149 results about "Liquid crystal elastomer" patented technology

The invention belongs to the technical field of an intelligent material and particularly relates to a reversible photoinduced deformation liquid crystal high polymer and carbon nano tube composite thin film and a preparation method thereof. A liquid crystal high polymer in the composite thin film is a cross-linked type liquid crystal elastic body containing a photosensitive azobenzene liquid crystal element; and a carbon nano tube is a highly and sequentially oriented carbon nano tube thin film. In the composite thin film, a carbon nano tube orienting structure induces the liquid crystal element to be oriented along the axial direction of the carbon nano tube; and other orienting layers are not needed. When the prepared composite thin film is in ultraviolet illumination, the composite thin film is bent towards lights and can be recovered to the original state when the composite thin film is irradiated by visible lights. Reversible deformation generated by alternatively illuminating the composite thin film by ultraviolet lights and visible lights can be repeated for hundreds of times and has no obvious attenuation and fatigue. Moreover, the introduction of the carbon nano tube greatly enhances the mechanical performance of the material, and the material has excellent electric performance.

The invention discloses a liquid crystal elastic body and fiber with bidirectional shape memory effect and a preparation method thereof. The liquid crystal elastic body or a fiber molecular structure is a mixed body of one or two polymers in two general formula polymers disclosed as right. The liquid crystal polymer is mainly made of a waist connecting type liquid crystal monomer and a crosslinkable monomer. The preparation method of the liquid crystal elastic body or fiber comprises the steps: firstly, the waist connecting type liquid crystal monomer, the smectic liquid crystal monomer and the crosslinkable monomer carry out polyreaction to obtain the liquid crystal polymer, and then, the liquid crystal polymer is heated to be in a liquid crystal phase state; and under the action of an outfield, the liquid crystal matrixes of the liquid crystal polymer are sequentially arrayed and then the crosslinking treatment is carried out to obtain the liquid crystal elastic body or prepare the liquid crystal fiber. The obtained liquid crystal elastic body or fiber has the advantages of large bidirectional distortion, sensitive response for temperature stimulation, low deformation response temperature and easy regulation. The preparation method has simple technology and wide application prospect.

A liquid crystal elastomer actuator to move in a fluid is described herein. The actuator includes a body with dimensions between 100 nm and 800 μm having a low Reynolds number. The body includes a first and a second spatially separated volume, each comprising a liquid crystal elastomer. The first volume is doped with a first photoactive doping substance to absorb electromagnetic radiation at a first wavelength and the second volume is doped with a second photoactive doping substance to absorb electromagnetic radiation at a second wavelength. The first and second volumes change shape as a consequence of light absorption at the first or second wavelength, defining a first and a second joint. A first absorbance of the first volume at a given wavelength is different than a second absorbance of the second volume at a given wavelength, the first and second absorbance are measured in the same time interval.

The invention discloses a self-healing liquid crystalline elastomer based on a chitin-type liquid crystal and a preparation method of the self-healing liquid crystalline elastomer. According to the self-healing liquid crystalline elastomer disclosed by the invention, the chitin-type liquid crystalline elastomer with the self-healing capability is constructed by introducing a reversible covalent-multiple hydrogen bond; due to self-healing introduction, cracks in the material can be remarkably reduced, the comprehensive performances and the reusability of the material are improved, and the service life of the material is prolonged. The preparation method comprises the following steps: firstly, selecting proper reaction materials and reaction paths, synthesizing a monomer containing the multiple hydrogen bond and a side group, with a large volume, containing a mesogenic unit, carrying out reaction on the monomer and the side group by virtue of a liquid crystalline monomer with connection of a short spacer and a double bond under the proper reaction conditions to design and synthesize a chitin-type effect polymer, regulating the dosage of a hydrogen bond crosslinking agent, and preparing the chitin-type self-healing liquid crystalline elastomers in different crosslinking degrees under the condition without influencing the liquid crystallinity.

