Polymer/layered inorganic nanocomposites

Some examples of the application of eq. (2.6) for polymer/layered-inorganic nanocomposites could be ... 

Rheology of various polymer layered-silicate nanocomposites - intercalated, exfoliated and end-tethered exfoliated (prepared by in-situ polymerization from reactive groups tethered to the silicate surface), have been performed in a conventional melt-state rheometer in both oscillatory and steady shear modes. These experimental studies have provided insight into the relaxation of polymer chains when confined by the layers of inorganic silicates, as well as the role of shear in orienting the layered nanocomposites. 

A classification of methods for preparing polymer-layered inorganic solid compounds takes into account the main processes involved in the synthesis of the final hybrid material. The nature of both the 2D host solid and the guest polyma- determines the pathway applicable to obtain a particular nanocomposite and, in certain cases, is decisive in the behavior of the resulting material. In... 

As for the thermodynamic consideration in Section 2.2.1, we attempt to highlight these challenges by describing in some detail the most common synthetic routes for nanocomposite formation employed for polymer/layered-inorganic hybrids. Most examples are drawn from layered-silicate fillers, but the conclusions are general across most nanofillers, and one should be able to envision similar strategies for nanocomposite formation based on other types of nanofillers. 

Due to its ease of use and availability, simple Bragg-refiection powder x-ray diffraction is most commonly used to probe nanocomposite structure, especially for polymer/layered-inorganic filler hybrids where the [Pg.42]

Filling a polymer matrix with inorganic microparticles is a well-known process, but it may lead to fragile and opaque materials, as the filler behaves like defects at the microscopic scale. The polymer layered silicate nanocomposites, because of the nanometre size of silicate sheets, even at low filler content (1-5 wt%) exhibit markedly improved properties, as mechanical, thermal, barrier or flame retardant properties, in comparison to the unfilled matrix and more conventional microcomposites. 

Alexandre M and Dubois P (2000) Polymer-layered silicate nanocomposites preparation, properties and uses of a new class of materials. Mater Sci Eng 28 1-63. Sanchez C, Lebeau B, Chaput F and Boilot J-P (2003) Optical properties of functional hybrid organic-inorganic nanocomposites, Adv Mater 15 1969-1994. 

It has been well documented that polymer/layered-inorganic and polymer/clay nanocomposites are being explored extensively due to their high promise for potential applications and as model systems for nanoscopically confined polymers. These polymer/inorganic nanocomposites can be prepared by... 

Z. Wang and T.J. Pinnavaia, Hybrid organic-inorganic nanocomposites Exfoliation of magadiite mono-layers in an elastomeric epoxy polymer, Chem. Mater., 1998, 10 1820-1826. 

To fabricate different polymer layers in a device using solution based techniques, mutually exclusive solvents have to be identified, which is often very difficult. CVD eliminates these difficulties and excellent heterojunctions and multilayered films can be fabricated relatively easily. Also, the capability to co-deposit compounds can be achieved. This ease of co-depositing compounds has enabled the synthesis of several inorganic-organic hybrids, which can also be tailored as nanocomposites at the molecular level. 

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