Adsorption

1. Surface chemistry
Adsorption: Physical and Chemical
Adsorption, types of adsorption
isotherms . Langmuir’s adsorption
isotherm (Postulates and derivation
expected).
B.E.T. equation for multilayer
adsorption, (derivation not expected).
Significance of the terms involved in
equation.

2. Determination of surface area of an adsorbent using
B.E.T. equation. Numericals on surface area.
Colloidal state
Origin of charges on colloidal particles,
Concept of electrical double layer, zeta
potential, Helmholtz and Stern model.
Electro-kinetic phenomena -
Electrophoresis, Electro-osmosis, Streaming
potential, Sedimentation potential; Donnan
Membrane Equilibrium.

3. Origin of charges on colloidal particles, Concept
of electrical double layer, zeta potential,
Helmholtz and Stern model.
Electro-kinetic phenomena - Electrophoresis,
Electro-osmosis, Streaming potential,
Sedimentation potential; Donnan Membrane
Equilibrium.
Surfactants: Classification and applications of
surfactants in detergents, food industry,
pesticide formulation.

4. •Physical adsorption
•Chemical adsorption
•Effect of Temperature and Pressure on rate of
adsorption
•Difference between physical and chemical
adsorption
•Adsorption isotherm: Plot of graph of amount
of substance adsorbed Vs the pressure .
•Five different types of adsorption isotherm are
there.

5. Freundlich Adsorption isotherm
x/m=Kp1/n
Langmuir Adsoption isotherm
a=K1p/K2p+1

6. BET adsorption isotherm
p/v(p0-p)=(1/c Vm)+(c-1)p/c Vm p0
Application of BET equation in
determination of surface area
S=p0 Vx N z /R T0
Z=sigma

7. Colloids (size between 1-100nm)
•Dispersed phase
•Dispersion medium
•Suspension(size>100nm)
•True solution(size<1nm)

8. Thank you