Contents
1 Introduction2 Solution blow spinning process2.1 Blow spinning classification2.2 Principle of solution blow spinning2.3 Process factors of solution blow spinning3 Solution blow spinning raw materials4 Application of solution blow spinning of Nanofibers4.1 Thermal Insulation Material4.2 Biomedical4.3 Flexible Electronic Devices4.4 Environmental Protection5 Solution Blowing Machine5.1 Scope of Application5. 2 Technical Features5.3 Technical Specification6 ReferencesIntroduction
Nanofiber materials have the advantages of large specific surface area, high porosity, low density, good mechanical flexibility, etc., which have broad application prospects in many fields. There are various methods to produce nanofiber materials, including electrospinning, solution blow spinning (SBS), centrifugal spinning, melt blow spinning, etc. SBS combines the advantages of electrospinning and melt blow spinningInning is the processn simple and safe, the spinning efficiency is high, suitable for a wider range of solution systems, more diverse raw materials can be selected, the structure and diameter of nanofibers can be controlled. Since its development in 2009, SBS has received great attention from many fields and has emerged as an efficient and versatile method to fabricate nanofiber materials with controllable microstructure and morphology.
In recent years, the number of publications has increased on SBS remains high (see Table 1). Tianjin Polytechnic University, Suzhou University, Beijing Institute of Fashion Technology, Jiangnan University, Donghua University, Dalian Polytechnic University and other universities are committed to using SBS to spin nanofibers to enhance the practicality of nanomaterials in various areas to investigate. The enthusiasm for researchg from universities on SBS show that blow spinning technology has great potential in the production of nanomaterials. With the deepening of research, spinning technology is becoming more mature. This article introduces the basic principle of solution blow spinning and applicable raw materials, focusing on the influence of process parameters on solution blow spinning, and explains the practical application of solution blow spinning of nanofibers.
Solution blow spinning processBlow spinning classification
The blow spinning process is mapped to the Divided into solution method and the melt method.
The solution method is to dissolve the polymer in a volatile solvent to make a spinning solution, which is spun from the spinneret hole at the spinneret at the same timeig, by the high-velocity hot gas around the spray, the solution flow is stretched, and the solvent evaporates and hardens and gets trapped in the web to form short fibers or non-woven fabrics or accumulate long filament bundles. This is spinning meThod is called Solution Blow Spinning (SBS). The melt method is used for melting polymer disks in screw extruder and quantitative extrusion. WHEN MEL T is extruded from the spin blow hole, it is sprayed at the high point by the surrounding thermal flux and processed into fibers, also known as melt blow spinning.
Principle of solution blow spinning
Medeiros et al. [1] first proposed the technology of producing nanofibers by solution blow spinning, which combined the properties of melt blowing technology and dry spinning technology. The basic principle of this technology is that the small flow of solution under the action of a high speedindity air flow is subjected to ultra-fine stretching and at the same time the solvent is vaporized and solidified into nanofibers. The schematic diagram of the principle is shown in the picture [2-3]. The core components of solution blow spinning equipment include injection pump, nozzle, compressed air and collector. During the spinning process, the spinning cleaning solution is transported to the spinneret hole of the spinneret head at a steady flow rate under the pressure of the syringe pump. At the same time, high-pressure air flows around the blowhole to form a stable ring, which accelerates the solution trickling and accelerates the stretching. Uniform stability of the solution. The formed trickling solution is formed in the process of rapid evaporation of the solvent, and under the action of a shell complex, auras are intertwined, curly, and finally formed in the shade on this network structure. Stable, random three-dimensional crimp von Nanofiber felt.
1. Polymer solution: polymer solution viscosity, polymer solution feed rate
Li Lei et al. [4] used solution bubble spinning to produce aluminum fibers and found that the influence of polymer solution viscosity, osity of fiber morphology and fiber diameter was different from general cases. If the viscosity was too low, the fiber diameter was coarser, possibly because there was too much solvent and it didn\'t fully evaporate when it reached the receiver. The nanofiber is compact and its properties are enhanced. When Kasiri et al. [5] used a low concentration (8%) polystyrene polymer solution for blow spinning was the Blasvotransition unstable and bead-shaped microstructures formed on the collector. When the concentration reached 10%, the viscosity increased. The amount of the solution increased, and the fibers were smoother and larger in diameter. The research results of Rotta et al. [6] showed that the average diameter of the fibers increased with the acceleration of the injection speed.
2.Nozzle Design
Han [7], for example through orthogonal experiments and numerical simulation studies, it was found that the diameter of the nozzle, the diameter of the needle and the extended length of the needle gradually reduce the influence of the linear velocity. The needle diameter is 4mm between the flow center and the nozzle, the needle diameter is 0.8mm and the protruding length is 5mm. This is the bEste geometric parameters ters, the preparation of the nanometer fiber surface is smooth, uniform morphology.
