Abstract

We propose a simple and effective method of liquid crystal photoalignment that does not require any preliminary treatment of the cell substrates. To this aim, a small amount (0.1 wt %) of azobenzene carboxylic acid is added into the nematic liquid crystal. After filling the liquid crystal cell, a part of the dopant molecules is spontaneously adsorbed and attached to the glass surface by hydrogen bonds. This allows one to switch the boundary conditions of liquid crystal between homeotropic and planar due to the reversible trans-cis photoisomerization.

© 2019 Optical Society of America under the terms of the OSA Open Access Publishing Agreement

1. Introduction

Numerous studies in the field of soft matter physics and chemistry are focused on the developing of light controllable liquid-crystalline (LC) materials [14]. Nowadays, a wide variety of light-induced phenomena in this field were investigated. Recent advances in this field show fascinating possibilities for developing of adoptive diffractive and polarizing elements, photodisplays, nano- and micro-structured materials, light-driven micro- and nano-objects, etc.

One of the possible realizations of light sensitive LC systems is based on the photoalignment effect [57] . This effect is usually obtained, when the LC cell substrates are coated by a photosensitive compound. Light irradiation modulates the orientational distribution of molecules deposited on the surface. The anisotropic interaction of photosensitive molecules with LC leads to the homogeneous alignment of LC film in the bulk. This method was first realized by Ichimura et al., in which the monolayer of azobenzene molecules was used as a command surface for the LC film orientation [8]. The switching between the trans- and cis-configurations of azobenzene compound allows one to modulate the boundary conditions from homeotropic to planar or vice versa by ultraviolet (UV) or blue light illumination. Since then many photoalignment methods were proposed in response to the evident demands in display and photonics technologies [9,10].

A part of these studies is related to the photoalignment effect which takes place without any special treatment of LC cell substrates by photosensitive materials. The principle of the so called bulk mediated photoalignment was described in [11]. This effect was found in nematic liquid crystal (NLC) doped with a small amount of Methyl Red dye and filled into the LC cell with substrates coated by polyvinilcinnamate. The dye molecules are partially adsorbed onto the polymer surface. Under the linearly polarized laser light irradiation, their orientational distribution is modulated by photoinuced exchange between the NLC bulk and the surface [12]. This rearrangement of the adsorbed dye molecules causes an efficient drift of NLC easy axis on the surface. Another study demonstrated more complex processes involving the dye molecule photoizomerization, reorientation, and diffusion [13]. An alternative explanation of this effect is based on the effect of the photo-induced space charges [14,15].

A number of studies focus on the LC systems containing dendrimer compounds [1618]. It was found that dendrimer molecules are adsorbed from the NLC bulk onto the surface and initiate homeotropic alignment. If the dendrimer compound contains azobenzene terminal fragments, it is possible to modify the boundary conditions of the NLC cell from homeotropic to planar by UV light illumination. It was recently shown that the high-molar-mass azobenzene additives, such as carbosilane dendrimers and side-chain polymers, can cause the photo-orientation processes at NLC-liquid interface [19,20].

There are other examples of photoalignment, which do not require the surface treatment by orienting materials. Specific azobenzene dopants can form nanosized cryslalline aggregates on the cell substrates under UV irradiation, modifying the boundary conditions [21]. If NLC consists of the photoisomerizable molecules, the anchoring transition under UV illumination takes place at the solid [22] and liquid [23] surfaces. The photoalignment is induced by the UV irradiation of typical cyanobiphenyl NLC (5CB) on a fused quartz [24,25], but the origin of this effect still remains unclear. The effect can be also achieved in the NLC doped with sophisticated azobenzene surfactants [26].

Here we propose and investigate the photoalignment processes in the NLC doped with azobenzene carboxylic acid. The main idea of our method consists of the possible monolayer formation of dopant molecules containing carboxyl group onto the NLC cell substrates due to hydrogen bonding [27].

2. Experimental

We used a commercially available nematic E7 liquid crystal (Merck) with the large thermal range of nematic phase. The NLC was doped with hexyloxyazobenzene carboxylic acid (HOAC) (Fig. 1(a)). The value of HOAC dopant was varied from 0.01 to 0.1 wt %. To elucidate the role of the hydrogen bonding, the mixture of E7 with 0.1 wt % of similar azobenzene derivative, hexyloxyazobenzene (HOA), which has no carboxylic group (Fig. 1(b)), was also under the study. The HOAC and HOA compounds were synthesized at Chemistry Department of MSU.

 

Fig. 1. Structural formulas of HOAC (a) and HOA (b). Normalized spectral absorbance of HOAC and HOA solution in tetrahydrofuran (c) corresponding to trans- (solid lines) and cis-forms (dashed lines).

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The spectral absorbance of the HOAC and HOA in tetrahydrofuran was measured using TIDAS (J&M) spectrophotometer. The spectra of stable trans-isomer measured in dark is shown by solid lines in Fig. 1(c), whereas the spectra of cis-isomer was obtained at UV illumination by the light emitting diode (LED) with the 370 nm wavelength and 10 mW/cm$^{2}$ intensity during 10 s (dashed lines in Fig. 1(c)). Thus, UV illumination can be used for the effective isomer conversion into the cis-form.

For each NLC mixture, the two kinds of NLC cells were prepared for investigation of photoalignment effect. Each cell consisted of the two glass plates made of soda-lime glass (Thermo Scientific) treated by a piranha solution (the mixture of concentrated sulfuric acid and hydrogen peroxide in the 3:1 ratio, v/v) during 4 hours. This procedure not only cleans the glass plates, but also increases the number of OH groups on the surface. The glass plates were separated by the 30-$\mu$m-thick Teflon stripes. One of the cells was made of two glass plates, each one without any additional treatment. Another LC cell was assembled from one clear glass plate and another one coated by polyimide with subsequent rubbing by tissue in a certain direction to provide a strong planar anchoring of NLC. The NLC mixtures were filled into the cells by capillarity forces at room temperature.

