Polymer/Carbon Nanotube Composite Nanofibers

To improve the compatibility between CNTs and polymers, the surface functionalization of CNTs has been developed (Kharaziha et al., 2014; Molnar et al., 2008; Ra et al., 2005; Mazinani et al., 2009; Yee et al., 2012; Subagia et al., 2014; Diouri et al., 2014). For instance, Kharaziha et al. established a simple strategy to prepare electrospun gelatin/CNT composite nanofibers by using carboxyl acid groupemodified CNTs, and the well-dispersed CNTs aligned along the fibrous axis could be observed (Fig. 3.15B). This work demonstrated CNTs as a component of tough and flexible scaffolds with outstanding electrical properties (Kharaziha et al., 2014). Molnar et al. (2008) synthesized PVA/CNT composite nanofibers with diverse types of CNTs and different functional groups via electrospinning. Furthermore, other synthetic methods such as electrospinning combined with electrospraying and a surface adsorption approach have been developed as well (Xuyen et al., 2009; Kim et al., 2006b; Vaisman et al., 2007; Dai et al., 2011; Rana and Cho, 2011).

Polymer/Fe3O4 Composite Nanofibers

Magnetic NPs have been receiving increased attention with the rapid development of nanotechnology.Among them, Fe3O4 NPs have caused widespread interest owing to their high superparamagnetism as well as facile preparation. Their easy oxidation and resulting decline in magnetic property is a problem, however, which is effectively solved by the dispersion of Fe3O4 NPs in polymer nanofibers. The simplest way to prepare polymer/Fe3O4 composite nanofibers is to disperse Fe3O4 NPs in the polymer solution and subsequently carry out the electrospinning process. Xin et al. successfully fabricated poly(p-phenylene vinylene)/Fe3O4 composite nanofibers via electrospinning of a precursor solution and subsequent thermal conversion (Fig. 3.14A). In addition, the aligned nanofibers can be obtained by employing two parallel magnets as the collector. A variety of polymer/ Fe3O4 composite nanofibers, including PAN/Fe3O4 composite nanofibers, gelatin/Fe3O4 composite nanofibers, etc., have been reported by means of a similar method, and their potential applications in various fields have been studied as well.

METAL NANOFIBERS

Metal nanomaterials possess unique physical and chemical properties and certain special functions compared with many other functional nanomaterials. Electrospun metal nanofibers show excellent thermal stability and conductivity and possess potential applications in photoelectricity, sensors, high temperature filtration, and other fields (Bognitzki et al., 2006; Hsu et al., 2012; Shao et al., 2011; Zhang et al., 2016c; Wu et al., 2007; Hansen et al., 2012). In 2006, Bognitzki et al. successfully prepared Cu nanofibers through a strategy involving an electrospinning technique followed by calcination in an air and H2 atmosphere. It was the first time that electrospun Cu nanofibers had been reported (Bognitzki et al., 2006). Later, Hsu et al. coated a passivation layer on electrospun Cu nanofibers (Fig. 3.12A). The results showed that the treated sample possessed superior durability as well as resistance over the bare Cu nanofibers. It is anticipated that the product can be applied as stable transparent electrodes (Hsu et al., 2012).

ZnO Nanofibers

The potential applications of electrospun ZnO nanofibers have been widely studied. For example, Zhang et al. (2009b) fabricated uniform ZnO hollow nanofibers and investigated their gas-sensing activity against ethanol. Similarly, Wei et al. (2011b) studied the performance of electrospun ZnO hollow fibers as an acetone gas sensor. Katoch et al. (2016a,b) measured the influence of hole diameter as well as crystallinity in ZnO hollow nanofibers on the gas-sensing property.

FexOy (Iron Oxide) Nanofibers

It is generally known that iron oxides mainly contain Fe2O3 and Fe3O4. Fe2O3 is stable in air, and possesses potential applications in adsorption, sensors, electrochemical catalysis, and other fields. On the other hand, Fe3O4 is a typical kind of magnetic material, which can be applied in magnetofluid as well as magnetic recording materials. Fe2O3 nanofibers with uniform structure can be easily prepared via an electrospinning technique followed by a calcination treatment (Fig. 3.6A). For example, Gao et al. prepared hollow a-Fe2O3 nanofibers via such a strategy and developed their potential in dye adsorption. Similarly, Nalbandian et al. found that electrospun Fe2O3 nanofibers possess promising prospects in heavy metal removal. Guo et al. studied the effect of the structure of electrospun Fe2O3 nanotubes on gas sensing; the results indicated that porous a-Fe2O3 nanotubes exhibited remarkably enhanced performance for acetone sensing over hollow a-Fe2O3 nanotubes. g-Fe2O3 nanofibers have also been successfully synthesized and their properties as acetone gas sensors have been found as well.

