Abstract: A method for treating at least one silicon carbide fibre includes a surface layer including carbon and/or a silicon oxycarbide, the treatment including at least removing the surface layer from the fibre by placing in contact with an ammonia phase in the supercritical state.

Abstract: A device for depositing a thick metal nitride on a sample by supercritical fluids includes a first enclosure forming a first closed volume; a second enclosure placed in the first enclosure and delimited by internal walls transparent to electromagnetic radiation forming a second closed volume intended to include fluid under supercritical conditions; a heat transfer dielectric fluid circulating in the first volume around the second enclosure; a sample holder present in the second volume; an induction heating device surrounding the second enclosure; inlets for introducing a fluid and at least one precursor material into the second enclosure, and an outlet to purge the second volume.

Abstract: A method for preparing an organic/inorganic hybrid composition including mineral nanoparticles functionalized by at least one molecule chosen from colored charged organic molecules, this method including providing a solution (a) of at least one colored charged organic molecule, providing a suspension (b) of non-swelling phyllosilicate nanoparticles, contacting the solution (a) and the suspension (b), the non-swelling phyllosilicate nanoparticles having a thickness of 1 nm to 100 nm, and a larger dimension of 10 nm to 10 ?m. A composition of organic/inorganic hybrid colored nanoparticles obtained by this method is also disclosed.

Abstract: Disclosed is a method and a device for retrieving, from an object A, elements G present in a matrix M, the method including at least the following steps: bringing said abject A into contact with a dense fluid Fd with a molar mass greater than 2 g mol?1 under temperature T1 and pressure P1 conditions suitable for transforming the intergranular phase and for releasing the elements G, modifying the temperature T2 and/or pressure P2 values to stop the reaction transforming the intergranular phase, and recovering the elements G separated front the matrix M.

Abstract: Disclosed is a method for preparing a hybrid organic/inorganic composition including inorganic nanoparticles functionalized by at least one molecule chosen from photoluminescent charged organic molecules, the method including bringing into contact, in a single-phase solvent medium, at least one photoluminescent charged organic molecule and non-swelling phyllosilicate nanoparticles having a thickness of 1 nm to 100 nm, and a larger dimension of 10 nm to 10 ?m. Also disclosed are hybrid photoluminescent nanoparticles compositions obtained by this method.

Abstract: A method of treating at least one silicon carbide fibre, the method including a) formation of a silica layer at the surface of a silicon carbide fibre having an oxygen content less than or equal to 1% in atomic percentage, the silica layer being formed by contacting this fibre with an oxidizing medium having a temperature greater than or equal to 50° C. and pressure greater than or equal to 1 MPa, and b) removal of the silica layer formed by hydrothermal treatment of the fibre obtained after implementation of step a) in which the fibre is treated with water at a pressure between saturating vapour pressure and 30 MPa and at a temperature less than or equal to 400° C.

Abstract: A method for manufacturing metal phosphate hydrate nanoparticles wherein metal reactants are selected from metal precursors of transition metals,phosphate precursors are selected from: Trisodium phosphate Na3PO4, disodium phosphate Na2HPO4, phosphoric acid H3PO4 and hypophosphoric acid H4P2O6, wherein said method comprises the following step of a reaction medium comprising at least a metal reactant, a phosphate precursor and a solvent, is submitted to a solvothermal treatment at a pressure superior to 50 MPa, and at a temperature of from 100 to 350° C.

Abstract: The invention relates to a method for preparing synthetic mineral particles with formula (AlyM1-y)2(SixGe1-x)2O5(OH)4, wherein M designates at least one trivalent metal selected from the group made up of gallium and the rare earths, which comprises the following steps: preparing a gel which is a precursor of said synthetic mineral particles by a co-precipitation reaction of at least one salt of metal selected among aluminium and M with at least one silicon source selected from the group made up of potassium metasilicate, sodium metasilicate, potassium metagermanate and sodium metagermanate, the molar ratio of (AlyM1-y) to (SixGe1-x) during the preparation of said precursor gel being equal to 1, at least one base being added during said co-precipitation reaction; and performing a solvothermal treatment of said precursor gel at a temperature of 250° C. to 600° C.

Abstract: The invention relates to a mineral compound, referred to as synthetic mica, with formula At(Six-Ge1x)4MzO10(OH)2, wherein: A designates at least one monovalent interfoliar cation of a metal element, A having the formula Liw(1)Naw(2)Kw(3)Rbw(4)Cssw(5), each instance of w(i) representing a real number in the interval [0; 1], such that the sum of the instances of w(i) is equal to 1; t is a real number in the interval [0.3; 1]; x is a real number in the interval [0; 1]; M designates at least one divalent metal having the formula Mgy(1)Coy(2)Zny(3)Cuy(4)Mny(5)Fey(6)Niy(7)Cr, each instance of y(i) representing a real number in the interval [0; 1], such as the formula (A); and z is a real number in the interval [2.50; 2.85]. The invention also relates to a composition comprising such a compound and a method for preparing such a compound.

Abstract: A process including introducing, into a device, an aqueous fluid containing at least one inorganic salt, the water of the aqueous fluid being in supercritical conditions or close to the supercritical range in the device, and measuring the concentration or the amount of inorganic salt in the device, this measurement preferably being carried out before the entry of the inorganic salt into the device, Then bringing the inorganic salt into contact with an aqueous flow containing at least one hydroxide salt to obtain in the device an aqueous fluid mixture containing an inorganic salt and a hydroxide salt and adjusting the concentration or amount of the hydroxide salt as a function of the concentration or amount of the inorganic salt needed to at least partially solubilize the inorganic salt. Preferably the measurement of the concentration or the amount of inorganic salt leaving the device is also performed.

