Non-monotonic exposure dependence of the pretilt angle and surface polarity of the photo-orientant F-PVCN

Bugayova, L.; Gerus, Igor I.; Glushchenko, Anatoliy; Dyadyusha, A.; Kurioz, Yu.; Reshetnyak, Victor; Reznikov, Yuriy; West, John L.

doi:10.1080/02678290110091644

Cited by 10 publications

(6 citation statements)

References 7 publications

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“…7. In that paper we found that the short−exposed and the long−exposed PVCN−F surfaces are much more polar than the PVCN−F surface irra− diated with the intermediate exposure.…”

Section: Resultsmentioning

confidence: 85%

“…UV−produced cross−linking of side fragments and their reorientation perpendicular to polarisation of UV−light are considered, the main mecha− nisms of formation of light−induced easy axis in these mate− rials [6]. At the same time we found a non−monotonic de− pendence of the pretilt of LC 4−n−pentyl−4'−cyanobiphenyl (5CB) on fluoro−polyvinyl−cinnamate (PVCN−F) [7] which cannot be explained by known models [9]. We assumed the observed increase in the pretilt at long UV−exposure to be caused by light−induced changes of polarity of the PVCN−F surface.…”

Section: Introductionmentioning

confidence: 71%

“…Inasmuch as the con− tact angle of isotropic liquid on a rigid surface usually in− creases with the increase in the polarity of this surface, one can suggest with confidence that the dependence q(t exp ) is governed by photochemical changes of the polarity of PVCN−F. At the same time, the last studies shown that the cross−linking of fluorocinnamoyl side fragments and their reorientation perpendicular to polarisation of UV−light trough consequent trans−cis−trans−… isomerization are the main microscopic mechanisms of photo−transformation of the PVCN−F [7]. In this concern, the pretilt angle is associ− ated with the concentration of the fluorocinnamoyl side fragments and the initial decrease in the pretilt angle (short exposure regime) is governed by decreasing number of side fragments due to their cross−linking.…”

Section: Resultsmentioning

confidence: 94%

“…Polymers with cinnamoil−containing side fragments and different side−chains are the most popular and studied photoaligning materials [6][7][8]. UV−produced cross−linking of side fragments and their reorientation perpendicular to polarisation of UV−light are considered, the main mecha− nisms of formation of light−induced easy axis in these mate− rials [6].…”

Section: Introductionmentioning

confidence: 99%

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Exposure and temperature dependences of contact angle of liquid crystals on photoaligning surface

Gvozdovskyy¹,

Kurioz²,

Reznikov³

2009

Opto-Electronics Review

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We report on first studies of wetting of liquid crystal on photoaligning surface. We observed strong light-induced variations of a contact angle of a liquid LC 5CB on a photoaligning surface of fluoro-polyvinyl-cinnamate (PVCN-F) and we connected these variations with changes of PVCN-F polarity. We also present drastic changes of the contact angle of a nematic liquid crystal (MLC-6080) on the PVCN-F surface in a vicinity of temperature anchoring transition of liquid crystal from homeotropic orientation to planar one. We did not find any peculiarities in temperature dependence of the contact angle of isotropic liquid (glycerol) on PVCN-F and of nematic liquid crystal on pure glass in the same temperature range. It allows us to suggest that rearrangement of LC molecules and flexible fragments in the LC-polymer interface are responsible for the change of surface tensions both of LC and polymer and the observed jump of the contact angle.

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“…7. In that paper we found that the short−exposed and the long−exposed PVCN−F surfaces are much more polar than the PVCN−F surface irra− diated with the intermediate exposure.…”

Section: Resultsmentioning

confidence: 85%

Section: Introductionmentioning

confidence: 71%

Section: Resultsmentioning

confidence: 94%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Exposure and temperature dependences of contact angle of liquid crystals on photoaligning surface

Gvozdovskyy¹,

Kurioz²,

Reznikov³

2009

Opto-Electronics Review

Self Cite

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show abstract

“…properties of nematic liquid crystals at the interface with a para-PVCN-F photosensitive polymer have been already investigated [5][6][7][8][9].…”

Section: Introductionmentioning

confidence: 99%

Measurements of the azimuthal anchoring energy at the interface between a nematic liquid crystal and photosensitive polymers

Faetti

Mutinati

Gerus

2004

Molecular Crystals and Liquid Crystals

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The azimuthal anchoring energy at the interface between the nematic liquid crystal 5CB and a photosensitive polymer(para-PVCN-F)is measured using a high accuracy reflectometric method. The anchoring well is represented by the Rapini-Papoular function and the azimuthal anchoring energy coefficient W goes linearly to zero at the clearing point. Qualitative and quantitative observations show that the PVCN-F films favor a reduced surface nematic order. The gliding of the easy axis is also investigated

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Light- and electro- induced Fredericks transition in liquid crystal cells with photosensitive chalcogenide glasses surfaces As2S3

Kurioz

Korniychuk

2018

Journal of Molecular Liquids

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Non-monotonic exposure dependence of the pretilt angle and surface polarity of the photo-orientant F-PVCN

Cited by 10 publications

References 7 publications

Exposure and temperature dependences of contact angle of liquid crystals on photoaligning surface

Exposure and temperature dependences of contact angle of liquid crystals on photoaligning surface

Measurements of the azimuthal anchoring energy at the interface between a nematic liquid crystal and photosensitive polymers

Light- and electro- induced Fredericks transition in liquid crystal cells with photosensitive chalcogenide glasses surfaces As2S3

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