An overview of HPDLC films and their applications

Katariya-Jain, Anuja; Deshmukh, Rajendra R.

doi:10.1080/02678292.2021.2000052

Cited by 12 publications

(4 citation statements)

References 61 publications

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“…Consequently, LC transfer occurs from bright to dark (destructive) regions. Well-defined phase separation structures with the generated photopolymer in bright regions and LC in dark regions can be envisaged when the photopolymerization kinetics and the LC transfer dynamics are in good balance. ,− But the reaction system is too complicated to identify the relative contributions of the photopolymerization and LC transfer kinetics on phase separation without using excess commercial or synthesized chemicals.…”

Section: Introductionmentioning

confidence: 99%

Computational Insight into Phase Separation of a Thiol-Ene Photopolymer with Liquid Crystals for Holography by Dissipative Particle Dynamics Simulation

Wei

Chen

Li³

et al. 2023

Macromolecules

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Holographic polymer nanocomposites comprising liquid crystals (LCs) are produced through periodic photopolymerization-induced phase separation upon laser interference. A high degree of phase separation normally favors the holographic function which is, however, difficult to predict. Herein, we demonstrate the first example of providing computational insights into the phase separation by dissipative particle dynamics simulation. Phase separation to produce alternating polymer-rich and LC-rich regions occurs in the way that LC molecules transfer from bright to dark regions upon laser interference when the thiol-ene click reaction takes place in the bright regions. Results show that the relative segregation degree (SDr) increases with LC content when it is lower than 40 wt %, which can be correlated with the transferred amount of LC molecules from bright to dark regions. The low SDr of the system with 40 wt % LC may be ascribed to the inhibitory LC transfer by polymerization compared with the case prior to reaction. In terms of the effects of reaction probability, either too high or too low reaction probability is not favorable for phase separation due to insufficient LC transfer. Despite that no nematic LC phase is found after phase separation, this work provides initial computation insights into the mass transfer behaviors during photopolymerization-induced phase separation, which help in the development of effective strategies to improve the phase separation and performance of holographic polymer nanocomposites.

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Section: Introductionmentioning

confidence: 99%

Computational Insight into Phase Separation of a Thiol-Ene Photopolymer with Liquid Crystals for Holography by Dissipative Particle Dynamics Simulation

Wei

Chen

Li³

et al. 2023

Macromolecules

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“…Moreover, this new ultrashort-pulse laser hierarchical nanopatterning modality is of interest for inscription of functional nanostructures in other, still unexplored dielectric materials (e.g., polymers, ferroelectrics, etc. [ 23 , 24 , 25 , 26 , 27 ]) regarding its relevance and universal performance. Finally, ultrafine visualization analysis could facilitate new emerging functional applications of the predicted hierarchical nanopatterns in nano-optics, quantum and non-linear optics and material science.…”

Section: Introductionmentioning

confidence: 99%

Hierarchical Multi-Scale Coupled Periodical Photonic and Plasmonic Nanopatterns Inscribed by Femtosecond Laser Pulses in Lithium Niobate

et al. 2022

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The ultrafast interaction of tightly focused femtosecond laser pulses with bulk dielectric media in direct laser writing (inscription) regimes is known to proceed via complex multi-scale light, plasma and material modification nanopatterns, which are challenging for exploration owing to their mesoscopic, transient and buried character. In this study, we report on the first experimental demonstration, analysis and modeling of hierarchical multi-period coupled longitudinal and transverse nanogratings in bulk lithium niobate inscribed in the focal region by 1030 nm, 300 fs laser pulses in the recently proposed sub-filamentary laser inscription regime. The longitudinal Bragg-like topography nanogratings, possessing the laser-intensity-dependent periods ≈ 400 nm, consist of transverse birefringent nanogratings, which are perpendicular to the laser polarization and exhibit much smaller periods ≈ 160 nm. Our analysis and modeling support the photonic origin of the longitudinal nanogratings, appearing as prompt electromagnetic and corresponding ionization standing waves in the pre-focal region due to interference of the incident and plasma-reflected laser pulse parts. The transverse nanogratings could be assigned to the nanoscale material modification by interfacial plasmons, excited and interfered in the resulting longitudinal array of the plasma sheets in the bulk dielectric material. Our experimental findings provide strong support for our previously proposed mechanism of such hierarchical laser nanopatterning in bulk dielectrics, giving important insights into its crucial parameters and opening the way for directional harnessing of this technology.

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“…21 Holographic PDLCs (HPDLCs) are a new optical application combining laser holography and PDLCs, where the PDLCs undergo photopolymerization reactions under the induction of a laser holographic interference light field to cause phase separation, forming a refractive-index-modulated grating with periodic distribution in the polymer-rich region, with the LC-rich region corresponding to the bright and dark stripes of laser interference, which is commonly called HPDLC grating. 22 For the transmissive HPDLC grating, when the period and thickness of the grating meet certain conditions, the light is incident at the Bragg angle, and the incident light is emitted in the first-order diffraction direction. 22 Reflective HPDLC gratings can be switched between selective reflection and transmission modes.…”

mentioning

confidence: 99%

“…22 For the transmissive HPDLC grating, when the period and thickness of the grating meet certain conditions, the light is incident at the Bragg angle, and the incident light is emitted in the first-order diffraction direction. 22 Reflective HPDLC gratings can be switched between selective reflection and transmission modes. HPDLC grating has been widely studied and applied in fiber-optical switches and other fields due to its remarkable optical control characteristics.…”

mentioning

confidence: 99%

Advancements and Applications of Liquid Crystal/Polymer Composite Films

Zhou,

Liu,

Miao

et al. 2023

ACS Materials Lett.

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An overview of HPDLC films and their applications

Cited by 12 publications

References 61 publications

Computational Insight into Phase Separation of a Thiol-Ene Photopolymer with Liquid Crystals for Holography by Dissipative Particle Dynamics Simulation

Computational Insight into Phase Separation of a Thiol-Ene Photopolymer with Liquid Crystals for Holography by Dissipative Particle Dynamics Simulation

Hierarchical Multi-Scale Coupled Periodical Photonic and Plasmonic Nanopatterns Inscribed by Femtosecond Laser Pulses in Lithium Niobate

Advancements and Applications of Liquid Crystal/Polymer Composite Films

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