Quantification of the distribution of cetylpyridinium chloride on the external and internal surfaces of montmorillonite: Relevance in antifungal activity assessment

Abstract

� Montmorillonites with cetylpyridinium (CP) adsorbed were evaluated against 2 fungi. � The CP adsorption on montmorillonites occurred by three different interactions. � DTGA allowed quantifying the % of adsorbed CP in the processes involved. � The inhibition diameters for both fungi were related to their susceptibility to CP. � Materials with antifungal activity for technological applications.

One-Pot Green-Synthesis of Supported Reductive Biogenic Iron-Based Materials for the Removal of Cr(VI)

“…The MMT mineralogy was evaluated by X-ray diffraction and chemical analysis in previous studies and consists of Na-rich montmorillonite (>88%) with minor phases as quartz and feldspars. Some physicochemical parameters of the raw MMT were determined elsewhere. − …”

Development of antibacterial magnetic clay-based nanocomposites for water treatment

“…The TGA first-order derivative (DTGA) was calculated. The actual surfactant loaded was determined, with respect to the clay CEC, considering the mass loss between 150 °C and 1000 °C, as previously reported [6].…”

“…Several biocide materials based on clays, such as clays modified by the sorption of biocide compounds, have been proposed for various applications, including cosmetics, medicine, food, and the detergent industry [2]. Among biocide compounds, alkyltrimethylammonium cations, especially quaternary amines, are commonly employed as organic compounds with antibacterial activity [3][4][5][6]. However, the isolated use of these compounds for wastewater treatment is limited because they are soluble and can become pollutants in the effluent.…”

“…Clays have been proposed as support materials for biocidal compounds. Among them, those based on montmorillonite (Mt) and alkyltrimethylammonium cations have been proposed as antifungal materials [6,7] and pollutant adsorption materials [8,9]. More recently, organoclays with a magnetic response, that is, organoclays modified by the growth of magnetic Fe oxide particles, have also been employed for the removal of heavy metals, dyes, and arsenic [10][11][12].…”

“…This study aimed to provide an overview of antibacterial activity against gram-positive and gram-negative bacteria of magnetic organoclays, synthesized by the incorporation of hexadecyltrimethylammonium or benzalkonium chloride on an Argentinean Mt, with posterior Fe oxide nucleation. [6]. The bentonite has an isoelectric point at pH 2.7, the external surface area (determined by N 2 adsorption) is 66.0 m 2 /g [19], and its cation exchange capacity (CEC) of 0.825 mmol/g [22].…”