MEDICAL AND ELECTRONIC
APPLICATIONS OF PARTICLE
TECHNOLOGY
By
Jennifer Sidletsky
Pre-Freshman
Major: Physics and Mathematics
Honors Program
Mentor: Richard Partch
With the increasing ability to delve into the technology of particles comes the ability to
use them in various applications Nanoparticles are now useful in areas ranging from electronics
to medicine. Much research has been conducted on the applications of particles, and there have
been several papers focusing on two particles- polystyrene and silica- and the many applications
of both.
Much research has been conducted into expediting the process of kidney dialysis, which,
at present, takes several hours to adequately filter the blood. Recent research in the field has
pointed to the possibility of using polystyrene (latex) nanoparticles of a uniform size stacked in a
lattice formation (figure 1) as a filter.
Figure 1: Lattice formation
Silica has been used commonly in dental resins as an inorganic filler material. The silica used is
usually 100nm and adds strength to the filling. In the curing process, normally, 8.5% shrinkage
of the filling can occur, which can lead to failure later. Recently, research has attempted bonding
layers (positively, negatively, and positively charged, respectively) to the silica particles. If the
negative charge of the second layer can be removed, the positive layers will repel and cause the
particle to expand, acting against the normal shrinkage. In another medical-related application, by
binding a molecule that will form a pi-pi complex with a toxin, the silica can be used as an
injectable toxin remover. The molecule binds with the toxin (such as an overdosed drug), and
eliminates the threat from the body. Regarding an electronic application, by binding silica to the
outside of a latex particle, one can create an abrasive used in microchip manufacturing.
We created polystyrene using the setup shown (figure 2) and attempted several variations
seeking to create more uniform particles, which are necessary to form the lattice. We used a
Malvern Mastersizer to determine the sizes of the particles produced and their uniformity.
Figure 2: Polystyrene lab setup
We generated silica particles using TEOS and used a ZetaPlus Particle Sizer to determine size
and uniformity of the resultant particles. We attached 3,5-dinitrobenzoylchloride to silica gel to
make the detoxification particle.
Through experimentation and variation, we discovered that there was a vast difference in
the product’s uniformity when a new flask was used as opposed to used flasks. Also, higher
temperatures and higher stirring speeds seemed to make the particles more uniform.
Figure 3: Polystyrene particles at 40K magnification
The silica particles produced ranged greatly in size. The particles were bound successfully to the
3,5- dinitrobenzoylchloride.
Figure 4: Silica particles at 10k magnification
The results led to the determination that new glassware, higher temperatures, and higher
stirring speeds should be used in the production of polystyrene in order to achieve the desired
uniformity for filters. Understanding how to achieve greater uniformity in the manufacture of
particles allows for uniformity in experimentation and in final product, and in many applications,
uniformity of particles is essential to the success.