Nanomaterials understand a subject that has revolutionized the

Nanomaterials and their
impact on modern society was an entirely foreign subject as I began research on
a relevant contemporary issue. Similarly, my experience in material science was
extremely limited prior to this fundamental engineering course. Just as I have
been challenged throughout this course, I sought out a subject that would
expand my knowledge into relevant engineering.  My goal was to research and understand a subject
that has revolutionized the way our society studies, designs, and builds useful
products and materials to improve on existing technology and subsequently enhance
our quality of life. Many different subjects in nanotechnology undeniably fall
within this constraint. However, with much focus on carbon in our material
science curriculum and the role that it plays in our metals and other materials
I began by learning of carbon nanotubes and their various applications. Although
improving on our understanding of carbon nanotubes continues, this material and
its useful applications has been well documented and implemented into our
society in areas of medicine, the environment, and electronics, among others. Pushing
further I came across boron nitride nanotubes (BNNTs), which ultimately became
the focus of my attention and will be discussed in this paper, many times in
comparison to the similar carbon nanotubes. I am a firm believer that passion
should guide one’s decisions, small or large. Boron nitride nanotubes became a
natural area of research for me because their potential applications coincide
with my areas of great interest in engineering. Contemporary issues to be
investigated involving BNNTS are applications in aviation, medical and biomedical,
and hydrogen storage.

 

            The recent societal craze around space travel, rocket
propulsion, and the improvement in aviation logically paired with my research
into BNNTs. The transition of space travel and accelerated Earth travel from government
to the private sector has been accelerated by companies such as SpaceX, Blue
Origin, and Boeing in recent years. This presents much work for current and
future engineers in a field that became somewhat stagnant as government funding
and public interest declined following the successful Apollo missions. Naturally,
material science and the development of technology to withstand the harsh
environment of such endeavors is critical to its success. Recent research has
shown BNNTs are likely to play a role in future materials that can withstand
high heat, strength, and radiation resistance. Boron nitride nanotubes are known
to have the same nanostructure as carbon nanotubes, but with superior
properties 1. Currently the synthesis of BNNTs is difficult and expensive and
therefore lacks the practical application that currently exists for carbon
nanotubes. However, twenty years ago carbon nanotubes were similarly expensive
and restricted primarily to research rather than application. The evolution of previous
technology displays that synthesis of materials inevitably becomes cheaper and
more practical. For this reason, the current practicality will be ignored and
the potential advantages will be analyzed. Composite materials that are light,
strong, and durable have been a center focus in the aviation industry and for
use in future space missions. Compared to carbon nanotubes, BNNTs possess much
better thermal stability. The mechanical integrity of BNNTs remain solid after
being heated up to 850 degrees Celsius as compared to the stability temperature
of 400 degrees Celsius for carbon nanotubes 3. Heat resistance without mechanical
strength would be useless in this industry. The mechanical strength of BNNTs is
astonishing, having a Young’s modulus of up to 1.3 TPa and a tensile strength of
33 GPa 2. The application here is using BNNTs as reinforcing fillers in
metals and polymers, where they remain stable at high temperatures such as
those that would potentially exist in commercial hypersonic travel, a
definitive future goal of aspirational aviation companies. Equally aspirational
is a modern space race with a goal of reaching and potentially colonizing Mars.

A primary difficulty in successfully utilizing Mars is the effect of space
radiation. Radiation can be very damaging to materials, electronics, and the
human body 4. For this reason, shielding materials are critical to these
future missions. BNNTs have the unique quality of high thermal stability in
combination with radiation shielding properties not exhibited in carbon
nanotubes. This could potentially make BNNTs great for structure of spacecraft
or spacesuits and a significant area of research for future human deep space
exploration.

 

            Medical and biomedical applications of BNNTs are promising
and potentially life changing for many humans. Primary potential applications are
drug delivery and use in biomaterials. The aforementioned applications may pass
unnoticed for the majority of our population. However, health is paramount to
quality of life and it cannot be forgotten that medical complications can
change one’s life overnight. Some medical conditions develop overtime and
others without warning. Having experienced the latter I have considered a
future career in bioengineering that can improve quality of life and better
prepare medical professionals to address patient’s issues as they arise.

