Liquid crystal elastomers, networks and gels: advanced smart materials

The principal concepts, preparation methods, important features of liquid crystal elastomers, anisotropic networks and gels, as well as recent exciting progress in this field are reviewed. Discussions are focused on their potential applications as smart materials for converting electrical or optical energy into mechanical energy and vice versa – such applications include artificial muscles, light scattering electro-optical switches and display materials, electro- or photo-controllable micro- or nano-machinery, electrically switchable color-tunable reflectors (mirrors) and full-color reflective display, fine-tunable and low-threshold mirror-less lasing, etc. In addition, some innovative anisotropic networks consisting of ferroelectric liquid crystals, discotic mesogens and mesomorphic ladder-like polysiloxanes are also highlighted.

[1]  Andro Chanishvili,et al.  Lasing in Dye‐Doped Cholesteric Liquid Crystals: Two New Tuning Strategies , 2004 .

[2]  H. Yokoyama,et al.  Smectic A Elastomers with Uniform Homeotropic Orientation Obtained by Applying a Biaxial Mechanical Field , 2004 .

[3]  K. Hanabusa,et al.  Homeotropically oriented nematic physical gels for electrooptical materials , 2003 .

[4]  P. Keller,et al.  Nematic Elastomer Fiber Actuator , 2003 .

[5]  T. Ikeda,et al.  Photomechanics: Directed bending of a polymer film by light , 2003, Nature.

[6]  B. Y. Tang,et al.  Assembly of Photopolymerizable Discotic Molecules on an Aligned Polyimide Layer Surface to Form a Negative Retardation Film with an Oblique Optical Axis , 2003 .

[7]  B. Kong,et al.  Photo‐Induced Orientation of a Film of Ladderlike Polysiloxane Bearing Dual Photoreactive Side Groups , 2003 .

[8]  Cheng Huang,et al.  Nematic Anisotropic Liquid‐Crystal Gels—Self‐Assembled Nanocomposites with High Electromechanical Response , 2003 .

[9]  Azriel Z. Genack,et al.  Photonic Materials Based on Mixtures of Cholesteric Liquid Crystals with Polymers , 2003 .

[10]  Richard A. van Delden,et al.  Controlling the Color of Cholesteric Liquid‐Crystalline Films by Photoirradiation of a Chiroptical Molecular Switch Used as Dopant , 2003 .

[11]  Takashi Kato,et al.  Fast and High‐Contrast Electro‐optical Switching of Liquid‐Crystalline Physical Gels: Formation of Oriented Microphase‐Separated Structures , 2003 .

[12]  Bin Li,et al.  Light‐Driven Side‐On Nematic Elastomer Actuators , 2003 .

[13]  Kenji Mishima,et al.  Thermally bandwidth-controllable reflective polarizers from (polymer network/liquid crystal/chiral dopant) composites , 2003 .

[14]  Tomiki Ikeda,et al.  Anisotropic Bending and Unbending Behavior of Azobenzene Liquid‐Crystalline Gels by Light Exposure , 2003 .

[15]  Sung Tae Kim,et al.  Laser Emission in a Dye Doped Cholesteric Polymer Network , 2002 .

[16]  A. Bobrovsky,et al.  Chiral nematic polymer mixture containing crosslinker and photosensitive chiral dopant: new type of materials with tunable photo-optical properties , 2002 .

[17]  F. Kremer,et al.  FT-IR Spectroscopic studies on reorientation of ferroelectric liquid crystals in a thermoreversible gel network , 2002 .

[18]  R. Hikmet,et al.  Patterned Multicolor Switchable Cholesteric Liquid Crystal Gels , 2002 .

[19]  K. Hanabusa,et al.  The positive effect on hole transport behaviour in anisotropic gels consisting of discotic liquid crystals and hydrogen-bonded fibres. , 2002, Chemical communications.

[20]  F. Kremer,et al.  Ferroelectric liquid crystalline elastomers: from the analysis of the molecular dynamics to the design of nanomachines , 2001 .

