1. Formation of Aluminum Nanoshells Using PEO 2012
Fibers on Quartz and Oxidized Silicate
González Pablo, Astrid Díaz
RISE, UPR Cayey
Abstract
Nanotechnology is a type of science that studies objects that are from 1 nanometer to a 100
nanometers. It is in charge of analyzing and experimenting with objects that are practically
invisible. To do this they use special tools such as electron microscopes, which can magnify
objects more than 100,000X its size. In the experiment performed, electrospining and sputtering
techniques were used to create aluminum oxide nanoshells. To accomplish this, PEO fibers were
created to serve as the mold for the shells. After all the processes were completed, the results
were the aluminum oxide nanoshells. This proved to be somewhat of a step forward because now
they could be used in future projects to create any sort of innovation. The shells could be used to
make chemical sensors, biochips, or many other inventions. The future of faster, smaller, and
more efficient technology might just be in this field of science.
Introduction
Not so long ago a new field of science started to emerge, namednanotechnology. It is the science
that dealswith phenomena in the range of nano (10-6). Things that are so diminutive, the human
eye can not perceive them on its own. The field of Nanotechnology is in charge of observing,
analyzing, and experimenting with such objects in the scale of nano (one billionth of a meter),
which is the size of atoms and DNA (Lakhtakia, 2010). The idea of manipulating atoms was first
expressed by Dr. Richard Feynman in 1959, but the creation of this field of science was a
contribution of many different scientists. During this time, the idea could not be practiced
because scientists were lacking the necessary tools. An essential tool would be an electron
microscope, which can be a transmission electron microscope, or a scanning electron
microscope. Both of these microscopes help to observe all the things that are in the nano scale
because electrons do not have wavelengths contrary to visible light.
In the experiment the objective was to prepare aluminum nanoshells using PEO fibers on
quartz and oxidized silicate substrates. To create the shells, electrospinning technique was used
along with the sputtering technique. The first one consists in creating fibers by applying a high
voltage charge to a solution, this breaks the surface tension of the liquid turning it into a fine jet.
When the jet travels towards the substrate, the liquid evaporates, leaving the solid nanofiber to be
collected (Chronakis, 2003). The second one utilizes a machine that coats the previously created
fibers with aluminum, creating something that is very close to being a nanoshell. Nanoshells are,
like the word implies, shells created by using a fiber as a mold. These shells can have many uses;
one of them is to work as chemical sensors. These are objects that depending on what they are
made of can detect different substances that come in contact with them (Nahar, 2000).

2. Materials and Methods
The objective of the experiment was to create aluminum oxide nanoshells using PEO fibers as a
mold, and oxidized silicate and quartz, as substrates. The first step was to make a solution of
polyethylene oxide (PEO), ethanol, and water. Using a balance, 0.5 grams of PEO were
measured. Later, it was diluted with 80% of ethanol and 20% of water. After this, a mixing
pellet was incorporated to start blending the contents. The time of mixing was not supposed to be
exact but it needed to become thick and viscous. The solution was left mixing, until it reached
the desired state, this took around six hours. Then, 0.5ml of the solution were added to the
syringe that was going to be used in the electrospinning machine. The voltage at which the
electrospinning machine was set was 20 kilowatts. The two substrates, oxidized silicate and
quartz, were placed in the stationary collector screen, andthe machine was turned on and left
running for 1 hour, until all the liquid was ejected. Afterwards, the fibers were collected and
observed through the scanning electron microscope (SEM). Some images were taken to show the
fibers on both substrates. Later, the fibers in the substrates were left in a Magnetron Sputtering
Deposition (MSD) machine so they could become coated with aluminum. The time of deposition
was 14 minutes with 39 seconds. After that, the substrates containing the fibers were heated in an
oven at 500°C for 2 hours so that the PEO fibers would evaporate and hollow aluminum oxide
shells were the only thing left. Since the oven did not contain a vacuum, oxygen was present and
the aluminum oxidized. Finallythey were observed under the SEM and some images were taken.
Results
The first results were the formation of the PEO fibers on the substrates. Images taken with a
SEM are shown in Figure 1 and 2. From the results of the rest of the procedure, we could
determine that aluminum nanoshells can be created, using the electrospinning and sputtering
techniques. These findings demonstrated progress because it was not certain that nanoshells
could be created with aluminum oxide.The nanoshells were successfully made with the
aluminum oxide. We discovered this because we used the SEM to see and take images of the
substrates. On both substrates the aluminum shells were seen. In Figure 3 we can see the
aluminum shells on quartz. Figure 4 shows the aluminum shells on the oxidized silicate.
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3. Figure 1. Shows the PEO fibers on oxidized Figure 2 Shows PEO fibers on quartz.
silicate.
Figure 3 Shows Aluminum shells on Figure 4 Shows Aluminum shells on
Quartz Oxidized Silicate
Discussion
The purpose of trying to form the shells was to see if indeed they could be created. Dr. Otaño
and other research students can now use the shells, in future experiments. It is because of these
and many more experiments that science keeps going forward, even if it is little by little, it never
stops moving ahead. Scientists working in this field have created many innovations that have
helped greatly in the improvement of technology. Some examples are carbon fibers,
microprocessors, nanoshells, and many more. All of these have caused an impact on today’s
technology weather by making electronics smaller, or improving human health (Panda).
Nanotechnology is a great field in science that needs more research students that are willing to
participate and understand all the great things that can come out of it.
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4. Acknowledgements
This experience proved to be truly enriching because of all the many new things that we learned.
This is why we would like to thank the RISE program for giving us the opportunity, and Dr.
Wilfredo Otaño for mentoring us and letting us participate in his area of expertise. Also, we
would like to thank Dr. Nelson Granda for helping us whenever he was available, and the lab
students, Bryan Vellez and Sheydanis Díaz for their help with all the processes during the
project.
References
• Chronakis I., Frenot A. Polymer nanofibers assembled by electrospinning. April 8, 2003.
http://www.sciencedirect.com/science/article/pii/S1359029403000049
• Lakhtakia A., Barllet R.V., Murphy P., Munshi D. Nanotechnology, Society, and
Environment. Comprehensive Nanoscience and Technology.2010. Volume 5. Pages 443-
476. http://www.sciencedirect.com/science/article/pii/B9780123743961001458
• Nahar R.K.Study of the performance degradation of thin film aluminum oxide sensor at
high humidity.Sensors and Actuators B: Chemical.2000 Vol.63 Issue 1-2. Pages 49-54.
http://www.sciencedirect.com/science/article/pii/S0925400599005110
• Panda J., Parveen S., Sahoo.The present and future of nanotechnology in human health
care. Nanomedicine: Nanotechnology, Biology, and Medicine.2007 Vol.3 Issue 1 Page
30-31. http://www.sciencedirect.com/science/article/pii/S154996340600342X
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