摘要:

In order to solve problems of photochromic memory, a super-low power readout method and a crosstalk reduction method for multi-wavelength recording were proposed. In the demonstration of 2-wavelength recording using photochromic diarylethenes, the crosstalk between multiplexed channels, which is caused from broad absorption bands of compounds, was effectively reduced by the method. A new high density optical memory, a super-resolution disk with a photochromic mask layer, was also introduced. The super-resolution method has enabled us to increase the recording density of conventional optical disks.

ISSN:1058-725X    

DOI:10.1080/10587259808044303

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

In this paper, different optical methods which lead to orientation or translation of several photochromes in polymer matrices are discussed. These methods lead to dichroic or birefringent, or nonlinear optically active materials or to stable surface gratings. They have mainly been demonstrated for azobenzene-type photochromes, but some of these effects also occur for other kinds of photochromes like spiropyrans, fulgides or diarylethenes.

ISSN:1058-725X    

DOI:10.1080/10587259808044304

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Fluidity of nonionic surfactant assembly formed at the silica-water interface was investigated on the basis of intramolecular excimer formation dynamics of 1,3-bis(1-pyrenyl)propane. It was found that the rate constant of intramolecular excimer formation is almost independent of the adsorption density of surfactant molecules. These results imply that local structure of hydrocarbon region in surfactant assembly is almost unchanged in a wide range of adsorption density, although whole structure of the assembly varies with the adsorption density at the interface.

ISSN:1058-725X    

DOI:10.1080/10587259808044305

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The copper hydroxy layered hybrids, Cu2(OH)3X, whereX=p−(phenylazo)-benzoate 1 andX= 8-((p−(phenylazo)phenyl)oxy)octanoate 2, were prepared. The material 1 is paramagnetic with an antiferromagnetic interaction above 3 K, while 2 becomes a weak ferromagnet below ca. 10 K. In 2 thetrans-to-cisisomerization reaction of the interlayer azobenzene moiety takes place by UV-light illumination, although the photoreaction is irreversible. There is little change in the magnetic properties, caused by the photoreaction.

ISSN:1058-725X    

DOI:10.1080/10587259808044306

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Radical generation from photoinitiation systems containing carbonylbiscoumarin dye with a radical-generating reagent, 3,3′-carbonylbis[7-(diethylamino)-2H-l-benzopyran-2-one](KCD-DA), with 2,2′-bis(2-chlorophenyl)-4,4′,5,5′-tetraphenyl-1,1′- bi- 1H- imidazole (BI) in a poly(methyl methacrylate) (PMMA) film have been investigated by laser flash photolysis using a total reflection cell.

ISSN:1058-725X    

DOI:10.1080/10587259808044307

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Carboxylic-acid derivatives of butadiyne and octatetrayne including ester and amide were prepared and solid-state polymerizability was investigated. Though octatetrayne derivatives and most of carboxylic acid and amide derivatives of butadiyne can be polymerized, no esters of butadiyne show polymerizability irrespective of success in crystal growth up to centimeter order. X-ray crystallographic analysis of three esters pointed out weak intermolecular interaction in these derivatives resulting in molecular packing which is based on space filling only.

ISSN:1058-725X    

DOI:10.1080/10587259808044308

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

The photochemical behavior of two kinds of side-chain type azobenzene-polymers, poly[2-(2-methacryloyloxyethoxy)-4-methoxyazobenzene] (pMAzS2) and poly[4-(2-methacryloyloxyethoxy)azobenzene] (pMAz2), was investigated in order to obtain information about effect of molecular structures on photoreorientation process. Irradiation of polymer films with linearly polarized visible light (488 nm) brought about reorientation of azobenzene moieties. Trans isomers in both polymers were aligned in the perpendicular direction to the electric vector of the actinic polarized light.

ISSN:1058-725X    

DOI:10.1080/10587259808044309

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Temperature-induced phase transitions of someN−isopropylacrylamide (NIPAM) copolymers in aqueous solutions were studied with 9-(4-N,N− dimethylaminophenyl)phenanthrene (DP) as an intramolecular fluorescence probe. Lower critical solution temperature (LCST) of DP-labeled NIPAM copolymers depends on the properties and contents of comonomers incorporated in the NIPAM copolymers, i.e., a hydrophobic comonomer such as methyl methacrylate (MMA) lowers the LCST, and a hydrophilic comonomer such as methacrylic acid (MAA) raises it. The higher contents of comonomers, the bigger changes of the LCST. And the micro-environments of the NIPAM copolymers in aqueous solutions also depend on them. The temperature-induced phase transitions of NIPAM copolymers withN-n−propylacrylamide (NNPAM), andN−isopropylmethacrylamide (NIPMAM) appear to be very sharp as well as that of NIPAM homopolymer aqueous solution and their LCST values are good correlated with their copolymer compositions.

ISSN:1058-725X    

DOI:10.1080/10587259808044310

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

From Nylon salts composed of dicarboxylic acid and diamine having butadiyne moiety in one or two of the components, two-dimensionally-crosslinked crystalline polymers were prepared by polymerization of butadiyne part to give polydiacetylene and following condensation of Nylon salt part to form amide group in solid state.

ISSN:1058-725X    

DOI:10.1080/10587259808044311

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor

摘要:

Preparation of a series of asymmetrically substituted diacetylenes containing thienyl moiety or quinolyl moiety as one of the sidegroups directly bound to the diacetylene backbone and a urethane derivative as the other sidegroup were carried out and their solid state polymerisation was investigated.

ISSN:1058-725X    

DOI:10.1080/10587259808044312

出版商:Taylor & Francis Group    

年代:1998

数据来源: Taylor