To initiate the trans$\rightarrow$cis isomerization process, the UV emitting diode (LED-1) with the luminescence maxima at $\lambda _{max}$ = 365 nm and FWHM = 10 nm was used. To obtain the linearly polarized light the Glan-Taylor prism was used. For the reversible cis-trans isomerization, the light emitting diode (LED-2) with the luminescence maxima at $\lambda _{max}$ = 466 nm and FWHM = 20 nm was employed. The light intensities $I$ = 1.2 mW/cm$^2$ and 15 mW/cm$^2$ for LED-1 and LED-2, respectively, were measured by a Hioki 3664 power meter. The LED’s light beam fell down onto the sample placed on the microscope table at 45$^\circ$ oblique incidence. In the case of linearly polarized UV light by LED-1, the polarization plane was parallel to the NLC cell substrates, which corresponds to s-polarization. The photoinduced orientational processes were studied with the help of Carl Zeiss Axio-Pol polarizing microscope with registration by CMOS sensor and photodiode.

3. Results and discussion

The first sample consisting of E7+0.1% HOAC was investigated. The NLC cell with two glass plates without orienting layers was used. Before LED irradiation, the sample does not transmit the light in crossed polarizers at any sample orientation (Figs. 2(a) and 2(b)). In conoscopic image, the dark cross appears (see the insertion in Fig. 2(a)). This indicates that the NLC film has vertical (homeotropic) alignment, i.e. the NLC director is oriented normally to the substrates.

 

Fig. 2. Microscope images of NLC (E7+0.1% HOAC) cell in crossed polarizers before (a, b) and after (c, d) the UV illumination ($\lambda _{max}$ = 365 nm, $I$ = 1.2 mW/cm$^2$) at two sample orientations (e, f). P and A are the directions of polarizer and analyzer, E is the UV light polarization direction. Insertion in (a) is the conoscopic image of the NLC cell.

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Under the action of LED-1 UV light, when the light polarization direction $\textbf {E}$ is at the 45$^\circ$ angle with respect to the directions of polarizer P and analyzer A (Fig. 2(e)), the sample becomes bright (Figs. 3(a)–3(f)). After the UV light illumination during the exposure time $\tau _{exp} =$ 100 s, the rotation of microscope table with the sample at the angle 45$^\circ$ leads to the darkening of the sample image (Figs. 2(c)–2(f)). From this, we can conclude that the optical axis of the NLC after the UV illumination is either perpendicular or parallel to the light polarization direction. If the UV light is unpolarized, the NLC film orientation becomes degenerated planar. Note that the increase of UV light intensity leads to the proportional reduction of the switching time.

 

Fig. 3. Microscope images of NLC (E7+0.1% HOAC) cell in crossed polarizers during the illumination at $\lambda _{max}$ = 365 nm ($I$ = 1.2 mW/cm$^2$, linearly polarized light, experimental geometry is shown in Fig. 2(e)) at the exposure time $\tau _{exp}$: 0 s (a), 30 s (b), 40 s (c), 50 s (d), 60 s (e), 100 s (f); and during the consequent illumination at $\lambda _{max}$ = 466 nm ($I$ = 15 mW/cm$^2$, unpolarized light) at the exposure time: 0 s (g), 7 s (h), 9 s (i), 10 s (j), 11 s (k), 14 s (l).

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To reverse the process, the sample was illuminated by the LED-2 unpolarized light (Figs. 3(g)–3(l)). During this process, the image of the sample in crossed polarizers gradually becomes dark. This corresponds to the reverse cis$\rightarrow$trans photoisomerization at which the boundary conditions become homeotropic again. The same process occurs due to the thermal cis$\rightarrow$trans relaxation during about 10 min. Practically, it is possible to use the ortho-substituted azobenzene compounds, which have the long-living cis-form [28].

The described photoalignment processes are well repeatable without any degradation of the sample within several hours. The quality of homogeneous orientation of the sample decreases with time (during several days), possibly, due to forming and subsequent adsorption of dimers consisting of two hydrogen-bonded HOAC molecules or their degradation under UV irradiation.

The similar experiments were performed with the NLC containing 0.1 wt % of HOA compound. After filling the E7+0.1% HOA mixture into the cell consisting of two glass plates without the orienting layers, the NLC has the homeotropic alignment: the microscope images are analogues to those for the E7+0.1% HOAC mixture (see Figs. 2(a) and 2(b)). Note that the homeotropic alignment is also observed in the case of the undoped E7. No orientational changes in E7+0.1% HOA layer were detected during the LED-1 UV illumination with intensity up to 10 mW/cm$^2$ and exposure time about several minutes. This indicates that HOA compound is mostly dissolved in the bulk of NLC and does not affect its alignment. In addition, the photoalignment processes for E7+0.1% HOAC mixture were not observed on the surfaces, which do not contain hydroxyl groups, for instance, on the polyimide coated substrates. Thus, one can conclude that the photoalignment is induced by HOAC molecules incorporated into the NLC matrix and adsorbed onto the glass surface due to the hydrogen bonds. In trans-form, the HOAC molecules are oriented normally to the substrate because of their hydrophobic tails and set homeotropic boundary conditions. The isomerization of the elongated trans-isomer into the bent cis-isomer gives rise to changing the surface anchoring from homeotropic to planar.

Now let us clarify, whether the director orientation of E7+0.1% HOAC on the glass substrates is induced parallel or perpendicular to the UV light polarization. For this purpose, let us consider the photoalignment effect in the NLC cell consisting of one untreated glass plate and one plate with the rubbed polyimide layer. Initially, the sample is dark in crossed polarizers and bright in parallel ones, when the rubbing direction r is perpendicular to the analyzer A (Figs. 4(a), 4(b), 4(g), and 4(h)). In this case, the NLC film has initially hybrid alignment (Fig. 4(c)). After the UV light exposure during 100 s, when the polarization direction is parallel to director orientation r on the bottom substrate, the light transmittance of the sample changes to the opposite one (Figs. 4(d)–4(h)). This corresponds to the formation of twisted structure in the NLC film (Fig. 4(f)). When the light comes through the sample, its polarization direction “follows” the NLC director due to Marguin regime and rotates by the angle of 90$^\circ$. The described easy axis alignment perpendicularly to the UV light illumination is typical for azobenzene-based orienting layers [6].

