In this study, we describe the physical and functional properties of a new powder cosmetic ingredient, an amorphous mesoporous magnesium carbonate (MMC, also known as Upsalite).
Mesoporous magnesium carbonate has high specific surface area and pore volume. It has excellent absorbency and can absorb oil and water at the same time. It provides immediate and long-lasting soothing effects, does not dry or irritate the skin and has no measured flashback effect when applied to human skin. Mesoporous magnesium carbonate has good sensory and visual properties as well as excellent absorption and reinforcing properties, and has great potential to replace other powdered ingredients currently used as fillers and absorbents in powder cosmetics.
Mesoporous magnesium carbonate for cosmetics is a porous powder ground into white, with irregular particle shape, light weight, and typical bulk density between 0.24 and 0.28gmL-1. Amorphous in nature, containing trace amounts of crystalline magnesium oxide and/or magnesium hydroxide. Mesoporous magnesium carbonate can absorb both oil and water without any additional modification or surface treatment. Mesoporous magnesium carbonate has high affinity for water and large specific surface area, making it an efficient hygroscopic agent. Previous studies have shown that MMC has a high water absorption capacity. This is expected because MMC is a porous disordered (x-ray amorphous) magnesium carbonate with a very high surface area, and magnesium is an efficient electron donor known for its high reactivity with moisture and oxygen. famous. The interaction between MMC surfaces and water has been previously studied by dielectric spectroscopy. Research shows that the adsorbed water not only reacts with the MMC surface, but also penetrates the MMC surface, enters the main body of the material, and induces the crystallization of magnesium carbonate.
In this study, we not only confirmed that MMC is hygroscopic, but also demonstrated that it has the functions of absorbing water and oil at the same time. In fact, MMC maintains approximately 80% moisture absorption capacity when loaded with 50% wt% oil, and nearly 90% oil absorption capacity when loaded with 30% wt% water. One possible explanation for this phenomenon is that water and oil are absorbed through different mechanisms. When water molecules are adsorbed from the gas phase, their mobility is high, and they can easily interact with the MMC surface and bulk structure, resulting in a dual absorption effect. Instead, the oil is absorbed into the pores through capillary force. Therefore, water and oil do not compete for the same compartment space.
