Chemical functionalization composites fabrication

In order to overcome this drawback, there are two main approaches for the surface modification of carbon nanostructures that reoccur in the literature. The first one is covalent functionalization, mainly by chemical bonding of functional groups and the second one is noncovalent functionalization, mainly by physical interactions with other molecules or particles. Both strategies have been used to provide different physical and chemical properties to the carbon nanostructures. Those that will be presented here are only a few examples of the modifications that can be achieved in carbon nanostructure surfaces and composite fabrication. 

A number of studies on CNT-polymer composites have focused on improving the dispersion and load transfer efficiency in other words the compatibility between the CNTs and polymer matrix through covalent chemical functionalization of CNT surface (12,40). Many of the studies reported above have used acid-functionalized CNTs to fabricate MWCNT-PMMA composites with improved mechanical properties using different processing methods (24,25,27,62). Yang et. al (68) modified the acid functionalized CNTs with octadecylam-ine (ODA) to obtain ODA-functionalized CNTs. These CNTs were reinforced in a copolymer P(MMA-co-EMA) to form composites with improved dispersion and mechanical properties. 

The purpose of this book is to summarize the basic principles of carbon nanotube chemistry in relation to the fabrication of polymer composites, but also to highlight some of the most remarkable advances that have occurred in the topic during the last recent years. Indeed, the rapid advances in the chemical functionalization of carbon nanotubes have paved the way towards the fabrication of hybrid polymer-based assemblies with enhanced potential in a wide range of applications. Recent studies have shown that such carbon... 

The synthesis and characterization of PANi-CNT composites has also been investigated [1,-22] Direct dissolution of pristine CNTs (without chemical functionalization) in aniline can occur via formation of donor acceptor charge complexes [23], Using this approach PANi-CNT composite films have been fabricated by chemical [24] or electrochemical[22, [25] polymerization of aniline containing dissolved CNTs. Alternatively, CNTs have been blended with PAne in solvents such as NMP, DMPU [26,27], The enhanced electroactivity and conductivity of the PANi-CNT composite films has been attributed to the strong interaction between CNTs and PANi, which enhances the effective degree of electron delocalization It was also shown that PANi... 

If a Lab-on-a-Chip is defined to be a unit that should be able to perform all chemical functions and detection in a monolithic device that fits in the palm of one s hand (or smaller), then existing Lab-on-a-Chip units are generally stiU quite underdeveloped. This miniaturization will require increased integration not only of fluidic elements, but also of electrical, optical or other t)q)es of elements. The major criteria that lead the choice of a detection scheme are the properties of the anal)d e (optical, electrical, electrochemical and physical), the composition of the sample (do the analytes have similar properties and/or similar concentrations ) and the required detection limit. Other specific criteria can be the price, ease of use and implementation and, as far as Lab-on-a-Chip devices are concerned, the ease of fabrication and the possibility for miniaturization. In applications where the Lab-on-a-Chip is discarded after a single use, the cost of the device is very important and can even limit the choice of detection scheme. 

Fabric Composition. The method of fabric manufacture dictates many of the characteristics of the sheet, but intrinsic properties are firmly estabhshed by the base polymer selected. Properties such as fiber density, temperature resistance, chemical and light stabiUty, ease of coloration, surface energies, and others are a function of the base polymer. Thus, because nylon absorbs more moisture than polypropylene, spunbonded fabrics made from nylon are more water absorbent than fabrics of polypropylene. 

There are many methods of fabricating the electrodes for these cell systems. The eadiest commercially successhil developments used nickel hydroxide [12054-48-7] Ni(OH)2, positive electrodes. These electrodes are commonly called nickel electrodes, disregarding the actual chemical composition. Alkaline cells using the copper oxide—2inc couple preceeded nickel batteries but the CuO system never functioned well as a secondary battery. It was, however, commercially available for many years as a primary battery (see BatterieS-PRIMARY cells). 

Chemical vapor deposition (CVD) of carbon from propane is the main reaction in the fabrication of the C/C composites [1,2] and the C-SiC functionally graded material [3,4,5]. The carbon deposition rate from propane is high compared with those from other aliphatic hydrocarbons [4]. Propane is rapidly decomposed in the gas phase and various hydrocarbons are formed independently of the film growth in the CVD reactor. The propane concentration distribution is determined by the gas-phase kinetics. The gas-phase reaction model, in addition to the film growth reaction model, is required for the numerical simulation of the CVD reactor for designing and controlling purposes. Therefore, a compact gas-phase reaction model is preferred. The authors proposed the procedure to reduce an elementary reaction model consisting of hundreds of reactions to a compact model objectively [6]. In this study, the procedure is applied to propane pyrolysis for carbon CVD and a compact gas-phase reaction model is built by the proposed procedure and the kinetic parameters are determined from the experimental results. 

Improved characterization of the morphological/microstructural properties of porous solids, and the associated transport properties of fluids imbibed into these materials, is crucial to the development of new porous materials, such as ceramics. Of particular interest is the fabrication of so-called functionalized ceramics, which contain a pore structure tailored to a specific biomedical or industrial application (e.g., molecular filters, catalysts, gas storage cells, drug delivery devices, tissue scaffolds) [1-3]. Functionalization of ceramics can involve the use of graded or layered pore microstructure, morphology or chemical composition. 

---