In personal care products such as creams, liquid foundations, sunscreens, or hair conditioners, volatile or non-volatile silicone oils (such as cyclopentasiloxane and polydimethylsiloxane) are widely used as skin-feel modifiers. Their core value lies not in providing nutrition or active efficacy, but in constructing subjective experiences like "lightweight," "silky," and "non-sticky" by regulating the product's spreadability, evaporation rate, and tactile feedback on the surface of the skin or hair. This process is essentially a precise design of the rheological behavior and interfacial interactions within a multiphase system.

While traditional oils (such as mineral oil or vegetable oil) offer moisturizing benefits, they often result in a heavy and residual feel due to their high viscosity and strong polarity. In contrast, silicone oils rely on their low surface tension (approx. 20–22 mN/m), low viscosity, and weak intermolecular forces to rapidly spread into an ultra-thin film layer the moment they are applied. This reduces shear resistance, creating a tactile sensation of "gliding" rather than "dragging." Volatile silicone oils (such as D5) evaporate within minutes after film formation, leaving behind only active ingredients or powders to achieve a "dry, matte" effect; non-volatile silicone oils form a lasting hydrophobic film, providing a soft, enveloping feel without clogging pores.

Furthermore, the hydrophobicity of silicone oil can block the influence of environmental humidity on powder agglomeration, enhancing the long-lasting stability of makeup. Its low refractive index (approx. 1.40), which is close to that of the stratum corneum, allows the product to present a natural sheen on the skin rather than a greasy shine. In hair care applications, silicone oil adsorbs into the gaps between hair cuticles, filling microscopic depressions and reducing friction and static electricity, making hair easier to comb and giving it a mirror-like reflection.

It is crucial to emphasize that such silicone oils are rigorously purified to comply with cosmetic safety regulations (such as the EU EC No 1223/2009), ensuring no risk of sensitization or bioaccumulation. From a formulation science perspective, silicone oil acts as a "sensory delivery medium"—it does not alter the physiological state of the skin, but through physical coverage and rheological intervention, it transforms chemical ingredients into perceivable user pleasure, embodying the engineering realization of "tactile aesthetics" in the daily chemical industry.


Low compression set fluorosilicone rubber MY FHTV 3961 series