2. Summary I. Introduction II. Pigment's origins III. Pigment's usages IV. Experience

3. Introduction What is a pigment ? It's a coloured substance, natural or artificial, of mineral, chemical or organic origin, who colour everything in the world. Pigment's usages ? Feeding, Paint, Industry, Medicine, Cosmetic.

4. Pigment's Origin ● Coloured earths ● Minerals ● Vegetables

5. Pigment's Origin ● Animals ● Artificial

6. Pigment's Usages 1) Feeding 2) Paint 3) Industry 4) Medicine 5) Cosmetic

7. Feeding ● Pigments are used to coulour some feeding colorants. Colorants serve to give some « fantasy » in dishes. ● But pigment are toxic : yellow of butter who served to colour margarines.

8. Paint ● Pigments have to have qualities : – Light resistance – Miscibility (with other pigments) – Covering power – Coulourant power

9. Paint There are methods to conserve picture : - Avoid hang picture on cold or/and humid wall - Avoid the sun exposition - Rejuvenate the back and the forefront - The temperature and humidity have to remain stable - Limit the transport of picture

10. Industry ● Use to colour plastic, paint, coating wood and car, fertilizers, packing industry,...

11. Industry ● Industry also use pigments with effects : - The pearly effect - The metallic finish - The irisation... The pearly effect : Create some shade effects who can change according the light.

12. Industry The metallic finish who can product the sensation to see metal (coating car). ● The irisation is an effect use the color modification according the light or/and the vision angle

13. Medicine ● Pigments are used like excipients in medicaments. ● Colorant in medicament have a psychological effect on patient. ● In C vitamin the patient think it is natural but it isn't.

14. Cosmetic ● Pigments serve to colour cosmetic product. It exist pigment with effect in cosmetic too ● Some pigments used erstwhile are toxic like ceruse white.

15. Experience : Chromatography ● First, cut 2 disks of 6 millimetres of diameter in the limb of oak's leaf. ● In second time, crush disks on two chromatographic paper at 3 centimetres of vertical edges

16. Experience : Chromatography ● Then, prepare 10 mL of solvent : ● - ether of petroleum : 85/100x10= 8,5 mL ● - ethanol : 10/100x10= 1 mL ● - cyclohexanol : 5/100x10= 0,5mL ● 8,5+1+0,5= 10mL

17. Experience : Chromatography ● After, pour 5 mL of the solvent in two test tubes. ● Next, dip the chromatographics papers in 1 cm in the solvent.

18. Experience : Chromatography ● Observe.

19. Experience : Chromatography ● Observe which are pigments who compose oak's leaf. ● So, we can say for obtain one colour (in nature), there are several pigments.

20. It was « Pigments » presented by Gaëtan & Arthur Any questions ?