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What unusual property do liquid crystals have when they melt?

Thermotropic crystal

Crystallization

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Journal Article•DOI Sequence segregation in molten liquid-crystalline random copolymers Simon Hanna, Angel Romo-Uribe, Alan H. Windle - Show less +2 more 01 Dec 1993-Nature 61 Citations	If, as has been believed, the melt is a nematic liquid crystal , the question of how the necessary large-scale molecular rearrangements can occur even when crystallization is rapid is puzzling.
Journal Article•DOI Characterisation of Crystals in Palm Olein Wai-Lin Siew, Wee-Lam Ng - Show less +1 more 01 Feb 1996-Journal of the Science of Food and Agriculture 18 Citations	The low-melting component is probably the palm olein liquid entrapped between the crystals.
Journal Article•DOI Liquid Crystals in an Electric Field Richard Williams 01 Jul 1963-Nature 41 Citations	Their appearance and behaviour suggest several properties of liquid crystals which have not previously been reported.
Journal Article•DOI Formation of Liquid Crystalline Phases from a Langmuir Monolayer K. A. Suresh, Amitabha Bhattacharyya - Show less +1 more 19 Mar 1997-Langmuir 19 Citations	Although these domains originate from a monolayer, we find that they exhibit features typical of liquid crystals.
Journal Article•DOI Synthesis and properties of transition metal benzoporphyrin compound liquid crystals Ming-Hui Qi, Guo-Fa Liu - Show less +1 more 23 Sep 2003-Journal of Materials Chemistry 34 Citations	The study contributes to further choice and applications of the liquid crystals.
Journal Article•DOI Solid state growth of Na1/2Bi1/2TiO3–BaTiO3 single crystals and their enhanced piezoelectric properties Kyoung-Seok Moon, Dibyaranjan Rout, Ho-Yong Lee, Suk-Joong L. Kang - Show less +3 more 15 Feb 2011-Journal of Crystal Growth 50 Citations	These values are comparable to the best reported properties of melt-grown single crystals.
Journal Article•DOI Piezoelectric Effects in Liquid Crystals Robert B. Meyer 05 May 1969-Physical Review Letters 911 Citations	The theory may explain some recently observed phenomena in nematic liquid crystals.
Journal Article•DOI Effects and Structural Model of Surfactants on the Hysteresis Behavior of Polymer Dispersed Liquid Crystals David B. Chung, Hideaki Tsuda, Hideo Chida, Akihiro Mochizuki - Show less +3 more 01 Sep 1997-Molecular Crystals and Liquid Crystals 11 Citations	Most suggest strong interaction relationship between the liquid crystals and the polymeric materials.
Journal Article•DOI The effect of the solidification front shape on the temperature distribution in the crystal V. A. Borodin, L.B. Davidova, V.N. Erofeev, A.V. Shdanov, S.A. Startsev, V. A. Tatarchenko - Show less +5 more 01 Jun 1979-Journal of Crystal Growth 16 Citations	The results obtained suggest that the case of a convex-towards-the-melt solid-liquid interface is the least advantageous to grow crystals with a low defect density.

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How do liquid crystals compare to ordinary liquids and crystalline solids?5 answersLiquid crystals exhibit properties that lie between those of conventional liquids and solid crystals. They possess anisotropy similar to solid crystals but also fluidity akin to liquids, showcasing characteristics of both states simultaneously. Liquid crystals can be categorized into thermotropic, lyotropic, and metallotropic phases, with thermotropic LCs transitioning with temperature changes, lyotropic LCs transitioning with both temperature and concentration variations, and metallotropic LCs dependent on inorganic-organic composition ratios. These unique materials have found applications in various fields, including pharmaceuticals and cosmetics, due to their advantageous properties like thermodynamic stability, controlled release capabilities, and improved bioavailability. Liquid crystals play a crucial role in modern technology, especially in electronic displays like LCDs, where their anisotropic and soft nature allows for easy manipulation through external stimuli.

What distinguish strong and fragile liquids?5 answersThe key factor distinguishing strong and fragile liquids lies in their structural characteristics and behavior under different conditions. Fragile liquids, such as binary Lennard-Jones mixtures, exhibit a sudden transition from unrestrained to restrained configurations below the melting point, indicating a high degree of fragility. In contrast, strong liquids like molten silica are highly constrained even at equilibrium, showcasing a different structural order parameter. Fragile liquids experience shear thinning due to a reduction in effective volume fraction, while strong liquids show accelerated relaxation from a reduction in activation energy. The fragility of glassy liquids is determined by their temperature-dependent viscosity, with strong liquids having nearly Arrhenius behavior and fragile liquids showing super-Arrhenius behavior. Liquid-liquid transitions can also influence fragility, as seen in the strong-to-fragile transition in metallic glass-forming supercooled liquids.

How do liquid crystal elastomers dissipate energy?5 answersLiquid crystal elastomers (LCEs) dissipate energy through various mechanisms. One mechanism is the viscoelastic response of the LCE, where energy is dissipated as heat during cyclic loading. Another mechanism is the soft-elasticity of LCEs, which allows them to absorb strain energy at constant stress. This soft-elastic behavior is particularly effective in reducing the severity of impacts, as demonstrated by drop testing. Additionally, LCE-based architected materials exhibit rate-dependent energy absorption, with energy absorption increasing with strain rate due to viscoelastic dissipation and snap-through buckling. The alignment of the liquid crystal mesogens in LCEs also plays a role in energy absorption, with the degree of mesogen alignment affecting the power-law relationship between strain rate and energy absorption. Overall, LCEs offer promising potential for impact-absorbing applications due to their unique energy dissipation capabilities.

What are some characteristics of impact melt rock?4 answersImpact melt rocks have several characteristics. They can contain diagnostic shock indicators such as planar deformation features (PDF) in quartz and shocked zircon. Impact melt rocks can have different textures and chemistry, including hypocrystalline, glassy, and carbonate-based melt rocks. These rocks can also preserve organic material, indicating the presence of abundant organic material in the area at the time of impact. Geochemical signatures of platinum-group elements in impact melt rocks suggest an extraterrestrial component and support the identification of a highly fractionated iron impactor. Impact melt rocks can display lobate margins, cooling cracks, columnar joints, and mineral textures typical of volcanic rocks. They can also show a wide variety of deformation features, including fluidal textures, rearrangement patterns between grains, recrystallization, and the generation of new phases.

How are liquid crystals manufactured?8 answers

When were liquid crystals invented?7 answers

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