Dr. Aaron T Wade

The COVID-19 pandemic forced introductory lab courses to shift to an online format. This implementation involved a shift in emphasis in learning goals towards transferable lab skills and involved a range of activities, including PhET simulations, video data collection, analysis of data sets, and open-ended free response conceptual questions. In this study, we examined student perceptions of aspects of the online lab activities and learning outcomes. We find that synchronous attendance is more likely to produce positive learning outcomes and that activities associated with data analysis are perceived to be more difficult. We discuss structural flaws with the learning management systems that can exacerbate student perceptions.

Studying the energy of a band gap in molecules has valuable applications in semiconductor physics. The energy of a band gap refers to the energy difference between the Highest Occupied Molecular Orbital (HOMO) and Lowest Unoccupied Molecular Orbital (LUMO) or the top of the valence band and the bottom of the conduction band. A lower band gap energy corresponds to higher efficiency or lower wavelength. Studying the conductivity of organic molecules is a very useful field since organic compounds are more versatile and cheaper to produce than regular silicon semiconductors. This has a wide array of applications, especially in LEDs and micro processing units.

The solvatochromic shift of a molecular fluorophore is the change in the absorption and emission spectra and is caused by the dipole interactions that take place between it and the solvent. Rhodamine-6G (R6G) was used because it is a good example of a molecular fluorophore that exhibits this phenomena. In most organic solutions, Rhodamine-6G becomes aqueous and acts similar to a salt. forming an organic ionic molecule and an ionized Chlorine atom. This ionic molecule is affected by the polarity of the solution into which it is dissolved.
To better understand the solvatochromic shifting of Rhodamine-6G, the dipole interactions must be further researched. This can be done by measuring R6G spectra of different solutions and calculating the Stokes Shift. The Stokes Shift is the difference between the peak absorption wavelength and peak emission wavelength. These peaks allow for the calculation of the dipole moments in each solution. There are several methods to determine dipole moments and change in dipole moments. The most commonly used methods were developed by Lippert-Malaga,
Bakhs.h..ie. v, Catalan, Kamlet-Taft, Reichardt, and Bilot-Kawski.

The solvatochromic properties of a novel fluorophore, 4-[2-[2-(dimethylamino)-3-pyridyl]ethynyl]anisole (NNDAP-O-CH3), developed by Dr. Tanay Kesharwani of The University of West Florida was studied. The absorption and emission spectra of the fluorophore in various solvents were measured. The ground state and singlet excited state dipole moments were determined using the Bilot-Kawski, Lippert-Mataga, Bakhshiev, and Reichardt correlation methods. The magnitude to which a certain solvent property contributes to the observed solvatochromic shifts was investigated using both Kamlet-Taft and Catalan models. The experimental system and environment are being computationally modeled in Gaussian16. Predictions of the software will be compared to experimental evidence to propose structural and dynamic factors contributing to the phenomenon as well as to predict other properties of the molecule.