The invention belongs to the technical field of liquid crystal polymer materials, and particularly relates to a side chained linear azobenzene liquid crystal polymer material and a preparation method thereof. In the method, a novel liquid crystal polymer material using butadiene-ethylene-functional group substituted ethylene ternary alternative polymer as a main chain and the azobenzene derivative as a side chain structure is synthesized by using an open loop translocation polymerization method through using a 5-substituted cyclooctene (a substituent group is an azobenzene derivative) monomer in the presence of a Grubbs catalyst. According to the invention, the problem that the conventional azobenzene liquid crystal elastomer material is insoluble and is not molted so as not to be prepared by adopting a common machine shaping method. Under the condition of no cross-linked network structure, the side chained linear azobenzene liquid crystal polymer material has the rubber elasticity and good optical response characteristic; and the side chained linear azobenzene liquid crystal polymer material can machined to form liquid crystal polymer materials, such as films and fibers, after molten or dissolved without being limited in machining size and appearance and can be recycled for re-machine shaping after machine-shaping, and is a novel low-carbon and environment-friendly optical response liquid crystal polymer material.

The invention discloses a liquid crystal elastomer composite material for an optical actuator and a preparation method thereof. The composite material is prepared by in-situ polymerization of a nano carbon material as a filler and a thermotropic liquid crystal elastomer as a matrix, wherein the weight ratio of the nano carbon material to the thermotropic liquid crystal elastomer is 0.02-3:100, and the nano carbon material is graphene, graphene oxide or carbon nanotubes. The composite material can efficiently absorb near infrared lasers; optical energy is converted into heat energy so as to trigger the liquid crystal elastomer to generate phase transition, so that the liquid crystal elastomer which has no light stimulus response in intrinsic performance can be used in the optical actuator; at the same time, the carbon nanotube reinforced liquid crystal elastomer can increase output force of the actuator; moreover, the carbon nanotubes shrink when being irradiated by the near infrared lasers, the shrinkage behavior is consistent to a liquid crystal elastomer thermal shrinkage behavior in the deformation direction, and synergistic effect of the carbon nanotubes and the liquid crystal elastomer improves the response rate and the deformation quantity of the actuator.

The invention relates to a liquid crystal elastomer driving element which comprises a liquid crystal elastomer. The liquid crystal elastomer can reversibly deform near the liquid crystal transformation temperature. The liquid crystal elastomer has a crosslinked network which comprises liquid crystal molecules connected with one another, molecules containing diallyl sulfide groups, a flexible chain and a crosslinking agent. The invention also relates to a preparation method of the liquid crystal elastomer driving element. The preparation method comprises the following steps of: adding the liquid crystal molecules, the molecules containing diallyl sulfide groups, the flexible chain and the crosslinking agent into a solvent to form a mixture solution; performing a polymerization reaction on the mixture solution, wherein the liquid crystal molecules, the molecules containing diallyl sulfide groups, the flexible chain and the crosslinking agent are polymerized to form a crosslinked network to form the liquid crystal elastomer; and orienting the liquid crystal elastomer to obtain the liquid crystal elastomer driving element. The invention also relates to application of the liquid crystal elastomer which is used as a driving element and is applied to an artificial muscle, a blind person display, a sensor, a micro-fluid system valve or an intelligent responding interface material.

A method of ink-extrusion printing an object, including providing a mixture including liquid crystal monomers and photo-catalyzing or heating the mixture to produce a liquid crystal ink. The ink is in a nematic phase. The method includes extruding the ink through a print-head orifice moving along a print direction to faun an extruded film of the object. The extruded film exhibits birefringence. Also disclosed are a liquid crystal ink. The ink includes a mixture including liquid crystal monomers. The mixture when at a target printing temperature is in a nematic phase. Also disclosed is ink-extrusion-printed object. The object includes an extrusion-printed film including a nematic liquid crystal elastomer, wherein the film exhibits birefringence along an extrusion axis of the film.

Described herein are liquid crystalline elastomer compositions comprising aromatic epoxy units crosslinked with alkylene diacid units having alkylene segments containing at least one methylene unit, and/or aromatic epoxy units crosslinked with polyphenolic units, wherein the aromatic epoxy units and alkylene diacid units and/or polyphenolic units are in a molar ratio that results in the liquid crystalline elastomer composition exhibiting a glass transition temperature (T_g) and a thermal stability of the liquid crystalline phase (T_lc) that make them particularly suitable as shape memory materials and for use in methods of additive manufacturing. Methods for producing these compositions and their use in additive manufacturing processes are also described.

