Take PVDF nanofiber membrane preparation as an example:
1 Main materials and instruments:
(1) Spinning material: PVDF, molecular weight 400,000; solvent DMF, analytically pure.
(2) Experimental equipment: 50mL conical flask, water bath magnetic stirrer, electronic balance, E05 electrostatic spinning machine.
2 Spinning solution configuration:
Use an electronic balance to weigh a certain quality of solvent DMF into an Erlenmeyer flask, add a magnetic stirrer, and stir in a water bath; then weigh a certain quality of PVDF and slowly add it to the stirring Erlenmeyer flask; cap the bottle tightly to prevent Water vapor enters the Erlenmeyer flask; set the temperature of the water bath to 60°C, and continuously stir and dissolve for 4 hours until the solution is clear and transparent, and a PVDF spinning solution with a certain mass concentration can be obtained. According to this method, prepare 20g, 18%wt PVDF spinning solution.
3 Spinning process and parameters
Pump the above PVDF spinning solution into a 20mL syringe, fix the syringe to the injection pump of the spinning machine, install a 20G (1/2 inch, flat mouth) stainless steel needle, connect the needle to the positive pole of the high-voltage power supply, and connect the receiving roller to the negative pole of the high-voltage power supply. The receiving substrate is pasted on the roller; the syringe pump specifications are set to 20mL, the liquid supply speed is 2mL/h, the roller speed is 300 rpm, the sliding table stroke is 20cm, the spinning distance is 15cm, and the spinning voltage is positive 15kV and negative 5kV. The temperature is 35℃, the humidity is 40%, and the timing is 120min. Finally, close the equipment door and open the exhaust air.
Commonly used electrospinning receiving substrate: aluminum foil paper, release paper, non-woven fabric, mesh cloth, etc.