If your "dimethylsilicone oil" is composed of polydimethylsiloxane, a low molecular weight polymer with liquid appearance, it is non-volatile at 25 ° C at room temperature, belongs to ultra-high boiling point organic solvent like peg and DINP, and its viscosity has nothing to do with volatility, There is no difference between 30cps and 10000cps, but the molecular weight is different (except if other solvents are used to dilute the viscosity, such as 6white oil or dioxane, the diluted solvent will volatilize).