1.Materials and Preparation.2.Configuration.Modules.Transport.Fouling
Aleksandra Różek
Maria Zator
MEMBRANE SEPARATION
MATERIALS
MATERIALS
STRUCTURE OF POLYMERSSTRUCTURE OF POLYMERS
CHARACTERISTIC OF POLYMERS
•STEREOISOMERISM
•MOLECULAR WEIGHT
•CHAIN INTERACTIONS
•STATE OF THE POLYMERS
•EFECT OF POLIMERIC STRUCTURE ON Tg
•THERMAL AND CHEMICAL STABILITY
•MECHANICAL PROPERTIES
CHARACTERISTIC OF POLYMERS
-H2C=CHR-H2C=CHR
•STEREOISOMERISM
CHARACTERISTIC OF POLYMERS
•MOLECULAR WEIGHT
nini
MiMi
Histogram demonstrating a possibleHistogram demonstrating a possible
molecular weight distribution in a polymermolecular weight distribution in a polymer
Number average molecular weightNumber average molecular weight
Weight average molecular weightWeight average molecular weight
CHARACTERISTIC OF POLYMERS
•CHAIN INTERACTIONS
Average values of strenght of primary and secondary forces
CHARACTERISTIC OF POLYMERS
•STATE OF THE POLYMERS
glassy
state
rubbery
state
Log E
Tg
T
Tensile modulus E as a function
of the temperature for an amorphous polymer
TENSILS MODULUS E
THE FORCE APPLIED
ACROSS AN AREA A
NECESSARY TO OBTAIN
A GIVEN DEFORMATION
E [N/m2]
THE GLASS TRANSITION
TEMPERATURE Tg
THE TEMPERATURE
AT WHICH TRANSITION
FROM THE GLASSY TO
THE RUBBERY STATE OCCURS
CHARACTERISTIC OF POLYMERS
•STATE OF THE POLYMERS
glassy
state
rubbery
state
Vs
Tg
T
Free
volume
Specific volume and free
volume as a function of temperature
FREE VOLUME
THE VOLUME
UNOCCUPIED
BY THE
MACROMOLECULES
Free
volume
CHARACTERISTIC OF POLYMERS
•EFECT OF POLIMERIC STRUCTURE ON Tg
CHAIN FLEXIBILITY
oTHE CHARACTER OF MAIN CHAIN
oTHE PRESENCE AND NATURE OF THE SIDE CHAINS OR SIDE GROUP
CHAIN INTERACTION
a
b
c
Tg
Tm
T
log E
glassy
state
rubbery
state
Tensile modulus of a semi-crystalline
polymers as a function of temperature
CHARACTERISTIC OF POLYMERS
THERMAL AND CHEMICAL STABILITY
FACTORS WHICH LEAD TO INCREASE TERMAL
STABILITY ALSO INCREASE THE CHEMICAL STABILITY
THOSE THAT INCREASE Tg AND Tm
THOSE THAT INCREASE THE CRYSTALLINITY
CHARACTERISTIC OF POLYMERS
•MECHANICAL PROPERTIES
STR: 44 I 45
THERMOPLASTIC ELASTOMERS
SOFT BLOCK FLEXIBLE AMORPHOUS LOW Tg
HARD BLOCK RIGIN CRYSTALLINE/GLASSYHIGH Tg
SCHEMATIC DRAWING OF SO-CALLED-(AB) n-BLOCK COPOLYMER
POLYELECTROLYTES
COUNTER
ION
FIXED
ION
-CH2-CH-CH2-CH-
R+A-
R+A-
-CH2-CH-CH2-CH-
R-A+
R-A+
POLYMERIC
SUPPORT
R= -NR3+
R= -SO3-
-COO-
CATION-EXCHANGE
ANION-EXCHANGE
MEMBRANE POLYMERS
DEFINICJA
METAL: ALUMINIUM
TITANIUM
SILICIUM
ZIRCONIUM
NON-METAL: OXIDE
NITRIDE
CARBIDE
γ-Al2O3 , ZrO2
SiO2
PROPERTIES
• TERMAL STABILITY
• CHEMICAL STABILITY
• MECHANICAL STABILITY
AlO4,SiO4
• Mainly made of metal oxides
(ceramics)such a silica, alumina
or oxides of Titanium, Zirconium
or Magnesium
• As well in glass, carbon or metal
• Expensive (5 to 10 times)
• High chemical resistance
