This procedure describes the preparation of spin-cast side chain LCE developed in Heino Finkelmann's lab. The total preparation for the material is approximately 48 hours. The image to the right shows an LCE film at the end of the spin casting process.

Chemical CAS #
mesogen
crosslinker  
platinum catalyst (COD)
methyl-hydrosiloxane
Toluene [65-45-3]
De-ionized H2O  

  • balance
  • weighing boat | paper
  • glass vial | plastic > 5mL
  • glass | plastic transfer pipette
  • Teflon film (~20um thick)
  • spin casting head
  • heated centrifuge | spinning apparatus
  • dry-ice | liquid nitrogen
  • Tefzel tape (DuPont)
  • 15 cm plastic | wood | metal rod for hanging LCE
  • drying oven
  • addition funnel
  • glass dish
  • aluminum foil | parafilm
  • Luer tip filter 0.2 um

  1. Next, cut a 3cm strip of Tefzel tape, and attach a paperclip to the bottom third of the tape. The paperclip will serve as a weight to stretch the LCE and should be parallel to the LCE film. The mass of the paperclip we use is approximately 0.3 grams.
  2. Attach the tape | paper clip to the bottom of the LCE so approximately the bottom 5mm of the film is covered. The LCE will begin to stretch but should not break. At this point, the tape | paperclip may slide off the LCE. In this case, get use a fresh piece of tape, and attach the paperclip a second time. Highslide JS

    LCE with one paperclip

  3. After approximately 30 minutes after all the paper clips are attached to the LCE, it is now time to place a second piece of tape on the opposite side of the LCE from the initial piece of tape at the top and bottom of the LCE.
  4. Approximately every 30 to 40 minutes, hang another paper clips until a total mass of approximately 2 to 2.5 grams is suspended from the LCE. It is better to use many light paperclips than one heavy clip. After each paperclip is attached to the LCE, carefully inspect the LCE for cracks along the edge of the film. If cracks appear, remove the paperclip.
  5. With time, the LCE will turn cloudy and then clear again. This process will take several hours. Let hang with weight for 18 to 24 hours.
  6. Remove 2/3 to ¾ of the paperclips, and place the LCE in an oven around 50oC for 36 to 48 hours to complete all chemical reactions. The temperature of the oven must be lower than the isotropic phase transition of the LCE!
  7. Remove the LCE film from the oven. Take off all paperclips, but the tape may be left on the LCE film. Store the LCE on Teflon film. The films are now complete and ready to be washed. Click here for information on washing the LCE films.