Synthesis electrospinning

Several main synthesis methods widely applied to produce carbon nanotube-polyurethane nanocomposites were summarized above. In addition, latex technology (27), thermally induced phase separation (28), electrospinning (29,30) and many other methods also show their own advantages and promises, however, these methods will not be discussed here. 

Fig. 4 Synthesis of chitosan-PEG-FA (a), and electrospinning process for generating adenoviral (Ad)/chitosan-PEG-FA nanocomplexes (b)...

One-dimensional (1-D) nanosbuctures (b) are composed mainly of nanowires, nanorods and nanobelts. Spontaneous growth, template-based synthesis and electrospinning are considered bottom-up approaches, while lithography is a top-down technique [7, 84]. Two-dimensional (2-D) nanostructures (c) involve thin films, which have been the object of intensive study for almost a century and for which many methods have been developed and improved. 

Electrospinning has been appUed to MIP synthesis employing membrane formation techniques with the help of a support polymer, promising higher surface area, faster diffusion and more efficient washing out of the template molecule [97]. 

Katepalli, H. et al. Synthesis of hierarchical fabrics by electrospinning of PAN nanofibers on activated carbon microfibers for enviromnenfal remediation applications. Chem. Eng. J. 2011,171(3), 1194-1200. 

Nanofibres can be produced by a number of methods. They can be extracted from natural materials (e.g., cellulose or protein fibres) via physical separation and/or chemical extraction. They can also be produced by means of drawing, template synthesis, phase separation, self-assembly and electrospinning. The details are briefly described below. 

Shukla, S., et al., 2005. Electrospinning of hydroxypropyl cellulose fibers and their application in synthesis of nano and submicron tin oxide fibers. Polymer 46 (26), 12130-12145. 

Hadipour-Goudarzi, E., Montazer, M., I,atifi, M., Aghaji, A.A.G., 2014. Electrospinning of chitosan/sericin/PVA nanofihers incorporated with in situ synthesis of nano silver. Carbohydrate Polymers 113, 231—239. 

Other studies in 2000 by Drew et al. reported that it is very difficult to spin fibers of PANI complexed to sulfonated polystyrene (PANFSPS), even when solutions containing sodium chloride and dodecyl benzene sulfonic acid sodium salt were used to lower the surface tension and thereby enhance electrospinning [16,17]. However, PANFSPS nanofibers can be produced by adding a carrier polymer such as PEO, polyacrylonitrile, or polyurethane. Also reported was the use of electrostatically layered sulfonated polystyrene as a template for the surface polymerization of conjugated polymers in their conducting form. Enzymatic synthesis of PANI and a copolymer of pyrrole and PEDOT was done on electrospun nanofiber... 

A novel route to pure and composite fibers of polypyrrole was recently reported by Han and Shi [42]. An organic salt (FeAOT) was synthesized by the reaction of sodium l,4-bis(2-ethyUiexyl)sulfosuccinate (AOT) and ferric chloride. It was fabricated into nanofibers by manual drawing and electrospinning. Long PPy fibers were obtained for the first time by a vapor deposition reaction of pyrrole on the FeAOT fibers, and this technique was extended to the synthesis of PPy composite fibers with multiwalled carbon nanotubes (PPy-MWCNT fibers). The PPy and PPy-MWCNT fibers had a nanoporous morphology, a conductivity of 10-15 S cm and a tensile strength of 12—43 MPa. Studies of the electrochemistry and current-voltage characteristics of the PPy fibers were also reported. 

Giller, C., Gururajan, G., Wei, J., et al., 2011. Synthesis, characterization, and electrospinning of architecturally-discrete isotactic-atactic-isotactic triblock stoeoblock polypropene elastomers. Macromolecules 44 (3), 471 82. 

Lu, X., Wang, C., Wei, Y, 2009. One-dimensional composite nanomaterials synthesis by electrospinning and their applications. Small 5, 2349-2370. 

There are several techniques that allow to produce polymeric nanofibers, such as drawing, template synthesis, phase separation, self-assembly, solution blow spinning, and electrospinning. The drawing process requires a polymer with appropriate viscoelastic properties that is able to be deformed and kept connected by cohesive forces. Besides being simple and inexpensive, this technique is very limited for conjugate polymers, since most of them have lower solubility and form solutions with a small viscous modulus. 

There are various methods to synthesize polymer nanostructures, i.e., template synthesis, chiral reactions, self-assembly, interfacial polymerization and electrospinning. Recent developments in conducting polymer nanotubes and nanofibers were summarized by Long et al. Different preparation methods, physical properties, and potential applications of one-dimensional nanostructures of conjugated polyaniline (PANI), pol5 3nrole (PPy) and poly (3, 4-ethylenediox3d hiophene) (PEDOT) were discussed. 

C. Jiang, G. Zhang, Y. Wu, L. Li, and K. Shi, Facile Synthesis of Sn02 Nanocrystalline Tubes by Electrospinning and Their Fast Response and High Sensitivity to NOx at Room Temperature, Cryst Eng Comm, 14, 2739-47 (2012). 

Polymer nanofibers can be synthesized by several general methods. The most common techniques are template synthesis [13], chiral reaction [14], self-assembly [15], interfacial polymerization [16,17], and electrospinning technique [18]. 

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