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2014 | Buch

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Nanostructured Materials Preparation via Condensation Ways

verfasst von: Anatolii D. Pomogailo, Gulzhian I. Dzhardimalieva

Verlag: Springer Netherlands

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

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Über dieses Buch

The book is devoted to novel nanostructured materials and nanotechnology. A comprehensive analysis of the condensing methods of preparation of novel nanostructured materials is given. The methodology of power-consuming preparation of nanostructured materials is discussed, including thermolysis, photo- and radiolytic, electrochemical and mechanochemical methods. The peculiarities of chemical transformations in organic and inorganic matrices are compared. Special attention is given to kinetics and mechanism of the formation of nanocomposites. The structure and properties of such nanostructured materials are analysed.

Inhaltsverzeichnis

Frontmatter

Chapter 1. General Introduction

Abstract

The nanocomposite science concerning the class of composite materials, whose typical feature is nanometer size of their structural elements (metal particles, their oxides, chalcogenides, carbides, nitrides, etc.) has appeared in the last decades of twentieth century at the junction of different fields of knowledge: physical, organic, colloid, polymer chemistry, biology, and materials science.

Progress in this area depends significantly on competence of materials scientists for development of contemporary nanomaterials, the task is not only in creation of nanostructures, and in reaching the best knowledge of properties of these ensembles, but in processing and controlling of their assembling in any form, in knowledge of its structure at different spatial levels. Despite variety of methods of production of nanocomposites it has been found that all versatility of synthetic approaches to preparation of nanometer particles and their self-assembling can be reduced to two principally different ways: “top-down” (descending way) and “bottom-up” (ascending way). The first of them appears in various ways of grinding of coarse particles to nanometer, the essence of the “bottom-up” way is in assembling of nanoparticles from different atoms (or ions with the following reduction) to nanoparticles of a given size in presence of polymer matrix (or its precursor). The latter method, which is considered in this monograph, is more widely used due to its variability and potential abilities than the dispersion method. A researcher can predict in advance properties of obtained nanoparticles: he can choose content and properties of initial components, stabilizing agents, can estimate their role, predict conditions of nucleation and growth of the nanoparticles at each stage, thus constructing designed materials.

Anatolii D. Pomogailo, Gulzhian I. Dzhardimalieva

Chapter 2. Reduction of Metal Ions in Polymer Matrices as a Condensation Method of Nanocomposite Synthesis

Abstract

The colloid-chemical methods of nanocomposite synthesis basically involves chemical reduction of metal salts in presence of additives such as surfactants, ligands, polymers, etc. In this Chapter we focus on the chemical reduction routes that are frequently used to prepare the metal nanocomposites, including electrochemical and photochemical pathways. Several new approaches on the preparation of colloidal metals in constrained environments as in the reduction of transition metal salts in micelles, surfactant emulsions, liquid crystals, or polymerized vesicles are also described. Special attention is paid to various types of reduction agents as well as reaction conditions (temperature, nature of solvents, pH medium, concentrations of reagents, etc.). The chapter highlights the factors that influence the particle size and morphology, composition and structure of nanocomposites. The basic principles and mechanisms of nucleation and growth of nanoparticles are discussed in detail.

Anatolii D. Pomogailo, Gulzhian I. Dzhardimalieva

Chapter 3. Physical-Chemical Methods of Nanocomposite Synthesis

Abstract

On the whole, methods of production of nanostructural materials can be divided in two groups: physical and chemical. However, this separation is conditional, because, for example, all physical methods contain considerable chemical component, and it is often difficult to draw a distinct boundary between different methods. Special character of physical methods, prevailingly vapor phased, is in formation of crystal nanoparticles with vast open surface, which advances formation of strong aggregates, difficultly parted into primary particles. Moreover, it is often impossible to obtain complex phases because of their segregation at high temperatures typical of gas phase processes. A special place has methods, in which nanoparticles form as a result of different “physical” impacts, for example, under ultrasonic or microwave radiation. This effect stimulates different processes in a reaction mixture, first of all, chemical reactions, which brings to formation of nanostructural material with a definite composition, structure and properties. Therefore, these methods are often related to intermediate physical-chemical group.

Most physical-chemical methods of production of nanoparticles are based on homogeneous nucleation in vapor phase or heterogeneous nucleation in contact with surface, followed by condensation and coagulation. A necessary condition for condensation from the vapor phase is supersaturation, which can be reached by physical or chemical methods. Depending on a character of the heating processes (resistive, laser, plasma, electric arc, induction, ionic) and cooling, different methods of production of nanomaterials are distinguished, such as flame pyrolysis, synthesis in a flow reactors, laser induced evaporation and pyrolysis, thermal and microwave plasma methods, laser ablation. This group also includes solvo-thermal synthesis, pyrolysis of aerosols, and most methods of growth of nanoparticles and films from vapor phase, for example, chemical deposition form vapor phase (CVD), etc. In this chapter, the most typical methods are considered, which are of keen interest for production of nanocomposite materials. These are synthesis by microwave irradiation, photochemical reduction, radiation induced and sonochemical pathways.

