Objectives

• The goal of this project is to develop a way in which the density of the Ferrite and Alginate in gel beads remains consistent.

• To magnetize the beads uniformly using Ferrite, so that when in space one could create a magnetic field holding the beads in place without losing beads due to lack of Ferrite.

• To decrease the amount of beads per batch that do not have sufficient density, thus developing a more functional gel bead yield .

Background

• The beads were placed in Calcium Chloride because it cross links with the Alginate (Sodium) and allows the beads to harden.

• As the Ferrite/Alginate solution decreased the beads began to appear with a marbled effect due to the lack of Ferrite.

Procedure

1 Place the Alginate solution under the mixer until dissolved. Repeat procedure for Ferrite/Alginate, Gellan/Alginate/Ferrite, and Calcium Chloride solutions.

2 Run 300 ml of Alginate solution though the bead machine into a beaker filled with Calcium Chloride. Change the beaker every twenty minutes. Repeat with the Ferrite/Alginate and Gellan/Alginate/Ferrite solutions

3 Place 30 beads from each increment of twenty minutes in separate containers and measure diameter and density.

Solutions 1.75 weight percent

Alginate Solution 17.509g Algenic Acid

902.141g dH2O

20 weight percent Ferrite Solution

118.5g Ferrite

475g 1.75 weight percent Alginate Solution

0.15 weight percent Gellan Gum 1.75 weight percent

Alginate solutions .75g Gellan Gum

8.75g Sodium Alginate

490.5g dH2O

123.658g Ferrite -add after Alginate

.1 molar Calcium Chloride Solution

14.729g Calcium Chloride (Cacl2)

985.271g dH2O

Density Calculations

Formulas

• V = 4/3πr3• N

• wb = weight of the picnometer

• w1 = wb + 25 ml of CaCl2

• w2 = wb - (25 - Vbeads) • ρCaCl2 + Vbeads • ρbeads

Density Calculations

Beads: (w2 • wb - (25 - Vbeads) • ρCaCl2)/ Vbeads

CaCl2: (w1- wb)/(25 ml)

Why We Used Gellan Gum

We chose to add Gellan Gum to the Alginate Ferrite mixture because we hoped that it would place a yield stress on the solution and allow the Ferrite and Alginate to remain a homogenous solution for a longer period of time. This would prevent the separation and filtration of the Ferrite from the Alginate and would allow one to receive a more uniform density.

Conclusion

• We have concluded that the addition of Gellan Gum to the Ferrite/Alginate solution, causes the density of the gel beads to become more consistent.

• There were several possible margins of error. – The diameter measurements were not precise when measured on

an overhead and volume measurements may have not been exact.

– The calculations were rounded.

– The beads are not completely sphere shaped.

– The beads may have shrunk as the days progressed.