3. The airflow field
Kasiri et al. [5] observed the fiber morphology of solution-blown polystyrene (PS) material under a high-velocity air flow with different air pressures and found that the average diameter and diameter distribution of the prepared fFibers increased slightly when the air pressure increased to a lower value. When the air pressure was higher, the optimal fiber orientation was narrowerand more fibers could be collected by the collector.
4.Receiving Distance
Studies have shown that solvent evaporation in solution blow spinning affects the final morphological properties of the fibers and the distance between the nozzle and the receiver affects the solvent evaporation rate, which largely determines whether the fibers eventually form films or intertwine [10].
Solution Blow Spinning of Raw Materials
Many materials can be used to produce nanofiber materials SBS technology can be used. Polymers are the most commonly used materials to make fibers using SBS. SBS does not impose any special requirements on the dielectric constant of the spinning solution and is therefore suitable for a wider range of spinning [11].
In the laboratory of Jia Chao et al. [11] they used SBS to test the spinnability of many polymeric materialsInvestigations: polyacrylonitrile (PAN), polyvinylpyrrolidone (PVP), poly(methyl methacrylate) (PMMA), polyamide (PA), polylactic acid (PLA), polyimide (PI), poly (ethylene oxide) (PEO), poly(imide dioxime) (PIDO) , SiO2 fiber, TiO2 fiber, ZrO2 fiber, BaTiO3 fiber, SnO2 fiber, SiO2-Al2O3 composite fiber, ZrO2-Al2O3 composite fiber, YSZ fiber, carbon fiber, metal fiber, polymer-based composite fiber, PAN-based carbon fiber , AgNF fibers, PLA-SiO2 composite fibers, PLA-TiO2 composite fibers, PLA-CeO2 composite fibers.
In addition to synthetic polymers, natural polymers such as cellulose, zein and gelatin have also been successfully blown and spun into fiber materials . For some non-spinnable natural polymers, blending with spinnable synthetic polymers is an effective strategy to obtain spinnable SBS solutions.
Glebert et al. [12] studied synthetic polymers and composites, including poly(acrylonitrile), poly(vinylidene fluoride), poly(vinylpyrrolidon), poly(methyl methacrylate), poly(vinyl chloride), sulfonated poly(etheretherketone) and sulfonated poly(ethersulfone), polyimide, poly(lactic acid), poly(lactic-co-glycolic acid), poly(ethylene oxide), cellulose, lignin, nylon, polyurethane, poly(vinyl acetate), poly(vinyl alcohol) and poly(ethyl-co-vinyl acetate), poly(styrene), poly(caprolactone). ).
Application of Solution-Blown Nanofibers Thermal Insulation Material
Lightweight thermal insulation materials with low thermal conductivity are urgently needed in aerospace, thermal power, battery thermal protection and other fields. Ceramic fibrous sponge-like materials are ideal for thermal insulation due to their low density and thermal conductivity. However, the efficient and cost-effective production of such insulating materials remains a challenge [11].
Biomedicine
Nanofibers have unique application advantages in biomedicine, and related products have gained a reputation et. ALS new NANOFIBER processing technology, the SOLUTION BLOW Spinning can deposit the fiber directly on the specified target, even on the surface of biological Ti-Ti SSUs, which FURER expands the application of nanofibers in the biometal field [13].
Flexible Electronic Devices
Metal materials have good electrical conductivity, but bulk metals have poor flexibility and are difficult to use in flexible electronic devices. Processing metals into fibers greatly increases their flexibility while retaining their inherent electrical conductivity. Metal fibers have excellent flexibility and electrical conductivity, which can meet the application needs of flexible electronic devices[11].
Environmental Protection
The nanoparticles produced by SBS technology can be used for air filtration and pollutant adsorption. KHALID et al. [14] Coated the window grille with nanof on a large scalefibers to protect the room from airborne pollution, and prepared a transparent air filter with light transmittance more than 80%, and the PM2.5 removal efficiency could reach more than 99%. KOLBASOV et al. [15] successfully prepared a PA6-based nanofiber membrane with bio-based polymer by solution blow-spinning method (bio-based polymer was prepared from lignin, oat, chitosan, sodium alginate and soy protein as raw materials) and studied the adsorption effect of this membrane on the heavy metal pollutant lead (Pb).< /p>Solution blow spinning machine
The thin stream of spinning dope is three-dimensionally crimped and entangled by the turbulent shearing action of high-speed airflow field in the spinning box. The process is short, the process is simple, the conditions are easy to control, and large-scale production can be done. The average diameter of the nanofibers of the non-woven fabrics produced is between 0.01 and 3 μm, which is smallert than that of traditional polypropylene meltblown nonwoven fabrics and has excellent performance.< p>Using unlimited polymer solution as the processing object, it can overcome the thermoplasticity requirements of existing meltblowing technology and high melt flowability of raw materials and is universally applicable.
Technical specification