Electrospun polymer fibers

A comparison of the diameter of the electrospun fibers with the electrical conductivity of the solutions was shown in Figure 6. There was a significant drop in the diameter of the electrospun polymer fibers when the electrical conductivity of the solution increased. Beads were also observed due to low eonductivity of the solution, which results in insufficient elongation of a jet by eleetrieal foree to produce uniform fiber. 

Similarly clear is the presence of a so-called double tip (Fig. 2.45a). Here, the tip exposes two points (sometime in different levels). Again, the features possess typical orientations, as demonstrated nicely below for electrospun polymer fibers (Fig. 2.45). The fibers appear to be double, depending on their orientation.Since two fibers are apparently visible when they are oriented horizontally, while these fibers... 

Fig. 2.45 (a) Schematic of a double tip (b) AFM height image of electrospun polymer fibers. The appearance of parallel fibers (i.e., a pair of fibers) is highly unlikely on the basis of the orientation dependence of the pairs... 

Fig. 6 Functionalization of polymer fibers for nerve regeneration, (a) Functionalization with adsorption or covalent binding of ECM molecules to electrospun polymer fibers [169]. (b) Functionalization by blending of ECM molecules with synthetic polymers before electrospinning [93]. (c) Functionalization by chemical bulk modification of the electrospinnuig solution [158]...

Nunes-Pereira, J., Sencadas, V, Correia, V, Rocha, J.G., Lanceros-M ndez, S., 2013. Energy harvesting performance of piezoelectric electrospun polymer fibers and polymer/ceramic composites. Sensors Actuat. A Phys. 196,55-62. 

Megelski S., Stephens J. S., Chase D. B., and Rabolt J. R, Micro- and nanostructured surface morphology on electrospun polymer fibers. Macromolecules, 2002,35,8456-8466f... 

The electrospun fiber mats possess a high surface area per unit mass, low bulk density, and high mechanical flexibihty. These features make these materials very attractive for a wide range of potential applications, as mentioned above. Among them, the use of electrospun polymer fibers for electronic applications is of particular interest. The high surface-to-volume ratio associated with electrospun conducting polymer fibers makes them excellent candidates for electrode materials since the rate of electrochemical reaction is proportional to the surface area of an electrode and diffusion rate of the electrolyte. 

Fig. 13 (a) Preparation of Ti02-coated electrospun polymer fibers using layer-by-layer deposition method, (b) SEM and (c) TEM images of Ti02-coatedpoly(dimethylsiloxane-b-etherimide) fibers. 

Kriha O, Becker M, Lehmann M, Kriha D, Krieglstein J, Yosef M, Schlecht S, Wehrspohn RB, Wendorff JH, Greiner A (2007) Connection of hippocampal neurons by magnetically controlled movement of short electrospun polymer fibers - a route to magnetic micromanipulators. Adv Mater 19 2483-2485... 

Yun, K.M., Hogan, C.J., Matsubayashi, Y, Kawabe, M., Iskandar, E, Okuyama, K., 2007. Nanoparticle filtration by electrospun polymer fibers. Chemical Engineering Science 62, 4751-4759. 

In 2011, Kaskel et al. [30], reported the use of electrospinning process for the immobilization of MOF particles in libers. They used HKUST-1 and MIL-100(Fe) as MOF particles, which are stable during the electrospinning process from a suspension. Electrospun polymer fibers containing up to 80 wt% MOF particles were achieved and exhibit a total accessible inner surface area. It was found that HKUST-l/PAN gives a spider web-like network of the fibers with MOF particles like trapped flies in it, while... 

Biomacromolecules 3(2) 232-238. doi 10.1021/bm015533u Megelski S, Stephens JS, Chase DB, Rabolt IF (2002) Micro- and nanostroctured surface morphology on electrospun polymer fibers. Macromolecules 35(22) 8456-8466. doi 10.1021/... 

Rebollar, E Cordero, D., Martins, A., Chiussi, S., Reis, R.L., Neves, N.M., and Leon, B. (2011) Improvement of electrospun polymer fiber meshes pore size by femtosecond laser irradiation. AppZ. Surf. ScL, 257,4091-4095. 

Camso, R. A., J. H. Schattka, and A. Greiner (2001). Titanium dioxide tubes from sol-gel coating of electrospun polymer fibers. Advanced Materials 13(20) 1577-1579. 

Zugle R, Nyokong T (2013) Comparative phototransformation of environmental pollutants using metallophthalocyanines supported on electrospun polymer fibers. J App Polymer Sci 128 1131-1142... 

A study of PET by Haubruge et al. [234] was conducted in the vapor phase, on both spin coated thin films and sections exposed at room temperature to vapors of the freshly made solution for 5min to Ih. The 13% active chlorine aqueous sodium hypochlorite used is stronger than shown in Scheme 4.3. A study of micro-and nanostructured surface morphology on electrospun polymer fibers was conducted on... 

Figure 6.4 shows the whole and simple process. The mechanism lies in the thermal annealing above the glass transition temperature of polymer nanofibers. At this time, the wetting of polymer chains within the polymer nanofiber will have enough mobility to move into the template. Finally, controllable hierarchical stmctures can be constmcted on the outer surface of electrospun polymer fibers [9]. 

Chen, J. T., W. L. Chen, and P. W. Fan, Hierarchical Structures by Wetting Porous Templates with Electrospun Polymer Fibers. ACS Macro Letters, 2011,1(1), 41. ... 

The aims of the addition of inert ceramic filler to the electrospun polymer fiber matrix to form polymer/ceramic composite fiber membrane for separator in LIB were on one hand to prevent dimensional changes by thermal deformation at high temperature because of the frame structure of the heat-resistant ceramic powder and on the other hand to increase the ionic conductivity of the membrane due to the intrinsic ionic conductivity of the ceramics. Various ceramic fillers had been incorporated into the electrospun polymer membranes to make composite separators, including aluminum oxide (AI2O3) [61], fumed silica (SiOa) [29,48,62], titanium dioxide (Ti02) [50, 63-65], lithium lanthanum titanate oxide (LLTO) [51], and lithium aluminum titanium phosphate (LATP) [52],... 

In the field of tissue engineering, more information on and a better understanding of the wettability and permeability of nanofiber yams, as well as their structural properties as a function of biodegradation, should lead to the development of highly functional tissue scaffolds and wound dressings. Successful electrospinning of other materials, such as metals and non-oxide ceramics, and better control over the crystallinity of electrospun polymer fibers will lead to significant advances in nanofiber reinforced composite materials. 

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