Photoalignment of Liquid Crystalline Polymer Films Containing Mesostructures and a Free Surface Command Layer

Seki, Takahiro; Fukuhara, Kei; Sano, Masami; Hara, Mitsuo; Nagano, Shusaku

doi:10.1080/15421406.2015.1050284

Cited by 3 publications

(3 citation statements)

References 33 publications

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“…Photoinduced phase transitions in liquid crystalline materials have been compiled in section . − Both pure molecular and macromolecular systems as well as doped LC mixtures have been covered in this section. Photoalignment and photoorientation of different molecular and macromolecular liquid crystalline materials have been collated in section . − Section deals with the photomodulation of chiral LC phases. Pitch, polarization, lattice constants, and handedness alteration of cholesteric, ferroelectric, and blue phases by light irradiation are discussed in this section. − Moreover, photochemical chiral induction has also been covered.…”

Section: Introductionmentioning

confidence: 99%

Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications

2016

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Light-driven phenomena both in living systems and nonliving materials have enabled truly fascinating and incredible dynamic architectures with terrific forms and functions. Recently, liquid crystalline materials endowed with photoresponsive capability have emerged as enticing systems. In this Review, we focus on the developments of light-driven liquid crystalline materials containing photochromic components over the past decade. Design and synthesis of photochromic liquid crystals (LCs), photoinduced phase transitions in LC, and photoalignment and photoorientation of LCs have been covered. Photomodulation of pitch, polarization, lattice constant and handedness inversion of chiral LCs is discussed. Light-driven phenomena and properties of liquid crystalline polymers, elastomers, and networks have also been analyzed. The applications of photoinduced phase transitions, photoalignment, photomodulation of chiral LCs, and photomobile polymers have been highlighted wherever appropriate. The combination of photochromism, liquid crystallinity, and fabrication techniques has enabled some fascinating functional materials which can be driven by ultraviolet, visible, and infrared light irradiation. Nanoscale particles have been incorporated to widen and diversify the scope of the light-driven liquid crystalline materials. The developed materials possess huge potential for applications in optics, photonics, adaptive materials, nanotechnology, etc. The challenges and opportunities in this area are discussed at the end of the Review.

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Section: Introductionmentioning

confidence: 99%

Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications

2016

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“…To overcome these issues, molecular design can be combined to directed self‐assembly through control of dynamics and introduction of external constraints, partially mimicking nature in which concentration gradients or fuel are driving forces . Current approaches rely on external macroscopic triggers, such as templates, evaporation‐induced surface tension, wettability, electric/magnetic fields, or light irradiation . However, the methods introduced so far are not satisfactory to introduce higher complexity.…”

Section: Introductionmentioning

confidence: 99%

Photocontrolled Hierarchical Self‐Assembly of Anisotropic Micropatterns of Nanofibers onto Isotropic Surfaces

Vet

Gartzia‐Rivero

Schäfer

et al. 2020

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Hierarchical self‐assembly is achieved using a visible light triggered photoreaction. A pro‐gelator, α‐diketone‐2,3‐didecyloxyanthracene, is photoconverted into a low molecular weight gelator, 2,3‐didecyloxyanthracene (DDOA), that self‐assembles into nanofibers. Spatial confinement and patterns of these nanofibers onto a surface are achieved by localizing initial nucleation with a focused laser and photogenerate subsequent fiber growth with the laser or gentler wide‐field irradiation. Remarkably, collective growth of nanofibers results in anisotropic micropatterns with orientation factors (OF) reaching 79%, resulting in collective emission of linearly polarized light. The OF, distance of collective growth and fiber density, are controlled by the photoirradiation conditions and the balance of interactions between DDOA aggregates and the glass surface. An unprecedented juxtaposition of orthogonally oriented nanofiber patterns on an isotropic surface is achieved with individual control of the fibers' main direction. In perspective, this photochemical method can be extended to a large variety of self‐assembling molecules.

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“…Additionally, in early 2018 light control of nano-objects especially focusing on using noncovalent interactions to couple azobenzene surfactants to these objects was reviewed, thus indicating the timeliness of employing supramolecular interactions in the design of photoresponsive materials. 63 For technological applications of light-responsive materials, which is out of the scope of the present review, we refer the readers to the reviews by Ichimura on the use of azobenzenes as LC alignment surfaces, 64 Lee et al on photofluidization lithography, 65 Seki et al on recent advancements in photoalignment, 66 Natansohn and Rochon on the application potential of both photo-orientation and photo-induced surface patterning, 67 and Priimagi and Schevchenko on the potential photonic applications of the photo-induced surface patterns. 68 2.…”

Section: Scope Of This Review and Complementary Readingmentioning

confidence: 99%

Supramolecular design principles for efficient photoresponsive polymer–azobenzene complexes

2018

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a Noncovalent binding of azobenzenes to polymers allows harnessing light-induced molecular-level motions (photoisomerization) for inducing macroscopic effects, including photocontrol over molecular alignment and self-assembly of block copolymer nanostructures, and photoinduced surface patterning of polymeric thin films. In the last 10 years, a growing body of literature has proven the utility of supramolecular materials design for establishing structure-property-function guidelines for photoresponsive azobenzene-based polymeric materials. In general, the bond type and strength, engineered by the choice of the polymer and the azobenzene, influence the photophysical properties and the optical response of the material system. Herein, we review this progress, and critically assess the advantages and disadvantages of the three most commonly used supramolecular design strategies:hydrogen, halogen and ionic bonding. The ease and versatility of the design of these photoresponsive materials makes a compelling case for a paradigm shift from covalently-functionalized side-chain polymers to supramolecular polymer-azobenzene complexes.

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Photoalignment of Liquid Crystalline Polymer Films Containing Mesostructures and a Free Surface Command Layer

Cited by 3 publications

References 33 publications

Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications

Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications

Photocontrolled Hierarchical Self‐Assembly of Anisotropic Micropatterns of Nanofibers onto Isotropic Surfaces

Supramolecular design principles for efficient photoresponsive polymer–azobenzene complexes

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