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

Santos, Eduardo A. Gonzalez-De Los; Lozano-Gonzlez, Ma. Josefina; Johnson, A. F.

doi:10.1002/(sici)1097-4628(19990110)71:2<267::aid-app10>3.0.co;2-z

Cited by 6 publications

(2 citation statements)

References 12 publications

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“…They found that λ max of the colored form of spirooxazine was shifted to higher wavelengths in polar matrices, according to the stabilization of metastable zwitterionic isomer by polar interactions with hydroxyl groups in the polymers. In another attempt, the effects of polyurethane–acrylate block copolymers containing SP derivatives on photochromic and photomechanical properties were studied. , It was found that the speed of color fade was inversely dependent on rigidity of the polymeric matrix.…”

Section: Introductionmentioning

confidence: 99%

“…In another attempt, the effects of polyurethane−acrylate block copolymers containing SP derivatives on photochromic and photomechanical properties were studied. 35,36 It was found that the speed of color fade was inversely dependent on rigidity of the polymeric matrix. Recently, we have reported the preparation of novel stimuliresponsive papers by modification of cellulosic fibers with functionalized acrylic nanoparticles containing a spiropyran derivative.…”

Section: ■ Introductionmentioning

confidence: 99%

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Effects of Chain Parameters on Kinetics of Photochromism in Acrylic–Spiropyran Copolymer Nanoparticles and Their Reversible Optical Data Storage

2017

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Chemical bonding between photochromic compounds and polymer matrices will induce several consitions such as photostability, photoreversibility, elimination of dye aggregation, and undesirable negative photochromism. In such polymeric systems, the switching rate and photoisomerization are closely dependent on several parameters like chain flexibility, steric restrictions, polarity, and even proticity of the surrounding medium. Here, copolymerization of a synthesized spiropyran-based monomer with butyl acrylate (BA) and methyl methacrylate (MMA) comonomers was carried out with various compositions of MMA and BA through emulsion polymerization, and the corresponding photoisomerization kinetics were studied. Particle sizes and their distributions were analyzed by dynamic light scattering, and morphologies were investigated by scanning and transmission electron microscopic analyses. The results showed the particles are spherical with diameter 62-82 nm. Differential scanning calorimetric thermograms were employed to determine T of the prepared copolymers, which ranged from -23 to 93 °C. The kinetics of photoisomerization was then studied by UV-vis spectroscopy. Finally, a latex containing spiropyran/acrylic copolymer with T of about 0 °C and optimum rate of coloration and decoloration was considered in reversible optical data storage studies due to its fast photochromism and good film-formation properties.

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Section: Introductionmentioning

confidence: 99%

Section: ■ Introductionmentioning

confidence: 99%

Effects of Chain Parameters on Kinetics of Photochromism in Acrylic–Spiropyran Copolymer Nanoparticles and Their Reversible Optical Data Storage

2017

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Photobreathing Zwitterionic Micelles

Niskanen

Vapaavuori

2019

ChemSystemsChem

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A significant and reversible size change (up to 80 nm, representing 100 % increase in diameter, i. e. “breathing”) of polymeric micelles of poly(styrene)‐block‐poly(3‐(4‐vinylpyridin‐1‐ium‐1‐yl)propane‐1‐sulfonate) (PS‐P4VP‐zwitter) was observed during phototriggered loading and release of spiropyran. The breathing (i. e. “inhaling/exhaling” of the small molecules by the micelles) could be controlled by switching the wavelength of the light used. Spiropyran, which was converted into the zwitterionic merocyanine by UV light, was readily diffused and incorporated into the zwitterionic micelle cores, thus causing the micelles to expand. At the same time, the merocyanine was stabilized by the polyzwitterionic core of the micelles. To the best of our knowledge, this is the first report of a supramolecular and reversibly photoloadable system that can be converted from a thermodynamically stable self‐assembled equilibrium system into a dynamic, self‐assembled system that is sustained by illumination.

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Reversible Adhesion Switching Using Spiropyran Photoisomerization in a High Glass Transition Temperature Polymer

Gately

Mostafavi

et al. 2021

Macromolecules

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Previous work has shown that photoisomerization of dopant molecules in a polystyrene film can either enhance or suppress its adhesion to a polar glass surface (MostafaviS. H. Mostafavi, S. H. Macromolecules20185123882394; MostafaviS. H. Mostafavi, S. H. Macromolecules20195263116317). In this paper, a different polymer host, Zeonex (ZX), is used in conjunction with the photochrome spiropyran. Nonpolar ZX has a higher glass transition temperature that makes it resistant to nanoscale mechanical deformations, while the spiropyran (SP) → merocyanine (MC) photoisomerization is a reversible reaction with a large polarity change. Ultraviolet light isomerizes SP to the polar MC form, increasing both the shear and pull-off adhesion forces to a clean glass surface by a factor of 5. Visible irradiation switches it back to the nonpolar SP form and returns the film back to its original weak adhesion, in contrast to the previously studied polystyrene films. The ability of visible light to switch off the polymer–glass adhesion is harnessed to make a light-controlled payload release device as well as to accelerate the polymer film delamination rate in water by a factor of 100. The kinetics of the water delamination, as well as the origin of residual adhesion after switching back to the SP form, are investigated. This work demonstrates how light-controlled noncovalent adhesion can be used as a solvent-free method to remove protective coatings or to disassemble structures.

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

Cited by 6 publications

References 12 publications

Effects of Chain Parameters on Kinetics of Photochromism in Acrylic–Spiropyran Copolymer Nanoparticles and Their Reversible Optical Data Storage

Effects of Chain Parameters on Kinetics of Photochromism in Acrylic–Spiropyran Copolymer Nanoparticles and Their Reversible Optical Data Storage

Photobreathing Zwitterionic Micelles

Reversible Adhesion Switching Using Spiropyran Photoisomerization in a High Glass Transition Temperature Polymer

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