Application of laboratory microsyringe pump in high-pressure electrospinning

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Electrospinning is the process of spinning with a polymer solution under high-voltage static electricity. Electrospinning can prepare fibers with a diameter of tens to hundreds of nanometers, the product has high porosity and large specific surface area, diversified composition, uniform diameter distribution, and has high application value in biomedical environmental engineering and textile and other fields. Common electrospun nanofibers can be used in water treatment, protective clothing, masks, etc. in filtration and personal protection; In the field of sensors, it can be used as resistive sensors, optical sensors, etc.; In the chemical field, it can be used for catalysts; In the field of biomedicine, it can be used for wound dressings, tissue engineering scaffolds, drug carriers, etc.W55Rongbai Pump

High voltage electrospinning technologyW55Rongbai Pump

Electrospinning is a spinning technology that prepares polymer fibers under high-voltage electrostatic electricity (several thousand volts to hundreds of thousands of volts) by applying an applied electric field to a polymer solution. The fibers prepared by electrospinning method are much thinner than the fibers made by the traditional spinning method, and the diameter is generally between tens of nanometers and several microns, and the minimum diameter can reach 1nm.W55Rongbai Pump

In the electrospinning process, the spinning needle is generally connected to the high-voltage positive electrode, and the receiving plate or receiver that keeps a certain distance from the needle is connected to the negative electrode. Under the action of surface tension, the polymer solution is a spherical droplet at the needle, as the voltage increases, the charge density on the surface of the droplet increases, when the electrostatic force is greater than the surface tension, the droplet on the surface of the spinnerets is elongated, and when the critical voltage is reached, the liquid will change from spherical to conical, that is, Taylor cone. As the voltage continues to increase, when the electrostatic force is greater than the equilibrium critical value, the liquid overcomes the outer surface tension of the nozzle droplet, moves towards the receiver, accelerates during the movement, stretches and splits many times, and finally forms nanofibers on the receiver.W55Rongbai Pump

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Schematic diagram of electrospinning deviceW55Rongbai Pump

The electrospinning device is mainly composed of a syringe pump, a syringe, a high-voltage power supply and a receiving device. Among them, the positive and negative electrodes of the high-voltage power supply are connected to the syringe needle and the receiving device respectively, and the form of the receiving device is also diverse, which can be a static plane, a high-speed rotating roller disk, or a special shape of the bracket mold, etc. Spinning parameter settings Environmental conditions are crucial to the effect of spinning.W55Rongbai Pump

Influencing factors of electrospinningW55Rongbai Pump

There are many factors and process parameters that affect electrospinning, which can be classified into 2 categories:W55Rongbai Pump

(1) System factors, including molecular weight, molecular mass distribution and solvent properties of polymers, such as (viscosity, conductivity, dielectric constant and surface tension).W55Rongbai Pump

(2) Electrospinning process parameters, including applied electric field strength, solution concentration, solution flow rate, size of the spinneret, distance from the receiver and environmental conditions (temperature, humidity, air flow rate), etc. Among them, the choice of solvent, the stability of the injection speed, the concentration of the solution, the applied electric field strength and the distance between the spinneret and the receiver are the main factors affecting the spinning.W55Rongbai Pump