Presentation is loading. Please wait.

Presentation is loading. Please wait.

Self-Darkening Sunglasses A Reversible Chemical Reaction.

Similar presentations


Presentation on theme: "Self-Darkening Sunglasses A Reversible Chemical Reaction."— Presentation transcript:

1 Self-Darkening Sunglasses A Reversible Chemical Reaction

2 Glasses that darken in sunlight and become clear in ordinary room light

3 Example of a Reversible Chemical Reaction Example of a Reversible Chemical Reaction Self-darkening sunglasses use a reversible chemical reaction called photochromic Photochromic is derived from photo, meaning light, and chromic meaning color - a change in color with light

4 Napthopyran Molecule Colorless Form Absorbs only Ultraviolet Light, not Visible Light Weak Bond

5 Napthopyran Molecule Effect of UV Light UltravioletLight UV Light Breaks the Weak Bond and Electrons Shift Positions

6 Napthopyran Molecule Dark Colored Form Molecule changes shape after new bonds are formed New molecule form absorbs long wavelength visible light

7 Reversible Photochromic Reaction of Napthopyran Sunlight No Sunlight ColorlessForm Dark Colored Form


Download ppt "Self-Darkening Sunglasses A Reversible Chemical Reaction."

Similar presentations


Ads by Google