• Withstand high temperatures
• Low selectivity
• Fragile
• Made of polymers or polymer blends
• Low cost
• Problems with their mechanical,
chemical resistance
Temperature
pH, Solvents
Pressure
BIOLOGICAL MEMBRANES
STRUCTURE OF MEMBRANES
PREPARATION
MEMEBRANES PREPARATON
1.THE POLYMER IS DISSOLVED IN A SOLVENT
2.THE POLYMER SOLUTION IS CAST ON A SUITABLE SUPPORT
(POROUS OR NONPOROUS)
3.SOLVENT IS ALLOWED TO EVAPORATE IN AN INTER ATMOSPHERE
4. ALLOWING THE DENSE MEMBRANES TO BE OBTINED
1. A CAST FILM (POLYMER AND SOLVENT) IS PLACED IN
A VAPOUR ATMOSPHERE OF A NONSOLVENT
SATURATED IN THE SAME SOLVENT
3.NONSOLVENT START PENETRATE THE CAST FILM
4.THE CAST FILM IS ALLOWED TO EVAPORATE
2. THE HIGH SOLVENT CONCENTRATION IN THE VAPOUR
PHASE PREVENTS THE EVAPORATION OF SOLVENT
FROM THE CAST FILM
1.THE POLYMER IS DISSOLVED IN A MIXTURE
OF SOLVENT AND NONSOLVENT
2.SINCE THE SOLVENT IS MORE VOLATILE THAN
NONSOLVENT,THE COMPOSITION SHIFTS DURING
EVAPORATION TO HIGHER
NONSOLVENT AND POLYMER CONTENT
1.A SOLUTION OF POLYMER INA MIXED OR SINGLE SOLVENT
IS COOLED TO ENABLE PHASE SEPARATION TO OCCURE
2. THE SOLVENT EVAPORATE FROM MEMBRANE
AND POROUS OCCUR
1. POLYMER SOLUTION
IS CAST ON THE SUITABLE
SUPPORT
2. POLYMER SOLUTION
IS IMMERSED IN A
COAGULATION BATH
CONTAINING
NONSOLVENT
top layer
poroussupport
(polyester)non- woven
permeatechannel
Interfaced polymerisation
1.Polymerisation reaction occurs between two very reactive monomers
at the interface of two immiscible solvents
2.The support layer is immersed in an aqueous solution
containing a reactive monomer
3.Then film is immersed in the second bath containing a water-immiscible solvent
In which another reactive monomer has been dissolved
4.The two reactive monomers , react with each other
to form a dense polymeric toplayer
Dip-coating
1. An asymmetric membrane , is immersed in the coating solution,
Containing the polymer and monomer
2.The concentration of the solute in the solution being low
3.When the asymmetric membrane is removed from the bath
containing the coating material and the solvent , a thin layer
of solution adheres to it
4.The film is then put in an oven ,where the solvent evaporates
and where crosslinking also occurs
Plasma polymerisation
1.The plasma being obtained by the ionisation of a gas by means
of an electrical discharge at high frequencies up to 10 MHz
2.On entering the reactor the gas is ionised
3.The reactants are supplied separately to the reactor
4.All kinds of radicals will be formed through colisions with
the ionised gas , which are capable of reeacting with each other
5.the resulting products will precipitate when
their molecular weight becomes to high
Modification of homogeneousdense membranes
Modification can drastically change intrinsic
properties of materials ,
Especially when the ionic groups are introduced