An intelligent compression device for controllable compression. The compression device includes a compressible body and a microprocessor. The compressible body encircles a limb of a user and includes an elastomer layer and an activation layer. The elastomer layer includes voxelated liquid crystal elastomers that contract in response to a stimulus. The activation element, which is positioned proximate to the elastomer layer, supplies the stimulus. The microprocessor actuates at least a portion of the activation element layer.

The invention belongs to the technical field of polymer composite materials, and discloses a high-thermal-conductivity remoldable liquid crystal elastomer composite material, and a preparation methodand application thereof. The high-thermal-conductivity reconfigurable liquid crystal elastomer composite material is obtained by mixing a sulfydryl-terminated liquid crystal prepolymer with a filler and then carrying out a cross-linking reaction A under the action of a sulfydryl cross-linking agent. The invention also provides a preparation method of the composite material. The preparation methodcomprises the following steps: firstly, preparing a sulfydryl-terminated liquid crystal prepolymer through photoinduced sulfydryl alkene click chemistry; then, the self-repairing liquid crystal elastomer containing the disulfide bond is obtained through an oxidation reaction between the prepolymer and the sulfydryl cross-linking agent; meanwhile, the heat-conducting filler and the like are introduced into the elastomer system in an in-situ polymerization mode, so that the composite material with good heat-conducting property and a recyclable remodeling function is obtained, and the composite material can be applied to the fields of aerospace, microelectronics and the like.

The purpose of the present invention is to provide: a single fibre including a thermally responsive liquid-crystal elastomer which reversibly expands and contracts in response to heat; a filament yarn including said single fibre; and a fibre product using the single fibre or the filament yarn. This single fibre includes a thermally responsive liquid-crystal elastomer which reversibly expands and contracts using, as a boundary, a transition temperature (Ti) at which phase transition from a liquid-crystal phase to an isotropic phase or from the isotropic phase to the liquid-crystal phase occurs.

The present invention relates to liquid crystal elastomers having two-way shape memory effect and methods of making such LCEs. The method of preparation includes the steps of polymerizing at least two monomers with crosslinking polymer, prealigning the resultant polymer, crosslinking the resultant polymer, and preparing the liquid crystal elastomer. The liquid crystal elastomer can be drawn to fibers.

The invention belongs to the technical field of advanced material preparation and forming, and discloses a preparation method based on a liquid crystal elastomer and 4D printing and a product. The preparation method comprises the following steps of (1) mixing and stirring a liquid crystal monomer, a crosslinking agent n-butylamine and a photoinitiator to obtain an oligomer and carrying out bubbleremoval treatment on the oligomer; (2) constructing a three-dimensional model of a to-be-formed component, and adopting slicing software for carrying out printing rate programming design and slicing on the basis of the oligomer and the three-dimensional model to obtain a file which can be directly read and run by a 4D printing device; (3) taking the oligomer as a material, carrying out printing forming of the to-be-formed component through the 4D printing device according to the file, and using ultraviolet light for irradiating printed parts during printing. The method can realize the preparation of complex deformable liquid crystal elastomer components.

The invention discloses a cyano-distyrene-containing photo-responsive luminescent liquid crystal elastomer material and a preparation method thereof. The liquid crystal elastomer material disclosed bythe invention is prepared by performing copolymerization on a cyano-distyrene group-containing monomer and a hydrogen bond crosslinking agent monomer, or performing copolymerization on the cyano-distyrene group-containing monomer, the hydrogen bond crosslinking agent monomer and a monomer containing a non-liquid crystal structural unit. The liquid crystal elastomer material disclosed by the invention shows a typical aggregation-induced fluorescence enhancement effect, can emit very strong fluorescent light in an aggregation state; in addition, the orientated single domain liquid crystal elastomer fibre also has photo-response; under the irradiation of ultraviolet light, the single domain liquid crystal elastomer fibre can deform, has the advantages that the deformation degree is high, thedeformation speed is high, the deformation can be stored for a long time and the like, and shows a broad application prospect in the fields of intelligent actuators, biomaterials, optical materials and the like.

