2.1 Introduction
27
inserts new functional groups onto the cross-linked chitosan surface becomes very
essential. Hence, the cross-linked beads were then grafted with 4-aminobenzoic acid
as indicated in Fig. 2.2. The inserted functionality, however, increases the number
of adsorption active sites and consequently the adsorption capacity. Hence in this
study, three sets of chitosan beads were developed, and they are pure chitosan (CS),
cross-linked chitosan (CR-CS), and grafted-cross-linked chitosan (G/CR-CS). This
modified chitosan was characterization by FTIR, SEM, XRD, BET and TGA to
provide evidence of successful modification process. Applicability of the graftedcross-linked chitosan (G/CR-CS) in determining the effectiveness of the produced
G/CR-CS then follows.
O
HO
OH
O
NH2
O
O
O
HO
OH
O
NH 2
CH2
HO
HO
O
N
CH
OH
H2
HO
HO
O
O
HO
NH2
OH
O
NH 2
O
O
CH 2
O
HO
OH
O
CH2
NH2
CH
CH 2
OH
COOH
NH2
+
O
HO
OH
O
O
O
O
HO
OH
O
NH 2
CH 2
HO
HO
O
N
CH
OH
H2
HO
HO
O
O
HO
NH 2
OH
O
NH 2
O
O
CH 2
O
HO
OH
O
CH 2
CH
CH 2
OH
NH
NH
COO
NH
COO
NH
MICROWAVE GRAFTING
n
n
Fig. 2.2 Projected structure of the grafting technique of cross-linked chitosan beads