Polymer nanocomposites optical properties

Highly structured, 3-D nanoparticle-polymer nanocomposites possess unique magnetic, electronic, and optical properties that differ from individual entities, providing new systems for the creation of nanodevices and biosensors (Murray et al. 2000 Shipway et al. 2000). The choice of assembly interactions is a key issue in order to obtain complete control over the thermodynamics of the assembled system. The introduction of reversible hydrogen bonding and flexible linear polymers into the bricks and mortar concept gave rise to system formation in near-equilibrium conditions, providing well-defined stmctures. 

It is evident that the incorporation of POSS cages into polymeric materials often results in substantial improvements in polymer properties and offer the possibility to control the mechanical, chemical and physical properties of the system during polymerization as well. Intense efforts have recently been directed toward the development of new porous materials because of their utihty and potential utihty as catalysts and catalyst supports [208,209], dielectric materials for electronic appHcations [210], media for optical [211] and sensor [212] applications, and selectively permeabihty membranes [213] and precursors [10] for POSS nanocomposites. Significant property enhancements imparted by the inclusion of a nanosized inorganic... 

Intercalation of electroactive polymers such as polyaniline and polypyrrole in mica-type layered silicates leads to metal-insulator nanocomposites. The conductivity of these nanocomposites in the form of films is highly anisotropic, with the in-plane conductivity 10 to 10 times higher than the conductivity in the direction perpendicular to the film. Conductive polymer/oxide bronze nanocomposites have been prepared by intercalating polythiophene in V2O5 layered phase, which is analogous to clays. °° Studies of these composites are expected not only to provide a fundamental understanding of the conduction mechanism in the polymers, but also to lead to diverse electrical and optical properties. 

Hydrodynamic and optical properties of polymers [NP(OR)2]n [R = CH2CF3, CH2(CF2)2H, CH2(CF2)4H] have been analysed. Mechanical properties of polyphosphazene-silicate nanocomposites, prepared from (NP[(0CH2CH2)20Me]2 n (MEEP) and tetraethoxysilane, have been investigated as function of the catalyst used. ... 

Metal sulphide semiconductors/polymer nanocomposites are considered to be highly functional materials with many applications, such as in photoluminescent, photoelectric and non-linear optical materials. The flexibility and processability of polymer matrices can provide good mechanical properties. 

The chemical-physical properties of nanocomposite and membrane finds unique place in sensor application due to combinational properties. The basic use of nanocomposite is to the products, which show many folds of improvement on the physical and mechanical properties or on the processing properties upon addition of very minute quantity of nanomaterials [99], Nanoscale particles not only enhance the mechanical properties but also have wide potential in the field of electronic, magnetic, optical, and chemical field. The polymer nanocomposites provide improvement over other known composites in thermal, mechanical, electrical, and even air barrier properties [64-70], Formulation of nanocomposite membranes with suitable polymer, suitable nanoparticles, and the processing technology of the nanocomposite are critical to success factor to dominate the gas sensor product in the market. 

Polymer clay nanocomposites are already used in many applications to enhance existing properties of a particular material, and development should be focused on the true multifunctional materials. Certainly, clay nanocomposites will continue to be used for enhanced mechanical, flammability, and gas barrier properties, but fundamental limits in clay chemistry prevent them from being used easily in applications requiring electrical/ thermal conductivity or optical properties. Similarly, combinations of... 

Nowadays a promising way to control the bulk polymer properties, such as conductivity, processability, thermal, and mechanical stabihties, is through the organization of the polymeric chains on the nanometer scale [7-9]. The first approach used to achieve this goal was the synthesis of conducting polymers in cavities of porous hosts. Commonly named nanocomposites, these materials have two or more different components on the nanoscale, and can show catalytic, electronic, magnetic, and optical properties better than those of the individual phases. The basic reason for this synergism is still not fully understood, but it is considered that confinement and electrostatic interactions between the components play an important role. 

Stability of common polymers, and consequently, thermal degradation of mercaptide molecules ean be also carried out with the mercaptide dissolved into a polymeric medium. In this case, a finely dispersed inorganic solid phase, embedded in polymer, is generated. Materials based on clusters confined in polymeric matrices are called nanocomposites [Mayer, 1998 Caseri, 2000]. Both semiconductor-polymer and metal-polymer nanocomposites have unique functional properties that can be exploited for applications in several advanced technological fields (e.g., optics, nonlinear optics, magnetooptics, photonics, optoelectronics) [Caseri, 2000]. 

Metal-polymer nanocomposites can be exploited for a number of technological applications. The functional uses of these materials are related primarily to their unique combination of high transparency in the visible spectral range with other physical properties (e.g., luminescence, magnetism, surface plasmon resonance, ultrahigh or ultralow refractive index, optical nonlinearity). 

Caseri, W., Nanocomposites of polymers and metals or semieonductors historical background and optical properties, Macromol. Rapid Corrmum., 21, 705-722 (2000). 

Botana et al. [50] have prepared polymer nanocomposites, based on a bacterial biodegradable thermoplastic polyester, PHB and two commercial montmorillonites [MMT], unmodified and modified by melt-blending technique at 165°C. PHB/Na and PHB/ C30B were characterized by differential scanning calorimetry [DSC], polarized optical microscopy [POM], X-ray diffraction [XRD], transmission electron microscopy [TEM], mechanical properties, and burning behavior. Intercalation/exfoliation observed by TEM and XRD was more pronounced for PHB30B than PHB/Na,... 

In this Chapter, we report on some examples of nanocomposites with CNTs, highlighting a meshwork of interactions between the mechanical, electrical and optical properties of CNTs and the interface with the polymer matrix. CNTs are considered ideal materials for reinforcing fibers due to their exceptional mechanical properties. Functionalization of CNTs seems to be the most effective way to incorporate these nanofibers into the polymer matrix. It is generally accepted that the fabrication of high-performance nanotube-polymer composite depends on the efficient load transfer from the host matrix to the tubes. If the percentage of nano-reinforcements is very low or if it is well-dispersed, there are more strong interfaces that slow down the progress of a crack. ... 

Ma, H., Cui, J., Chen, J., Hao, J. Self-organized polymer nanocomposite inverse opal films with combined optical properties. Chemistry 17, 655-660 (2011)... 

M. G. Murali, U. Dalimba, K. Sridharan, Synthesis, Characterization, and Nonlinear Optical Properties of Donor-acceptor Conjugated Polymers and Polymer/Ag Nanocomposites. /. Mater. Sci. 2012,47, 8022-8034. 

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