METHOD FOR PRODUCING A HEAT-ACCUMULATING MATERIAL Russian patent published in 2023 - IPC C09K5/06 C09K5/14 

FIELD: chemistry.

SUBSTANCE: invention relates to a method for producing heat-accumulating materials capable of reversibly absorbing and releasing thermal energy due to the first-order phase transitions (melting and crystallising), and can be used in passive temperature control systems or as a filler for various materials and coatings used to increase the specific heat capacity and heat accumulation capacity thereof. Proposed is a method for producing a heat-accumulating material, including the stages of mixing a phase transition component, constituting saturated normal hydrocarbons (paraffins), fatty alcohols, or fatty acids, alkoxyalkylsilane and tetraalkoxysilane at a temperature above the final melting point of the phase transition component; dispersing the resulting mixture in water preheated to a temperature above the final melting point of the phase transition component while exposing to ultrasound at a frequency of 20 to 40 kHz and a power of 100 to 1,000 W, resulting in a dispersion product constituting an oil-in-water emulsion with 100 nm to 100 mcm droplets, wherein the dispersed phase is a solution of alkoxyalkylsilane and tetraalkoxysilane in the phase transition component; mixing the dispersion product with an alkaline agent and holding the resulting mixture at a temperature of 20.0 to 90.0 °C for 5.0 to 600.0 minutes while stirring, leading to hydrolysis of the tetraalkoxysilane on the surface of the emulsion droplets, forming 100 nm to 100 mcm particles containing the phase transition component, coated with a silicon dioxide shell; followed by adding a neutralisation agent to the mixture until the hydrogen index reaches a value of 5.0 to 8.0; separating and drying the above particles, resulting in the target powdered heat-accumulating material.

EFFECT: possibility of localising the hydrolysis of tetraalkoxysilane on the surface of droplets of the emulsion of the molten phase transition component in water.

1 cl, 1 dwg, 4 ex