45results about How to "Wide phase transition temperature range" patented technology

The invention discloses a preparation method of a paraffin / polyurethane solid-solid composite double-phase change energy storage material, comprising the following steps: selecting raw materials which comprises the following components: by weight, 40-90 parts of polyethylene glycol, 4-20 parts of isocyanate, 0-10 parts of a chain extender, 0-50 parts of paraffin, 0-5 parts of a surfactant and 0-1 part of a catalyst; melting glycol and carrying out vacuum-pumping processing, mixing the molten glycol with the surfactant and paraffin, adding isocyanate, the chain extender and the catalyst to react at a temperature of 60-90 DEG C to obtain a performed polymer, carrying out deaeration on the performed polymer, injecting the deaerated performed polymer into a mould, solidifying, cooling and demoulding. According to the composite double-phase change energy storage material provided by the invention, a paraffin hydrocarbon compound with large latent heat of phase change is used as a filling material, and a polyurethane material with a phase change function is used as a matrix. Latent heat of phase change of the prepared paraffin / polyurethane solid-solid composite double-phase change energy storage material reaches 154J / g, phase-change temperature ranges from 15 DEG C to 70 DEG C, and the material is a composite phase change material having a double-phase change character.

The invention discloses a shape-stabilized phase change material with shaped sintered carbon as the carrier and a preparation method thereof. The shape-stabilized phase change material with the shapedsintered carbon as the carrier and the preparation method thereof solve the technical problems easy loss of accumulated energy, low thermal conductivity, poor encapsulation properties and poor dimension and shape design of existing composite phase change materials. The shape-stabilized phase change material with the shaped sintered carbon as the carrier is composed of, by weight percentage, 85-95% of organic high-polymer phase change materials and 5-15% of the shaped sintered carbon, wherein the shaped sintered carbon is processed through surface compatibility treatment; the high-polymer phase change materials are distributed inside gaps formed among particles of the shaped sintered carbon. The preparation method of the shape-stabilized phase change material with the shaped sintered carbon as the carrier comprises preparation of the shaped sintered carbon, surface compatibility treatment, heating and melting of the phase change materials and pressurized permeation.

The invention discloses a preparation method for phase-M vanadium dioxide nanometre powder. The preparation method comprises the following steps: mixing polyhydric alcohol with a carbon chain length of 3 to 10 with monohydric alcohol with a carbon chain length of 1 to 5 in a volume ratio of 1: (6 to 15), so as to obtain a mixed alcohol solution; then adding quaternary ammonium salt with a carbon chain length of 1 to 16 in the mixed alcohol solution, so as to obtain electrolyte, wherein the concentration of quaternary ammonium salt in the electrolyte is 1-5 g / L; then using a vanadium metal block as an anode, using a platinum metal block or a vanadium metal block as a cathode, keeping a distance between the anode and the cathode to be 2 mm to 5 cm, placing the anode and the cathode in the electrolyte, and electrolysing for 1 to 3 hours under a voltage of 2 to 30 V, so as to obtain a reaction solution containing precipitates; then performing a solid-liquid treatment and a washing treatment on the reaction solution, so as to obtain an intermediate product; and after that, annealing the intermediate product for 1 to 3 hours at a temperature of 350 to 450 DEG C and under a pressure of 10 to 100 Pa, so as to prepare the target product with a particle size of 50 to 100 nm. The preparation method has the characteristics of being time-saving, energy-saving, environment-friendly, low in preparation cost, and easy to realize large-scale industrialized production.

The invention relates to a nematic liquid crystal composition. The composition contains at least a nematic liquid crystal compound as shown in the formula (I), at least a nematic liquid crystal compound as shown in the formula (II), at least a nematic liquid crystal compound as shown in the formula (III), at least a nematic liquid crystal compound as shown in the formula (IV), at least a nematic liquid crystal compound as shown in the formula (V) and at least an optionally optically active compound. The nematic liquid crystal composition provided by the invention has high birefringence, low visco-elastic coefficient ratio gamma 1 / k11 and a wide phase transition temperature range. In addition, the liquid crystal composition has high ultraviolet ray stability and high thermal stability.

The invention provides a composite phase-change thermal storage material. A porous material with high thermal conductivity is used as a supporting framework, and low-melting-point metal or low-melting-point metal with nano-particles is distributed in pores of the porous material, wherein melting point or solidus temperature of the low-melting-point metal is less than or equal to 80 DEG C; and thermal conductivity of the porous material is within 40-400 W / (m.K). The material provided by the invention has high equivalent thermal conductivity and high storage energy density; there is a large contact area between the liquid metal and the porous material; and the material has a wide application temperature range, has good fixability, stable physico-chemical property and good reversibility; and the problem of decreasing heat storage efficiency after multiple times of heat adsorption and release cycles is avoided.

The invention discloses a magnetic material with a magnetic field for driving martensite twin crystal rearrangement and a preparation method thereof. The material has ferromagnetism and a two-way shape memory effect, and is a novel magnetically controlled shape memory alloy capable of driving martensite twin crystal rearrangement to generate macro-strain by an outer magnetic field, wherein the chemical component is CoxNiyAlzGaj, x is less than or equal to 42 and greater than or equal to 28; y is less than or equal to 32 and greater than or equal to 25, z is less than or equal to 35 and greater than or equal to 23, j is less than or equal to 10 and greater than or equal to 0.5, x+y+z+j =100, and x, y, z and j represent the molar percentage content. Compared with the existing alloy, the magnetically controlled shape memory alloy CoxNiyAlzGaj disclosed by the invention has large magnetic strain, a wide martensite phase transformation temperature range and good mechanical property, and has important application to the field such as a high-power underwater sonar, a micro positioner, vibration and noise control, a linear motor, a microwave device, a robot and the like.

The invention discloses a liquid crystal composition. The liquid crystal composition has a wide phase transition temperature scope, high resistance, high stability, high double refraction anisotropy and rapid response and good high- and low-temperature stability, can still produce fast response at a low temperature of 0-30 DEG C and is especially suitable for industrial control instruments and vehicle-carried TNTFT-LCD. The liquid crystal composition comprises 1-20wt% of a compound I, 1-50wt% of a compound II, 1-30wt% of a compound III, 1-50wt% of a compound IV, 1-20wt% of a compound V and 0.05-0.5wt% of an optical rotation component.