hybrid materials (rus. гибридные материалы) — materials obtained through interaction of chemically different constituents (components), usually organic and inorganic, which form a specific (crystal, spatial) structure that is different from the structures of initial reagents, but often inherits certain motifs and functions of the original structures.

Description

If the basic component of the material is organic (polymer etc), such materials are called inorganic-organic, in the opposite case they are called organic-inorganic (complex metal framed structure, modified materials based on clays, zeolites, etc.). In some cases, mixtures of spatially distributed phases (composites, nanocomposites) are also considered hybrid materials, for example, when nanoparticles or nanowires are distributed in a polymer matrix; however, it is correct to include in hybrid materials only composites characterised by a fairly obvious chemical interaction between the components. This definition also covers many supramolecular compounds, such as metal complexes, but they are usually treated as a separate class of materials. Sometimes nanoparticles with chemically modified surfaces are also classified as hybrid materials.

The main methods for producing hybrid materials include intercalation, template synthesis, sol-gel process , and hydrothermal synthesis. In natural composites the size of inorganic particles ranges from several microns to several millimetres, and therefore the resulting materials are non-uniform, and can sometimes be seen with the naked eye. If we decrease the size of inorganic particles in such material to the size of the molecules of the organic part (several nanometres), we can improve the homogeneity of the composite and obtain improved or even completely new properties of the material. Such composites are often called hybrid nanomaterials.

Inorganic building blocks of these materials may be composed of nanoparticles, macromolecules, nanotubes, layered materials (including clays, layered double hydroxides, several xerogels). The number of organic building blocks is huge, so the number of possible combinations of organic and inorganic blocks is very large. Depending on the purpose all hybrid materials are divided into structural, functional (multifunctional) and bio-inorganic. Thus, substances consisting of an inorganic matrix formed by various silicates with inclusions of organic molecules are used as photochromic (changing colour upon exposure to light) and electrochromic (changing colour in response to an electric charge) materials whose optical properties can be varied by changing the organic component. Complexing of low molecular weight (drug) substances by nanoparticles or creating supramolecular complexes on the basis of biopolymers result in the formation of hybrid materials, nano-conjugates, "two-faced" particles (Janus particles), demonstrating specific activity of components.

A very broad application area is related to the creation of various coatings on the basis of hybrid materials that can be characterised by their high mechanical strength and scratch resistance. As well as this, additional components can be introduced into such composites in order to ensure specific characteristics, e.g. hydrophobic properties. Hybrid materials are traditionally used in medicine to make prostheses, since these materials have good mechanical strength due to their inorganic components, and good biocompatibility due to their organic molecules. Hybrid solid electrolytes combine the ion- and electron-conducting properties of various organic molecules with the heat resistance and durability of their inorganic matrix. One of the most promising applications for hybrid functional materials, primarily those on the basis of various morphological derivatives of vanadium oxides, is the production of electrode materials for advanced chemical power sources. Hybrid materials are also used in the manufacture of heterosurface sorbents for chromatography, sensors, heterogeneous catalysts, magnetic fluids, substrates for immobilisation of enzymes, and sorbents of heavy metals and organic pollutants.

Illustrations

Vanadium pentoxide nanotubes - a typical example of hybrid nanomaterials. Inside such nano
Vanadium pentoxide nanotubes - a typical example of hybrid nanomaterials. Inside such nanotubes, the vanadium-oxygen layers alternate with a structural guide template represented by molecules of a surfactant chemically bound with inorganic layers and coiled, together with such layers, into a nanotube or nanoroll. Nanotubulenes of this sort are produced during hydrothermal treatment of vanadium oxide in the presence of surfactants (hexadecylamine, etc.). Author: A. V. Grigorieva, Lomonosov Moscow State University, Department of Materials Science. Quoted from Nanometer Nanotechnology Community portal, www.nanometer.ru

Authors

  • Goodilin Evgeny A.
  • Shlyakhtin Oleg A.

Sources

  1. Bulk Synthesis of Transparent and Homogeneous Polymeric Hybrid Materials with ZnO Quantum Dots and PMMA // Wiley InterScience. — http://onlinelibrary.wiley.com/doi/10.1002/adma.200700736/abstract (reference date: 12.12.2011).
  2. Functional hybrid materials. — www.materialstoday.com/view/2086/functional-hybridmaterials-/ (reference date: 12.12.2011).

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