Chemical vapor deposition polymerization method

A doped Si substrate with as-grown multiwalled (MW) CNTs synthesized through a thermal chemical vapor deposition (CVD) method was attached to a stainless steel working electrode, as shown in Fig. 27a [141]. A P3HT layer with a thickness of 20 nm was directly deposited on the surface of the MWCNTs using an electrochemical polymerization method. The electrolyte for the electrochemical polymerization consisted of 3-HT monomers, BMIMPFs as the ionic liquid, and anhydrous acetonitrile as the solvent. 

Typical processing methods - chemical vapor deposition polymerization electrospinning spin coating ... 

According to Ref. [12], template for synthesis of nanomaterials is defined as a central structure within which a network forms in such a way that removal of this template creates a filled cavity with morphological or stereochemical features related to those of the template. The template synthesis was applied for preparation of various nanostructures inside different three-dimensional nanoporous structures. Chemically, these materials are presented by polymers, metals, oxides, carbides and other substances. Synthetic methods include electrochemical deposition, electroless deposition, chemical polymerization, sol-gel deposition and chemical vapor deposition. These works were reviewed in Refs. [12,20]. An essential feature of this... 

Chemical vapor deposition (CVD) is a process whereby a thin solid film is synthesized from the gaseous phase by a chemical reaction. It is this reactive process that distinguishes CVD from physical deposition processes, such as evaporation, sputtering, and sublimation.8 This process is well known and is used to generate inorganic thin films of high purity and quality as well as form polyimides by a step-polymerization process.9-11 Vapor deposition polymerization (VDP) is the method in which the chemical reaction in question is the polymerization of a reactive species generated in the gas phase by thermal (or radiative) activation. 

We can easily classify the fabrication methods for SiC as conventional and nonconventional. The former category would include chemical vapor deposition while the latter would include controlled pyrolsis of polymeric precursors. There is yet another important type of SiC available for reinforcement purposes, SiC whiskers. We give a brief description of these. 

The design of the interstices filling in colloidal crystals with appropriate media and subsequently fluid-solid transformation is central to the whole synthesis. Fluid precursors in the voids of crystal arrays can solidify by polymerization and sol-gel hydrolysis. More recently, many methods have been developed including salt precipitation and chemical conversion, chemical vapor deposition (CVD), spraying techniques (spray pyrolysis, ion spraying, and laser spraying), nanocrystal deposition and sintering, oxide and salt reduction, electrodeposition, and electroless deposition. 

In order to find the domain of LCVD, it is necessary to compare various vacuum deposition processes chemical vapor deposition (CVD), physical vapor deposition (PVD), plasma chemical vapor deposition (PCVD), plasma-assisted CVD (PACVD), plasma-enhanced CVD (PECVD), and plasma polymerization (PP). All of these terms refer to methods or processes that yield the deposition of materials in a thin-film form in vacuum. There is no clear definition for these terms that can be used to separate processes that are represented by these terminologies. All involve the starting material in vapor phase and the product in the solid state. 

There are four main routes to the synthesis of PAVs [9] polymerizations via quinodimethane intermediates, polycondensations, transition-metal-mediated polycouplings, and metathesis polymerizations. Other methods such as chemical vapor deposition and electropolymerization have also been used on occasion but generally give poorer quality polymers. 

For forming a protective layer, dependent on the nature of the material, a vacuum vapor deposition method, a sputtering method, a plasma polymerization method, a chemical vapor deposition method or a coating method, can be applied. ... 

Thus, optimization of all of the parameters in one experiment is difficult. In contrast, chemical polymerization does not require any special instruments it is a rather simple and fast process. Chemical polymerization method involves oxidative polymerization of pyrrole monomer by chemical oxidants either in aqueous or non-aqueous solvents or oxidation by chemical vapor deposition in order to produce bulk polypyrrole as fine powders. Fe(III) chloride and water are found to be the best oxidant and solvent for chemical polymerization of pyrrole respectively regarding desirable conductivity characteristics. 

The methods of the preparation of parylene nanofibers by oblique angle vapor deposition polymerization have been detailed [114]. Monomer vapors produced by the pyrolysis of chemically functionalized / -xylylene precursors are directed in an oblique angle toward a surface to initiate a structured polymer growth. 

Design and fabrication of multidimensional nanostructures have been discussed for metals and ceramics in the previous chapters and most of the fabrication methods introduced earlier can be transferred to polymeric and composite systems. Generally, polymeric and composite nanostructures of different dimensions from 0-D (e.g., nanoparticles, nanodots) to 3-D (nanoscaffolds) can be fabricated by nanopattem-ing techniques, colloidal processes, electrospinning, physical and chemical vapor depositions, porogen strategy, self-assembly, and so on. These fabrication techniques discussed in the previous chapters are transferrable for preparing nanopolymers and... 

Plasma treatment is a method of modifying the chemistry and often the topography of a surface. It uses a highly ionized, activated gas to react with the molecules of a surface. The plasma gas can vary from an inert gas, such as argon or helium, which would be expected to cause the species at the surface to react with one another, or a polymeric monomer, which could polymerize on the surface and create a thin plasma-treated layer. Plasmas can also be employed to clean surfeces before modification. Chemical vapor deposition is a technique in which the sample is exposed to a vapor that reacts with the surface to modify it. 

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