Photomechanical effects in crosslinked photochromic polymers

Matějka, Libor; Ilavský, M.; Dušek, Karel; Wichterle, O.

doi:10.1016/0032-3861(81)90321-9

Cited by 67 publications

(28 citation statements)

References 14 publications

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“…Herein, we report on wireless molecular-crystal actuators, which work upon photoirradiation. Rodlike mixed crystals of 1-(5-methyl-2-phenyl-4-thiazolyl)-2-(5-methyl-2-p-tolyl-4-thiazolyl)perfluorocyclopentene (1 a) and 1,2-(5-methyl-2-p-tolyl-4-thiazolyl)perfluorocyclopentene (2 a; Scheme 1) with sizes ranging from micrometers to millimeters were found to exhibit rapid, reversible, and fatigue-resistant bending upon alternate irradiation with UV (365 nm) and visible (> 500 nm) light.Various types of artificial molecular muscles have been reported, such as rotaxanes, [1][2][3][4][5][6][7] catenanes, [8][9][10][11][12] polymer films and gels, [13][14][15][16] conductive polymers, [17] liquid-crystal elastomers, [18][19][20][21] molecular crystals, [22][23][24][25][26] and nanotubes.[27] Although the supramolecular systems (e.g., bistable rotaxanes and catenanes) exhibit musclelike sliding motion at the molecular level, the movement fails to be effectively linked to macroscopic motion of materials. Polymer artificial muscles primarily depend upon the response of bulk materials rather than upon individual molecular behavior.…”

mentioning

confidence: 99%

Light‐Driven Molecular‐Crystal Actuators: Rapid and Reversible Bending of Rodlike Mixed Crystals of Diarylethene Derivatives

2011

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Piezoelectric crystals are useful in industrial and consumer applications because of their special characteristics: they can be bent by electricity. But the crystals require a wire connection so that the electricity can be supplied. This wire connection prevents their use in water and reduction of their size to the micrometer scale. Herein, we report on wireless molecular-crystal actuators, which work upon photoirradiation. Rodlike mixed crystals of 1-(5-methyl-2-phenyl-4-thiazolyl)-2-(5-methyl-2-p-tolyl-4-thiazolyl)perfluorocyclopentene (1 a) and 1,2-(5-methyl-2-p-tolyl-4-thiazolyl)perfluorocyclopentene (2 a; Scheme 1) with sizes ranging from micrometers to millimeters were found to exhibit rapid, reversible, and fatigue-resistant bending upon alternate irradiation with UV (365 nm) and visible (> 500 nm) light.Various types of artificial molecular muscles have been reported, such as rotaxanes, [1][2][3][4][5][6][7] catenanes, [8][9][10][11][12] polymer films and gels, [13][14][15][16] conductive polymers, [17] liquid-crystal elastomers, [18][19][20][21] molecular crystals, [22][23][24][25][26] and nanotubes.[27] Although the supramolecular systems (e.g., bistable rotaxanes and catenanes) exhibit musclelike sliding motion at the molecular level, the movement fails to be effectively linked to macroscopic motion of materials. Polymer artificial muscles primarily depend upon the response of bulk materials rather than upon individual molecular behavior. It is a challenge to construct molecular materials that perform macroscopic mechanical motion that stems from stimuli-responsive geometrical structure changes of individual molecules.In previous reports, [22] we demonstrated that photochemical geometrical structure changes of individual diarylethene molecules in crystals induced changes in molecular packing and alignment, resulting in the anisotropic deformation of the bulk crystals. For example, a rodlike crystal of 1,2-bis(5-methyl-2-phenyl-4-thiazolyl)perfluorocyclopentene exhibits reversible bending upon alternate irradiation with UV and visible light.[22a] For practical applications, the crystal actuators should have sufficient durability and substantial mechanical properties. The above single-component diarylethene crystal lacks this durability and breaks in less than 100 deformation cycles. To improve fatigue resistance, we prepared a platelike two-component cocrystal composed of 1,2-bis(2-methyl-5-(1-naphthyl)-3-thienyl)perfluorocyclopentene and perfluoronaphthalene.[22d] The cocrystal exhibits reversible bending for up to 250 cycles. During the course of the study on such multicomponent crystals it was found that the durability is further improved by mixing two diarylethene derivatives, 1 a and 2 a, in a crystal. The bending can be repeated more than 1000 times without any crystal damage, and the crystals exhibit light-driven bending in all directions toward the UV light source in wide temperature range from 4.6 K to 370 K. Moreover, the photogenerated maximum stress of the crystals was found to be comparable...

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confidence: 99%

Light‐Driven Molecular‐Crystal Actuators: Rapid and Reversible Bending of Rodlike Mixed Crystals of Diarylethene Derivatives

2011

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“…The second, which was postulated by Matejka et al 17 and Irie and Suzuki, 18 suggest that some photochromic molecules have a big dipolar moment; hence, they tend to orient parallel each others, socompact coil conformations are preferred. Hence, some reduction in the entropy of the system will bring about an expansion in the sample.…”

Section: Polyurethane-acrylate Block Copolymers IImentioning

confidence: 94%

Photoresponsive polyurethane-acrylate block copolymers. II. Photomechanical effects in copolymers containing 6?-nitro spiropyranes and 6?-nitro-bis-spiropyranes

Santos¹,

Lozano-Gonzlez²,

Johnson

1999

J. Appl. Polym. Sci.

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The photochromic effect of polyurethane-acrylate block copolymers containing 6Ј-nitro spiropyranes and 6Јnitro-bis-spiropyranes has been investigated. The influence of incorporation of the photochromic agent into the polymeric matrix as a simple solid solution or via a chemically bonded form and the effect of the composition rate (polyurethane-acrylate) of the block copolymer were studied. In general, it was observed that the photoresponse (photomechanical effect) for the spiropyranes and, especially, the bis-spiropyranes is influenced by a combination of several factors, primarily, the spatial and electronic differences between the two forms (Sp.-Mer.) in the photoisomerization of these compounds. Such factors are discussed here.

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“…Azobenzene is a well-known chromophore with a light-induced cis-to-trans isomerization that is accompanied by a fast and complete change in electronic structure, geometric shape, and polarity (Scheme 2.4) [155,166]. By incorporating azobenzene derivatives, materials with variable shape, polarity, and self-assembly behavior can be obtained [167].…”

Section: Photoresponsive Polymersmentioning

confidence: 99%

Biological‐ and Field‐Responsive Polymers: Expanding Potential in Smart Materials

Roy

Cambre

Sumerlin

2011

Handbook of Stimuli‐Responsive Materials

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Photomechanical effects in crosslinked photochromic polymers

Cited by 67 publications

References 14 publications

Light‐Driven Molecular‐Crystal Actuators: Rapid and Reversible Bending of Rodlike Mixed Crystals of Diarylethene Derivatives

Light‐Driven Molecular‐Crystal Actuators: Rapid and Reversible Bending of Rodlike Mixed Crystals of Diarylethene Derivatives

Photoresponsive polyurethane-acrylate block copolymers. II. Photomechanical effects in copolymers containing 6?-nitro spiropyranes and 6?-nitro-bis-spiropyranes

Biological‐ and Field‐Responsive Polymers: Expanding Potential in Smart Materials

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