# US 11,306,002 B2 · Process for synthesis of MG2SI/MGO nanocomposites > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,306,002 B2 - Document ID: US11306002B2 - Status: Granted - Kind: B2 - Application number: 16/491,741 - Filed: 2017-03-07 - Published: 2021-05-06 - Granted: 2022-04-19 - Earliest claimed: 2017-03-07 - Assignees: Toyota Motor Europe; UniversitäT Salzburg - Applicants: Toyota Motor Europe; UniversitäT Salzburg - Inventors: Sachin Kinge; Michael S. Elsaesser; Raphael Berger; Nastaran Hayati-Roodbari - Web page: https://patentgrep.com/patent/US11306002B2 ## CPC - C01B 33/06: Metal silicides (alloys C22) - C01B 33/023: by reduction of silica or {free} silica-containing material - C01F 5/02: Magnesia - B82Y 40/00: Manufacture or treatment of nanostructures - C01P 2002/72: by d-values or two theta-values, e.g. as X-ray diagram - C01P 2004/03: obtained by SEM - C01P 2004/04: obtained by TEM, STEM, STM or AFM - H01B 1/06: mainly consisting of other non-metallic substances - C01B: NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; {METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C} - C01F: COMPOUNDS OF THE METALS BERYLLIUM, MAGNESIUM, ALUMINIUM, CALCIUM, STRONTIUM, BARIUM, RADIUM, THORIUM, OR OF THE RARE-EARTH METALS (metal hydrides {monoborane, diborane or addition complexes thereof} C01B6/00; salts of oxyacids of halogens C01B11/00; peroxides, salts of peroxyacids C01B15/00; sulfides or polysulfides of magnesium, calcium, strontium, or barium C01B17/42; thiosulfates, dithionites, polythionates C01B17/64; compounds containing selenium or tellurium C01B19/00; binary compounds of nitrogen with metals C01B21/06; azides C01B21/08; {compounds other than ammonia or cyanogen containing nitrogen and non-metals and optionally metals C01B21/082; amides or imides of silicon C01B21/087}; metal {imides or} amides C01B21/092, {C01B21/0923}; nitrites C01B21/50; {compounds of noble gases C01B23/0005}; phosphides C01B25/08; salts of oxyacids of phosphorus C01B25/16; carbides C01B32/90; compounds containing silicon C01B33/00; compounds containing boron C01B35/00; compounds having molecular sieve properties but not having base-exchange properties C01B37/00; compounds having molecular sieve and base-exchange properties, e.g. crystalline zeolites, C01B39/00; cyanides C01C3/08; salts of cyanic acid C01C3/14; salts of cyanamide C01C3/16; thiocyanates C01C3/20; {double sulfates of magnesium with sodium or potassium C01D5/12; with other alkali metals C01D15/00, C01D17/00}) - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES - C01P: INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS - H01B: CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES (selection for magnetic properties H01F1/00; waveguides H01P {; printed circuits H05K}) ## Abstract The present invention relates to a process for the synthesis of a composite material comprising steps of: (a) reacting gaseous magnesium (Mg) and silica (SiO2) in an inert atmosphere; (b) washing the product obtained in step (a) in an acidic medium; and (c) reacting further gaseous magnesium (Mg) with the silica (SiO2) and silicon (Si) product obtained in step (b). The process of the invention allows Mg2Si/MgO nanocomposites to be prepared without too many separate steps, and wherein the MgO phase is homogeneously dispersed within the Mg2Si matrix. The nanocomposites obtained may for example find practical application as thermoelectric materials in thermoelectric generators. ## Claims ### Claim 1 A process for the synthesis of a composite material comprising the steps of: (a) reacting gaseous magnesium (Mg) and silica (SiO2) at a temperature of at least 500° C. and at most 1200° C. in an inert atmosphere; (b) washing the product obtained in step (a) in an acidic medium until neutralization is achieved to obtain a product containing the silica (SiO2) and silicon (Si); and (c) reacting further gaseous magnesium (Mg) with the product obtained in step (b) at a temperature of at least 500° C. and at most 1200° C. in an inert atmosphere. ### Claim 2 (depends on 1) The process according to claim 1, wherein the silica (SiO2) used in step (a) consists of cylindrical slices with 5 to 20 mm in diameter and 1 to 5 mm in height. ### Claim 3 (depends on 1) The process according to claim 1, wherein the silica (SiO2) used in step (a) consists of silica particles having size ranges of 100 nm to 1000 nm and porosities of 70 to 95%. ### Claim 4 (depends on 1) The process according to claim 1, wherein the molar ratio of Mg:SiO2 in step (a) is at least 0.5 and at most 2. ### Claim 5 (depends on 1) The process according to claim 1, wherein in step (a), the maximum temperature reached is at least 500° C. and at most 1200° C. ### Claim 6 (depends on 1) The process according to claim 1, wherein the duration of step (a) is at least 30 min and at most 5 hrs. ### Claim 7 (depends on 1) The process according to claim 1, wherein in step (a), the maximum temperature is reached by heating from room temperature to the maximum temperature at a rate of at 1-30° C./min. ### Claim 8 (depends on 1) The process according to claim 1, wherein in step (b), the acidic medium consists of aqueous HCl. ### Claim 9 (depends on 1) The process according to claim 1, wherein for step (c), the molar ratio of Mg:SiO2 is at least 2 and at most 8. ### Claim 10 (depends on 1) The process according to claim 1, wherein the maximum temperature for step (c) is at least 500° C. and at most 1200° C. ### Claim 11 (depends on 1) The process according to claim 1, wherein the duration of step (c) is at least 30 min and at most 5 hrs. ### Claim 12 (depends on 1) The process according to claim 1, wherein, the maximum temperature is reached by heating from room temperature at a rate of at least 0.5° C./min and at most 10° C./min in step (c). ### Claim 13 (depends on 1) The process according to claim 1, wherein the inert atmosphere in step (a) and/or step (c) contains at least one of the following: nitrogen (N2), argon (Ar). ### Claim 14 (depends on 7) The process according to claim 7, wherein the rate is 10-30° C./min. ### Claim 15 (depends on 10) The process according to claim 10, wherein the maximum temperature is at least 600° C. and at most 800° C. ### Claim 16 (depends on 13) The process according to claim 13, wherein the inert atmosphere is at least argon. ### Claim 17 (depends on 1) The process according to claim 1, wherein in step (a) and step (b), the maximum temperature is at least 600° C. and at most 800° C.