DES-Based Chitin Processing
Bioplastics
Deep Eutectic Solvents (DES)
Procedure
Step 1.
Add 300ml of Choline Chloride/malic acid DES to a 500ml round bottomed flask.
Step 2.
Insert a stir bar and thermometer; place in heater/stirrer unit.
Step 3.
Turn heater/stirrer on. Adjust stir speed until magnet is spinning moderately rapidly. Turn on heating element.
Step 4.
Monitor solution temperature. You want the temperature to be between 92–95°C
Step 5.
Once the solution has reached target temperature, slowely add 20g insect exuvia over several minutes. The solution will turn dark brown.
Step 6.
Continue stirring for 4-6 hours.
6 hr
@ 95 °C
Step 7.
Turn the heater off but continue stirring until the soloution had reached room temperature.
Step 8.
Transfer the cooled mixture into centrifuge tubes.
Step 9.
Centrifuge at 5000g for ~15 minutes. Pour off supernatant (DES) into contianer for recycling.
15 min
@ 5000 𝘨
Step 10.
Fill microcentrifuge tube with distilled water; vortex 20 seconds. Water will be amber colored.
Step 11.
Centrifuge for 10 minutes at 5000g.
10 min
@ 5000 𝘨
Step 12.
Pour off supernatant. Repeat distilled water wash two more times or until water remains clear.
Step 13.
To remove residual water, add ethanol to centrifuge tube and vortex 20 sec.
Step 14.
Spin for 5 minutes at 5000g. Pour off supernatant.
5 min
@ 5000 𝘨
Step 15.
Scrape pellet out of tube into pateri dish or weigh boat. Dry overnight.
Required recipes
ChCl–Malic Acid DES
Recipe calculator ·
Scales ingredients to target volume
Step 1.
Add to a 500ml round-bottomed flask.
Choline Chloride
13.35
g
Step 2.
Add on top of ChCl in flask
L-Malic Acid
12.81
g
Step 3.
Insert thermometer and magnetic stir bar into flask and place the flask in electric mantel heater
Step 4.
Turn heater/stirer on and monitor heat. You want to maintain the temperature between 70–75°C.
Step 5.
As the sample heats up, monitor phase transition: grainy (5 min) → pasty (15 min) → liquid (40–60 min). As the mixture transitions to liquid phase, periodically hold flask to light; inspect for particles. If clear → proceed; if cloudy → heat 10 min more.
Step 6.
Turn off the heater. Turn down the stirring speed and continue stirring while cooling to room temp (~25°C)