Post Tagged with: "#picpickoftheweek"

A Year in the Life of a New Research Lab…in Less than One Minute

The Hanson Research Group’s first experiment—initiated my second day on the job—involved two strategically placed Brinno TLC200 time-lapse cameras programmed to take one photo per day. The video from our first camera that covered our less-trafficked support space was posted in March. Below is the video from our second camera, which was placed in the main lab and focused on one of our fume hoods.



By July 18, 2014 8 comments fun, general chemistry

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.

By May 21, 2014 0 comments Uncategorized

New Lab Time Lapse

Eight months ago the Hanson Research Group announced our first experiment on twitter. We set out to capture, via pictures, the transition from an empty space to a fully functioning lab. This involved two Brinno TLC200 time-lapse cameras programmed to take one photo per day. Last week we stopped the camera located in the support lab. Here are the results:

The support lab is predominantly dedicated to solar cell assembly so—from the right side of the screen and moving towards the left—you can see the following: a glass cutting mat, the pressure-heat, cell sealing apparatus and the box furnace. Here are a few things to note:

  • Every time the red handle on the cell sealing apparatus moves a solar cell was born.
  • The fume hood was largely used for storage until about the 6 month mark when we added a horn sonicator.
  • We decided to add a short pause whenever someone was caught on camera.
  • After the initial explosion of activity one of my favorite parts of the video is the dancing chairs.

We originally planned to let the support lab camera run for a full year but then decided to stop it early for two reasons. First, there is relatively low traffic in the area and most of the major changes were completed in the first 3 to 4 months. Second, we became impatient and decided that there were more interesting things in lab  we could capture. Follow us on twitter (@HansonFSU, #picpickoftheweek) to keep up with our future time-lapse experiments – and let us know in the comments if you have any suggestions for other things to capture.

By March 20, 2014 2 comments Uncategorized

Photo Friday (#picpickoftheweek)

My graduate student, Sean Hill, became the Hanson Research Group twitter account manager last week. We first talked about what is and isn’t acceptable to post on the internet. Then Sean explained to me the nuances of hash tags and how I’ve underutilized them.  He also suggested something brilliant: a photo of the week.

One of the things I like most about doing research in molecular photophysics is the beautiful color chemistry. Now, every Friday, Sean will tweet (#picpickoftheweek) our best photo taken during the prior week. Our first image (below) is very fun and depicts a photon upconversion solution.

Upconversion

This image shows green laser pointer light (532 nm) causing blue (~430 nm) emission from the solution.  What makes this image really interesting, from a photophysics standpoint, is that we’re  observing the conversion of lower energy green photons into higher energy blue photons.

The reverse—higher energy blue light turning into lower energy green light—is easy. Many molecules absorb a single high energy photon and then emit a single lower energy photon with some energy lost in the process due to vibrational relaxation.  The more difficult green-to-blue light change depicted above is only possible if we combine the energy from two green photons to produce one higher energy blue photon.  This process is known as photon upconversion.

While it can be observed in inorganic nanoparticles, the solution above is a mixture of two types of molecules that undergo excitation, energy transfer, triplet-triplet annihilation and then emission.  Our research group is interested in studying these upconversion systems because they could potentially provide a mechanism to harness low energy light and increase the theoretical maximum solar cell efficiency from 33% to >40%. If you’re interested in learning more about photon upconversion through triplet-triplet annihilation, here is a good review article.

Follow us, @HansonFSU, on twitter for more molecular color chemistry.

By January 18, 2014 4 comments fun