A method of making a shape-programmable liquid crystal elastomer. The method includes preparing an alignment cell having a surface programmed with a plurality of domains. A cavity of the alignment cell is filled with a monomer solution. The monomers of the monomer solution are configured to align to the surface of the alignment cell. The aligned monomers are polymerized by Michael Addition. The polymerized monomers are then cross-linked to form a cross-linked liquid crystal elastomer. The cross-linking traps monomer alignment into a plurality of voxels with each voxel having a director orientation.

The invention relates to a liquid crystalline monomer with reaction property, and a relative preparation method. The compound structural formula is showed as above, wherein n1 is integer 6-12, n2 is integer 1-5, and n3 is integer 1-4, the substitution position of terminal olefine oxide group is at the ortho-position or para-position with respect to the benzene carbonic acid substrate. The inventive synthesis method comprises that uses dihydroxybenzoic acid as substrate to lead steric hindrance group into carboxyl group to generate ester, to be synthesized with alkyl halide to generate para-position ether, grafts alkylene on ortho-position or para-position hydroxyl group via alkoxylation, to be hydrolyzed into acid, to be esterified with alkyl substituted phenylphenol generated by Friedel-Crafts reaction and reduction, to generate the liquid crystalline monomer. The invention has reactive star polymer which can be polymerized or grafted on polymer chain, to a new type of liquid crystalline polymer or liquid crystalline elastomer connected as waist positions, with easily obtained raw materials, simple and safe operation, and wide application for thin plate display, artificial muscle, shape memory, biological medicine, and high strength material.

The invention provides a mixture of monomer and liquid crystal to improve a uneven concentration case of a polymer/liquid crystal composite material. Thus, the invention provides a liquid crystal element, which is made of the polymer/liquid crystal composite material obtained by polymerizing the mixture of monomer and liquid crystal. The mixture of monomer and liquid crystal is characterized in that: the polymer/liquid crystal composite material is obtained by mixing more than one kind of polymerized monomer represented by a general formula (1) into an optical isotropic liquid crystal compositions containing a non-Chiral liquid crystal component A and a chiral compound k. In the formula (1), such as Ra represents straight chain alkyl with 1~30 carbon atoms, Rb represents straight chain subalkyl with 1~30 carbon atoms, ring A1 represents 1,4-phenylene, X1 represents -O-,P1 represents acryloyl.

The invention discloses a magnetically controlled optical drive flexible robot and relates to the technical field of robots. The magnetically controlled optical drive flexible robot comprises a base,a first mechanical arm, a second mechanical arm, a third mechanical arm, a fourth mechanical arm, a liquid crystal elastomer layer, a photothermal conversion reagent layer and a magnetofluid layer, wherein the first mechanical arm, the second mechanical arm, the third mechanical arm and the fourth mechanical arm are sequentially arranged on the top of the base and arranged around the upper surfaceof the base in a bonding mode. According to the magnetically controlled optical drive flexible robot, the application positions, directions and angles of control signals and a driving source are notstrictly limited, signals need to be aligned at different positions in a traditional control mode, different movement direction control is realized, the magnetically controlled optical drive flexiblerobot has a non-contact characteristic, the control and the driving adopt magnetic fields and light sources respectively, wires are not needed, and the magnetically controlled optical drive flexible robot is suitable for complex occasions such as human body targeted drug delivery, complex terrain detection and the like; and when the robot changes the moving direction, the robot does not need to rotate.

The invention relates to a preparation method of a 4D printing liquid crystal elastomer and an application of the 4D printing liquid crystal elastomer in an actuator, a liquid crystal elastomer oligomer containing a dynamic disulfide bond is used as printing precursor liquid ink, a device of the 4D printing liquid crystal elastomer is realized by adopting aqueous solvent curing, and the 4D printing liquid crystal elastomer is applied in the actuator. Meanwhile, a freeze-drying technology is adopted, so that the shrinkage rate of the device is effectively improved, and the printing device can better maintain the overall morphological characteristics. The invention provides an effective rapid curing method for 4D printing material forming and structural design. Meanwhile, water-based solventcuring is systematically applied to the 4D printing material, the manufacturing and processing limitation of a traditional photocuring or photo-thermal curing 4D printing process method is broken through, and a new method is provided for deep curing of 4D printing of opaque materials.