A Study on Adsorption of Surfactant Molecules on Magnesium Oxide Nanocrystals Prepared by an Aerogel Route

Abstract

Adsorption of surfactant molecules, cationic as well as anionic, has been carried out on nanocrystals of magnesium oxide, prepared by an aerogel route (AP-MgO). Aerosil OT (AOT) and didodecyl dimethylammonium bromide (DDAB) have been chosen as examples of anionic surfactant and cationic surfactant, respectively. The adsorption studies were mainly carried out in nonaqueous media. For comparison, adsorption experiments were also carried out for two other magnesium oxide samples, namely, conventionally prepared MgO (CP-MgO) and commercial MgO (CM-MgO), which consist of microcrystals. The adsorption properties of the surfactants have been studied by determining the adsorption isotherms. The results have been interpreted on the basis of the fact that nanocrystals possess increased surface reactivity compared to microcrystals and particle shapes do have a role to play.

Preparation, characterization and application of octadecyl modified magnesium oxide microspheres

“…To the best of our knowledge, the heterogeneous surface of C18-MgO is attributable to the uneven dispersion of n-octadecyltrichlorosilane at the surface of MgO particles in the reaction medium. As reported by Jeevanandam and Klabunde [22], such an obstacle could be overcome by the addition of surfactants or polymers to modify the surface properties of particles. By studying the adsorption of different surfactant molecules on MgO, they pointed out that anionic surfactants were more easily adsorbed on MgO than cationic ones.…”

Controlled morphological structure of magnesium oxide particles

“…A great number of applications such as refractory materials [4], catalyst [1,5,[7][8][9], carbon dioxide chemisorbents [6], reflecting and anti-reflecting coating [10], toxic waste remediation [11] and additive to heavy fuel oil [2] utilized MgO powders. These applications requires different characteristic of MgO including the morphology of the particle [12].…”

Bifunctional Catalysts Stabilized on Nanocrystalline Magnesium Oxide for One‐Pot Synthesis of Chiral Diols

“…[17] The presence of edge-corner and other defect sites allow the nanostructured MgO materials to possess a high concentration of reactive surface ions. The reactive sites on the surface of MgO are as follows: [18] 1) Mg 2 þ site, which is of the Lewis acid type, 2) O 2 À site which is of the Lewis base type, 3) lattice bound and isolated hydroxyl groups, and 4) anionic and cationic vacancies. The presence of corner and edge sites on the surface of NAP-MgO (aerogel prepared) could approach 20% while on NA-MgO (conventionally prepared) it is less than 0.5% and on CMMgO (commercially prepared) essentially 0%.…”