 

Fig. 4. Microscope images in crossed (a, d) and parallel (b, e) polarizers of the NLC (E7+0.1% HOAC) cell with one polyimide-treated substrate possessing planar alignment along vector r before (a, b) and after (d, e) the illumination at $\lambda _{max}$ = 365 nm ($I$ = 1.2 mW/cm$^2$, $\tau _{exp}$ = 100 s, linearly polarized light, the experimental geometries for (a, d) and (b, e) are shown in (g) and (h)). Before the UV illumination the NLC film has a hybrid orientation (c), while after the illumination it has a twisted planar orientation (f). Blue dashes in (c, f) show schematically the NLC director projection on the image plane. Time dependences of the transmitted light intensity $I_{th}$ for NLC cells with one polyimide-treated substrate at different HAOC dopant concentrations (i). The sample was placed between crossed polarizers and illuminated by LED-1 with $\lambda _{max}$ = 365 nm,$I$ = 1.2 mW/cm$^2$, polarized light, the experimental geometry is shown in (g).

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The variation of NLC film orientation from hybrid to twist occurs gradually that gives us a convenient way to investigate the effect of the HOAC concentration. For this aim, the mixtures of E7 with different concentrations (0.1, 0.08, 0.05, 0.02, and 0.01 wt %) of HOAC were prepared. NLC was filled in the glass cell with one polyimide-coated substrate and illuminated by the polarized UV light ($I$ = 1.5 mW/cm$^2$) in the previously described geometry (Fig. 4(g)). The transmittance of microscope white backlight passed through the sample in crossed polarizers was registered by a photodiode. The signal from photodiode was passing through the analog-digital converter and recordering on PC. For the samples with 0.1, 0.08, 0.05 %, the corresponding time dependences of the transmitted intensity $I_{tr}$ are almost identical (Fig. 4(i)). At further decrease of the HOAC concentration to 0.02 % transmittance varies more slowly. Finally, at 0.01 %, the transmittance almost does not change with time.

It is reasonable to assume that the photoalignment effect is mainly obliged to the existence of the adsorbed monolayer of HOAC molecules and does not depend on the HOAC concentration in the bulk of NLC. When the HOAC concentration is not sufficient to form a monolayer, the photoalignment process is suppressed. Using the critical dopant concentration $n_{cr} \approx 0.05\%$, one can easily evaluate the relation of adsorbed HOAC molecules to those in the bulk of NLC $X = l/Ln_{cr} \approx 10$ %, where $l$ and $L$ are the dopant molecule length and cell thickness. This indicates that a relatively small fraction of HOAC molecules is adsorbed onto the glass substrate because of the dimer formation and environment of polar NLC molecules possessing C$\equiv$N group.

4. Conclusion

To summarize, the light-induced anchoring transition was observed in the dye-doped NLC filled into the glass cell without any special treatment of the substrates. The NLC was doped with carboxylic azobenzene compound, which is spontaneously adsorbed and attached to the glass surface by hydrogen bonds, providing homeotropic boundary conditions. The linearly polarized UV light illumination causes the trans$\rightarrow$cis photoizomerization process, and the boundary conditions changed from homeotropic to planar. The easy axis orientation is found to be perpendicular to the UV light polarization. The reverse transition can be caused by the blue light illumination or occur spontaneously during the thermal cis$\rightarrow$trans relaxation.

This approach can be useful for realization of a particular LC alignment in confined geometries, for instance, in capillaries and microcavities, where the direct surface treatment is hindered.

Funding

Russian Science Foundation (RSF) (18-72-00242).

References

1. A. M. Menzel, “Tuned, driven, and active soft matter,” Phys. Rep. 554, 1–45 (2015). [CrossRef]  

2. H. K. Bisoyi and Q. Li, “Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications,” Chem. Rev. 116(24), 15089–15166 (2016). [CrossRef]  

3. A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013). [CrossRef]  

4. V. P. Shibaev and A. Yu. Bobrovsky, “Liquid crystalline polymers: development trends and photocontrollable materials,” Russ. Chem. Rev. 86(11), 1024–1072 (2017). [CrossRef]  

5. K. Ichimura, “Photoalignment of Liquid-Crystal Systems,” Chem. Rev. 100(5), 1847–1874 (2000). [CrossRef]  

6. O. Yaroshchuk and Yu. Reznikov, “Photoalignment of liquid crystals: basics and current trends,” J. Mater. Chem. 22(2), 286–300 (2012). [CrossRef]  

7. T. Seki, “Light-directed alignment, surface morphing and related processes: recent trends,” J. Mater. Chem. C 4(34), 7895–7910 (2016). [CrossRef]  

8. K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988). [CrossRef]  

9. V. Chigrinov, “Photoaligning and Photopatterning — A New Challenge in Liquid Crystal Photonics,” Crystals 3(1), 149–162 (2013). [CrossRef]  

10. K.-Y. Yu, C.-R. Lee, C.-H. Lin, and C.-T. Kuo, “Controllable pretilt angle of liquid crystals with the formation of microgrooves,” J. Phys. D: Appl. Phys. 46(4), 045102 (2013). [CrossRef]  

11. D. Voloshchenko, A. Khyzhnyak, Yu. Reznikov, and V. Reshetnyak, “Control of an easy-axis on nematic-polymer interface by light action to nematic bulk,” Jpn. J. Appl. Phys. 34, 566–571 (1995). [CrossRef]  

12. D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008). [CrossRef]  

13. C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004). [CrossRef]  

14. I. C. Khoo, S. Slussarenko, B. D. Guenther, M.-Y. Shih, P. Chen, and W. V. Wood, “Optically induced space-charge fields, dc voltage, and extraordinarily large nonlinearity in dye-doped nematic liquid crystals,” Opt. Lett. 23(4), 253–255 (1998). [CrossRef]  

15. L. Lucchetti, M. Di Fabrizio, O. Francescangeli, and F. Simoni, “Colossal optical nonlinearity in dye doped liquid crystals,” Opt. Commun. 233(4-6), 417–424 (2004). [CrossRef]  

16. G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013). [CrossRef]  

17. H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017). [CrossRef]  

18. A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018). [CrossRef]  

19. S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018). [CrossRef]  

20. S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018). [CrossRef]  

21. S. Kundu, M.-H. Lee, S. H. Lee, and S.-W. Kang, “In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification,” Adv. Mater. 25(24), 3365–3370 (2013). [CrossRef]  

22. L. Komitov, K. Ichimura, and A. Strigazzi, “Light-induced anchoring transition in a 4,4’-disubstituted azobenzene nematic liquid crystal,” Liq. Cryst. 27(1), 51–55 (2000). [CrossRef]  

