W. Richard Bowen and Nidal Hilal 4

160 5. AFM AND DEvELOPMENT OF (BIO)FOULINg-REsIsTANT MEMBRANEs
Adhesion force (mN m –1 )
7
6
5
4
3
2
1
0
40 60 80 100 120 140
Loading force (mN m –1 )
1 mM NaCl
10 mM NaCl
100 mM NaCl
fIgurE 5.16 Relationship of adhesion and loading forces between BSA probe and
PVDF membrane modified with qDMAEMA (DM � 530 �g cm �2 ) in different ionic strength
solutions at pH � 5.8.
Adhesion force (mN m –1 )
12
10
8
6
4
2
0
1 2 3 4 5 6 7 8 9
pH
Initial PES
Modified PES DM = 202 μg cm –2
Modified PES DM = 367 μg cm –2
Modified PES DM = 510 μg cm –2
fIgurE 5.17 Comparison of adhesion forces of BSA-modified probe to initial and
modified with qDMAEMA membranes in various pH solutions.