40
1.Materials and Preparation. 2.Configuration.Modules.Tr ansport. Fouling Aleksandra Różek Maria Zator MEMBRANE SEPARATION
1.Materials and Preparation.
2.Configuration.Modules.Transport. Fouling
Aleksandra Różek
Maria Zator
MEMBRANE SEPARATION
MATERIALS
MATERIALS
B IO LO G IC A L
P O L Y M E RS
O R G A N IC
G L A S S E S C E R A M IC S
Z E O L IT IC M E T A L L IC
IN O R G A N IC
S Y N T H E T IC
M E M B R A N E S
HO M O PO LYM ER
...AAABBBBBBBBBBBBAAAAAA...
R A N D O M
...AABABBABAABABBABAABBAB...
B L O C K
...AAAAAAAAAAAAAAAAAAAAAA... B B B B B
G R A F T
CO PO LYM ERS
P O L Y M E R S
L IN E A R
B R A N C H E D
C R O S S L IN K E D
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
-H-H22C=CHR C=CHR
• STEREOISOMERISM
IS O T A C T IC
A T A C T IC
S Y N D IO T A C T IC
CHARACTERISTIC OF POLYMERS
• MOLECULAR WEIGHT
nnii
MMii
Histogram demonstrating a possible Histogram demonstrating a possible molecular weight distribution in a polymermolecular weight distribution in a polymer
ii
iii
n n
MnM
ii
iii
w w
MwM
Number average molecular weightNumber average molecular weight
WeightWeight average molecular weight average molecular weight
CHARACTERISTIC OF POLYMERS
• CHAIN INTERACTIONS
type of force kJ/mol covalent ~ 400
ionic ~ 400 hydrogen bonding ~ 40
dipole ~ 20 dispersion ~ 2
Average values of strenght of primary and secondary forces
CHARACTERISTIC OF POLYMERS
• STATE OF THE POLYMERS
glassystate
rubberystate
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
glassystate
rubberystate
Vs
Tg T
Freevolume
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 FLEXIBILITYo THE CHARACTER OF MAIN CHAIN
o THE PRESENCE AND NATURE OF THE SIDE CHAINS OR SIDE GROUP
CHAIN INTERACTION
a
b
c
Tg Tm T
log E
glassystate
rubberystate
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
dd
E
THERMOPLASTIC ELASTOMERS
SOFT BLOCK FLEXIBLE AMORPHOUS LOW Tg
HARD BLOCK RIGIN CRYSTALLINE/GLASSY HIGH 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
S Y M E T R ICA S Y M E T R IC
P O R O U S M E M B R A N E S
N O N P O R O U S M E M B R A N E
M E M B R A N E P O L Y M E R S
DEFINICJA
THIN LAYER SUPPORT
POROUS
C E R A M IC S G LA S S Z E O L ITE
IN O R G A N IC M E M B R A N E S
METAL: ALUMINIUM
TITANIUM
SILICIUM
ZIRCONIUM
NON-METAL: OXIDE
NITRIDE
CARBIDE
γ-Al2O3 , ZrO2 SiO2
PROPERTIES
• TERMAL STABILITY
• CHEMICAL STABILITY
• MECHANICAL STABILITY
AlO4,SiO4
IN O R G A N IC O R G A N IC
M A T E R IA L
• 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
P O R O U S M E M B R A N E S C O M P O S IT E M E M B R A N E S
N O N P O R O U S M E M B R A N E S(D E N S E M E M B R A N E S )
R E IN F O R C E D M E M B R A N E S
D Y N A M IC M E M B R A N E S IO N -E C H A N G E M E M B R A N E S
B IP O L A R M E M B R A N E S IO N M U L T IL A Y E R M E M B R A N E S
R E A C T IV E M E M B R A N E S L IQ U ID M E M B R A N E S
M E M B R AN E S
PREPARATION
S IN T E R IN G
S T R E C H IN G
T R A C K -E T C H IN G
T E M P A L A T E L E A T C H IN G
P H A S E IN V E R S IO N
C O A T IN G
PREPARATION OF SYNTHETIC M EM BRANES
MEMEBRANES PREPARATON
P R E C IP ITA T IO N B YS O L V E N T E V A P O R A T IO N
P R E C IP IT A T IO N F R O MT H E V A P O U R P H A S E
P R E C IP ITA T IO N B YC O N T R O L E D E V A P O R A T IO N
T H E R M A LP R E C IP IT A T IO N
IM M E R S IO NP R E C IP IT A T IO N
PHASE INVERSIO N M EMBRANES
P R E C IP ITA T IO N B YS O L V E N T E V A P O R A T IO N
PHASE INVERSIO N M EMBRANES
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
P R E C IP IT A T IO N F R O MT H E V A P O U R P H A S E
PHASE INVERSIO N M EMBRANES
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
P R E C IP ITA T IO N B YC O N T R O L E D E V A P O R A T IO N
PHASE INVERSIO N M EMBRANES
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
T H E R M A LP R E C IP IT A T IO N
PHASE INVERSIO N M EMBRANES
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
IM M E R S IO NP R E C IP IT A T IO N
PHASE INVERSIO N M EMBRANES
1. POLYMER SOLUTION
IS CAST ON THE SUITABLE
SUPPORT
2. POLYMER SOLUTION
IS IMMERSED IN A
COAGULATION BATH
CONTAINING
NONSOLVENT
F L A T M E M B R A N E S
T A B U L A R M E M B R A N E S
PREPARATION TECHNIQUES FORIM M ERSION PRECIPITATION
IN T E R F A C IA LP O L IM E R IS A T IO N
D IP -C O A T IN G
P L A S M AP O L IM E R IS A T IO N
M O D IF IC A T IO N O F H O M O G E N E O U SD E N S E M E M B R A N E S
PREPARATIO N TECHNIQ UES FORCO M PO SITE M EMBRANES
top layerporous support
(polyester) non- woven
permeate channel
Interfaced polymerisation1.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 polymerisation1.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 homogeneous dense membranes
Modification can drastically change intrinsic
properties of materials ,
Especially when the ionic groups are introduced