[21]  Banahalli R. Ratna,et al.  Liquid Crystal Elastomers with Mechanical Properties of a Muscle , 2001 .

[22]  Peter Palffy-Muhoray,et al.  Tunable Mirrorless Lasing in Cholesteric Liquid Crystalline Elastomers , 2001 .

[23]  Takashi Kato,et al.  Hydrogen-bonded Liquid crystalline materials : Supramolecular polymeric assembly and the induction of dynamic function , 2001 .

[24]  H. Finkelmann,et al.  A new opto-mechanical effect in solids. , 2001, Physical review letters.

[25]  F. Kremer,et al.  Giant lateral electrostriction in ferroelectric liquid-crystalline elastomers , 2001, Nature.

[26]  H. Finkelmann,et al.  A smectic A Liquid Single Crystal Elastomer (LSCE) : Phase behavior and mechanical anisotropy , 2001 .

[27]  Sung Tae Kim,et al.  Cholesteric Liquid Single-Crystal Elastomers (LSCE) Obtained by the Anisotropic Deswelling Method , 2001 .

[28]  J. Gong,et al.  Liquid crystalline gels. 3. Role of hydrogen bonding in the formation and stabilization of mesophase structures , 2001 .

[29]  Yue Zhao,et al.  Self-Assembly of a Liquid Crystalline Anisotropic Gel , 2000 .

[30]  H. Finkelmann,et al.  A Simple and Versatile Synthetic Route for the Preparation of Main-Chain, Liquid-Crystalline Elastomers , 2000 .

[31]  Yue Zhao,et al.  Liquid crystalline Anisotropic gels prepared from optical alignment : Polymer network formed in the isotropic phase , 2000 .

[32]  E. W. Meijer,et al.  A Scattering Electro‐Optical Switch Based on Dendrimers Dispersed in Liquid Crystals , 2000 .

[33]  K. Hanabusa,et al.  Electro‐optic effects and phase behavior of liquid‐crystalline physical gels: self‐assembly of hydrogen‐bonded molecules for the formation of dynamically functional composites , 2000 .

[34]  Chunqing Liu,et al.  A glance at the relation of stepwise coupling polymerization to supramolecular chemistry , 1999 .

[35]  K. Hanabusa,et al.  Self-Aggregation of an Amino Acid Derivative in a Liquid-Crystalline Physical Gel—Faster Response to Electric Fields , 1999 .

[36]  Hui Xu,et al.  Synthesis and characterization of reactive ladderlike polyallylsilsesquioxane and polyvinylsilsesquioxane , 1999 .

[37]  L. Cui.  Stable photoalignment layer for nematic liquid crystals based on ladder-like polysilsesquioxanes , 1998 .

[38]  F. Kremer,et al.  Piezoelectricity in ferroelectric liquid crystalline elastomers , 1998 .

[39]  K. Hanabusa,et al.  Gelation of Room‐Temperature Liquid Crystals by the Association of a trans‐1,2‐Bis(amino)cyclohexane Derivative , 1998 .

[40]  F. Kremer,et al.  The inverse electromechanical effect in mechanically oriented S * C -elastomers examined by means of an ultra-stable Michelson interferometer , 1998 .

[41]  R. Hikmet,et al.  Electrically switchable mirrors and optical components made from liquid-crystal gels , 1998, Nature.

[42]  P. Xie,et al.  Functionalization and application of ladder-like polysilsesquioxanes , 1997 .

[43]  H. Finkelmann,et al.  Smectic A liquid single crystal elastomers showing macroscopic in-plane fluidity , 1997 .

[44]  S. Kelly.  Anisotropic Networks, Elastomers and Gels , 1996 .

[45]  P. Xie,et al.  Synthesis and Anisotropic Behavior of New Ladderlike Polysilsesquioxanes with Side-on and End-on Fixed NLO Chromophores , 1996 .

[46]  Xie Ping,et al.  Synthesis and characterization of polymerizable β-diketone-based liquid crystalline metal chelates , 1996 .

