Synthesis Methods of Nanomaterials

E. Omurzak, J. Jasnakunov, N. Mairykova, A. Abdykerimova, A. Maatkasymova, S. Sulaimankulova, M. Matsuda, M. Nishida, H. Diara, and T. Mashimo, Synthesis method of nanomaterials by pulsed plasma in liquid, J. Nanosci. Nanotechnol. 7 (2007) 3157-3159. 

The methods used for the synthesis of metal NPss in colloidal solution are very important as they control the size and shape of NPs, which in turn affects their properties. Moreover, successful utilization of NPs in biological assays relies on the availability of nanomaterials in desired size, their morphology, water solubility and surface functionality, Several reviews on the synthesis of nanoparticles are available [93], Some reviews dedicatedly covered the synthesis of gold nanoparticles [109,127,140], Synthesis methods of CG (and other metal colloids) can arbitrarily be divided into following two major categories ... 

Mishra et al. (2010) reported basic documented principles regarding synthesis methodologies of nanomaterials. Nanotechnology-based synthetic methods are most commonly developed on the basis of two rational designs top-down or bottom-up engineering of individual components (Alexis et al. 2008). 

This article reviews the synthesis, characterization, and applications of rare earth oxide and snlphide nanomaterials. Special focus is placed on nanoparticulate materials and the description on nanoscale films and bulk nanoporous materials are intentionally excluded. In the first section, the synthesis methods of nanoparticles in general are reviewed, and examples of the production of rare earth oxides and sulphides are presented. The second section deals with the applications of rare earth oxides and sulphides, and they are discussed in relation to the unique properties of nanoscale particles. 

Figure 17.18 Schematic shows the typical synthesis method of carbon nanomaterials-based BC composite.

Narkiewicz, U. (2009) Methods of nanomaterials synthesis. Lecture, Co-Nan Summer School, West Pomeranian University of Technology, Gdansk. 

The most important nanomaterial synthesis methods include nanolithography techniques, template-directed syntheses, vapor-phase methods, vapor-liquid-solid (VLS) methods, solution-liquid-solid (SLS) approaches, sol-gel processes, micelle, vapor deposition, solvothermal methods, and pyrolysis methods [1, 2]. For many of these procedures, the control of size and shape, the flexibility in the materials that can be synthesized, and the potential for scaling up, are the main limitations. In general, the understanding of the growth mechanism of any as-... 

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... 

Hydrothermal synthesis is a powerful method used for the fabrication of nanophase materials due to the relatively low temperature during synthesis, facile separation of nanopartides in the product, and ready availability of apparatus for such syntheses. Versatile physical and chemical properties of nanomaterials can be obtained with the use of this method that involves various techniques (e.g., control of reaction time, temperature and choice of oxidant and its concentration). Several extensive reviews are available that discuss the fundamental properties and applications of this method [2, 3]. These reviews cover the synthesis of nanomaterials with different pore textures, different types of composition [2, 4—6], and different dimensionalities in terms of morphology [6-8]. 

Studies on the use of hydrothermal, microwave-assisted, and reflux synthesis methods for the development and application of nanomaterials have been reviewed. An important aspect of the green synthesis of metallic nanopartides involves techniques that make use of biological materials such as plant extracts and microorganisms. The design of nanomaterials and control of their desired properties have been reviewed. The unique properties of manufactured nanomaterials offer many potential benefits. 

During past decades, a relatively new method attracted much of attention of experimentalists, namely, the sol-gel method widely implemented in numerous scientific and industrial applications. Actually, it caused a breakthrough in material science it is worth mentioning that sol-gel routes are cmcial for synthesis of nanomaterials, and one of methods of the 21st century namely, commercial nanoporous glasses are readily available on the market just thanks to sol-gel technologies. 

Studies of useful size-dependent properties of nanomaterials are only possible when they are prepared and isolated in a monodisperse form. The synthesis, therefore, should address the need for a great degree of control over the structure, size, and also the composition of the particles. The design of successful synthetic strategies has enabled continuous exploration and exploitation of the unusual properties of nanomaterials that differ both from the single atom (molecule) and the bulk. This also suggests that the intended use of the nanomaterials will dictate the method that can be conveniently applied to obtain them. 

