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Copolymers photochromic

N. and Hiraga, T. (2004) Selective doping of photochromic dye into nanostructures of diblock copolymer films by vaporization in a vacuum. Chem. Mater., 16, 3469-3475. [Pg.222]

Photochromic materials with liquid-crystal polymer40 2 are interesting advanced materials, due to their sensitivity to light, electric, and magnetic fields. Copolymers of polyacrylic or polysiloxane backbone, con-... [Pg.21]

First, the recording layer which contains photochromic spirobenzothiopyran in liquid-crystal polymer or polymer such as vinyl chloride-vinylidene chloride copolymer, is made colored by UV irradiation. In the recording (writing) process, a colorless recording dot in the recording layer is formed by semiconductor laser beams (789 nm, 15-20 mW).100 This process is essentially thermal decoloration of the photomerocyanine form by laser beam. [Pg.43]

Stumpe and his co-workers [ 122-124] synthesized several SCLC methaciy-late copolymers containing the photochromic N-salicylideneaniline (NSA) chro-mophore together with several other mesogenic and nonmesogenic groups. Copolymers, 58, had from 0 to 100% of the NSA chromophore. Most of these polymers had an unspecified 5 mesophase. The NSA chromophore undergoes an excited state proton transfer (Fig. 17) to the Z-keto (often called cw-keto form)... [Pg.179]

The easiest technique to establish a polymer-photochromic molecule (PC) interaction is to dissolve the photochrome in a polymer solution from which the solvent is evaporated afterwards. DHI 7 has been incorporated by this technique into poly(methyl)- or poly( -butyl methacrylate), vinylidene chloride, acrylonitrile (Saran F), polycarbonate, and polystyrene-butadiene copolymer (Panarez). [Pg.251]

Photochromic [1,2-b] naphthopyran derivatives, (IV), prepared by Hughes [4] exhibited absorption in the 400-550 nm (brown) range and were used in graft copolymer reactions. [Pg.532]

Fig. 1. Decoloration of a photochromic copolymer (27 C) Determination of the rate constant kj (slowest step) 585 nm... Fig. 1. Decoloration of a photochromic copolymer (27 C) Determination of the rate constant kj (slowest step) 585 nm...
It can be seen from Table 2 that the rate constants at 27 are higher for the a lymers than for the mixtures. Hiis order is reversed at higher temperature, due to the naUer Ea-value for the copolymers. The strong negative values of the activation entropies for the copolymers should be pointed out. Worth noting is also that the kinetic parameters vary with the photochrome content in the copolymer. [Pg.25]

For copolymers of photochrome X the situation is however different from the previous one the mixtures decolorize about twice as fast as the copolymers while the activation energies differ only slightly. [Pg.26]

Table 5. Decoloration of photochrome VIII copolymers. Influence of the glass transition tempera-... Table 5. Decoloration of photochrome VIII copolymers. Influence of the glass transition tempera-...
Noteworthy is also the discussion of Krysrewski and Nadolski on the photochromic properties of spirobenzopyran copolymers and copolyesters. They interpreted the photo-chromic feding on the basis of the formation of defects within the matrix resulting from the excess of energy on irradiation as mentioned above. [Pg.32]

FIG. 5.8 Absorption spectra of the photochromic IsoSm copolymers (A) KW40 (chloroform tion, 12 mg/l) (B) spin-coated films of (/ ) KM55, (2) SK28, (3) KW40, and (4) SK5. [Pg.154]

We should underline here one peculiarity of the chiral photochromic copolymers under discussion The ds-isomers have an extremely long lifetime... [Pg.154]

To summarize, photochromic chiral IsoSm copolymers are capable of photoreorientation under illumination with polarized light. If irradiated within the UV wavelength range (band T), the Anj j value achieves maximum... [Pg.159]

The combination of these features presents photochromic IsoSm films as interesting and diverse media for optical data storage. In Section 5.4, we consider holographic grating recording in copolymer films and related (combined) photorecording techniques. [Pg.160]

FIG. 5.2S Scheme af phase transitions in darkness and under illumination in chiral photochromic copolymers (A) SK8 and SK16 and B) KW40 and KM45. [Pg.169]

Btibrovsky, A., Boiko, N., and Shibaev, V. Photo-optical properties of new combined chiral photochromic liquid crystalline copolymers. Liquid Crystals 25, 393 (1998). [Pg.175]

Hayashi, T., Kawakami, H., Doke, Y., Tsuchida, A., Onogi, Y., and Yamamoto, M. Photo-induced phase transition of side-chain liquid crystalline copolymers with photochromic group. Eur. Polym.J. 31, 23 (1995). [Pg.175]

Chen, X., Xue, Q. B., Yang, K. Z., Zhang, J. Z., and Zhang, Q. Z. Monolayer Behaviours for the Photochromic Liquid Crystalline Copolymers with Azobenzene and Cholesterol Side Groups. Supramol. Sci. 5, 591 (1998). [Pg.216]

The fact that large-modulation SRGs are formed only above a certain threshold amount of functionalization was also shown by Andruzzi et al.J for amorphous as well as LC polymers. They investigated copolymers derived from two photochromic monomers, 6-(4-oxy-4 -cyanoazobenzene)h x-l-yl methacrylate and 8-(4-oxy-4 -cyanoazobenzene)oct-l-yl methacrylate, and a nonphotochromic comonomer, (-)-menthyl methacrylate. Considerable amplitudes were obtained for all polymers with more than 30% of azofunctionalization. The maximum amplitudes were observed for copolymers possessing 75-80% of dye content, not the fully functionalized homopolymers. [Pg.456]


See other pages where Copolymers photochromic is mentioned: [Pg.151]    [Pg.140]    [Pg.151]    [Pg.118]    [Pg.366]    [Pg.165]    [Pg.165]    [Pg.166]    [Pg.182]    [Pg.57]    [Pg.646]    [Pg.25]    [Pg.160]    [Pg.25]    [Pg.28]    [Pg.42]    [Pg.145]    [Pg.147]    [Pg.147]    [Pg.152]    [Pg.153]    [Pg.154]    [Pg.158]    [Pg.160]    [Pg.162]    [Pg.172]    [Pg.197]    [Pg.275]   
See also in sourсe #XX -- [ Pg.15 , Pg.16 ]




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Photochrome

Photochromic

Photochromic IsoSm copolymers

Photochromic block copolymers

Photochromic/photochromism

Photochromism

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