Nanoparticle manufacture methods

The Pd-Pb intermetallic catalyst and Au-NiO, nanoparticle catalyst developed and industrialized by Asahi Kasei are both unprecedented and unique aerobic oxidative esterification catalysts. We believe that three production processes - our oxidative esterification method (TEA to C4 isobutene hydrocarbon feedstock) in addition to the alpha process (C2 ethylene hydrocarbon feedstock) and the improved ACH process (C3 propene hydrocarbon to acetone feedstock see Chapter 7 in this book on the cumene-based phenol process) - will be competing for the top position in the global market as the MMA manufacturing method. 

Solid heterogeneous catalysts are typical finely dispersed systems. Depending on the manufacturing method, the porous stmcture of catalyst grain is formed by numerous microparticles or nanoparticles bound together. The diameter of these particles varies from a few nanometers to... 

Generally, the choice of the manufacturing method affects the type of fibers that nanoparticles will produce. This in turn will have consequences for the scaffold. There are three techniques known as phase-separation, electrospinning and self-assembly which can be employed for the construction of nanoscaffolds. Some common polymers used for nanoparticle fabrication by the electrospray technique are listed in the Table 11.1 below. 

There has been a vast increase in publications on carbon nanoparticles, such as Buckminster fullerene (C60) and single-walled nanotubes (SWNTs), since the late 1990s in response to the successful mass production methods of manufacturers... 

ENPs are emerging class of airborne nanoparticles having a main impact on the air quality of indoor environments these are unintentionally released into the ambient environment during the manufacture (commercial or research), handling, use or disposal of nanomaterials integrated products. Their physical and chemical characteristics differ from other nanoparticles produced through traffic [4], The health consequences of their inhalation are not yet well known. A number of studies have reported their number concentrations and size distributions in workplaces but their concentrations in ambient urban environments are largely unknown and warrant further research. Adequate methods have yet to be developed to quantify them in the presence of nanoparticles from other sources. 

The studies of metal-dielectric nanocomposites and methods of their manufacture also have a long history (see review [1]). Recently, the technological progress has ensured the development of a wide collection of new methods and techniques suitable for production of nanoparticles and nanomaterials, including nanocomposites. It is possible to classify these methods as the following ... 

Nanoparticles of synthetic polymers are usually manufactured by dispersion of preformed polymers. Although many methods can be used, they may be classified as monomer polymerization, nanoprecipitation, emulsion diffusion/solvent evaporation, and salting out. An appropriate method is selected mainly depending on polymer and drug natures. Polymerization of polymer monomers has been developed usually using poly(alkyl cyanoacrylate) [96,97]. Organic solvents are usually used in polymerization. A detailed description of this method is not provided here. 

Silver nanoparticles and nanopowders are manufactured by a wide variety of techniques. Methods for producing silver nanoparticles can be broadly classified into the following groups ... 

The nanomaterials thus manufactured in different industries—particularly drugs and pharmaceuticals— might pose risks to human health and other organisms due to their composition, reactivity, and unique size. Nanotechnology research and development, particularly in medical research, work at the micro- and nanoscale levels to develop new drug delivery methods, therapeutics, and pharmaceuticals. In such areas of research it is equally important to consider the potential interactions of nanomaterials with the environment and the associated risks. This involves studying the effects of natural nanoparticles in the air and soil, life cycle aspects of manufactured nanomaterials, and their fate and transport. Risk assessment also includes studies... 

Microfabrication has emerged from microelectronics manufacturing and is using its proven processes and process sequences. Additionally, specific methods have been developed to fabricate mechanical, electrical, optical, or sensor structures, which are characteristics of microfabrication. In order to stay within the scope of this book, only top-down methods, that is, the manufacture of smaller structures with higher functionality from larger structures by the use of subtractive methods, will be discussed. Bottom-up methods, which create larger structures by ordered arrangement of small units (molecules, nanoparticles), are still in their infancy and mainly employed for biosensors. 

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