Nanomaterial research for medical use has exploded in recent years with carbon
nanotubes attracting much of this attention for addressing similar applications.

However, with the development and acknowledgment of preferable characteristics
that BNNTs possess, more research has been aimed at determining specific cases where
boron nitride nanotubes would be a better nanomaterial. Some of these
characteristics, such as thermal stability and high strength, have been
discussed above with regards to aviation and space travel also have benefit in
the medical field. Others, such as insulating properties, superior flexibility,
and solubility of BNNTs when compared to carbon nanotubes are more specific to
medicine 5. In addition, of utmost importance, BNNTs have been shown to be non-toxic
and biocompatible using newly developed processing techniques 5. The known chemical
stability of BNNTs previously hindered much research into biomedical areas
because of the necessity for easy dispersion in aqueous solvents needed for
biological applications 6. The solution to this problem has been a technique
that uses a non-covalent polymeric wrapping that enables this needed
dispersion, promoting further studies on interactions with cells 6.  In the future, it is hypothesized that BNNTs
and carbon nanotubes both have significant importance in medicine, each
tailored specifically to certain tasks for which they are best suited. One such
task exploits an interesting property of BNNTs, magnetism. One application of
this that strikes close to home is use in magnetic resonance imagery as a contrast
agent. Having undergone six MRIs on the brain in the previous year and half the
contrast agent injected each time was a concern I discussed with my doctor. The
radioactive properties of contrast agents are minimal, but present, and the
development of safe agents was not without experimentation. Side effects of
these agents exist to a small population and it is in our best interest to
continue to develop agents that present zero risk and zero side effects. BNNTs
are potentially applicable because of the slight magnetism and biocompatibility
7. Targeted drug delivery is one of the important goals of modern medicine. This
magnetism BNNTs possess enable BNNTs to be exploited for magnetic, physically
guided, drug targeting by using magnetic fields to drive the delivery of drugs
in the right concentration to the target site, away from natural biological barriers
6. The applications here are endless with some examples including targeted
cancer treatment that only attack the specified regions or the treatment of
drug resistant epilepsy that is the result of specific neuron deficiencies in
the brain.

 

            Hydrogen storage became of interest to me when I learned
of its excellent potential as an energy source. An area that has attracted my
interests as a future engineer is addressing perhaps the most pressing issue of
my generation, climate change. Complete clean energy is perhaps the next greatest
achievement that mankind must attain. Critical to our long term survival as a
species is migrating away from our current practices of generating energy that
harms the health of our environment and puts our lives at increased risk.

Currently, the biggest hurdle that hydrogen energy must overcome for widespread
use is the issue of storage and transportation 1. Once again a comparison to
carbon nanotubes in this category favors the BNNTs as a superior nanomaterial
for this use. By analyzing binding energy curves of the interaction of hydrogen
with all possible site on a nanotube’s walls it was determined that hydrogen
binding is more efficient and more easily attained using BNNTs than carbon
nanotubes. 8. This is the result of ionic bonds of BNNTs, as opposed to the
covalent carbon bonds.

 

            As I work towards a career in mechanical engineering I
have begun to understand the importance of performing research on my own,
simply as an exercise of self-improvement and awareness of the advancements in
the world around me. The societal issues discussed in this paper and the impact
that boron nitride nanotubes have, and will have, on these areas are of great
importance to me. Aviation and space travel, biomedical and medical, and
hydrogen storage issues each have innumerable variables and complex problems to
be addressed and they will never be able to be referred to as solved. They each
are analogous to a living breathing organism that will continue to evolve,
advance, and require that new questions be asked to continue on the path of
improvement. The intelligence we as humans possess will one day make boron
nitride nanotubes a well understood and successfully integrated material with far
reaching applications.