[47]  H. Boots,et al.  Anisotropic‐network‐stabilized ferroelectric gels for active matrix addressing , 1996 .

[48]  R. Zentel,et al.  Combined LC main chain/side chain polymers , 1996 .

[49]  J. W. Doane,et al.  Polymer networks formed in liquid crystals , 1995 .

[50]  S. D. Hudson,et al.  Morphology of Polymer-Stabilized Liquid Crystals , 1995 .

[51]  T. Berzina,et al.  Langmuir-Blodgett films of bipolar lipids from thermophilic archaea , 1995 .

[52]  Martin Brehmer,et al.  Ferroelectric liquid-crystalline elastomers with short switching times , 1995 .

[53]  H. Boots,et al.  Ferroelectric liquid crystal gels Network stabilized ferroelectric display , 1995 .

[54]  Stephen M. Kelly,et al.  Photo-Induced Alignment and Patterning of Hybrid Liquid Crystalline Polymer Films on Single Substrates , 1995 .

[55]  Boots,et al.  Domain structure and switching behavior of anisotropic gels. , 1995, Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics.

[56]  M. Schadt,et al.  Photo-Generation of Linearly Polymerized Liquid Crystal Aligning Layers Comprising Novel, Integrated Optically Patterned Retarders and Color Filters , 1995 .

[57]  H. Ringsdorf,et al.  Macroscopically ordered discotic columnar networks , 1995 .

[58]  Rifat Ata Mustafa Hikmet,et al.  Anisotropic network stabilized ferroelectric gels , 1995 .

[59]  L. M. Wilson.  A highly ordered hydrogen-bonded network , 1995 .

[60]  P. Schuhmacher,et al.  Fast photoconduction in the highly ordered columnar phase of a discotic liquid crystal , 1994, Nature.

[61]  Takashi Kato,et al.  Aufbau eines flüssigkristallinen Polymernetzwerks durch Selbstorganisation über intermolekulare Wasserstoffbrückenbindungen , 1994 .

[62]  C. Bazuin,et al.  Use of noncovalent interactions to form novel liquid crystalline polymeric materials , 1994 .

[63]  F. Davis.  Liquid-Crystalline Elastomers , 1993 .

[64]  R. Hikmet,et al.  Cholesteric gels formed by LC molecules and their use in optical storage , 1993 .

[65]  Adam,et al.  Transient photoconductivity in a discotic liquid crystal. , 1993, Physical review letters.

[66]  R. Hikmet.  Piezoelectric networks obtained by photopolymerization of liquid crystal molecules , 1992 .

[67]  R. Hikmet.  Anisotropic gels in liquid crystal devices , 1992 .

[68]  H. Finkelmann,et al.  Nematic liquid single crystal elastomers , 1991 .

[69]  H. Finkelmann,et al.  Nematic elastomers, 1. Effect of the spacer length on the mechanical coupling between network anisotropy and nematic order , 1991 .

[70]  R. Zentel,et al.  Mechanical behaviour of liquid-crystalline polymers and their networks , 1991 .

[71]  G. Mitchell,et al.  Memory effects in liquid crystal elastomers , 1991 .

[72]  F. Kremer,et al.  Collective and molecular relaxations in polymeric ferroelectric liquid crystals and experimental proof of piezoelectricity in chiral smectic C-elastomers , 1991 .

[73]  R. Hikmet,et al.  Gel layers for inducing adjustable pretilt angles in liquid crystal systems , 1991 .

[74]  R. Hikmet.  From Liquid Crystalline Molecules to Anisotropic Gels , 1991 .

[75]  R. Hikmet.  Anisotropic gels and plasticized networks formed by liquid crystal molecules , 1991 .

[76]  H. Finkelmann,et al.  Piezoelectricity of cholesteric elastomers , 1990 .

[77]  F. Kremer,et al.  Experimental proof of piezoelectricity in cholesteric and chiral smectic C*‐phases of LC‐elastomers , 1990 .

[78]  N. Platé,et al.  Peculiarities of the thermoelastic behaviour of liquid- crystalline elastomers , 1990 .