23. A. V. Dubtsov, S. V. Pasechnik, D. V. Shmeliova, and S. Kralj, “Light and phospholipid driven structural transitions in nematic microdroplets,” Appl. Phys. Lett. 105(15), 151606 (2014). [CrossRef]  

24. G. Magyar, J. West, Yu. Reznikov, and O. Yaroshchuk, “Light Induced LC Alignment on the Isotropic Non-Photosensitive Surface,” Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 329(1), 71–79 (1999). [CrossRef]  

25. Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000). [CrossRef]  

26. D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015). [CrossRef]  

27. I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016). [CrossRef]  

28. Z. Ahmed, A. Siiskonen, M. Virkki, and A. Priimagi, “Controlling azobenzene photoswitching through combined ortho -fluorination and -amination,” Chem. Commun. 53(93), 12520–12523 (2017). [CrossRef]  

References

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  • |

  1. A. M. Menzel, “Tuned, driven, and active soft matter,” Phys. Rep. 554, 1–45 (2015).
    [Crossref]
  2. H. K. Bisoyi and Q. Li, “Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications,” Chem. Rev. 116(24), 15089–15166 (2016).
    [Crossref]
  3. A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
    [Crossref]
  4. V. P. Shibaev and A. Yu. Bobrovsky, “Liquid crystalline polymers: development trends and photocontrollable materials,” Russ. Chem. Rev. 86(11), 1024–1072 (2017).
    [Crossref]
  5. K. Ichimura, “Photoalignment of Liquid-Crystal Systems,” Chem. Rev. 100(5), 1847–1874 (2000).
    [Crossref]
  6. O. Yaroshchuk and Yu. Reznikov, “Photoalignment of liquid crystals: basics and current trends,” J. Mater. Chem. 22(2), 286–300 (2012).
    [Crossref]
  7. T. Seki, “Light-directed alignment, surface morphing and related processes: recent trends,” J. Mater. Chem. C 4(34), 7895–7910 (2016).
    [Crossref]
  8. K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988).
    [Crossref]
  9. V. Chigrinov, “Photoaligning and Photopatterning — A New Challenge in Liquid Crystal Photonics,” Crystals 3(1), 149–162 (2013).
    [Crossref]
  10. K.-Y. Yu, C.-R. Lee, C.-H. Lin, and C.-T. Kuo, “Controllable pretilt angle of liquid crystals with the formation of microgrooves,” J. Phys. D: Appl. Phys. 46(4), 045102 (2013).
    [Crossref]
  11. D. Voloshchenko, A. Khyzhnyak, Yu. Reznikov, and V. Reshetnyak, “Control of an easy-axis on nematic-polymer interface by light action to nematic bulk,” Jpn. J. Appl. Phys. 34, 566–571 (1995).
    [Crossref]
  12. D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
    [Crossref]
  13. C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004).
    [Crossref]
  14. I. C. Khoo, S. Slussarenko, B. D. Guenther, M.-Y. Shih, P. Chen, and W. V. Wood, “Optically induced space-charge fields, dc voltage, and extraordinarily large nonlinearity in dye-doped nematic liquid crystals,” Opt. Lett. 23(4), 253–255 (1998).
    [Crossref]
  15. L. Lucchetti, M. Di Fabrizio, O. Francescangeli, and F. Simoni, “Colossal optical nonlinearity in dye doped liquid crystals,” Opt. Commun. 233(4-6), 417–424 (2004).
    [Crossref]
  16. G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
    [Crossref]
  17. H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
    [Crossref]
  18. A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
    [Crossref]
  19. S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
    [Crossref]
  20. S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018).
    [Crossref]
  21. S. Kundu, M.-H. Lee, S. H. Lee, and S.-W. Kang, “In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification,” Adv. Mater. 25(24), 3365–3370 (2013).
    [Crossref]
  22. L. Komitov, K. Ichimura, and A. Strigazzi, “Light-induced anchoring transition in a 4,4’-disubstituted azobenzene nematic liquid crystal,” Liq. Cryst. 27(1), 51–55 (2000).
    [Crossref]
  23. A. V. Dubtsov, S. V. Pasechnik, D. V. Shmeliova, and S. Kralj, “Light and phospholipid driven structural transitions in nematic microdroplets,” Appl. Phys. Lett. 105(15), 151606 (2014).
    [Crossref]
  24. G. Magyar, J. West, Yu. Reznikov, and O. Yaroshchuk, “Light Induced LC Alignment on the Isotropic Non-Photosensitive Surface,” Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 329(1), 71–79 (1999).
    [Crossref]
  25. Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
    [Crossref]
  26. D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
    [Crossref]
  27. I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
    [Crossref]
  28. Z. Ahmed, A. Siiskonen, M. Virkki, and A. Priimagi, “Controlling azobenzene photoswitching through combined ortho -fluorination and -amination,” Chem. Commun. 53(93), 12520–12523 (2017).
    [Crossref]

2018 (3)

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018).
[Crossref]

2017 (3)

V. P. Shibaev and A. Yu. Bobrovsky, “Liquid crystalline polymers: development trends and photocontrollable materials,” Russ. Chem. Rev. 86(11), 1024–1072 (2017).
[Crossref]

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

Z. Ahmed, A. Siiskonen, M. Virkki, and A. Priimagi, “Controlling azobenzene photoswitching through combined ortho -fluorination and -amination,” Chem. Commun. 53(93), 12520–12523 (2017).
[Crossref]

2016 (3)

I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
[Crossref]

H. K. Bisoyi and Q. Li, “Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications,” Chem. Rev. 116(24), 15089–15166 (2016).
[Crossref]

T. Seki, “Light-directed alignment, surface morphing and related processes: recent trends,” J. Mater. Chem. C 4(34), 7895–7910 (2016).
[Crossref]

2015 (2)

A. M. Menzel, “Tuned, driven, and active soft matter,” Phys. Rep. 554, 1–45 (2015).
[Crossref]

D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
[Crossref]

2014 (1)

A. V. Dubtsov, S. V. Pasechnik, D. V. Shmeliova, and S. Kralj, “Light and phospholipid driven structural transitions in nematic microdroplets,” Appl. Phys. Lett. 105(15), 151606 (2014).
[Crossref]

2013 (5)

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
[Crossref]

S. Kundu, M.-H. Lee, S. H. Lee, and S.-W. Kang, “In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification,” Adv. Mater. 25(24), 3365–3370 (2013).
[Crossref]

