A brief introduction to super hydrophobic coating.

1. B.sc TCM
SUPERHYDROPHOBI
C
COATINGS
By BALAJIVAIJAYANTHI

2. What is SUPERHYDROPHOBIC
coatings?
● A SUPERHYDROPHOBIC coatings is a nanoscopic
surface layer that repels water.
● Shows contact angle > 150° & sliding angle <5°

3. Natural
examples:
1.Lotus leaf
2.Insect wings
3.Prickly pear

5. Materials used:
SUPERHYDROPHOBIC
coatings can be made from
many different materials.
● Manganese oxide polystyrene
nano- composite
● Zinc oxide polystyrene nano-
composite
● Precipitated calcium carbonate
● Carbon nano- tube structures
● Silica nano- coating.

6. Silica based coatings:
● Most cost effective to use.
● Gel based & easily applied either by dipping the object into the gel/
via aerosol spray.
Oxide polystyrene composites:
● More durable than gel based coatings.
● The process of applying this coatings is much more involved & costly.
Carbon nano-tubes:
● Expensive
● Difficult to produce with current technology.

7. Thus, the silica -
based gels
remain the most
economically
viable option at
present.

8. Types of
SUPERHYDROPHOBIC
coatings:
(1) DURABLE
WATER
REPELLENT:
This being used
in fabrics in
order to protect
them from
water.
(2)RAIN
REPELLENT:Thi
s is made for car
windshield for
repelling rain
water during rain
in order to
improve driving
visibility.

10. Coating
techniques:
1. Dipping
2. Spraying
3. Blading
4. Painting
5. Rolling
6. Flow coating.

11. Fabrication of
SUPERHYDROPHOBIC
coatings:
● Chemical etching
● Solution
immersion
● Laser
electrodeposition
● Template
deposition
● Spray coating
etc…,,,,

12. Applications:
1. Anti-adhesion & self cleaning
-self cleaning glasses
- self cleaning textile
2. Anti- biofouling applications
3. Corrosion inhibitions
4. Drag reduction

14. Examples of SUPERHYDROPHOBIC coatings in
Tissue engineering:
● Control protein adsorption
● Cellular interaction
● Bacterial growth
● Platforms for drug delivery devices
● & For diagnostic tools.

15. Thank you!!!!!