User:Karlena L. Brown/Notebook/PVOH Research/2013/02/01

OBJECTIVES

• Continue preparing polyvinyl alcohol hydrogels for experimental analysis
• Prepare and replenish new surfactant exchanged clays

PVOH 130K Prepared Samples

Preparations For Clay - Surfactant Exchanged Soils

(Important Information and Notes About Clay)

1. Clay is made from silicon dioxide
2. If ions within the clay are changed, then clay absorbance, color, and exchange functions are affected

(Such ions incldue: Al³⁺, Mg²⁺, Si²⁺, Li⁺, and Fe^{2+ or 3+},)

• In a 100mL closed cap beaker, weigh out ~ 2 grams of NaMT clay to do a 110% ion exchange with DMHXLBR

• Next, complete calculations to determine how much DMHXLBR will be needed to complete 110% exchange

  1.9999 g NaMT x (92 meqv/100 g NaMT) x (1 mol DMHXLBR/1000 meqv) x (110/100)% x (431.45 g DMHXLBR/1 mol DMHXLBR) = 0.8732 g DMHXLBR

• Then add a stir bar along with ~ 25mL of both H₂O and ethanol to the clay and surfactant DMHXLBR mixture
• Afterwards, cap the beaker and begin stirring the solution on a stir plate for ~ 1 week

(Repeat the entire process again in order to complete a 110% exchange with laponite clay and surfactant DMHXLBR)

• Complete calculations to determine how much Bu₃HdP⁺ will be needed to complete 50% exchange

  2.9672 g NaMT x (55 meqv/100 g NaMT) x (1 mol DMHXLBR/1000 meqv) x (110/100)% x (431.45 g DMHXLBR/1 mol DMHXLBR) = 0.7745 g DMHXLBR

(Repeat the entire process again in order to complete a 50% exchange with NaMT clay and surfactant, Bu₃HdP⁺)

• Complete calculations to determine how much Bu₃HdP⁺ will be needed to complete 50% exchange

  2.0001 g NaMT x (92 meqv/100 g NaMT) x (1 mol Bu3HdP+/1000 meqv) x (50/100)% x (507.65 g Bu3HdP+/1 mol Bu3HdP+) = 0.4671 g Bu3HdP+

Notes

• Two types of clay that were used included:

    # Laponite
    # Sodium Montmorrillonite (NaMT)

• Two types of surfactants that were used included:

    # Tributyl hexadecyl phosphonium bromide (Bu3HdP+)
    # Methyl 16 bromohexadecanoate (DMHXLBR)

• Surfactant exchanged clays were prepared based upon the exchange ratios and calculations.
• For the 110% CEC Laponite w/ DMHXLBR actually 50mL of each of both ethanol and water was used.
• For the 110% CEC NaMT w/ DMHXLBR actually 50mL of each of both ethanol and water was used.
• For the 50:50 110% CEC Laponite in PVOH 130K solution when making hydrogels, an extra 3mL of H₂O was added; therefore, the dye amount added had to be increased, ~ 54.5μL of 165μM added.
• For the 50:50 110% CEC NaMT in PVOH 130K solution when making hydrogels, an extra 2mL of H₂O was added; therefore, the dye amount added had to be increased, ~ 48.5μL of 165μM added.
• For the 90:10 110% CEC NaMT in PVOH 130K solution when making hydrogels, an extra 2mL of H₂O was added; therefore, the dye amount added had to be increased, ~ 87.0μL of 92μM added.

Notes