Every so often, I get an email from someone who wants to use one of my liquid crystal photographs for some purpose or another. Once, this was for a book cover; another time, it was for a presentation. Yesterday, I was asked for permission to use a liquid crystal picture for the cover of a Ph.D. thesis. Curious about which picture it was, I followed the link to a long defunct version of my SFU webpage. To put it mildly, this page had not aged well: to see it in all of its retro-glory, click here. Here's an important lesson: nothing ever disappears from the internet.
How and why had anyone come across this old page? It turns out that the person who contacted me had worked extensively with 4-(trans-4-pentylcyclohexyl)benzonitrile, also known as PCH5. Googling this compound's name brings up several of my old photos and the mortifying webpage. My favorite of the old photos is shown to the right. It captures the transition between the nematic and isotropic phases.
I have a soft spot for nematic phases, for a variety of reasons that I'll explore in later posts. One of these reasons is that nematic phases were the first kind of liquid crystal that I worked with as a grad student. So, for all of those researchers out there who worked with PCH5, here are a few more recent pictures.