Mineral material for use in dermocosmetic products based on a modification kaolin from the Jegłowa deposit (Poland)

The aim of the research was to produce a microbiologically safe, modified mineral material with increased sorption parameters, enabling use in the cosmetics industry as an active substance in the line of dermocosmetic products. Samples of selected kaolin (from the Jegłowa deposit, part of Silesia, Poland) were subjected to thermal (at 600 ℃) and chemical activation (using 2 or 4 M HCl). The modified material was characterized using the XRD, SEM and gas porosimetry methods (the specific surface of the samples was determined based on the assumptions of the BET model). The microbiological purity of the newly manufactured materials has been tested in accordance with the applicable standards ISO 21149:2017-07 (for bacteria) and ISO 16212:2017-08 (for yeasts). The results showed that both modifications affected the structure and properties of the tested samples. The acid activation caused the displacement and increase in the intensity of XRD reflections of kaolinite, which is the result of the removal of poorly crystalline mineral phases from the sample, present in unmodified samples. SEM imaging confirmed the change in the morphology of kaolinite plates. The measured surface properties of the samples (specific surface area, micropore area) were significantly higher in the case of acid activation and increased with the use of a stronger acid (4M HCl). Microbiological tests have shown that both the thermally and acid-activated samples meet the quality requirements for materials used in the dermocosmetics. The conducted research proves that kaolin from Jegłowa can be an attractive raw material for the cosmetics industry.