Polymer blends, dyeing

Nylon blends, dyeing, 9 204 Nylon block copolymer, 19 762 Nylon carpet fibers, stain-resistant, 19 764 Nylon-clay nanocomposites, 11 313-314 Nylon extrusion, temperatures for, 19 789t Nylon feed yarns, spin-oriented, 19 752 Nylon fiber(s), 24 61 production of, 19 740 world production of, 19 7654 Nylon fiber surfaces, grafting of polymers on, 19 763-764... 

Figure 4.28 Dye-polymer blend, distributed heterojunction photovoltaic cell.

Energy is absorbed from the light field by an inert dye (quinizarin) that is added to the polymer blend in minute quantities. Neither the phase behavior nor the critical... 

The polymer blend PDMS/PEMS with molar masses of Mw = 16.4 and 22.3kgmol 1, respectively, is similar to the one which has previously been used for the investigation of transport properties in the critical regime [81]. A 515nm and 20 mW laser was used for local heating. The blend with a PDMS weight fraction of c = 0.536 is almost critical with a critical temperature of Tc = 37.7°C. A minute amount of an inert dye (quinizarin) was added for optical absorption at... 

The structure of the low bandgap polymeric semiconductor and the dopant dye is plotted in Fig. 5.19. The average thickness of the active layers, determined by AFM measurements, is between 80 and 110 nm. In order to obtain a better understanding of the transport behavior of polymer blends, low temperature studies of cells with pristine MDMO-PPV and MDMO-PPV/PTPTB 1 1 (wt. %) with Au electrodes were carried out. Au has a high work function and should therefore be a good hole injection contact and provide a high barrier for electron injection. The device will therefore be a hole-only device, as described earlier in this chapter [14]. 

The field-dependent mobility expression is universal and applicable to a large class of materials including conjugated polymers, blends, and mixtures of polymers and dyes. 

Lee T. W., Park O. O., Cho H. N., and Kim Y. C. Cascade enerev transfer in dye-dot>ed ternary polymer blend lieht-emittine diodes Synthetic Metals, Volume 131, Issues 1-3, 20 November 2002, Pages 129-133... 

Synthalube. [PiedmotuChem. Industries] Anionic/polymer blend protecting knits and woven fabrics during preparation and dyeing. 

On the other hand, fibers of miscible blends obviously yield a single-phase stmcture. This type of fiber is rare, firsfly because the known miscible polymer blends do not lend themselves to fiberforming (usually they are amorphous), and secondly because the effects sought by blending often require properties provided by a two-phase structure. One property that could be modified by fiber spinning a miscible blend is dyeabUity, an important parameter of some commercial fibers, e.g., used for textile or carpet yams. An addition of a miscible polymer could enhance the number of dye-active sites. 

Bruttig, W., Berleb, S., Egerer, G., Schwoerer, M., Wehrmann, R., and Elschner, A. 1997. Full color electroluminescence using dye-dispersed polymer blends. Synth. Met. 91 325-327. 

Park et al. [18] reported the synthesis of dye-sensitized solar cells (DSSCs) based on electrospun polymer blend nanofibers as electrolytes. Electrospun poly(vinylidenefluoride-co-hexafluoropropylene) (PVDF-HFP) and PVDF-HFP/polystyrene (PS) blend nanofibers were prepared as shown in Figure 1.16. The authors reported that the photovoltaic performance of dye-sensitive solar cell (DSSC) devices using electrospun PVDF-HFP/PS (3 1) nanofiber was much better as compared to DSSC devices using electrospun PVDF-HFP nanofiber. It was further observed that the overall power conversion efficiency of the DSSC device using PVDF-HFP nanofiber had a lower value than that of the DSSC device using electrospun PVDF-HFP/PS blend nanofibers... 

H. K. Lee, T.-H. Kim, J. H. Park, J.-K. Kim, O. O. Park, White-Light-Emitting Diodes Using Miscible Polymer Blend Doped with Phosphorescent Dye. Org. Electron. 2011,12,891-896. 

Supercritical modification of polymers was studied by several scientists to improve or change the properties of polymers. Polymers can either be chemically or physically modified. Examples of chemical modifications are the functionalization of polymers (grafting) or a chemical reaction of the functional groups of polymers to obtain new materials [38, 39]. Examples of physical modifications are the preparation of polymer blends, impregnation of polymers with additives [46], or foaming of polymers [59-61]. Another studied topic of polymer modification and impregnation is the supercritical dyeing of polymer fibers [40, 41). 

Another fluorene copolymer containing the luminescent dye [4-dicyanomethylene-2-methyl-6-4//-pyran (DCM) as acceptor compound was irradiatiated with UV light in the presence of gaseous triaUcylsilanes. This reagent selectively saturates the C = C bonds in the DCM comonomer units while leaving the fluorene units essentially unaffected. As a result of the photochemical process, the red electroluminescence of the acceptor compound vanishes, and the blue-green electroluminescence from the polyfluorene units is recovered. Compared with previous processes based on polymer blends, this copolymer approach avoids problems associated with phase-separation phenomena in the active layer of OLEDs [256]. 

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