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The magnetic behavior of individual magnetite (Fe3O4) nanoparticles (MNPs) has arisen considerable attention in environmental application. However, magnetic properties and stability weaken due to their high susceptibility to chemical activity (oxidation). Efforts have increasingly been made to encapsulate MNPs by green organic matrix, which considerably improve functionality, stability, cost and reduce back toxicity. Besides, the use of natural zeolite materials has been reported to endows considerable dispersibility and chemical stability for the composite MNPs. In this study, bio-based magnetite nanoparticles were synthesized using an aqueous extract of Cordia Africana (CA) leaves incorporated into the modified Natrolite (NAT) framework as an adsorbent for methylene blue (MB)dye removal from aqua solution. The prepared high dispersible Magnetite-NAT Nanocomposite (M/NAT-NC) was characterized by Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (XRD), and scanning electron microscope (SEM). The optimum adsorption efficiency of M/NAT-NCs was estimated by employing Response Surface Methodology (RSM)-based Box-Behnken Design (BBD) at different parameters. Accordingly, 0.5 g M/NAT-NCs, 40 mg/L, and pH 9 at 40 min were found to be the optimal conditions for best removal (98.6%). The adsorption data fitted best with the pseudo-second-order and Freundlich model, and the negative value of ∆G0 confirms the feasibility and spontaneity of the MB adsorption onto M/NAT-NCs. Besides, the regeneration of exhausted M/NAT-NCs reflected nearly similar removal efficiency as the new one; as such, M/NAT-NCs could be reasonably used for cationic dyes removal from aqueous media.

Herein we provide a detailed result about the effect of various additives, viz. inorganic salts, quaternary ammonium bromides (QABs) and amino acids on clouding behavior of amphiphilic drug amitriptyline hydrochloride (AMT). The continuous increase in the cloud point (CP) of drug by increase in inorganic salt concentration and the magnitude of increases rely upon the position of the salts in Hofmeister series and hydrated radii. The QABs also influence continuous increase in the CP, which is illustrated in terms of the alkyl chain length of peculiar QAB. The effect of amino acids on CP of the drug solution is dependent upon the characteristics (acidic, basic, polar or nonpolar) of particular amino acids. The overall behavior of additives has been analyzed and discussed on the basis of electrostatic repulsion or interaction, micellar growth, and mixed micelle formation between the ingredients. In addition to this, thermodynamic parameters are also evaluated.

Herein we have studied the interaction of β-cyclodextrin (β-CD) with the amphiphilic drug promazine hydrochloride (PMZ) by using conductimetry and viscometry. From the observed results it was concluded that critical micelle concentration (cmc) of the pure drug was lower than the apparent critical micelle concentration (cmc∗) of the drug in the presence of β-CD. The cmc∗ increased on increasing the concentration of β-CD due to the encapsulation of the amphiphilic drug to the hydrophobic cavities of the β-CD which delayed the micelle formation. Viscosity of the solution decreased drastically on the addition of β-CD which further increased on increasing the drug solution. Free energies of micellization (ΔGmic) were calculated with the help of degrees of micelle ionization and cmc obtained from the specific conductivity−[PMZ] plots. Micellization was found to be less spontaneous in the presence of cyclodextrin.

Effect of the micelles of anionic, cationic and non-ionic surfactants on the fluorescence quenching of 1- and 2-naphthols has been studied in the presence of copper ion. The excited state lifetime, dynamic and static quenching constants for these systems have been determined. Fluorescence quenching in water and SDS micelle is due to the collision of the fluorophore with the quencher with a small static component. The negatively charged naphtholate ions in the excited state are quenched with significantly higher rates than the neutral naphthol molecules, which are located further inside the mesophase. CTAB micelle is less effective than the SDS micelle for fluorescence quenching. The effect of CTAB on water-assisted excited-state deprotonation has been investigated in the presence of ZnSO4. For TX-100 micelle there is negligible quenching even at higher concentration of the quencher.