Poly , optical limiting

Goh HW, Goh SH, Xu GQ, Lee KY, Yang GY, Lee YW, Zhang WD (2003). Optical limiting properties of double-C60-end-capped poly(ethylene oxide), double-C -end-capped polyethylene oxide)/poly(ethylene oxide) blend, and double-C -end-capped poly(ethylene oxide)/multiwalled carbon nanotube composite. J. Phys. Chem. B 107 6056-6062. 

P35 as photoconductors was also investigated in a single-layer device.67 A recent study also showed that polymer P35 displays a large optical-limiting response to a nanosecond laser pulse with satisfactory threshold value at 0.12J/cm2, and its behavior is superior to that for poly(4,4 -diethynyl-5,5 -bithiazole) organic polymer.60... 

H.-X. Wu, X.-Q. Qiu, R.-F. Cai, and S.-X. Qian. Poly(V-vinyl carbaz-ole)-grafted multiwaUed carbon nanotubes Synthesis via direct free radical reaction and optical limiting properties. Appl. Surf. ScL, 253(11) 5122-5128, March 2007. 

Although materials containing Ceo have been demonstrated as optical limiters, most are in the form of solutions [31,98-105], Comparable optical limiting has been reported for thick layers (several mm) of Ceo in poly(methyl methacrylate), however, when pumped on resonance at 532 nm [106]. 

Tang and Xu [68] have prepared soluble MWNT-containing photoconductive poly(phenylacetylenes) (NTs/PPAs) by in situ polymerizations of phenylacetylene catalyzed by WClis-Ph4Sn and [Rh(nbd)Cl]2 (nbd = 2,5-norbornardiene) in the presence of the NTs. They demonstrated that the NTs in the composite solutions can be easily aligned by mechanical shear, and an efficient optical limiting property was observed in these nanocomposite materials. 

In one of the early studies on this topic, Chen and co-workers observed third-order optical nonlinearity in an SWNT/polyimide composite. O Flaherty and co-workers reported that the optical limiting of the poly(9,9-di-n-octylfluorenyl-2,7-diyl)/MWNT samples was dependent upon the mass fraction of CNTs in the composites and foimd that the magnitude of the nonlinear effect increased with the mass fraction of the CNTs increasing from 0.011 to 0.038. 

The first type of polycarbosilane synthesized by using ADMET methodology was a poly[carbo(dimethyl)silane].14c Linear poly(carbosilanes) are an important class of silicon-containing polymers due to their thermal, electronic, and optical properties.41 They are also ceramic precursors to silicon carbide after pyrolysis. ADMET opens up a new route to synthesize poly(carbosilanes), one that avoids many of the limitations found in earlier synthetic methods.41... 

Fluorescence is much more widely used for analysis than phosphorescence. Yet, the use of fluorescent detectors is limited to the restricted set of additives with fluorescent properties. Fluorescence detection is highly recommended for food analysis (e.g. vitamins), bioscience applications, and environmental analysis. As to poly-mer/additive analysis fluorescence and phosphorescence analysis of UV absorbers, optical brighteners, phenolic and aromatic amine antioxidants are most recurrent [25] with an extensive listing for 29 UVAs and AOs in an organic solvent medium at r.t. and 77 K by Kirkbright et al. [149]. 

A flow injection optical fibre biosensor for choline was also developed55. Choline oxidase (ChOX) was immobilized by physical entrapment in a photo-cross-linkable poly(vinyl alcohol) polymer (PVA-SbQ) after adsorption on weak anion-exchanger beads (DEAE-Sepharose). In this way, the sensing layer was directly created at the surface of the working glassy carbon electrode. The optimization of the reaction conditions and of the physicochemical parameters influencing the FIA biosensor response allows the measurement of choline concentration with a detection limit of 10 pmol. The DEAE-based system also exhibited a good operational stability since 160 repeated measurements of 3 nmol of choline could be performed with a variation coefficient of 4.5%. 

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