Children's understanding of quantity and their ability to use graphical information

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Involving High School Students in Computational Physics University Research: Theory Calculations of Toluene Adsorbed on Graphene

<div><p>To increase public awareness of theoretical materials physics, a small group of high school students is invited to participate actively in a current research projects at Chalmers University of Technology. The Chalmers research group explores methods for filtrating hazardous and otherwise unwanted molecules from drinking water, for example by adsorption in active carbon filters. In this project, the students use graphene as an idealized model for active carbon, and estimate the energy of adsorption of the methylbenzene toluene on graphene with the help of the atomic-scale calculational method density functional theory. In this process the students develop an insight into applied quantum physics, a topic usually not taught at this educational level, and gain some experience with a couple of state-of-the-art calculational tools in materials research.</p></div

The atomic structures of benzene, and the methylbenzenes toluene, para-xylene, and mesitylene.

<p>The student research project focuses on toluene (top right), whereas the continuation of the project involves also benzene and para-xylene (bottom left), the so-called BTX-family, as well as mesitylene (bottom right).</p

Adsorption energies <i>E</i>_<i>a</i> for toluene on graphene.

<p>Calculated with various values of parameters, of real-space grid points (gpts), number of Brillouin zone k-points (kpts), and exponent of energy convergence threshold <i>n</i>, 1.5 ⋅ 10^−<i>n</i> eV/electron. The student research project provided the “student” data for toluene, whereas the medium- and high-quality toluene data were obtained later by the research group [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159168#pone.0159168.ref002" target="_blank">2</a>]. As a comparison, results of experimental measurements from the literature [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159168#pone.0159168.ref020" target="_blank">20</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0159168#pone.0159168.ref021" target="_blank">21</a>] are also shown, however, these results cannot be directly compared, as discussed in the main text.</p

Illustration of the toluene molecule adsorbed on graphene, seen perpendicular to the plane of graphene.

<p>Here the configuration found by the students is shown, with one H atom of the methyl group pointing towards graphene, and the other two methyl-group H atoms pointing away (termed “methyl corner” in the text and table).</p

From the student report.

<p>Estimating the atomic positions in toluene using symmetry considerations and the bond lengths of C-C and C-H, as well as typical angles (in degrees) of the C-C-H bonds.</p