Magnetic Nanoparticle SynthesisRachel Jones and Jonathan Duhon

BackgroundCreated by NASA 1963

A colloidal liquid that becomes strongly magnetized in the presence of a magnetic field

Biomedical- used in aqueous formulations for eye surgery

Electronics- used in advanced computer disk drives of high speed to disallow the formation of impurities

Target drug delivery for cancer treatment

Properties of Ferrofluids •Ferrofluids possess the unique property of spiking when exposed to a suitable magnet.

•Must be ~10 nm in diameter so that thermal energy can overcome the magnetic interactions between particles

•Use of surfactant to prevent aggregation

Synthesis2FeCl3+FeCl2+8NH3+4H20-->Fe3O4+8NH4Cl

TMAH is a strong base

Surfactant: dipole moment, the polar oxygen in TMAH (C4H14O)attacks the oxygen in water and they repel, thus the particles remain suspended in the vile

Hypotheses1. Adding too little or too much tetramethylammonium hydroxide might prevent

“spikes” from forming. For further trials, Instead of using 5.9 grams of TMAH, maybe decrease amount of TMAH used each trial

2. Not removing enough excess ammonia may halt formation of “spikes”

3. Removing excess water may improve quality of spike formation

Materials pt. 1- (FeCl3) Ferric Chloride (2 g in 3 mL H2O)

- (FeCl2) Ferrous Chloride (2.3 g in 4 mL H2O)

- Ammonia Hydroxide (60 mL)

- Tetramethylammonium hydroxide (3 g in 3 mL H2O)

- Magnetic stirrer

- Separatory Funnel (250 mL+)

- Hot plate

- Beakers (150 mL)

- Graduated Cylinder (10 mL)

- DI water

- Pipette

- Round bottom Flask (250 mL)

- Pipette

Materials pt. 2Ferric Chloride (FeCl3)

Materials pt. 3Ferrous Chloride (FeCl2)

Materials pt. 4

TMAH - Strong base and good

Surfactant used to

Clumping of nanoparticles

Materials pt. 5Waste beaker full of water and ammonia

Procedure Part 1- Precipitation of Magnetite by Mixing the Iron Salts and Ammonia

1. Set up separatory funnel

2. Fill burette with 60 mL of ammonia

3. Place empty round bottom flask with magnetic stirrer on hotplate

4. Place round bottom flask under burette, turn stirrer about half speed

5. While stirrer is turning, add of ferric chloride solution (black) to flask

6. Add ferrous chloride solution (yellow) to flask

7. While solution is stirring, add the 60 mL of ammonia into the burette and slowly let it drop into the flask (should take 5 minutes)

(color change and precipitate will form)

8. Once all ammonia is added, solution should be black.

Procedure Part 2- Converting Magnetite Nanoparticles into Magnetic Liquid

1. Remove stirring bar from solution with magnet, and rinse stirring bar with DI water

2. Place magnets under beaker with solution to let precipitate form

3. Pour liquid into a waste beaker to keep precipitate at bottom

4. Once you pour liquid into waste beaker, remove magnets and wash particles inside with DI water to remove

ammonia. Swirl solution for 10 seconds

5. Repeat last step about 3 to 4 times

6. Transfer nanoparticles into glass vile and place magnets under it to let nanoparticles settle

7. Add tetramethylamonium hydroxide solution into vile

8. Stir for 1 minute

9. Let nanoparticles settle by placing magnets under vile

Procedure Part 3 - Testing FerroFluid Nanoparticles

Place magnet on side of the sample vile. If the consistency and properties are correct, then the nanoparticles should form spikes due to the magnetic field.

Successful Experimental Data #1

1.)

- 1.5 g of FeCl3 in 14 mL of H2O

- 1.87 g of FeCl2 in 4 mL of H2O

- 50 mL of Ammonia Hydroxide

- 3 g TMAH in 5 mL of H2O

(Trial produced spikes, very magnetic substance. Reduce excess water in further trials.)

Successful Experimental Data #2

2.)

- 2 g FeCl3 in 10 mL of H2O

- 2.2 g of FeCl2 in 3 mL of H2O

- 50 mL of Ammonia Hydroxide

- 2 solutions of 2 g of TMAH in 2 mL of H2O

(Trial produced spikes, extremely magnetic substance. Keep reducing excess water and possibly increase amount of

ammonia hydroxide used in further trials.)

Successful Experimental Data #3

3.)

- 2 g FeCl3 in 5 mL of H2O

- 2 g FeCl2 in 3 mL of H2O

- 60 mL of Ammonia Hydroxide

- 3 g TMAH in 3 mL of H2O

(Increased Ammonia Hydroxide and decreased water seemed to improve spike results. Filtering excess water

improved results as well.)

Future of Ferrofluids?•Expected to advance in the biomedical field as a medication carrier, and in resonance

imaging.

Sources

http://www.innovateus.net/science/what-ferrofluid

http://ferrofluid.today/pages/what-is-ferrofluid

http://education.mrsec.wisc.edu/background/ferrofluid/