Preparation and characterization of bio-organoclays using nonionic surfactant

Abstract

The present study was aimed at the preparation and characterization of tailor made hybrid materials, whose peculiar hosting capability could be exploited in biotechnological applications. With this purpose, the modification of K10 montmorillonite by intercalation of Tween 20 surfactant, was accomplished. The influence of two internal parameters, namely pH and surfactant/clay ratio, on the surfactant uptake ability by clay was investigated. The adsorption mechanism was elucidated on the basis of complementary kinetic and equilibrium studies and, then, corroborated by the useful information provided by the FT-IR, TGA and XRD characterization. The gathered results allow to draw the conclusion that the whole surfactant uptake is the result of two contributions: a site-limiting component, governed by negative cooperative interactions, which takes into account for the Tween 20 adsorption onto the pristine clay, and a non-specific linear partitioning component, related to the adsorption of the surfactant onto the in situ prepared organo-clay. Moreover, at strongly acidic pH, a mechanism consisting of two-steps pathways involving two non-energetically equivalent binding sites of the clay surfaces, was proposed, while, on increasing the pH, the clay interlayer becomes the sole available site for the surfactant uptake. In the light of the interesting results obtained, among the plethora of potential biotechnological applications, the present paper suggests the exploitation of the prepared organo-clays to improve the performance of either hydrophilic or hydrophobic drug carriers systems

Simultaneous Removal and Recovery of Metal Ions and Dyes from Wastewater through Montmorillonite Clay Mineral

“…It is worth to underline that the different behavior of metal and dye is in accordance with the results of the adsorption isotherms and it corroborates the hypothesis that the dye adsorbs onto Mt Perusal of diffractograms evidences the presence of the peaks characteristic of the hydrated montmorillonite k10 clay, i.e., one at 2θ approximately equal to 8.9 • (peak 1) which corresponds to the basal interlayer, and a reflection peak at a lower 2θ value (~6 • ) (peak 2), which, according to literature [74,[126][127][128][129][130], is attributed to the majority of the interlayer spaces being intercalated with water molecules as proved by the disappearance of this refection peak after dehydration processes [129].…”

Montmorillonite-surfactant hybrid particles for modulating intestinal P-glycoprotein-mediated transport

“…The (001) reflection shifted to a lower diffraction angle for MSH particles as compared to untreated montmorillonite, which implied an increased interlayer distance from 14.9 to 18.0 Å. This 3.1 Å increase agrees well with previous studies (Calabrese et al, 2016;Calabrese et al, 2017). Under the assumption that the thickness of an individual montmorillonite layer is 10 Å (Ploehn and Liu, 2006), the resulting distance between individual montmorillonite layers was 8 Å, corresponding to 5-6 C-C alkane bonds (Skinner, 1945).…”

“…Calabrese and co-workers have successfully incorporated polysorbate 20 in montmorillonite to obtain delayed release of cinnamic acid (Calabrese et al, 2016;Calabrese et al, 2017), and they showed that 5 polysorbate 20 facilitated the release of cinnamic acid from montmorillonite. Their studies also confirm the strong interactions between montmorillonite and polymers or surfactants that contain oxyethylene groups (-CH2-CH2-O-), like polysorbate (Aranda and Ruiz-Hitzky, 1992).…”

Clay-biosurfactant materials as functional drug delivery systems: Slowing down effect in the in vitro release of cinnamic acid

“…In the blank Mt case, the 001 reflection was observed at 2θ = 5.37°( d = 16.5 Å). According to the literature (Bromberg et al, 2011;Cui et al, 2008;Calabrese et al, 2016;Bertolino et al, 2016) this reflection has been ascribed to the Mt with interlayer spaces filled with hydrated cations.…”