Abstract: Some embodiments are directed to a method and device for reducing a component composed of at least one graphene oxide and a matrix consisting of at least one polymer, characterized in that the method includes at least the following steps: introducing a mixture of polymer(s) and graphene oxide GO into a reactor subject to a value of temperature T and a value of pressure P suitable for placing a fluid under supercritical or subcritical conditions for a given period, the temperature T being suitable for not degrading the polymer; and cooling the reactor and removing the obtained product R consisting of reduced polymer(s) and graphene oxide rGO.

Abstract: Method and device for delamination/dismantling of multi-layer systems SM comprising several layers including at least one organic layer, wherein the layers are separated by interfaces, characterized in that it comprises at least the following steps: Mixing the multilayer system with a fluid composed of at least one gas having the particularity of causing the swelling of at least one of the layers and one or more non-reactive liquids having the particularity of allowing the separation of each layer unitarily or of subsets of layers composing the multilayer system without degradation of the constituents of the layers, the gas/liquid fluid being raised in temperature and pressure, Recovering separately at least one or more layers or a subset of undegraded layers.

Abstract: A process for preparing phyllomineral synthetic particles formed from constituent chemical elements in stoichiometric proportions including at least one chemical element selected from the group formed from silicon and germanium, and at least one chemical element selected from the group formed from divalent metals and trivalent metals, by a continuous solvothermal treatment at a pressure above 1 MPa and at a temperature between 100° C. and 600° C., by making the reaction medium circulate continuously in a solvothermal treatment zone of a continuous reactor (15) with a residence time of the reaction medium in the solvothermal treatment zone that is suitable for continuously obtaining, at the outlet of the solvothermal treatment zone, a suspension including the phyllomineral synthetic particles.

Abstract: The invention relates to a method for recovering organic fibers from a composite material comprising a polymer matrix and organic fibers, wherein the method comprises the following steps: providing a solution comprising a mixture of water and alcohol; placing the composite material inside a reactor; contacting the mixture and the composite material in order to perform a solvolysis reaction of the composite material; and recovering the organic fibers; wherein the pressure and the temperature in the reactor are adjusted such as to fall within the homogeneous sub-critical range of the phase diagram, within the super-critical range or near the critical point; and wherein the temperature is lower than the melting temperature of the organic fibers.

Abstract: The invention concerns a method whereby: (E1) an inner liquid phase is made to flow in an inner flow member, and an outer liquid phase in an outer flow member, the flow of the inner liquid phase opening within the flow of the second liquid phase; and the temperature and pressure in the contact area between the first and second liquid phases being such that the first and/or second liquid phase is in the supercritical state, (E2) the flow rate of the inner phase and/or outer phase is varied in such a way as to modify the flow profile, and a torque is identified from values of the flow rates of the inner and outer phases, called transition flow rates, from which the modification in the flow profile occurs (from drops to a jet; or from a jet to drops); (E3) from the transition torque identified in step (E2), the value of the interfacial tension between the two inner and outer liquid phases is calculated, or the result obtained is compared to that obtained for another torque in the conditions of steps (E1) and (E2

Abstract: The invention relates to a method for recovering organic fibers from a composite material comprising a polymer matrix and organic fibers, wherein the method comprises the following steps: providing a solution comprising a mixture of water and alcohol; placing the composite material inside a reactor; contacting the mixture and the composite material in order to perform a solvolysis reaction of the composite material; and recovering the organic fibers; wherein the pressure and the temperature in the reactor are adjusted such as to fall within the homogeneous sub-critical range of the phase diagram, within the super-critical range or near the critical point; and wherein the temperature is lower than the melting temperature of the organic fibers.

Abstract: The invention concerns a method whereby: (E1) an inner liquid phase is made to flow in an inner flow member, and an outer liquid phase in an outer flow member, the flow of the inner liquid phase opening within the flow of the second liquid phase; and the temperature and pressure in the contact area between the first and second liquid phases being such that the first and/or second liquid phase is in the supercritical state, (E2) the flow rate of the inner phase and/or outer phase is varied in such a way as to modify the flow profile, and a torque is identified from values of the flow rates of the inner and outer phases, called transition flow rates, from which the modification in the flow profile occurs (from drops to a jet; or from a jet to drops); (E3 ) from the transition torque identified in step (E2), the value of the interfacial tension between the two inner and outer liquid phases is calculated, or the result obtained is compared to that obtained for another torque in the conditions of steps (E1) and (E

Abstract: The invention relates to a method of preparing a particle-based composition, comprising: (i) bringing into contact a mixture comprising a dendritic structure and a metal compound precursor in a fluid, under temperature and pressure conditions such that the mixture is not soluble in the fluid; and (ii) chemically converting the metal compound precursor.

Abstract: Subjects of the present invention are: a method of desensitizing crystals of an energetic explosive substance by coating them, said method comprising the deposition, carried out within a fluid, outside the normal temperature and pressure conditions, preferably under supercritical conditions, of a metal and/or polymer film, advantageously of a metal film or of a polymer film, on the surface of said crystals, the metal(s) and/or polymer(s) in question having been firstly dissolved in a solvent; the coated crystals of an energetic explosive substance obtainable by said method; and the energetic materials containing said crystals coated by said method and/or said crystals desensitized by said method.

Abstract: The invention relates to a method of preparing a particle-based composition, comprising: (i) bringing into contact a mixture comprising a dendritic structure and a metal compound precursor in a fluid, under temperature and pressure conditions such that the mixture is not soluble in the fluid; and (ii) chemically converting the metal compound precursor.