Cobalt (II) Ions under Optimized Conditions by Micellar-Enhanced Ultrafiltration

Micellar-enhanced ultrafiltration (MEUF), being a separation technique, was used to remove cobalt metal ion (Co²⁺) from their aqueous solutions in an application to reduce the toxicity level from industrial effluents using a micellar solution of anionic and cationic surfactants. The metal ions were first adsorbed by using anionic surfactants, i.e., sodium dodecyl sulfate (SDS) and sodium oleate (SO). The calculations for partition (K_x) and binding constants (K_b) and their respective free energy of partition and binding (ΔG_p and ΔG_b kJmol^-1) helped significantly to find out the extent of binding or interaction of Co²⁺ with the surfactant and ΔG_p and ΔG_b were found to be -29.50 and -19.38 kJmol^-1 for SDS and -23.95 and -12.67 kJmol^-1 in the case of SO. MEUF work was also performed to find out the optimal conditions to remove metal pollutants from the aqueous system. For the said purpose, various factors and concentrations effect were studied, such as the concentration of the surfactant, concentration of the electrolyte (NaCl), transmembrane pressure, RPM, and pH. The efficiency of this process was checked by calculating various parameters, such as rejection percentage (R%) and permeate flux (J). A maximum rejection of 99.95% with SDS and 99.99% with SO was attained.

CMC determination using isothermal titration calorimetry for five industrially significant non-ionic surfactants

Surfactants are used in a vast array of products including pharmaceuticals, cosmetics and household formulations. From an industrial perspective, non-ionic surfactants are ideal for inclusion within such products as they are non-toxic, simple to formulate and economic to use. This study considers five non-ionic surfactants (Tween 20, Tween 80, Crodasol, Croduret and Etocas 35) to determine the critical micellar concentration (CMC) for each using isothermal titration calorimetry, thus avoiding issues regarding poor accuracy found with other techniques. Furthermore, this methodology has not previously been applied to this group of surfactants. For the most commonly used non-ionics (Tween 20 and Tween 80) a further study was undertaken to consider the influence of surfactant purity on the CMC determined, using standard grade (Tween 20 and 80), high purity (Tween 20 HP and Tween 80 HP) and Super Refined (SR PS20 and SR PS80). Results permitted calculation of the CMC for the surfactants whereupon the values were determined to range from 1.0 mM for Tween 20 HP to 2.9 mM for Tween 80 HP. Such information regarding the CMC event is useful from a formulation perspective as it can ensure that the most optimum concentration of surfactant is included within a formulation to maximize its efficacy.