... of shape4. Top quality and made by environment-friendly material, without any special smell.5. Wear-resistant, grease-resistant, not easy to ... following advantages:(1) non-toxic, odorless, chemically stable, insoluble in any solvents and solutions, in addition to hydrofluoric acid (HF) and ... strong base, but does not react with any substance.(2) thermal stability, pore type silica gel can be ...