Low-density thermoplastic expandable microspheres are disclosed. Various low-density structures, in particular, sandwich panels, based on foam prepared from the low-density microspheres, are also disclosed. Process of preparing low-density polymeric microspheres, per se, and the corresponding low-density structures, based on the microsphere foam, are also disclosed.

A method of forming a sandwich structure including at least partially filling an open volume of an open cellular core with a sacrificial mold material, consolidating the sacrificial mold material to form a sacrificial mold, laying up a composite facesheet on each of at least two surfaces of the open cellular core, co-curing the composite facesheets by applying a consolidation temperature and a compaction pressure to the composite facesheets to form the sandwich structure, and removing the sacrificial mold. The compaction pressure is greater than a compressive strength of the open cellular core and less than a combined compressive strength of the open cellular core and the sacrificial mold.

The invention describes the construction of more or less thin house walls, of which the load-bearing panels are stabilized in such a way that they have an insulating middle layer, the middle layer containing carbon, which is brought in as insulation material by means of suitable binders such as cement, geopolymers, resins or foams or glass. In particular, biochar mortars and biochar foams are used, which with the help of fiber reinforcement of the outer stone slices become self-supporting wall and facade elements, which are able to store more carbon than what is produced in the form of CO2, escaping into the atmosphere. Fiber-stabilized stone disks with an insulating middle layer based on pyrogenic or otherwise manufactured or extracted carbon are constructed symmetrically and dimensioned in such a way that they can absorb loads and buckling forces with a comparatively very low weight. For this reason, in addition to its high carbon content, the insulation material should preferably have sufficient tensile stability.

The present invention provides a solar absorber incorporated bilayer foam solar evaporator for seawater and wastewater purification including a plurality of solar absorbers partially incorporated into a porous polymer framework and partially forming a thermal insulation layer proximal to solar irradiation. In particular, low-cost commercially available B.sub.4C powders are embedded into a porous polymer foam in a one-pot method to form a scaffold of boron carbide bilayer foam (BCBF) with good hydrophilic wettability, heat-shielding, and solar-thermal conversion. The boron carbide bilayer foam (BCBF) of the present invention enables a high cost-performance seawater desalination and wastewater purification at a high evaporation rate of 2.8 kg/m.sup.2/h with 93% solar evaporation efficiency under 1 sun illumination (or 1 kW/m.sup.2). The present invention thereby provides an excellent and cost-effective solar evaporator tool for industrial-level water purification. Following the present method to prepare the BCBF solar evaporator, the fabrication cost can be as low as 3.6 $/m.sup.2.

The present disclosure relates to a multilayer composite that may include a first porous layer, and a first barrier layer overlying the first porous layer. The first barrier layer may include a polyaramid material, a polyimide material, or any combination thereof. The multilayer composite may have a flame resistance rating of at least about 180° C. and a 50% strain compression rating of not greater than about 600 kPa.

Provided is an face mask comprising: (a) a mask body configured to cover at least wearer's mouth and nose; and (b) a fastener to hold the mask in place on the wearer; wherein the mask body includes (i) an air-permeable outer layer preferably comprising a hydrophobic material (e.g. water-repelling fibers), (ii) an inner layer located on a wearer's side when the mask is worn, and (iii) a graphene foam layer disposed in the mask body between the outer layer and the inner layer or embedded (totally or partially) in the outer layer or the inner layer. The foam pore wall graphene surfaces may be deposited with an antiviral or anti-bacteria compound.

The present disclosure can provide an aerogel composite. The aerogel composite comprises at least one base layer having a top surface and a bottom surface, the base layer comprising a reinforced aerogel composition which comprises a reinforcement material and a monolithic aerogel framework, a first facing layer comprising a first facing material attached to the top surface of the base layer, and a second facing layer comprising a second facing material attached to the bottom surface of the base layer. At least a portion of the monolithic aerogel framework of the base layer extends into at least a portion of both the first facing layer and the second facing layer. The first facing material and the second facing material can each comprise or consist essentially of elastic fibers such as spandex, nylon, lycra, elastane, or combinations thereof.

A multi-layered membrane comprising a first thermoplastic first layer and a second thermoplastic layer, where the second layer includes expandable graphite.

The present invention provides articles and methods related to insulation panels made from aerogels, and specifically polyimide based aerogels. Such insulation panels have a wide variety of applications, including specifically in aerospace applications.

Composite panels and methods of preparation are described herein. In some embodiments, the composite panel can include a first fiber reinforcement, a polyurethane composite having a first surface and a second surface opposite the first surface, wherein the first surface is in contact with the first fiber reinforcement; and a cementitious material adjacent the first fiber reinforcement opposite the polyurethane composite. The polyurethane composite can be formed from (i) one or more isocyanates selected from the group consisting of diisocyanates, polyisocyanates, and mixtures thereof, (ii) one or more polyols, and (iii) a particulate filler. The fiber reinforcement can be formed from a woven or non-woven material, such as glass fibers. The composite panel can further include a material, such as a second fiber reinforcement and a cementitious layer, in contact with the second surface of the polyurethane composite. Articles comprising the composite panels are also disclosed.