W. Richard Bowen and Nidal Hilal 4

4.7 THE UsE OF AFM IN MEMbRANE dEvELOPMENT 125
CH 3
O C O S
CH3
PSU
O O C
SO 3H
SPEEK
FIgURE 4.19 Structures of polysulphone and sulphonated poly (ether ether) ketone.
Jw / ms –1
1.2e−4
1.0e−4
8.0e−5
6.0e−5
4.0e−5
2.0e−5
P-O
P-P
S0.5-20
S2-20
S5-20
ΔP / kN m –2
0.0e+0
0 100 200 300 400 500 600
FIgURE 4.20 Water flux as a function of applied pressure for five membranes of various
percentages of SPEEK. P-O and P-P: 0%; S0.5-20: 0.5%; S2-20: 2.0%; S5-20: 5%.
The adhesion of a range of colloid probes, both inorganic and biological,
is greatly reduced at the PSU/SPEEK membranes, as shown by the
data in Table 4.5.
Such low adhesion forces show that the membranes are well suited to
many types of separation. The removal of humic acid has been investigated
as an example of a challenging separation. The blend membranes
O
O
O
n
n