V. Chigrinov, “Photoaligning and Photopatterning — A New Challenge in Liquid Crystal Photonics,” Crystals 3(1), 149–162 (2013).
[Crossref]

K.-Y. Yu, C.-R. Lee, C.-H. Lin, and C.-T. Kuo, “Controllable pretilt angle of liquid crystals with the formation of microgrooves,” J. Phys. D: Appl. Phys. 46(4), 045102 (2013).
[Crossref]

2012 (1)

O. Yaroshchuk and Yu. Reznikov, “Photoalignment of liquid crystals: basics and current trends,” J. Mater. Chem. 22(2), 286–300 (2012).
[Crossref]

2008 (1)

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

2004 (2)

C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004).
[Crossref]

L. Lucchetti, M. Di Fabrizio, O. Francescangeli, and F. Simoni, “Colossal optical nonlinearity in dye doped liquid crystals,” Opt. Commun. 233(4-6), 417–424 (2004).
[Crossref]

2000 (3)

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

L. Komitov, K. Ichimura, and A. Strigazzi, “Light-induced anchoring transition in a 4,4’-disubstituted azobenzene nematic liquid crystal,” Liq. Cryst. 27(1), 51–55 (2000).
[Crossref]

K. Ichimura, “Photoalignment of Liquid-Crystal Systems,” Chem. Rev. 100(5), 1847–1874 (2000).
[Crossref]

1999 (1)

G. Magyar, J. West, Yu. Reznikov, and O. Yaroshchuk, “Light Induced LC Alignment on the Isotropic Non-Photosensitive Surface,” Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 329(1), 71–79 (1999).
[Crossref]

1998 (1)

1995 (1)

D. Voloshchenko, A. Khyzhnyak, Yu. Reznikov, and V. Reshetnyak, “Control of an easy-axis on nematic-polymer interface by light action to nematic bulk,” Jpn. J. Appl. Phys. 34, 566–571 (1995).
[Crossref]

1988 (1)

K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988).
[Crossref]

Ahmed, Z.

Z. Ahmed, A. Siiskonen, M. Virkki, and A. Priimagi, “Controlling azobenzene photoswitching through combined ortho -fluorination and -amination,” Chem. Commun. 53(93), 12520–12523 (2017).
[Crossref]

Aoki, K.

K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988).
[Crossref]

Araoka, F.

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

Bisoyi, H. K.

H. K. Bisoyi and Q. Li, “Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications,” Chem. Rev. 116(24), 15089–15166 (2016).
[Crossref]

Bobrovsky, A. Yu.

V. P. Shibaev and A. Yu. Bobrovsky, “Liquid crystalline polymers: development trends and photocontrollable materials,” Russ. Chem. Rev. 86(11), 1024–1072 (2017).
[Crossref]

A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
[Crossref]

Boiko, N. I.

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018).
[Crossref]

Bubnov, A.

A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
[Crossref]

Bugakov, M. A.

S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018).
[Crossref]

Chattham, N.

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

Chen, P.

Cheng, K.-T.

C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004).
[Crossref]

Chigrinov, V.

V. Chigrinov, “Photoaligning and Photopatterning — A New Challenge in Liquid Crystal Photonics,” Crystals 3(1), 149–162 (2013).
[Crossref]

Choi, Y.-J.

D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
[Crossref]

Di Fabrizio, M.

L. Lucchetti, M. Di Fabrizio, O. Francescangeli, and F. Simoni, “Colossal optical nonlinearity in dye doped liquid crystals,” Opt. Commun. 233(4-6), 417–424 (2004).
[Crossref]

Dubtsov, A. V.

A. V. Dubtsov, S. V. Pasechnik, D. V. Shmeliova, and S. Kralj, “Light and phospholipid driven structural transitions in nematic microdroplets,” Appl. Phys. Lett. 105(15), 151606 (2014).
[Crossref]

Emelyanenko, A. V.

S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018).
[Crossref]

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

Eremin, A.

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

Fedorenko, D.

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

Francescangeli, O.

L. Lucchetti, M. Di Fabrizio, O. Francescangeli, and F. Simoni, “Colossal optical nonlinearity in dye doped liquid crystals,” Opt. Commun. 233(4-6), 417–424 (2004).
[Crossref]

Fu, T.-L.

C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004).
[Crossref]

Fuh, A. Y.-G.

C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004).
[Crossref]

Glogarová, M.

A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
[Crossref]

Guenther, B. D.

Ha, K.

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

Haba, O.

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

Hamplová, V.

A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
[Crossref]

Hirankittiwong, P.

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

Hosoki, A.

K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988).
[Crossref]

Ichimura, K.

K. Ichimura, “Photoalignment of Liquid-Crystal Systems,” Chem. Rev. 100(5), 1847–1874 (2000).
[Crossref]

L. Komitov, K. Ichimura, and A. Strigazzi, “Light-induced anchoring transition in a 4,4’-disubstituted azobenzene nematic liquid crystal,” Liq. Cryst. 27(1), 51–55 (2000).
[Crossref]

K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988).
[Crossref]

Ishikawa, K.

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

Ito, A.

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

Jeong, K.-U.

D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
[Crossref]

Kang, D.-G.

D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
[Crossref]

Kang, S.-W.

S. Kundu, M.-H. Lee, S. H. Lee, and S.-W. Kang, “In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification,” Adv. Mater. 25(24), 3365–3370 (2013).
[Crossref]

Karapinar, R.

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

Kašpar, M.

A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
[Crossref]

Khokhlov, A. R.

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

Khoo, I. C.

Khyzhnyak, A.

D. Voloshchenko, A. Khyzhnyak, Yu. Reznikov, and V. Reshetnyak, “Control of an easy-axis on nematic-polymer interface by light action to nematic bulk,” Jpn. J. Appl. Phys. 34, 566–571 (1995).
[Crossref]

Kiang-Ia, J.

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

Kim, C.

I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
[Crossref]

Kim, D.-Y.

D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
[Crossref]

Kim, J. H.

I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
[Crossref]

Kim, J.-H.

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

Komitov, L.

L. Komitov, K. Ichimura, and A. Strigazzi, “Light-induced anchoring transition in a 4,4’-disubstituted azobenzene nematic liquid crystal,” Liq. Cryst. 27(1), 51–55 (2000).
[Crossref]

Kralj, S.

