Materials and Methods Note: All water is deionized and distilled

QUESTION: How does our scaffold behave at different pHs?

1) Prepare 20 ml vials of sodium hydroxide and hydrochloric acid

2) Prepare six 20 ml vials of water

3) Test our sample with pH probe—4.05 acidic

4) Distribute 200 ml of colloidal scaffold equally into the 6 bottles filled with water to make solution of colloidal scaffold and water

5) Add sodium hydroxide or hydrochloric acid to each to change the pHs

The following table shows each bottle and its pH:

 

 

 

 

 

 

 

 

 

6) Using dynamic light scattering, measure the size of the particles

Pinhole diameter: 400 μm

Filter: 636 nm

Angle: 90°

1. Surfactant + monomer and free radical initiator are added

The making of the magnetic nanoparticle

First Step: Synthesis of the polymeric scaffold

Mini Magnetic Muck Managers

The development of magnetic nanoparticles for the removal of pharmaceutical contaminants in drinking water

2. Polymers are formed

3. Colloidal scaffold is created

Studying the Properties of the colloidal scaffold

EMULSION POLYMERIZATION METHOD

 

 

 

 

 

 

 

 

 

Recipe for surfactant + monomer (in 30-ml burette)

1.3 g methacrylic acid

1.5 g ethyl acrylate

0.056g di-allyl phthalate (DAP—for cross linking polymers)

6.0 ml water (deionized and distilled)

3.0 g of 75% solution Aerosol OT surfactant (dioctyl sulfosuccinate)

Shake mixture

 

Recipe for free radical initiators

0.05 g sodium persulfate

0.015 g sodium bicarbonate

5.0 g water (deionized and distilled)

 

Recipe for Initial Catalyst solution

0.1 g sodium persulfate

4.0 g water (deionized and distilled)

 

Reaction Vessel Initial Mixture

28.0 g water

0.03 g of 75% solution of Aerosol OT surfactant

Mix in a 500ml 3-necked flask (reaction vessel).

 

PROCEDURE

1) Nitrogen purge put in (to clear oxygen), reaction vessel heated to 80°C for 30 minutes.

2) 10 wt% of monomer mixture (1.2 g) added.

3) Catalyst solution was added to the reactor to initiate the reaction.

4) After 30 minutes of in situ seed production, the remaining monomer and initiator feed mixtures are mixed in the burette and conveyed to the reaction vessel  a few drops at a time over an hour.

5) 5 minutes before the completion of addition of the monomer feed, 1.0 g of poly(ethylene glycol) methacrylate (PEGMA-a stabilizer) was added to the monomer feed burette.

6) Colloidal scaffold formed

7) Use static light scattering to verify geometric shape of the particles (we are aiming for a spherical shape as that will capture pharmaceutical contaminants most effectively)

Pinhole diameter: 1 μm

CO-PRECIPITATION METHOD

Recipe for iron oxide solution

0.25 g FeSO₄

10 ml water

Mix with Brainsonic (uses sound waves to dissolve solute)

 

Recipe for polymer solution

12 ml colloidal scaffold solution (0.5 wt% of colloidal scaffold)

2 ml water (to wash container)

 

In titration device:

1) Add polymer solution and water

2) Add NaOH (a few drops at a time) to increase the pH from 4.1 to 6.5 (we need a small polymer so iron oxide does not escape)

3) Put in nitrogen purge (to clear oxygen so it does not react with iron)

4) When pH has reached 6.5, turn on water bed to heat flask to 35°C

5) Wait 30 minutes. Meanwhile, prepare oxidizing agent

 

Recipe for oxidizing agent

0.025 g NaNO₂

1.5 ml NH₄OH

6)          Add oxidizing agent and mix till mixture turns black

Step 2: Magnetize the nanoparticle

QUESTION: How does our particle behave at different pHs?

1) Prepare 20 ml vials of sodium hydroxide and hydrochloric acid

2) Prepare four 18 ml vials of water

3) Test our sample with pH probe—9.2 alkaline

4) Put 1 ml of the magnetic nanoparticle sample each into the 4 bottles filled with water to make a more diluted solution (if the concentration of the nanoparticle sample is too high, it will scatter too much light and skew the results). Disperse by shaking

5) Add sodium hydroxide or hydrochloric acid to each to change the pHs

The following table shows each bottle and its pH:

 

 

 

 

 

 

6) Filter the sample (to get rid of dust and big particles that will skew the results) using VWR Nylon Syringe Filters.

             a)          Fill syringe with water

             b)          Put filter on

             c)          Wash

             d)          Remove filter

             e)          Put air in and flush out any water

             f)          Draw out solution from vial

             g)          Put filter on

             h)          Flush off initial solution

             i)           Fill test tube until about half full

             j)           Leave some solution in syringe

             k)          Cap and label test tube

7)          Using dynamic light scattering, measure the size of the particles

Pinhole diameter: 400 μm

Filter: 636 nm

Angle: 90°

Studying the Properties of the Magnetic Nanoparticle

First solution

0.6 g α-cyclodextrin

5 ml water

 

Second solution

0.0657 g NaOH

0.2 ml water

 

Third solution

0.1008 g p-toluenesulfonyl chloride

0.3 ml acetonitrile

 

1) Second and third solutions are added dropwise to the first solution.

2) Solution is stirred for 2h at 23°C to form a white precipitate.

3) Precipitate removed by suction filtration.

4) Filtrate is refrigerated overnight at 4°C.

 

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Making of β–cyclodextrin