Anatolii D. Pomogailo, Gulzhian I. Dzhardimalieva

Chapter 4. Physics and Chemistry of Sol-Gel Nanocomposites Formation

Abstract

This method called sol-gel is one of the most universal condensation ways of production of nanoparticles stabilized by inorganic oxide or polymeric matrices. Traditional sol-gel concept is based on hydrolysis and condensation of metal alkoxides and many metalloids including different ways of their modification. Main reactions proceed at relatively low temperatures with usage of prepared in advance or synthesized in parallel polymers, and are convenient techniques for preparation of organic-inorganic nanocomposites compared with commercial silicate-intercalation technique. Sizes of formed nanoparticles in a composite can be reduced to 10 nm by choice of relative conditions. Sol-gel process makes it possible to obtain homogeneous products of constant chemical composition, high purity, with good reproducibility. Homogeneity of the initial solution provides good control over sizes and microstructures of inorganic filler, and conservation of these features in a polymer. This approach allows, on the one hand, studying in more detail mechanism of formation of nanoparticles, control over their sizes, and, on the other hand, construction of the class of the novel materials having synergetic properties of the initial components: inorganic phase can capture into “a trap,” oxide network, not only nanoparticles, but monomers or polymer links. The leading role in these non-equilibrium self-organized systems have interphase interactions between inorganic and polymer components.

In this chapter we briefly focus on these problems from uniform position of “bridge building” between “inorganic” sol-gel synthesis of precursor nanoparticles and organic polymer phase taking part some way or other in formation of a nanocomposite.

Anatolii D. Pomogailo, Gulzhian I. Dzhardimalieva

Chapter 5. Physical Chemistry of Intercalated System

Abstract

The driving force of development of intercalation chemistry is significant improvement of properties of fabricated nanocomposites and design of materials with new properties. Forming hybrid structures define important functional characteristics: improved mechanical strength (increase in modulus), enhanced stiffness, heat resistance (decrease in thermal expansion coefficient), heat stability, and other thermal physical properties, water resistance, interesting barrier properties for gas separation, high flame and fire resistance, electric and electrochemical behavior, size stability, chemical stability, different from the simple additive properties. In this chapter physico-chemical peculiarities and intercalation properties of natural and synthetic layered materials of various types are considered. Special attention is paid to the features of polymerization of monomers and assembly of polymers in layers of silicates as well as to formation of nanocomposites by an direct intercalation of polymers from their solutions or melts. The practical value post-intercalation transformations of “guest” molecules in layered lattices of “host” are analysed. The main data on the structure and properties of inclusion nanocomposites (including those of metal chalcogenides) are summarized. The problems and future prospects of such nanosystems are outlined.

Anatolii D. Pomogailo, Gulzhian I. Dzhardimalieva

Chapter 6. Thermolysis of Metallopolymers and Their Precursors as a Way for Synthesis of Nanocomposites

Abstract

The thermal transformations of metallopolymers and their most typical precursors, resulting in the formation of nanocomposite materials, are considered. Thermolysis is an easy, reproducible and well-controlled route to prepare the nanocomposite materials. The attention is focused on the methodology of thermolysis including kinetic approaches. The most important chemical reactions taking place during this process conducted in organic matrices are discussed. The microstructure of the nanoparticles being formed and the mechanisms of their self-conservation upon thermolysis of metal-containing precursors are analyzed.

The key method for the preparation of metal-containing polymeric composites is thermolysis of metal compounds that are readily decomposed both in the pure state and in the polymer matrix (carbonyls, nitrosyls, thiolates, saturated carboxylic acid salts, organometallic and complex compounds) where destruction of the organic part affords the polymeric shell. A new approach based on the use of metal-containing monomers as precursors is also considered. In this case, polymerization and synthesis of metal-containing nano-sized particles occur simultaneously during the thermal transformation.

An important application of the thermolysis is the preparation of carbon nanomaterials (for example, single- and multiwalled nanotubes, nanorods, nanospheres, etc.). Depending on the nature of the polymer and conditions of thermolysis, various carbon structures can be formed, including graphite- and diamond-like structures.

Anatolii D. Pomogailo, Gulzhian I. Dzhardimalieva

Chapter 7. Bionanocomposites Assembled by “From Bottom to Top” Method

Abstract

Nanobiotechnology is a rapidly increasing research field located at the crosslink of materials science, nanotechnology and molecular biotechnology. Interaction of nanoparticles with biopolymers (proteins, nucleic acids, polysaccharides) plays very important role in enzyme catalysis, biosorption, biohydrometallurgy, geobiotechnology, etc.). There is a great interest to nanomaterials, which can be used in biomedical and pharmaceutical applications due to their biocompatibility and biodegradation. Functional nanoparticles, covalently bound to biological molecules can be used as nano-carriers in drug delivery, cancer treatment, nano-structured films or scaffolds for medical implants, artificial bones and tissues, etc. In this chapter recent routes including sol-gel and intercalation processes for the bottom-up assembly of bionanocomposites are considered in detail.

Biologic production systems are of special interest due to their effectiveness and flexibility, as environmentally friendly pathways for nanoparticle synthesis. Biogenic nanoparticles often exhibit water-soluble and biocompatible properties, which are essential for many applications. The potential of biological organisms such as plant extracts, bacteria, actinomycetes, algae, yeasts and fungi for biosynthesis of nanoparticles is analysed as promising alternative to the known physical and chemical production methods when their disadvantages could be overcome. Special attention is paid to enzymatic strategy for the synthesis of nanomaterials of different chemical compositions, well-defined shapes and sizes. A number outlooks for applications of bionanocomposites are discussed.

Anatolii D. Pomogailo, Gulzhian I. Dzhardimalieva

Backmatter

Titel: Nanostructured Materials Preparation via Condensation Ways
verfasst von: Anatolii D. Pomogailo
Gulzhian I. Dzhardimalieva
Verlag: Springer Netherlands
Electronic ISBN: 978-90-481-2567-8
Print ISBN: 978-90-481-2564-7
DOI: https://doi.org/10.1007/978-90-481-2567-8

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