[79]  H. Finkelmann,et al.  Nematic elastomers: The influence of external mechanical stress on the liquid-crystalline phase behavior , 1989 .

[80]  R. Zentel,et al.  Liquid‐crystalline elastomers with cholesteric and chiral smectic C* phases , 1989 .

[81]  R. Zentel.  Liquid Crystalline Elastomers , 1989 .

[82]  H. Brand.  Electromechanical effects in cholesteric and chiral smectic liquid‐crystalline elastomers , 1989 .

[83]  F. Kremer,et al.  Ferroelectric modes in combined side-group main chain liquid-crystalline polymers , 1989 .

[84]  N. R. Barnes,et al.  Molecular Switching in Liquid Crystal Elastomers , 1989 .

[85]  R. Zentel,et al.  Orientability of Crosslinked and of Chiral Liquid Crystalline Polymers , 1988 .

[86]  H. Finkelmann,et al.  Synthesis and characterization of biaxial nematic side chain polymers with laterally attached mesogenic groups , 1987 .

[87]  R. Zentel,et al.  Stress‐induced orientation in lightly crosslinked liquid‐crystalline side‐group polymers , 1987 .

[88]  R. Zentel.  Shape variation of cross-linked liquid-crystalline polymers by electric fields , 1986 .

[89]  R. Zentel,et al.  Liquid crystalline elastomers based on liquid crystalline side group, main chain and combined polymers , 1986 .

[90]  R. Zentel,et al.  Structure‐property relations in linear and crosslinked liquid crystalline polymers , 1986 .

[91]  D. Gray,et al.  Crosslinked cholesteric network from the acrylic acid ester of (hydroxypropyl) cellulose , 1984 .

[92]  H. Finkelmann,et al.  Investigations on liquid crystalline polysiloxanes, 5. Orientation of LC‐elastomers by mechanical forces , 1984 .

[93]  H. Ringsdorf,et al.  Liquid crystalline polymers with disc-like mesogens , 1983 .

[94]  H. Finkelmann,et al.  Investigations on liquid crystalline polysiloxanes 3. Liquid crystalline elastomers — a new type of liquid crystalline material , 1981 .

[95]  Masayuki Yokota,et al.  Polymer-stabilized liquid crystal blue phases , 2002, Nature materials.

[96]  K. Hanabusa,et al.  Electrooptical properties of liquid-crystalline physical gels: a new oligo(amino acid) gelator for light scattering display materialsElectronic supplementary information (ESI) available: AFM and SEM images of the aggregates of gelators 1???3. See http://www.rsc.org/suppdata/jm/b2/b201484j/ , 2002 .

[97]  Yue Zhao,et al.  Self-assembled gels of liquid crystals: hydrogen-bonded aggregates formed in various liquid crystalline textures , 2001 .

[98]  G. Mitchell,et al.  Liquid crystal elastomers based upon cellulose derivatives , 1992 .

[99]  G. Mitchell,et al.  Coupling between mesogenic units and polymer backbone in side-chain liquid crystal polymers and elastomers , 1991 .

[100]  P. Keller.  Photo-crosslinkable liquid-crystalline side-chain polysiloxanes , 1990 .

[101]  G. Mitchell,et al.  Structural studies of side-chain liquid crystal polymers and elastomers , 1987 .

[102]  G. Mitchell,et al.  Mechanically induced molecular switching in liquid-crystal elastomers , 1987 .

[103]  H. Finkelmann,et al.  State of Order in Liquid Crystalline Elastomers , 1987 .

[104]  G. Mitchell,et al.  The synthesis and properties of liquid crystal elastomers , 1986 .

[105]  C. Ober,et al.  Liquid crystal polymers with flexible spacers in the main chain , 1984 .

[106]  H. Finkelmann,et al.  Investigations on liquid crystalline polysiloxanes, 1. Synthesis and characterization of linear polymers , 1980 .

[107]  E. C. Hsu,et al.  Structure and Thermal Expansion of Some Polymers with Mesomorphic Ordering , 1976 .