ABSTRACT
MAT ............................................................................................. 231 9.11 Production of Nanocomposites .................................................. 232
9.11.1 Biopolymers ................................................................... 233 9.11.2 Nanobiocomposites with Chitosan Matrix ..................... 236 9.11.3 Nanotube Composites .................................................... 239 9.11.4 Mechanical and Electrical Properties of
Nanocomposites................................................................ 242 9.12 Applications ............................................................................... 244 9.13 Chitosan or Carbon Nanotube Nanofluids ................................. 245 9.14 Preparation Methods of Chitosan or CNTS Nano-Composites .... 246
9.14.1 Solution-casting-evaporation ......................................... 246 9.14.2 roperties and Characterization ....................................... 247 9.14.3 Crosslinking-casting-evaporation .................................. 248
9.15 Case Study II .............................................................................. 253 9.16 Concluding Remarks .................................................................. 263 Keywords .............................................................................................. 264 References ............................................................................................. 264
9.1 INTRODUCTION
Electrospinning is an economical and simple method used in the preparation of polymer fibers. The fibers prepared via this method typically have diameters much smaller than what is possible to attain using standard mechanical fiber-spinning technologies [1]. Electrospinning has gained much attention in the last few years as a cheap and straightforward method to produce nanofibers. Electrospinning differs from the traditional wet or dry fiber spinning in a number of ways, of which the most striking differences are the origin of the pulling force and the final fiber diameters. The mechanical pulling forces in the traditional industrial fiber spinning processes lead to fibers in the micrometer range and are contrasted in electrospinning by electrical pulling forces that enable the production of nanofibers. Depending on the solution properties, the throughput of single-jet electrospinning systems ranges around 10ml/min. This low fluid throughput may limit the industrial use of electrospinning. A stable cone-jet mode followed by the onset of the characteristic bending instability, which eventually leads to great reduction in the jet diameter, necessitate the low flow rate [2]. When the diameters of cellulose fiber materials are shrunk from micrometers (e.g., 10-100mm) to submicrons or nanometers, there appear several amazing characteristics such as very large surface area to volume ratio (this ratio for a nanofiber can be as large as 103 times that of a microfiber), flexibility in surface functionalities, and superior mechanical performance (e.g., stiffness and tensile strength) compared with any other known form of the material.
