Enrichment of clay from Vitoria da Conquista (Brazil) for applications in cosmetics

Abstract A clay sample, off-green color, from Vitoria da Conquista, northeastern Brazil was size fractionated by dispersion and centrifugation. Three different grain-size fractions with different colors (pink, red and light green) were then isolated. The aim was to characterize the physical and chemical properties of the raw clay and the resulting grain-size fractions in order to evaluate their use in cosmetic products. X-ray diffraction, Attenuated Total Reflectance - Fourier Transformed Infrared, scanning electron microscopy, X-ray fluorescence spectroscopy, inductively coupled plasma-atomic emission spectrometry, cation exchange capacity measurements, oil absorption and swelling capacity, plastic and apparent viscosities and microbiological tests were used to characterize the samples. The grain-size fractions are composed of smectite and kaolinite, without the presence of Si-polymorphs (α-quartz or cristobalite), and showed attractive colors, good swelling capacity, good oil absorption, microbiological safety and chemical inertia. These characteristics make these samples potentially interesting for applications in pharmaceuticals and cosmetics.