NANO coatings

1. Preet Kumar
M. Tech 1st Year
Enrollment No.- 14551009
Centre of Nanotechnology

2.  Dip coating refers to the immersing of a substrate
into a tank containing coating material, removing
the piece from the tank, and allowing it to drain. The
coated piece can then be dried by force-drying or
baking. It is a popular way of creating thin film
coated materials along with the spin coating
procedure.

3. The dip coating process can be, generally, separated into 3
stages:
 Immersion: the substrate is immersed in the solution of
the coating material at a constant speed preferably
judder free
 Dwell time: the substrate remains fully immersed and
motionless to allow for the coating material to apply
itself to the substrate
 Withdrawal: the substrate is withdrawn, again at a
constant speed to avoid any judders. The faster the
substrate is withdrawn from the tank the thicker the
coating material that will be applied to the board.

5. Fig. 2: Gelation process during dip coating process,
obtained by evaporation of the solvent and subsequent
destabilization of the sol

6.  Owing to its simplicity, this method lends itself to
automation. Film thickness is controlled by coating
viscosity and rate of withdrawal from the tank. Dip
tanks come in all shapes and are sized to accommodate
the largest object to be coated.
 Dip coating has its drawbacks, including: light parts
tend to float and fall from the conveyor; film thickness
can vary from top to bottom ("wedge effect"); fatty
edges develop on the bottom of parts as excess coating
drains; and refluxing by the solvent vapors above the
tank removes some of the coating

7.  Dip coating processes are used for plate glass for
solar energy control systems (Calorex®) and anti-
reflective coatings (Amiran®) on windows. The dip
coating technique is also applied for optical
coatings, e.g. on bulbs, for optical filters or
dielectric mirrors by various SMEs and other
companies, fabricating multilayer systems with up
to 30 or 40 coatings with very high precision.

8.  What is Electro deposition?
 Electro deposition is the process of coating
a thin layer of one metal on top of a
different metal to modify its surface
properties.
Done to achieve the desired electrical and
corrosion resistance, reduce wear &
friction, improve heat tolerance and for
decoration.
 E.D. is a surface coating method that forms
an adherent layer of one metal on another.

10.  Electrodeposition is a key method for making the
materials used in computer chips and magnetic data
storage systems; every day it helps lower the cost
and improve the performance of our information
society.
 However, electrodeposition is also emerging as a
uniquely capable method for making materials and
structures needed for a nanotechnology- and
nanobiotechnology based future.
 It also provides some unique opportunities for
directly writing materials onto a surface without
going through the photoresist masking steps that are
used in conventional electrochemical
microfabrication.

11. Electrodeposition has three main attributes that make it
so well suited for nano-, bio- and
microtechnologies:
• It can be used to grow functional material through
complex 3D masks.
• It can be performed near room temperature from
water-based electrolytes.
• It can be scaled down to the deposition of a few
atoms or up to large dimensions.

12.  Automotive parts
 Printed circuitry and electrical contacts
 General engineering components
 Gold-Silver wares and Jewelry
 Musical Instruments and
 Trophies Soft metal gaskets
 Anti-seize bearings
 Decorative door, light & bathroom
fittings
 Production of micro parts for MEMS
(MicroElectroMechanical systems)