Nanocomposite Biomaterials<br />A nanocomposite is as a multiphase solid material where one of the phases has one, two or three dimensions of less than 100 nanometers (nm), or structures having nano-scale repeat distances between the different phases that make up the material.<br /><ul><li> The mechanical, electrical, thermal, optical, electrochemical, catalytic properties of the nanocomposite will differ markedly from that of the component materials. </li></li></ul><li>PROPERTIES OF NANOCOMPOSITES<br />Nanocomposites can dramatically improve properties like:<br /><ul><li>Mechanical properties including strength, modulus and</li></ul> dimensional stability<br /><ul><li>Electrical conductivity
Decreased gas, water and hydrocarbon permeability
CERAMIC-MATRIX NANOCOMPOSITES<br /><ul><li> In this group of composites, the main part of the volume is occupied by a ceramic, i.e. a chemical compound from the group of oxides, nitrides, borides, silicides etc.
In most cases, ceramic-matrix nanocomposites encompass a metal as the second component.
Ideally both components, the metallic one and the ceramic one, are finely dispersed in each other in order to elicit the particular nanoscopic properties.
Nanocomposite from these combinations were demonstrated in improving their optical, electrical and magnetic properties as well as tribological, corrosion-resistance and other protective properties</li></li></ul><li>POLYMER-MATRIX NANOCOMPOSITES<br /><ul><li>An appropriately adding nanoparticulates to a polymer matrix can enhance its performance, often in very dramatic degree, by simply capitalizing on the nature and properties of the nanoscale filler
These materials are better described by the term nanofilled polymer composites
This strategy is particularly effective in yielding high performance composites, when good dispersion of the filler is achieved and the properties of the nanoscale filler are substantially different or better than those of the matrix, for example, reinforcing a polymer matrix by much stiffer nanoparticles of ceramics, clays, or carbon nanotubes.</li></li></ul><li>POLYMER – SILICATE NANOCOMPOSITES<br /><ul><li> Polymer – silicate nanocomposites are hybrid organic inorganic materials, in which mixing of the filler phase is achieved at the nanometer level, so that at least one dimension of the filler phase is less than 100 nm.
The fillers generally used for such composites are layered aluminosilicates, and most commonly montmorillonites ( MMT s) from the family of aluminosilicates.</li></li></ul><li>ELASTOMERIC NANOCOMPOSITES<br /><ul><li>Elastomeric Nanocomposites are further divided into two types:
Dendrimer Nanocomposites</li></li></ul><li>CLAY-POLYMER (NANO-)COMPOSITES<br /><ul><li> The Clay minerals are aluminosilicates with a 2:1-layer structure i.e. a central alumina octahedral sheet is sandwiched between two silica tetrahedral sheets.
Examples are : muscovite, phlogopite, smectites
The aluminosilicate layers are held together by cations (usually alkali or earth alkali metals) in the interlayer.
The thickness of one such layer is approximately 1 nm.
The surface cations as well as the interlayer cationsin smectitescan be exchanged against organic cations</li></ul>(e.g. ammonium, phosphonium). <br /><ul><li> This offers the possibility to modify the silicate surfaces and hence tune the filler matrix interaction.</li></li></ul><li>DENDRIMER NANOCOMPOSITES<br /><ul><li>Dendrimer composite nanoparticles are nanosized organic inorganic hybrid particles made from dendrimer templates that contain small clusters of inorganic nanomaterials of interest entrapped in the network of the macromolecular templates.
The method of reactive encapsulation involves preorganization of an appropriate reactant by the active interior sites of a dendrimer molecule, followed by immobilization of the product with respect to the host.
Combination of inorganic guests and dendritic building blocks into multiple structures such as chains, films and covalent clusters in solvents and solid matrices afford a wide repertoire of nanosized building blocks and architectures for more complex nanocomposite structures.</li></li></ul><li>BIONANOCOMPOSITES<br /><ul><li>Bionanocomposites form a fascinating interdisciplinary area that brings together biology, materials science, and nanotechnology.
Bionanocomposites add a new dimension to enhance the properties in that they are biocompatible and/or biodegradable materials.
These nanocomposites are of immense interest to biomedical technologies such as tissue engineering, bone replacement/repair, dental applications, and controlled drug delivery.</li></li></ul><li>BIOPOLYMERS COMMONLY USED IN BIOMEDICAL APPLICATIONS<br /><ul><li>Hydroxyapatite–Polymer Nanocomposites