How to control powder alignment to maximize functionality and performance of color cosmetics and sunscreen

Control of powder alignment is essential for maximizing the functionality of color cosmetics and sunscreens. Various surface treatments were applied to nanosized titanium dioxide to modify their surface characteristics. Such modifications can be used to control the behavior of dispersions in cosmetics, enabling them to align uniformly. The powders were mixed with solvents and applied to a cellulose triacetate film. The features of powder alignment on the film were evaluated using several approaches. When the type of surface treatment changed by varying the weight ratio, there was no significant correlation between its alignment and treatment. However, when we focused on the pseudo-HLB each treated pigment, their alignments were correlated. It was confirmed that the powders subjected to the appropriate surface treatment combinations from the pseudo-HLB standpoint made it possible to align uniformly and create a smooth coating film. As a result, it has a high UV-shielding ability. The surface-treated powders in this study were found to change the UV shielding ability and surface roughness of the layer formed when they were formed by spreading the sample powder dispersion and drying of the film. It was suggested that the pseudo-HLB, which is calculated based on the chemical structure after the surface treatment process, is useful for choosing the optimum surface treatment to create a uniformly aligned pigment layer.