The advances in nanotechnology and synthesis methods have enabled nanomaterials to be produced in various shapes and structures. Coating of a luminescent layer activated by lanthanide ions on nanoparticles such as SiC>2 or AI2O3 is one of such approaches to develop new nanophosphors. In section 6, we review recent work on interesting spectroscopic features and luminescence dynamics of lanthanide ions in other novel low-dimensional nanostructures including core-shell, one-dimensional (ID) nanowires and nanotubes, two-dimensional (2D) nanofilms, hollow nanospheres, 2D nanosheet and nanodisk which have also attracted extensive attention. 

A third possibility for the synthesis of nanomaterials in constrained volumes is the use of molds (Figure 3.1c). Advantages of this method include its simplicity, versatility, and precise control over the shape of the solid, even with intricate forms. An elegant example of this strategy is the preparation of zeolites which precisely replicate the complex microstructure of wood. To do this, Dong et al. [43] infiltrated a zeolite synthesis solution into a wood sample. After the necessary hydrothermal treatment, and subsequent calcination to remove the template as well as the wood, a zeolitic structure was obtained that reproduced with full detail and fidelity the wooden sample used as a mold. 

New spatial forms of carbon - fullerenes, nanotubes, nanowires and nanofibers attract significant interest since the time of their discovery due to their unique physicochemical and mechanical properties [1-3]. There are three basic methods of manufacturing of the carbon nanomaterials (CNM) - laser evaporation, electric arc process, and catalytic pyrolysis of hydrocarbons. However, the multi-stage manufacturing process is a serious disadvantage for all of them. For example, the use of organic solvents (benzol, toluene, etc.) for separation of fullerenes from graphite soot results in delay of the synthesis process and decrease in the final product quantity. Moreover, some environmental problems can arise at this. 

There were developed two new technologies for manufacturing of novel carbon nanomaterials (fullerenes, nanotubes, carbonic nanoclusters) based on the idea of high-energy plasmochemistry synthesis with the use of the methods of electrical wire explosion and spark erosion of graphite and metallic materials (nickel, iron, copper) in organic medium. 

Abstract. Nanocarbon materials and method of their production, developed by TMSpetsmash Ltd. (Kyiv, Ukraine), are reviewed. Multiwall carbon nanotubes with surface area 200-500 m2/g are produced in industrial scale with use of CVD method. Ethylene is used as a source of carbon and Fe-Mo-Al- mixed oxides as catalysts. Fumed silica is used as a pseudo-liquid diluent in order to decrease aggregation of nanotubes and bulk density of the products. Porous carbon nanofibers with surface area near 300-500 m2/g are produced from acetylene with use of (Fe, Co, Sn)/C/Al203-Si02 catalysts prepared mechanochemically. High surface area microporous nanocarbon materials were prepared by activation of carbon nanofibers. Effective surface area of these nanomaterials reaches 4000-6000 m2/g (by argon desorption method). Such materials are prospective for electrochemical applications. Methods of catalysts synthesis for CVD of nanocarbon materials and mechanisms of catalytic CVD are discussed. 

Synthesis forms a vital aspect of the science of nanomaterials. In this context, chemical methods have proved to be more effective and versatile than physical methods and have therefore, been employed widely to synthesize a variety of nanomaterials, including zero-dimensional nanocrystals, one-dimensional nanowircs and nanotubes as well as two-dimensional nanofilms and nanowalls. Chemical synthesis of inorganic nanomaterials has been pursued vigorously in the last few years and in this article we provide a perspective on the present status of the subject. The article includes a discussion of nanocrystals and nanowires of metals, oxides, chalcogenides and pnictides. In addition, inorganic nanotubes and nanowalls have been reviewed. Some aspects of core-shell particles, oriented attachment and the use of liquid-liquid interfaces are also presented. 

---