A. V. Dubtsov, S. V. Pasechnik, D. V. Shmeliova, and S. Kralj, “Light and phospholipid driven structural transitions in nematic microdroplets,” Appl. Phys. Lett. 105(15), 151606 (2014).
[Crossref]

Kumar, S.

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

Kundu, S.

S. Kundu, M.-H. Lee, S. H. Lee, and S.-W. Kang, “In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification,” Adv. Mater. 25(24), 3365–3370 (2013).
[Crossref]

Kuo, C.-T.

K.-Y. Yu, C.-R. Lee, C.-H. Lin, and C.-T. Kuo, “Controllable pretilt angle of liquid crystals with the formation of microgrooves,” J. Phys. D: Appl. Phys. 46(4), 045102 (2013).
[Crossref]

Lavrentovich, O.

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

Lee, B.

I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
[Crossref]

Lee, C.-R.

K.-Y. Yu, C.-R. Lee, C.-H. Lin, and C.-T. Kuo, “Controllable pretilt angle of liquid crystals with the formation of microgrooves,” J. Phys. D: Appl. Phys. 46(4), 045102 (2013).
[Crossref]

C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004).
[Crossref]

Lee, G.

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

Lee, J. H.

I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
[Crossref]

Lee, M.-H.

S. Kundu, M.-H. Lee, S. H. Lee, and S.-W. Kang, “In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification,” Adv. Mater. 25(24), 3365–3370 (2013).
[Crossref]

Lee, S. H.

S. Kundu, M.-H. Lee, S. H. Lee, and S.-W. Kang, “In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification,” Adv. Mater. 25(24), 3365–3370 (2013).
[Crossref]

Lee, S.-A.

D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
[Crossref]

Li, Q.

H. K. Bisoyi and Q. Li, “Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications,” Chem. Rev. 116(24), 15089–15166 (2016).
[Crossref]

Lin, C.-H.

K.-Y. Yu, C.-R. Lee, C.-H. Lin, and C.-T. Kuo, “Controllable pretilt angle of liquid crystals with the formation of microgrooves,” J. Phys. D: Appl. Phys. 46(4), 045102 (2013).
[Crossref]

Liu, J. H.

S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018).
[Crossref]

Liu, J.-H.

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

Lucchetti, L.

L. Lucchetti, M. Di Fabrizio, O. Francescangeli, and F. Simoni, “Colossal optical nonlinearity in dye doped liquid crystals,” Opt. Commun. 233(4-6), 417–424 (2004).
[Crossref]

Magyar, G.

G. Magyar, J. West, Yu. Reznikov, and O. Yaroshchuk, “Light Induced LC Alignment on the Isotropic Non-Photosensitive Surface,” Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 329(1), 71–79 (1999).
[Crossref]

Menzel, A. M.

A. M. Menzel, “Tuned, driven, and active soft matter,” Phys. Rep. 554, 1–45 (2015).
[Crossref]

Mo, T.-S.

C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004).
[Crossref]

Momoi, Y.

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

Nádasi, H.

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

Ostroverkhova, O.

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

Ouskova, E.

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

Park, M.

D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
[Crossref]

Pasechnik, S. V.

A. V. Dubtsov, S. V. Pasechnik, D. V. Shmeliova, and S. Kralj, “Light and phospholipid driven structural transitions in nematic microdroplets,” Appl. Phys. Lett. 105(15), 151606 (2014).
[Crossref]

Priimagi, A.

Z. Ahmed, A. Siiskonen, M. Virkki, and A. Priimagi, “Controlling azobenzene photoswitching through combined ortho -fluorination and -amination,” Chem. Commun. 53(93), 12520–12523 (2017).
[Crossref]

Reshetnyak, V.

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

D. Voloshchenko, A. Khyzhnyak, Yu. Reznikov, and V. Reshetnyak, “Control of an easy-axis on nematic-polymer interface by light action to nematic bulk,” Jpn. J. Appl. Phys. 34, 566–571 (1995).
[Crossref]

Reznikov, Yu.

O. Yaroshchuk and Yu. Reznikov, “Photoalignment of liquid crystals: basics and current trends,” J. Mater. Chem. 22(2), 286–300 (2012).
[Crossref]

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

G. Magyar, J. West, Yu. Reznikov, and O. Yaroshchuk, “Light Induced LC Alignment on the Isotropic Non-Photosensitive Surface,” Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 329(1), 71–79 (1999).
[Crossref]

D. Voloshchenko, A. Khyzhnyak, Yu. Reznikov, and V. Reshetnyak, “Control of an easy-axis on nematic-polymer interface by light action to nematic bulk,” Jpn. J. Appl. Phys. 34, 566–571 (1995).
[Crossref]

Rudyak, V. Yu

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

Seki, T.

T. Seki, “Light-directed alignment, surface morphing and related processes: recent trends,” J. Mater. Chem. C 4(34), 7895–7910 (2016).
[Crossref]

K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988).
[Crossref]

Shibaev, V.

A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
[Crossref]

Shibaev, V. P.

V. P. Shibaev and A. Yu. Bobrovsky, “Liquid crystalline polymers: development trends and photocontrollable materials,” Russ. Chem. Rev. 86(11), 1024–1072 (2017).
[Crossref]

Shih, M.-Y.

Shmeliova, D. V.

A. V. Dubtsov, S. V. Pasechnik, D. V. Shmeliova, and S. Kralj, “Light and phospholipid driven structural transitions in nematic microdroplets,” Appl. Phys. Lett. 105(15), 151606 (2014).
[Crossref]

Shvetsov, S. A.

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018).
[Crossref]

Siiskonen, A.

Z. Ahmed, A. Siiskonen, M. Virkki, and A. Priimagi, “Controlling azobenzene photoswitching through combined ortho -fluorination and -amination,” Chem. Commun. 53(93), 12520–12523 (2017).
[Crossref]

Simoni, F.

L. Lucchetti, M. Di Fabrizio, O. Francescangeli, and F. Simoni, “Colossal optical nonlinearity in dye doped liquid crystals,” Opt. Commun. 233(4-6), 417–424 (2004).
[Crossref]

Singer, K. D.

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

Slussarenko, S.

Slyusarenko, K.

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

Son, I.

I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
[Crossref]

Stannarius, R.

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

Strigazzi, A.

