Thermally enhanced photoinduced in‐plane reorientation in photo‐cross‐linkable polymer liquid crystalline films and its application to linear polarizer

Kawatsuki, Nobuhiro; Tsutsumi, Ryoji; Hiraiwa, Akie; Takatsuka, Hirofumi; Sakai, Takeya

doi:10.1002/pola.22803

Cited by 11 publications

(7 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Kawatsuki group has synthesized a variety of LC polymers containing photo cross-linkable cinnamate side chains. − These polymer films upon irradiation with polarized UV light undergo axis-selective cross-linking which produces alignment of the mesogens in the polymer film. This light-driven orientation of the mesogens yields high value of birefringence for the polymer films.…”

Section: Photoalignment and Photoorientation Of Liquid Crystalsmentioning

confidence: 99%

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

2016

View full text Add to dashboard Cite

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.

show abstract

Section: Photoalignment and Photoorientation Of Liquid Crystalsmentioning

confidence: 99%

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

2016

View full text Add to dashboard Cite

show abstract

“…98100,102,103 For 34, an effective photoinduced molecular reorientation is observed when n = 3, but the reorientation order is small when n = 2. 101 The linearity between biphenyl and cinnamate end groups plays an important role for sufficient molecular reorientation.…”

mentioning

confidence: 99%

Photoalignment and Photoinduced Molecular Reorientation of Photosensitive Materials

Kawatsuki¹

2011

Chemistry Letters

Self Cite

116

View full text Add to dashboard Cite

Photosensitive materials for photoalignment of liquid crystals (LCs) and photoinduced molecular reorientation are described, especially focusing on azobenzene-containing materials and photocrosslinkable polymers. All the materials generate photoinduced optical anisotropy by means of linearly polarized (LP) light exposure. The large optical anisotropy is induced when the axis-selective photoreaction is accompanied by molecular reorientation. Ç IntroductionDue to practical applications of the alignment layer of functional materials such as low-molecular-weight liquid crystals (LCs), photoalignment and photoinduced molecular reorientation of photosensitive films have received much attention. 13 Additionally, these films have been investigated for molecularly oriented birefringent devices due to the absence of mechanical damage, absence of electric charge, and patterning ability.13 Photoinduced optical and physical anisotropies can be generated in a photoreactive polymeric film by light exposure because the photoreaction changes the inherent refractive index of the molecules. Irradiating with linearly polarized (LP) light causes the photosensitive molecules parallel to the polarization (E) of LP light (y axis) to preferentially photoreact (Figure 1). This axis-selective photoreaction leads to optical anisotropy (birefringence) between the y axis and xz plane if the photoreaction changes the inherent refractive indices of the molecules.To obtain uniaxial alignment of LCs on thin polymeric films, the LC photoalignment layer should exhibit optical or physical anisotropy. Under this circumstance, a large molecular orientation of the film is unnecessary. The anisotropic interaction between the photoalignment layer and LC molecules induces uniaxially oriented LC molecules.1 Because the axis-selective photoreaction induces a small change in the refractive index of the photoalignment layer, 4 a thick film is necessary for optically anisotropic devices such as a birefringent film. Consequently, a large optical anisotropy in the photoreacted film is generated when molecular reorientation occurs during an anisotropic photoreaction. 3Various types of materials that undergo an axis-selective photoreaction to generate photoinduced optical anisotropy have been investigated, including azobenzene-containing polymers 2,57 and photocrosslinkable polymers. 1,3,4 For the azobenzene molecules, axis-selective photoisomerization is generated when the film is irradiated with linearly polarized (LP) light (Figure 2a). Similarly, irradiating with LP ultraviolet (LPUV) light induces both axis-selective [2 + 2] photo/cycloaddition (photocrosslinking) reaction and photoisomerization for cinnamic ester derivatives (Figure 2b). Low-molecular LC molecules easily align on these anisotropically photoreacted films. When an axis-selective photoreaction occurs without generating molecular reorientation, the photoinduced birefringence (¦n) is less than 0.01. 4 An anisotropic photoreaction combined with molecular motion may generate a large optica...

show abstract

“…For this, cinnamic acid was selected as the reaction partner for the Passerini-3CR due to the photo-responsive property arising from the [2 + 2] cycloaddition reaction. [27][28][29][30][31][32] As such, poly(-mPEGA-co-acrolein) was subjected to the Passerini-3CR with cinnamic acid and 1,1,3,3-tetramethyl butyl isocyanide, thereby affording polymers poly-mPEGA featuring cinnamate units in their pendants (poly-mPEGA-CA). The obtained poly-mPEGA-CA was thus subjected to photo-crosslinking based on the photoinduced [2 + 2] cycloaddition reaction of cinnamate carboncarbon double bonds.…”

Section: Resultsmentioning

confidence: 99%

Acrolein-free synthesis of polyacrolein derivatives via the chemo-selective reduction of polyacrylates

et al. 2023

View full text Add to dashboard Cite

show abstract

Thermally enhanced photoinduced in‐plane reorientation in photo‐cross‐linkable polymer liquid crystalline films and its application to linear polarizer

Cited by 11 publications

References 28 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

Photoalignment and Photoinduced Molecular Reorientation of Photosensitive Materials

Acrolein-free synthesis of polyacrolein derivatives via the chemo-selective reduction of polyacrylates

Contact Info

Product

Resources

About