Update: Photo Friday (#picpickoftheweek)

In January the Hanson Research Group (@HansonFSU) introduced Photo Friday, a twitter-based ‘best picture of the week’ (#picpickoftheweek). Since then my students have created an amazing collection of photographs depicting our research, equipment, and chemicals. I’d like to highlight my six favorite photos so far (in no particular order).

In the first picture a reaction mixture, under UV light, is cooled to -78°C using a dry ice-acetone bath. Emission is usually more intense when molecules are cooled because it slows vibrational relaxation (non-radiative decay).

rxnThe second picture shows a fluorescent dye in dichloromethane being poured into an Erlenmeyer flask under UV-light (365 nm).

PourPicture three offers a glimpse inside the excitation monochromator of our fluorometer. The device is composed of a grating, to disperse the white light (xenon lamp source) into its components, and mirrors to direct the monochromatic light toward the sample.

MonochrometerPhoto four is a very stylized look at one of our variable magnetic field cuvette holders. The knob you see in the bottom right is used to move the neodymium magnets closer or further away from the cuvette. With the magnets next to the cuvette we get a field of about 0.35 T at the point of emission. The dry ice adds an ethereal feel to the photo but more importantly allows us to see the laser beam.

Laser through magnetic fieldEmission from molecules bound to semiconducting films depend on the energy of the chromophore, the conduction band of the semiconductor, the solvent, and other variables. Photo five demonstrates how the distance between the molecule and the semiconductor can affect emission intensity.

Film emissionThe concentration gradients that occur when a solid dissolves in solvent is easy to visualize using fluorescent molecules, as shown in picture six. Eventually the color will even out but the process is relatively slow without stirring.

DissolveFollow us on twitter (@HansonFSU) for more more of our #picpickoftheweek.

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