Fire-resistant, fire retardant and/or thermal insulation
An open cell foam, and particularly aerogels or other foams, having an inorganic, hydraded phase change material (PCM) embedded within pores or cells or a network within the foam have fire retardant, fire resistant and thermal insulating properties. These composite materials are preferably monolithic in character, and are mechanically robust allowing for example the attachment of nails or screws. With the PCM distributed throughout the open cell foam, the composite material has a wide array of applications including providing thermal, fire resistant, and fire retardant uses in battery containers, in automotives and other vehicles, etc.
1 . A method of making a material, comprising:
i) providing, using a sol-gel process using a gelation solvent, an open cell foam comprising a network of open pores or cells with at least some interior pores or cells in the network being accessible by a gas or liquid through at least some surface pores or cells in the network, wherein the sol-gel process is performed such that the gelation solvent remains in at least some of the open pores or cells;
wherein the at least some interior pores or cells are within an interior portion of the open cell foam and the at least some surface pores or cells are positioned at one or more external surfaces of the open cell foam, and the at least some interior pores or cells and the at least some surface pores or cells comprise pore or cell walls defining a pore or cell;
ii) exchanging, by solvent exchange, the gelation solvent with a miscible solvent or solvent mixture in which one or more phase change materials (PCMs) are soluble;
iii) exchanging, by solvent exchange, the miscible solvent or solvent mixture with a miscible solvent or solvent mixture comprising the one or more PCMs such that the one or more PCMs infiltrate the at least some of the open pores or cells;
iv) exchanging, by solvent exchange, the solvent or solvent mixture comprising the one or more PCMs with a solvent or solvent mixture in which the one or more PCMs are not soluble such that the one or more PCMs are deposited in or adjacent to at least some portions of at least some of the pore or cell walls of both the at least some surface pores or cells and the at least some interior pores or cells;
v) exchanging, by solvent exchange, the solvent or solvent mixture in which the one or more PCMs are not soluble with a drying solvent; and
vi) removing the drying solvent from the open cell foam by evaporation at ambient temperature and pressure so as to leave the one or more PCMs deposited on or adjacent to the at least portions of the pore or cell walls of a plurality of pores or cells of the network;
wherein the one or more PCMs is or are hydrated inorganic materials and is or are deposited in 50-100% of the at least some surface pores or cells and the at least some interior pores or cells in the network, and wherein the one or more PCMs fills 1-25% of a volume of either or both of the at least some surface pores or cells and the at least some interior pores or cells.
2 . The method of claim 1 , wherein the open cell foam is an aerogel.
3 . The method of claim 1 , wherein the open cell foam is a rigid open cell foam.
4 . The method of claim 1 , wherein a size of the open pores or cells ranges from 100 nm-1 mm.