Is Titanium Dioxide Safe For Skin-What Are The Physical And Chemical Properties Of Titanium Dioxide

What Are The Physical And Chemical Properties Of Titanium Dioxide

Titanium dioxide (TiO2), also known as titania, is a white, powdery substance that is widely used as a pigment, in sunscreen products, and in various industrial applications. Below are some of its physical and chemical properties:

Physical Properties:

1. Appearance: Titanium dioxide is a white, odorless, crystalline powder.

2. Melting Point: Approximately 1,825 degrees Celsius (3,307 degrees Fahrenheit).

3. Boiling Point: Approximately 2,500 degrees Celsius (4,532 degrees Fahrenheit).

4. Density: About 3.9 g/cm³.

5. Solubility: It is practically insoluble in water and most organic solvents. It can dissolve in concentrated sulfuric acid or hydrofluoric acid.

6. Crystal Structure: It can exist in several crystalline forms (phases), including rutile, anatase, and brookite, with rutile being the most stable form.

7. Hardness: On the Mohs scale of mineral hardness, TiO2 has a hardness of 6 to 7.

8. Refractive Index: It has a high refractive index, which makes it an effective opacifier in products like paints and sunscreens.

Chemical Properties:

1. Composition: Titanium dioxide consists of one titanium atom and two oxygen atoms per molecule.

2. Oxidation State: Titanium in TiO2 has an oxidation state of +4, which is its highest oxidation state.

3. Reactivity: TiO2 is relatively inert and stable under normal conditions. It does not react with most chemicals but can react with strong acids or bases under certain conditions.

4. Photocatalytic Activity: TiO2 is known for its photocatalytic properties, where it can use light energy to catalyze reactions. This property is utilized in self-cleaning surfaces and in the degradation of organic pollutants.

5. Stability: It is stable in the presence of heat, light, and moisture, which contributes to its widespread use in various products.

6. pH: The pH of a TiO2 slurry is typically around 6.5 to 7, which is close to neutral.

Titanium dioxide’s properties make it valuable in numerous applications. For example, its opacity and brightness make it an excellent white pigment in paints, plastics, papers, and inks. Its UV-absorbing capabilities are utilized in sunscreen products to protect the skin from harmful UV rays. Additionally, its photocatalytic properties are harnessed for environmental applications such as air purification and water treatment.