Single-Component Synthetic Polymer Nanofibers

Herein, we divide the synthetic polymers into several species. Among them, organic solvent-soluble polymers have been greatly developed, for example, electrospun polystyrene (PS) nanofibers have been prepared from different solvent systems (Fig. 3.5A). DMF, tetrahydrofuran, and their mixtures are the most commonly used solvents (Lin et al., 2010; Nitanan et al., 2012). Electrospinning of polyacrylonitrile (PAN) nanofibers also employs DMF as solvent (Fig. 3.5B), and they are a kind of excellent precursor for the fabrication of carbon nanofibers, which have been widely studied (Fen nessey and Farris, 2004; Gu et al., 2005). Polymethylmethacrylate (PMMA) is another familiar synthetic polymer; electrospun PMMA nanofibers as well as blended fibers have been developed for more than 10 years (Fig. 3.5C) (Ji et al., 2008; Carrizales et al., 2008).

Near Field Direct Writing Electrospinning Equipment M08

1. Printing resolation less than 50nm;
2. Nanofiber highly oriented and controllable;
3. International R & D team pioneering technology;
4. Exclusive patented technology;
5. Micro nano manufacture excellent tools

Near Electrospinning Technology Classification

Solution Near-field Electrospinning

Solution near-field electrospinning process, the printing material is prepared into a solution, and using electrostatic field print orientation nanofibers. It can produce a fiber orientation controllable fiber diameter range is 50nm-20μm, the solution electrospun near-field have more suitable materials.

Melt near-field electrospinning

Melt Near-field electrospinning process, the printed material is heated and melted, assisted with the electrostatic field, fibers with a diameter range of 500nm-50μm can be prepared, high 3D printing capability, very suitable for producing three-dimensional biological tissue engineering scaffolds.

Near field electrospinning equipment parameters

1. High voltage power supply: 0-30kv, adjustable;
2. Solution spinning nozzle: solution supply volume at least 10μl/h;
3. Melt spinning nozzle: nozzle temperature: 0-300℃, adjustable, precision pneumatic extrusion;
4. Printing environment temperature: indoor temperature -50℃, adjustable;
5. Collection platform: printing range 150*150mm, platform speed: 0-200mm/s, resolution: 50nm;
6. Nozzle height: 0-80mm, adjustable, resolution: 50nm;
7. Printable materials: PE0, PVA, PLA, PCL, PLGA, chitosan, sodium alginate, collagen, hydroxyapatite, PVDF and other hundreds of organic or inorganic materials;
8. printable user-defined patterns;
9. printable 3D structure;
10. customizable : temperature controllable collector;
11. customizable : multi-nozzle device. 

Lab Scale Electrospinning Machine E03-001

Features:

1. Desktop style,  small size;
2. Function integrated, professional;
3. Superior performance, CE/FCC certification;
4. 4.3 inch numerical screen, simple and clean integration operating system;
5. Highly cost effective, elegant appearance;
6. Tool machine, affordable;

Parameters:

1. Spinning voltage: 0-30kv;
2. Both roller and panel collector;
3. Nozzle reciprocating motion breadth: 150mm
4. Dimension: 600*600*800mm
5. Net weight: 47.46KG

Multifunctional Nanofiber Electrospinning Equipment E06

Features:

1. Temperature and humidity can be control in high precision and high speed;
2. Can timing control the experiment;
3. Modular design, multifunction;
4. Multiple nozzle system;
5. Automatic control intake and exhaust;
6. Color touch screen, numerical control system;
7. Operation is simple and clear.

Parameters:

1. High voltage power supply: positive : 0-50kv; negative : 0-30kv;
2. Double pump: the smallest solution supply volume is 10μl/h;
3. Temperature control: indoor temperature: -70℃, precision: ±1℃;
4. Humidity control: indoor humidity: -30%HR, precision: ±3%, humidity control time: 3-5min;
5. High precision CNC system, can control experiment time, check the history data etc.;
6. Coaxial nozzle, prepare hollow fiber.