Functionalized sepiolitic clay nanofibers as a natural ingredient in medical cosmetics

Abstract

Medical clay, also known as medicinal clay, was first used in Mesopotamia around 2500 BC and is still a relevant topic today. Among typical medical clays, sepiolite, a fibrous clay in the family of palygorskite is often ignored by cosmetic brands as it is not found abundantly in nature as much as other clays like bentonite. However, much of the world reserves of this clay are in Turkey. In this study, antibacterial sepiolite clay was prepared from nanosilver added dispersed sepiolite samples. These Ag-nanoparticles (Ag-NPs) were formed according to green synthesis under microwave heating using the additives like alginate polymer and ascorbic acid later these fibers were put through serial dilution antibacterial tests using gram +/-bacteria (ATCC 25922 and ATCC 25923) for general quality control and determining minimum inhibitory concentrations. Although the best antibacterial clay samples (Ag-NPs have theoretically 30 mg/L of silver content) were washed at least five times with distilled water, it was observed that their antibacterial stability was still maintained. Finally, the morphology of sepiolite fibers smaller than 40 nm was characterized by AFM images show that highly dispersed single fibers can be used as a natural raw material and have a great opportunity in the development of new products in the cosmetic and medical sector. © 2021, Turkish Chemical Society. All rights reserved.