Nanotechnology: ferrofluids to liquid crystals  (Page 3/4)

 Page 3 / 4

Part i. synthesis of gold nanoparticles (demo)

Chemicals

1.0 mM ${\text{HAuCl}}_{4}$ (stored in amber bottle)

• 1% trisodium citrate dihydrate solution

Nanoparticle synthesis

• Add 20 mL of 1.0 mM ${\text{HAuCl}}_{4}$ to a 50 mL Erlenmeyer flask on a stirring hot plate. Add a magnetic stir bar and bring the solution to a boil
The TA’s need to be told to add the citrate as soon as the reaction boils or the solution turns colorless.
.
• Add 2 mL of 1% trisodium citrate dihydrate solution and observe the properties.

Chemicals

1 M ${\text{FeCl}}_{3}$ in 2 M HCl Solution:

2 M ${\text{FeCl}}_{2}$ in 2 M HCl Solution

• 25% tetramethylammonium hydroxide in water

1.0 M ${\text{NH}}_{3}$ Solution: Dilute at least 200 mL of concentrated ammonium hydroxide with water to 3.0 L) Open containers of ammonia are odorous and their concentration will decrease over periods of time.

CAUTION: Ferrofluids can be messy. This particular ferrofluid will permanently stain almost all fabrics. Also DO NOT LET THE MAGNETITES TOUCH THE SURFACE OF THE MAGNET DIRECTLY.

Magnetite synthesis

• In a hood, place 4.0 mL of 1M ${\text{FeCl}}_{3}$ and 1.0 mL of 2M ${\text{FeCl}}_{2}$ solution into a 100 mL beaker. Stir on a magnetic stir plate.
• While stirring, slowly add 50 mL of 1.0 M aqueous ${\text{NH}}_{3}$ solution over a 5 minute period using a buret. Initially a brown precipitate will form followed by a black precipitate, which is magnetite.
• CAUTION: Even though 1M NH3 is fairly dilute, ${\text{NH}}_{3}$ is a strong base.
• Remove from stirring and immediately use a strong magnet to work the stir bar up the walls of the beaker. Remove the stir bar with a gloved hand being careful not to let it touch the magnet.
• Allow the magnetite to settle, then decant off the clear liquid into a waste beaker without losing a large amount of precipitate. The settling process can be expedited by placing a strong magnet below the beaker.
• Transfer the solid to a plastic weighing boat. Rinse out the beaker with a wash bottle.
• Use a strong magnet to attract the ferrofluid to the bottom of the weigh boat. Carefully decant as much clear liquid as possible into the waste beaker. Rinse again with water from the wash bottle and decant. Repeat the rinsing process a third time. What are you removing by rinsing?
• Add 1-2 mL of 25% tetramethylammonium hydroxide. Gently stir the solution with a glass stir rod for at least a minute to suspend the solid in the liquid. Use a strong magnet to attract the ferrofluid to the bottom of the weigh boat. Pour off and discard the dark liquid. Move the strong magnet around and again pour off any liquid. If the ferrofluid does not produce spikes, continue to move the strong magnet around, pouring off any liquid.

Ferrrofluid properties

• Hold a magnet underneath the weigh boat that contains the ferrofluid. Move the magnet around the underside of the weigh boat. Move the magnet close to and far from the weigh boat. Record your observations
• Add a couple of drops of ferrofluid to a small piece of clean paper. Let the solution dry. Once it is dry, bring a strong magnet close to the paper. What happens?
• Use several different magnets to observe the properties of the ferrofluid and record your observations in your notebook.

Is there any normative that regulates the use of silver nanoparticles?
what king of growth are you checking .?
Renato
What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
Tarell
what is the actual application of fullerenes nowadays?
Damian
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
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