L. Komitov, K. Ichimura, and A. Strigazzi, “Light-induced anchoring transition in a 4,4’-disubstituted azobenzene nematic liquid crystal,” Liq. Cryst. 27(1), 51–55 (2000).
[Crossref]

Suzuki, Y.

K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988).
[Crossref]

Takezoe, H.

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

Virkki, M.

Z. Ahmed, A. Siiskonen, M. Virkki, and A. Priimagi, “Controlling azobenzene photoswitching through combined ortho -fluorination and -amination,” Chem. Commun. 53(93), 12520–12523 (2017).
[Crossref]

Voloshchenko, D.

D. Voloshchenko, A. Khyzhnyak, Yu. Reznikov, and V. Reshetnyak, “Control of an easy-axis on nematic-polymer interface by light action to nematic bulk,” Jpn. J. Appl. Phys. 34, 566–571 (1995).
[Crossref]

Wang, B.

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

West, J.

G. Magyar, J. West, Yu. Reznikov, and O. Yaroshchuk, “Light Induced LC Alignment on the Isotropic Non-Photosensitive Surface,” Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 329(1), 71–79 (1999).
[Crossref]

West, J. L.

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

Wood, W. V.

Yaroshchuk, O.

O. Yaroshchuk and Yu. Reznikov, “Photoalignment of liquid crystals: basics and current trends,” J. Mater. Chem. 22(2), 286–300 (2012).
[Crossref]

G. Magyar, J. West, Yu. Reznikov, and O. Yaroshchuk, “Light Induced LC Alignment on the Isotropic Non-Photosensitive Surface,” Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 329(1), 71–79 (1999).
[Crossref]

Yonetake, K.

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

Yoo, J. Y.

I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
[Crossref]

Yu, K.-Y.

K.-Y. Yu, C.-R. Lee, C.-H. Lin, and C.-T. Kuo, “Controllable pretilt angle of liquid crystals with the formation of microgrooves,” J. Phys. D: Appl. Phys. 46(4), 045102 (2013).
[Crossref]

Zhang, Y.-S.

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

ACS Appl. Mater. Interfaces (1)

D.-Y. Kim, S.-A. Lee, D.-G. Kang, M. Park, Y.-J. Choi, and K.-U. Jeong, “Photoresponsive Carbohydrate-based Giant Surfactants: Automatic Vertical Alignment of Nematic Liquid Crystal for the Remote-Controllable Optical Device,” ACS Appl. Mater. Interfaces 7(11), 6195–6204 (2015).
[Crossref]

Adv. Mater. (1)

S. Kundu, M.-H. Lee, S. H. Lee, and S.-W. Kang, “In Situ Homeotropic Alignment of Nematic Liquid Crystals Based on Photoisomerization of Azo-Dye, Physical Adsorption of Aggregates, and Consequent Topographical Modification,” Adv. Mater. 25(24), 3365–3370 (2013).
[Crossref]

Appl. Phys. Lett. (1)

A. V. Dubtsov, S. V. Pasechnik, D. V. Shmeliova, and S. Kralj, “Light and phospholipid driven structural transitions in nematic microdroplets,” Appl. Phys. Lett. 105(15), 151606 (2014).
[Crossref]

Chem. Commun. (1)

Z. Ahmed, A. Siiskonen, M. Virkki, and A. Priimagi, “Controlling azobenzene photoswitching through combined ortho -fluorination and -amination,” Chem. Commun. 53(93), 12520–12523 (2017).
[Crossref]

Chem. Rev. (2)

K. Ichimura, “Photoalignment of Liquid-Crystal Systems,” Chem. Rev. 100(5), 1847–1874 (2000).
[Crossref]

H. K. Bisoyi and Q. Li, “Light-Driven Liquid Crystalline Materials: From Photo-Induced Phase Transitions and Property Modulations to Applications,” Chem. Rev. 116(24), 15089–15166 (2016).
[Crossref]

Crystals (1)

V. Chigrinov, “Photoaligning and Photopatterning — A New Challenge in Liquid Crystal Photonics,” Crystals 3(1), 149–162 (2013).
[Crossref]

J. Mater. Chem. (1)

O. Yaroshchuk and Yu. Reznikov, “Photoalignment of liquid crystals: basics and current trends,” J. Mater. Chem. 22(2), 286–300 (2012).
[Crossref]

J. Mater. Chem. C (1)

T. Seki, “Light-directed alignment, surface morphing and related processes: recent trends,” J. Mater. Chem. C 4(34), 7895–7910 (2016).
[Crossref]

J. Mol. Liq. (1)

S. A. Shvetsov, V. Yu Rudyak, A. V. Emelyanenko, N. I. Boiko, Y.-S. Zhang, J.-H. Liu, and A. R. Khokhlov, “Photoinduced orientational structures of nematic liquid crystal droplets in contact with polyimide coated surface,” J. Mol. Liq. 267, 222–228 (2018).
[Crossref]

J. Phys. D: Appl. Phys. (1)

K.-Y. Yu, C.-R. Lee, C.-H. Lin, and C.-T. Kuo, “Controllable pretilt angle of liquid crystals with the formation of microgrooves,” J. Phys. D: Appl. Phys. 46(4), 045102 (2013).
[Crossref]

Jpn. J. Appl. Phys. (1)

D. Voloshchenko, A. Khyzhnyak, Yu. Reznikov, and V. Reshetnyak, “Control of an easy-axis on nematic-polymer interface by light action to nematic bulk,” Jpn. J. Appl. Phys. 34, 566–571 (1995).
[Crossref]

Langmuir (1)

K. Ichimura, Y. Suzuki, T. Seki, A. Hosoki, and K. Aoki, “Reversible change in alignment mode of nematic liquid crystals regulated photochemically by command surfaces modified with an azobenzene monolayer,” Langmuir 4(5), 1214–1216 (1988).
[Crossref]

Liq. Cryst. (3)

A. Eremin, H. Nádasi, P. Hirankittiwong, J. Kiang-Ia, N. Chattham, O. Haba, K. Yonetake, and H. Takezoe, “Azodendrimers as a photoactive interface for liquid crystals,” Liq. Cryst. 45(13-15), 2121–2131 (2018).
[Crossref]

I. Son, B. Lee, C. Kim, J. H. Kim, J. Y. Yoo, and J. H. Lee, “In situ self-assembled homeotropic alignment layer for fast-switching liquid crystal devices,” Liq. Cryst. 43(4), 517–523 (2016).
[Crossref]

