Polymer nanocomposites films

As mentioned above, the new method of cryochemical synthesis of polymer nanocomposite films has been developed based on co-deposition of M/ SC and monomer vapors at temperature 80K and subsequent low-temperature solid-state polymerization of monomer matrix ([2] and works cited herein). It has been established that a number of monomers (acrylonitrile, formaldehyde, /i-xylylene and its derivatives) polymerize in solid state in absence of thermal movement of molecules owing to own specific supra-molecular structure. When reaction is initiated by y- or UV-radiation the formation of a polymer matrix occurs even at the temperatures close to temperature of liquid helium [66-69]. 

The LBL, in-situ self-assembled LBL films of PPy, PANI, polyhexylthiophene, and poly(ethylene dioxythiophene) (PEDT) and hybrid cross-linked nanocomposite thin film for NOx gas sensing were fabricated [68,70,101-106] for NO2 sensing application. Layered films of conducting polymer nanocomposite films were fabricated similar to the one explained in Sections 2.2.1 and 2.2.2. 

Liu, Y, Wang, A. and Claus, R. 1997. Molecular self-assembly of TiOj/polymer nanocomposite films../. Phvs. Chem. B 101(8) 1385-1388. 

In the large field of nanotechnology, polymer-based nanocomposites have become a prominent area of current research and development for biomedical applications.In principle, nanocomposites are an extreme case of composite materials in which interface interactions between the two phases, the matrix and the reinforcement, are maximized. In the literature, the term nanocomposite is used for polymers with sub-micrometre dispersions. In polymer-based nanocomposites, nanometre sized particles of inorganic or organic materials are homogeneously dispersed as separate particles in a polymer matrix. Researchers have tried a variety of processing techniques to obtain dense polymer nanocomposite films. The incorporation of nanostructures into polymers can generally be done in different ways as indicated below ... 

Nakayama N, Hayashi T (2007) Preparation and characterization of Ti02 and polymer nanocomposite films with high relractive index. J Appl Polym Sci 105(6) 3662-3672... 

Shah MdSAS, Nag M, Kalagara T, Singh S, Manorama SV. Silver on PEG-PU-T102 polymer nanocomposite films an excellent system for antibacterial applications. Chem Mater March 2008 20 2455-60. 

As mentioned previously, the barrier properties of PLA nanocomposites depend both on the particle size and on the dispersion. If the dispersion in two samples is of the same order, the barrier properties depend on the size of the particles and vice versa [118]. Gas and vapor barrier properties of polymer nanocomposite films are increased because of the large aspect ratios of the clays that result in strong interfacial interactions between the polymeric matrix and the nanoclays [123]. Depending on the strength of the polymer/clay interfacial interactions, three broad classes of nanocomposites are thermodynamically achievable (Figure 12.9) [118] ... 

Fig. 4.4 (a) Schematic of Pd-based optical sensor and (b) calibration curve of a 40-nm thick Pd-polymer nanocomposite film at 370 nm (Reprinted with permission from Fedtke et al. (2004). Copyright 2004 Elsevier)... 

Ihere are only a few recent studies on the fabrication and characterization of stand-alone bio-polymer nanocomposite films or coatings displaying Hquid repellent properties. Obeso et al. [23] developed a superhydrophobic surface by precipitation of poly(hydroxybutyrate) (PHB) on the surface of cellulose fibers of papers using a phase separation process. The same authors used a similar approach to synthesize biodegradable superhydrophobic poly (L-lactic acid) substrates in order to control cell adhesion. Superhydrophobic/superoleophilic porous poly (L-lactic acid) films were also prepared by Xue et al. for water-oil separation applications [24]. Yohe et al. [25] prepared 3D superhydrophobic materials from biocompatible... 

FIG U RE 3.53 Schematic of in situ diazonium generation and electroreduction onto an ITO-coated flexible PEN substrate. The digital photograph shows the flexible TTO substrate grafted with silver-polymer nanocomposite film under bending stress. (Adapted from Samanta, S. et al. Langmuir 30, 2014 9397-9406.)... 

Chandran, S., Basu, J.K., Mukhopadhyay, M.K. Variation in glass transition temperature of polymer nanocomposite films driven by morphological transitions. J. Chem. Phys. 138(1), 014902 (2013)... 

The PL decay patterns for polymer nanocomposites films with two different Si02 Au nanoparticles are shown in Fig. 15.9. The rate of PL decay in PPV nanocomposites doped with Si02 Au nanoparticles was drastically reduced, as compared with that of the pristine PPV. This suggests that the rate of luminescence-quenching by exciton trap formation is slowed considerably. The protection against photo-oxidation inherited by Si02 Au nanoparticles in PPV could be accomplished with an extremely low concentration, corresponding to... 

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