# Liquid crystals: order between solid and liquid

> A phase spectrum of a rod-like liquid crystal: on heating, 8CB goes from crystal to smectic A, nematic and isotropic liquid, losing positional order before orientational order. A live 3D nematic shows the director, the shared axis that walls or an electric field can turn, and a twisted-nematic pixel between crossed polarisers shows how that becomes bright and dark in a display.

- Page: https://www.labcanvas.com/templates/graphical-abstracts/liquid-crystals-order-between-solid-liquid
- Open in the LabCanvas editor (LabCanvas account): https://www.labcanvas.com/editor.html?template=liquid-crystals-order-between-solid-and-liquid
- Updated: 2026-10-14
- Category: Materials graphical abstracts
- Method: Graphical abstract
- Starting materials: A rod-like mesogen: 8CB (4-cyano-4′-octylbiphenyl)
- Product: A nematic liquid crystal whose director an electric field can turn: the twisted-nematic display pixel
- Key result: 8CB: smectic A 24–34 °C, nematic 34–42.6 °C; latent heat ≈ 250 J/g (crystal → LC) vs ≈ 5 J/g (LC → isotropic), typical values (Popa-Nita et al. 2009). TN director twist 90°, published 1971 by Schadt and Helfrich (Chen et al. 2018)
- Figure: 1920 × 1080 px, 307 editable layers (5 generated objects with settings)

## Steps

1. **The mesogen**: Elongated molecules, rigid over part of their length, such as 8CB (4-cyano-4′-octylbiphenyl), form calamitic liquid crystals
2. **Crystal**: Positional and orientational order; melting into the mesophase costs about 250 J/g, so most of the order goes here
3. **Smectic A (8CB, 24–34 °C)**: Fluid layers about one molecule thick, the molecular axes normal to the layers
4. **Nematic (8CB, 34–42.6 °C)**: No positional order; the molecules share one axis, the director n, set by the walls or an electric field
5. **Isotropic liquid (8CB, above 42.6 °C)**: Orientational order is gone too (S = 0); this last step costs only about 5 J/g
6. **Twisted-nematic pixel**: Between crossed polarisers the 90° twist guides the light through (bright); above a threshold voltage the directors unwind and the light is blocked (dark)

## Uses

- Liquid crystal displays (TN mode: wristwatches, signage, laptops)
- Teaching phases and phase transitions of soft matter
- Electro-optic switching

## References

1. Popa-Nita, Gerlič & Kralj, “The Influence of Disorder on Thermotropic Nematic Liquid Crystals Phase Behavior”, Int. J. Mol. Sci. 2009. https://doi.org/10.3390/ijms10093971 (review)
2. Chen et al., “Liquid crystal display and organic light-emitting diode display: present status and future perspectives”, Light Sci. Appl. 2018. https://doi.org/10.1038/lsa.2017.168 (review)
3. Piccardi, Alberucci & Assanto, “Nematicons and their electro-optic control: light localization and signal readdressing via reorientation in liquid crystals”, Int. J. Mol. Sci. 2013. https://doi.org/10.3390/ijms141019932 (review)
4. Schinas et al., “Influence of Carbon Quantum Dots on the Orientational Order and Rotational Viscosity of 8CB”, Nanomaterials 2025. https://doi.org/10.3390/nano15161278 (further reading)

Credit: Drawn by LabCanvas after Popa-Nita et al., Int. J. Mol. Sci. 2009 (doi:10.3390/ijms10093971), Chen et al., Light Sci. Appl. 2018 (doi:10.1038/lsa.2017.168) and Piccardi et al., Int. J. Mol. Sci. 2013 (doi:10.3390/ijms141019932).

## Questions

**What does the “Liquid crystals: order between solid and liquid” template show?** A phase spectrum of a rod-like liquid crystal: on heating, 8CB goes from crystal to smectic A, nematic and isotropic liquid, losing positional order before orientational order. A live 3D nematic shows the director, the shared axis that walls or an electric field can turn, and a twisted-nematic pixel between crossed polarisers shows how that becomes bright and dark in a display.

**What are the steps shown in “Liquid crystals: order between solid and liquid”?** 1. The mesogen: Elongated molecules, rigid over part of their length, such as 8CB (4-cyano-4′-octylbiphenyl), form calamitic liquid crystals. 2. Crystal: Positional and orientational order; melting into the mesophase costs about 250 J/g, so most of the order goes here. 3. Smectic A (8CB, 24–34 °C): Fluid layers about one molecule thick, the molecular axes normal to the layers. 4. Nematic (8CB, 34–42.6 °C): No positional order; the molecules share one axis, the director n, set by the walls or an electric field. 5. Isotropic liquid (8CB, above 42.6 °C): Orientational order is gone too (S = 0); this last step costs only about 5 J/g. 6. Twisted-nematic pixel: Between crossed polarisers the 90° twist guides the light through (bright); above a threshold voltage the directors unwind and the light is blocked (dark).

**What are the starting materials and the product?** Starting materials: A rod-like mesogen: 8CB (4-cyano-4′-octylbiphenyl). Product: A nematic liquid crystal whose director an electric field can turn: the twisted-nematic display pixel.

**Which papers is “Liquid crystals: order between solid and liquid” based on?** Popa-Nita, Gerlič & Kralj, “The Influence of Disorder on Thermotropic Nematic Liquid Crystals Phase Behavior”, Int. J. Mol. Sci. 2009 (doi:10.3390/ijms10093971); Chen et al., “Liquid crystal display and organic light-emitting diode display: present status and future perspectives”, Light Sci. Appl. 2018 (doi:10.1038/lsa.2017.168); Piccardi, Alberucci & Assanto, “Nematicons and their electro-optic control: light localization and signal readdressing via reorientation in liquid crystals”, Int. J. Mol. Sci. 2013 (doi:10.3390/ijms141019932); Schinas et al., “Influence of Carbon Quantum Dots on the Orientational Order and Rotational Viscosity of 8CB”, Nanomaterials 2025 (doi:10.3390/nano15161278).

**Can I edit the “Liquid crystals: order between solid and liquid” template?** Yes. Open it in the LabCanvas editor: all 307 layers are editable, including 5 generated objects (structures, plots, equipment) with their own settings. Change the text, colours and layout, then export PNG, TIFF, SVG or PDF.

**Do I need an account to use this template?** Not to view it here. To open and edit it, sign in to LabCanvas or create a free account (the free plan keeps up to 3 designs). Downloading the figure is part of LabCanvas Pro (US$19 a month or US$199 a year).