L. Komitov, K. Ichimura, and A. Strigazzi, “Light-induced anchoring transition in a 4,4’-disubstituted azobenzene nematic liquid crystal,” Liq. Cryst. 27(1), 51–55 (2000).
[Crossref]

Macromolecules (1)

A. Yu. Bobrovsky, V. Shibaev, A. Bubnov, V. Hamplová, M. Kašpar, and M. Glogarová, “Effect of Molecular Structure on Chiro-Optical and Photo-Optical Properties of Smart Liquid Crystalline Polyacrylates,” Macromolecules 46(11), 4276–4284 (2013).
[Crossref]

Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A (1)

G. Magyar, J. West, Yu. Reznikov, and O. Yaroshchuk, “Light Induced LC Alignment on the Isotropic Non-Photosensitive Surface,” Mol. Cryst. Liq. Cryst. Sci. Technol., Sect. A 329(1), 71–79 (1999).
[Crossref]

Opt. Commun. (1)

L. Lucchetti, M. Di Fabrizio, O. Francescangeli, and F. Simoni, “Colossal optical nonlinearity in dye doped liquid crystals,” Opt. Commun. 233(4-6), 417–424 (2004).
[Crossref]

Opt. Lett. (1)

Part. Part. Syst. Charact. (1)

G. Lee, F. Araoka, K. Ishikawa, Y. Momoi, O. Haba, K. Yonetake, and H. Takezoe, “Photoinduced Ordering Transition in Microdroplets of Liquid Crystals with Azo-Dendrimer,” Part. Part. Syst. Charact. 30(10), 912 (2013).
[Crossref]

Phys. Chem. Chem. Phys. (1)

H. Nádasi, R. Stannarius, A. Eremin, A. Ito, K. Ishikawa, O. Haba, K. Yonetake, H. Takezoe, and F. Araoka, “Photomanipulation of the anchoring strength using a spontaneously adsorbed layer of azo dendrimers,” Phys. Chem. Chem. Phys. 19(11), 7597–7606 (2017).
[Crossref]

Phys. Rep. (1)

A. M. Menzel, “Tuned, driven, and active soft matter,” Phys. Rep. 554, 1–45 (2015).
[Crossref]

Phys. Rev. E (2)

D. Fedorenko, K. Slyusarenko, E. Ouskova, V. Reshetnyak, K. Ha, R. Karapinar, and Yu. Reznikov, “Light-induced gliding of the easy orientation axis of a dye-doped nematic liquid crystal,” Phys. Rev. E 77(6), 061705 (2008).
[Crossref]

C.-R. Lee, T.-L. Fu, K.-T. Cheng, T.-S. Mo, and A. Y.-G. Fuh, “Surface-assisted photoalignment in dye-doped liquid-crystal films,” Phys. Rev. E 69(3), 031704 (2004).
[Crossref]

Phys. Rev. Lett. (1)

Yu. Reznikov, O. Ostroverkhova, K. D. Singer, J.-H. Kim, S. Kumar, O. Lavrentovich, B. Wang, and J. L. West, “Photoalignment of Liquid Crystals by Liquid Crystals,” Phys. Rev. Lett. 84(9), 1930–1933 (2000).
[Crossref]

Polym. Sci., Ser. C (1)

S. A. Shvetsov, A. V. Emelyanenko, M. A. Bugakov, N. I. Boiko, and J. H. Liu, “Photo-orientation at the interface between thermotropic nematic liquid crystal and water caused by azobenzene polymer additives with different polymerization degrees,” Polym. Sci., Ser. C 60(1), 72–77 (2018).
[Crossref]

Russ. Chem. Rev. (1)

V. P. Shibaev and A. Yu. Bobrovsky, “Liquid crystalline polymers: development trends and photocontrollable materials,” Russ. Chem. Rev. 86(11), 1024–1072 (2017).
[Crossref]

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Figures (4)

Fig. 1.
Fig. 1. Structural formulas of HOAC (a) and HOA (b). Normalized spectral absorbance of HOAC and HOA solution in tetrahydrofuran (c) corresponding to trans- (solid lines) and cis-forms (dashed lines).
Fig. 2.
Fig. 2. Microscope images of NLC (E7+0.1% HOAC) cell in crossed polarizers before (a, b) and after (c, d) the UV illumination ($\lambda _{max}$ = 365 nm, $I$ = 1.2 mW/cm$^2$) at two sample orientations (e, f). P and A are the directions of polarizer and analyzer, E is the UV light polarization direction. Insertion in (a) is the conoscopic image of the NLC cell.
Fig. 3.
Fig. 3. Microscope images of NLC (E7+0.1% HOAC) cell in crossed polarizers during the illumination at $\lambda _{max}$ = 365 nm ($I$ = 1.2 mW/cm$^2$, linearly polarized light, experimental geometry is shown in Fig. 2(e)) at the exposure time $\tau _{exp}$: 0 s (a), 30 s (b), 40 s (c), 50 s (d), 60 s (e), 100 s (f); and during the consequent illumination at $\lambda _{max}$ = 466 nm ($I$ = 15 mW/cm$^2$, unpolarized light) at the exposure time: 0 s (g), 7 s (h), 9 s (i), 10 s (j), 11 s (k), 14 s (l).
Fig. 4.
Fig. 4. Microscope images in crossed (a, d) and parallel (b, e) polarizers of the NLC (E7+0.1% HOAC) cell with one polyimide-treated substrate possessing planar alignment along vector r before (a, b) and after (d, e) the illumination at $\lambda _{max}$ = 365 nm ($I$ = 1.2 mW/cm$^2$, $\tau _{exp}$ = 100 s, linearly polarized light, the experimental geometries for (a, d) and (b, e) are shown in (g) and (h)). Before the UV illumination the NLC film has a hybrid orientation (c), while after the illumination it has a twisted planar orientation (f). Blue dashes in (c, f) show schematically the NLC director projection on the image plane. Time dependences of the transmitted light intensity $I_{th}$ for NLC cells with one polyimide-treated substrate at different HAOC dopant concentrations (i). The sample was placed between crossed polarizers and illuminated by LED-1 with $\lambda _{max}$ = 365 nm,$I$ = 1.2 mW/cm$^2$, polarized light, the experimental geometry is shown in (g).

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