33results about How to "Change phase transition temperature" patented technology

The invention provides a cyclohexane oxane liquid crystal monomer compound and a preparation method of the cyclohexane oxane liquid crystal monomer compound. The structural formula of the compound isshown in the following formula, wherein R is any one of fluorine, chlorine, H, cyano, C1-C5 linear chain alkyl and C1-C5 linear alkoxy. The cyclohexane oxane liquid crystal monomer compound provided by the invention contains sulfonyl laterally and can change the phase transition temperature of molecules, the prepared monomer mixture not only has the advantage of low viscosity, but also has the characteristics of wide phase transition temperature and long screw pitch, and can be taken as raw materials of liquid crystal materials, thereby being beneficial to lowering the rotational viscosity ofthe liquid crystal materials and improving various dielectric coefficients.

The invention provides a rare earth magnetic material with controlled deformation of a magnetic field and a preparation method thereof. The material has the capability of generating micro-deformation controlled by an outer magnetic field at a room temperature and a temperature higher than the room temperature and is a novel rare earth magnetic control shape memory alloy capable of driving twin boundary migration of martensite by change of the external magnetic field to generate stress at a room temperature and a temperature higher than the room temperature. The chemical formula of the alloy is CoxNiyAlzDyj, wherein x is greater than or equal to 28 but less than or equal to 42, y is greater than or equal to 25 but less than or equal to 32, z is greater than or equal to 23 but less than or equal to 37, j is greater than or equal to 0.5 but less than or equal to 10, x+y+z+j=100, and x, y, z and j represent molar percentage contents. Compared with existing materials, the rare earth magnetic material has a wide magnetoelastic strain temperature range, great magnetoelastic strain and good mechanical property, and has important application in the fields such as micro-actuators, vibration and noise control, linear motors, microwave apparatuses and robots which can be used in temperatures higher than room temperature.

The invention discloses a consistent melting composite phase change material and a preparation method, and belongs to the technical field of phase change energy storage materials. The consistent melting composite phase change material comprises a phase change material and a heat conduction material, wherein the phase change material comprises a main phase change material and an auxiliary phase change material; the main phase change material is magnesium nitrate hexahydrate, and the content of the main phase change material in the phase change material is 60-70 mol%; the auxiliary phase change material is lithium nitrate, and the content of the auxiliary phase change material in the phase-change material is 30-40mol%; the content of the heat conduction material is 0-5wt% of the sum of the main phase change material and the auxiliary phase change material, and the content is not 0. The phase-change temperature of the main-phase phase-change material is adjustable by using the auxiliary phase, the eutectic phase-change material can relieve the problems of large supercooling degree and serious phase separation of a single hydrated salt phase-change material, and the supercooling degree of the phase-change material is extremely small, so that a nucleating agent does not need to be added in the preparation process; and the phase change material has high compatibility with aluminum and stainless steel 304, and can be widely applied to the field of clean heating.

The invention provides a side group-functionalized polyamino acid block polymer, which includes an A block and a B block. Compared with the prior art, the present invention uses the A block as a hydrophilic segment, and the B block as a hydrophilic and hydrophobic adjustable segment, and both have different degrees of polymerization, so that block polymers with different molecular weights can be obtained. Thereby forming temperature- and pH-sensitive hydrogels with different phase transition temperatures; at the same time, the block represented by the formula (III-C) in the B block can be protonated and deprotonated to achieve hydrophilic-hydrophobic transition, and then realize sol-gel The reversible transformation of the glue; moreover, the type and quantity of side groups can be changed by controlling the composition of the B block, which is beneficial to the further modification and application of the material; moreover, the polyamino acid block polymer provided by the invention significantly strengthens the material PMMA, The adhesion function of stainless steel and cells expands the application range of temperature-sensitive hydrogels and is beneficial to the application of temperature-sensitive hydrogels in biomedicine.

The invention discloses a method for preparing a vanadium dioxide film through an inorganic sol-gel method. The method comprises the following steps that (1) a precursor is prepared; (2) a substrate is cleaned; (3) film coating is conducted through a lifting method; and (4) annealing treatment is conducted, specifically, a quartz glass sheet coated with the film is put into a tubular furnace, thetubular furnace is internally vacuumized firstly, then temperature-rising annealing treatment is conducted, and thus the vanadium dioxide thermochromic film is obtained. The required cost of the method is low, precursor raw materials are easy to obtain, the preparation process is simple and easy to carry out, technical repeatability is good, and mass production is easy.

The invention provides a rare earth magnetic material with magnetic field controlled deformation and a preparation method thereof, and belongs to the field of shape memory materials.The material has the ability of producing micro deformation under the control of an external magnetic field at indoor temperature or higher temperature.The rare earth magnetic material is the novel rare earth magnetic control shape memory alloy capable of producing stress when martensite twin boundaries are driven by external magnetic field changes at indoor temperature or higher temperature.The chemical formula of the alloy is CoxNiyALzTbj, wherein x is larger than or equal to 27 and is smaller than or equal to 45, y is larger than or equal to 20 and is smaller than or equal to 31, z is larger than or equal to 20 and is smaller than or equal to 34, j is larger than or equal to 0.5 and is smaller than or equal to 8, the sum of x, y, z and j is 100, and x, y, z and j represent mole percentage content.Compared with existing materials, the rare earth magnetic material has the wide field-induced strain range, large field-induced strain and good mechanical property, and has the important application in the fields of micro displacement devices, vibration and noise control, linear motors, microwave devices, robots and the like capable of being used at the temperature higher than indoor temperature.

