Sodium alginate and calcium chloride were used to immobilize MnO2 catalyst particles in alginate beads. MnO2-loaded beads were prepared using 3% sodium alginate and 2% calcium chloride solutions and tested in the decomposition of hydrogen peroxide over 4 days. The rate of reaction and efficiency decreased slightly each day, from an initial rate of 0.1976 kPas-1 and 100% efficiency on day 1 to 0.1528 kPas-1 and 77% efficiency on day 4, demonstrating the durability of the immobilized MnO2 catalyst beads over multiple reuse cycles.

1. Effect of duration on efficiency of immobilized MnO2 in alginate beads (3%SA with 2%CC)
Sodium alginate reacts with calcium chloride to form calcium alginate
These beads can be used to immobilise enzymes so it can be recycle/reuse
Encapsulation of drugs/enzymes can be done using alginate beads.
1, 2, 3% (w/v) sodium alginate and 1, 2, 3% (w/v) calcium chloride investigated.
Sodium alginate + calcium chloride
forming alginate beads.
Procedure:
Weigh 3g of sodium alginate (SA) in 100ml water - 3% SA.
Weigh 2g calcium chloride (CC) in 100ml water – 2% CC.
0.034g MnO2 powder mixed with 3ml of 3% SA.
Pipette 1ml 3% SA/MnO2 and drop it into 2%CC, making 12 beads in total.
12 beads added into 5ml H2O2.
Rate of rxn – measured by change of pressure over 20s. (Day 1).
Keep the beads in fridge and use them for Day 2 to Day 4
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1, 2, 3% (w/v) calcium chloride
1% and 2% (w/v) sodium alginate
12 beads of same size taken out Beads added to 5ml H2O2, bubbles were seen
3% SA with 0.034g MnO2 + 2% CC
Pipette tip used to form the beads

2. 3% SA and 2%CC will be used to immobilized catalyst MnO2 as the catalyst can be reused/recycle
instead of throwing it away after rxn with H2O2
Day 1. MnO2 beads with H2O2
Rate = slope = 0.1976 kPas-1
1% SA + 1% CC with MnO2 2% SA + 2% CC with MnO2 3% SA + 2% CC with MnO2
Day 2. MnO2 beads with H2O2
Rate = slope = 0.1760 kPas-1
Day Rate Efficiency
1 0.1976 100%
2 0.1760 89%
3 0.1531 78%
4 0.1528 77%
MnO2 beads placed in H2O2
pressure is measured
After 4 days, still has 77% efficiency in rate
Effect of duration on efficiency of immobilized MnO2 in alginate beads (3%SA with 2%CC)
Day 3. MnO2 beads with H2O2
Rate = slope = 0.1531 kPas-1
Day 4. MnO2 beads with H2O2
Rate = slope = 0.1528 kPas-1
0
50
100
150
0 1 2 3 4 5
Efficiency
Duration/day
Duration/day vs Efficiency