The invention discloses a Ti-Nb-O memory alloy having a high recoverable strain and a preparation method thereof. The method comprises the steps: mixing uniformly a pure Ti powder, a pure Nb powder, a pure TiO2 powder and a pure TiH2 powder according to the ratio of Ti atoms, Nb atoms, O atoms and H atoms being (77-91):(8-18):(1-3):(0-5), and carrying out compression molding to obtain a green body; putting the green body into a sintering furnace, sintering under a protective gas atmosphere, and thus obtaining a sintered-state Ti-Nb-O alloy; putting the Ti-Nb-O alloy into a tube furnace, carrying out solid solution treatment under the argon gas protection, putting the solid solution state Ti-Nb-O memory alloy into the tube furnace, carrying out aging treatment under the argon gas protection, and then rapidly cooling in ice water to obtain the high recoverable strain. The Ti-Nb-O alloy shows low elastic modulus, extremely high compressive strength and relatively high recoverable strain, and is suitable for use in medical hard tissue replacement and reparation materials.

The invention provides a rare earth magnetic-control shape memory alloy low in starting critical stress and a preparation method thereof and belongs to the field of memory alloy materials. The material has the capacity to generate deformation under the control of a weak external magnetic field under the indoor temperature condition and is novel rare earth magnetic-control shape memory alloy according to which strain can be generated due to martensite twin boundary migration under the driving of the external magnetic field change with small strength at the indoor temperature. The chemical formula of the alloy is CoxNiyAlzCej, wherein 18<=x<=43, 27<=y<=34, 26<=z<=40, 1<=j<=15, x+y+z+j=100, and x, y, z and j represent the molar percentages. Compared with existing materials, the rare earth magnetic material has the low martensite twin crystal migration starting critical stress, wide magnetic-induced strain temperature range, high magnetic-induced strain capacity and good mechanical property and has important application value in the fields of micro displacement machines used at the indoor temperature, vibrating and noise control, linear motors, microwave devices, robots and the like.

The invention discloses a Ni-Fe-Al alloy with linear superelasticity and a preparation method thereof. The composition and content (by atomic percentage) of the alloy are: nickel (Ni) is 56.5-51%, iron (Fe) It is 18.5-22%, and the rest is aluminum (Al). The Ni-Fe-Al alloy is directly prepared by powder metallurgy technology, and the process includes mixing, pressing, sintering and heat treatment (quenching). The alloy sintered billet exhibits linear superelasticity after quenching treatment, and the elastic recovery is 3-7%. The invention has a wide range of applications. In actual engineering, the superelasticity can be used to absorb and dissipate the vibration energy of the structure. It can be used to make mechanical sensing and control elements, human body orthopedic elements, damping elements, high-efficiency elastic elements, and wave absorbing and reducing elements. Shock and noise prevention devices, overload protection monitoring and forecasting of structural parts.

The invention provides a cyclohexane oxane liquid crystal monomer compound and a preparation method of the cyclohexane oxane liquid crystal monomer compound. The structural formula of the compound isshown in the following formula, wherein R is any one of fluorine, chlorine, H, cyano, C1-C5 linear chain alkyl and C1-C5 linear alkoxy. The cyclohexane oxane liquid crystal monomer compound provided by the invention contains sulfonyl laterally and can change the phase transition temperature of molecules, the prepared monomer mixture not only has the advantage of low viscosity, but also has the characteristics of wide phase transition temperature and long screw pitch, and can be taken as raw materials of liquid crystal materials, thereby being beneficial to lowering the rotational viscosity ofthe liquid crystal materials and improving various dielectric coefficients.

The invention provides a magnetic memory alloy with long function life and a preparation method thereof and belongs to the field of shape memory alloys. Compared with other magnetic shape memory alloys, the magnetic memory alloy has the two advantages of the two aspects of good mechanical properties and long function life. The chemical formula of the magnetic memory alloy is CoxNiyAlzNdj, wherein31.9 <= x <= 39.8, 30.1 <= y<= 34.6, 29.2 <= z <= 35.7, 0.8 <= j <= 1.5, x+y+z+j = 100, and x, y, z and j represent mole percentages. Compared with existing materials, the magnetic shape memory alloyhas the advantages that the coherent superfine Co7Nd2 intermetallic compound is formed around the second phase of the memory alloy, magnetic performance and function fatigue resistance of the magneticmemory alloy are improved greatly while mechanical properties of the second phase are enhanced, thus the magnetic memory alloy has both good mechanical properties and the long function life, and theindustrial application range of the magnetic memory alloy is widened greatly.

The invention relates to a preparation method of submicron-level vanadium trioxide powder. The preparation method comprises 1, preparing an oxalic acid solution, 2, heating the oxalic acid solution, adding vanadium pentoxide powder into the oxalic acid solution, and carrying out a stirring reaction process until complete dissolution to obtain a vanadyl oxalate solution, 3, slowly adding ammonium hydroxide into the vanadyl oxalate solution and carrying out stirring for a reaction to obtain precipitates, 4, filtering the precipitates and carrying out drying to obtain a high-activity precursor and 5, roasting the high-activity precursor in an inert atmosphere to obtain submicron-level vanadium trioxide powder. The submicron-level vanadium trioxide powder has high product purity and a single phase, contains submicron-level spherical particles with the uniform sizes less than 1 microns and high particle surface activity and is conducive to further processing and use. The preparation method has simple processes, can be operated easily, has a low cost, is free of hydrogen or other reducing atmospheres, has high safety and a low three waste treating capacity and can be easily industrialized.