An insulative and lightweight fire barrier composition contains foam or lightweight aggregate and calcium sulfoaluminate cement or their blend with Portland cement or gypsum hemihydrate. The blocks, coatings, and panels made with such compositions are as non-combustible as fiberglass, mineral, and rock wool insulation, yet possess the dimensional stability and rigidity for manufacturing into blocks and panels with good handling and installation features that these fibrous counterparts are lacking. The fire barrier properties of this composition are comparable with or better than cellular glass, cement, gypsum, and intumescent coatings.

The invention provides a composition having a bulk density of 0.8 g/cm.sup.3 or less comprising (a) 25-65 weight % of an inorganic binder comprising (i) 83 to 100 weight % of calcium aluminate cement, (ii) 0 to 14 weight % of calcium sulphate, (iii) 0 to 9 weight % of portland cement wherein the weight % of (i), (ii), (iii) is based on the sum of (i)+(ii)+(iii), (b) 0.5-15 weight % of one or more organic polymers, (c) 30-75 weight % of one or more inorganic fillers wherein the bulk density of the fillers is less than 0.5 g/cm.sup.3, wherein weight % is calculated on the total weight of all the non-volatile components in the composition.

Suggested is a solid formed with Si, Al, Ca, O and at least one of Na and K, characterized in that in the .sup.27Al-MAS-NMR spectra of the solid compared to the .sup.27Al-MAS-NMR spectrum of calcium aluminate, an additional signal is present which has a chemical shift which lies between that of the main peak of calcium aluminate and that peak of calcium aluminate which is closest to the main peak in the higher field. 2.

A porous refractory in the K.sub.2OSiO.sub.2B.sub.2O.sub.3 system is formed by chemical direct foaming by heating to over 600 C., resulting in adherent black or white foam. The foam can function as highly porous thermal insulation, a high or low thermal emissivity surface, as a sealant for deteriorated refractory surfaces, as a filler for pockmarks/holes/gaps or as a bonding agent for parts with large gaps between them.

A coating and devices using the coating are provided. The coating is applied in liquid form and dried or otherwise cured to form a durable adherent coating resistant to high temperatures and having optional hydrophobic properties. The coating formulation contains an aqueous formulation of silica, one or more fillers, and sufficient base, (e.g., potassium hydroxide), to have a pH exceeding about 10.5 during at least part of the formulation process. The formulation may contain a compound(s) that affects surface free energy, energy to make the cured coating hydrophobic. Such compounds include silanes containing halogens (e.g., fluorine or chlorine) and in particular silanes containing one or more hydrolyzable groups attached to at least one silicon atom and a group containing one or more halogens (e.g., chlorine or fluorine). A medical instrument (e.g., electrosurgical instrument) may be at least partially covered by a coating using the formulation.

A method includes forming a ceramic member that has a plurality of closed pores within a ceramic matrix. The forming includes compacting a ceramic powder to form intra-particle pores between particles of the ceramic powder, and sintering the compacted ceramic powder to cause diffusion of the ceramic powder and formation of the ceramic matrix. The diffusion does not fill the intra-particle pores and leaves the closed pores.

A porous refractory in the K.sub.2OSiO.sub.2B.sub.2O.sub.3 system is formed by chemical direct foaming by heating to over 600 C., resulting in adherent black or white foam. The foam can function as highly porous thermal insulation, a high or low thermal emissivity surface, as a sealant for deteriorated refractory surfaces, as a filler for pockmarks/holes/gaps or as a bonding agent for parts with large gaps between them.

A porous refractory in the K.sub.2OSiO.sub.2B.sub.2O.sub.3 system is formed by chemical direct foaming by heating to over 600 C., resulting in adherent black or white foam. The foam can function as highly porous thermal insulation, a high or low thermal emissivity surface, as a sealant for deteriorated refractory surfaces, as a filler for pockmarks/holes/gaps or as a bonding agent for parts with large gaps between them.

Stone slabs, and systems and methods of forming slabs, are described. Some example slabs include a first pattern defined by a first particulate mineral mix and a second pattern defined by a second particulate mineral mix different from the first particulate mineral mix. The first particulate mix includes greater than 50 weight percent of first metallic particles.

A method for coating a structural element includes laser ablating a structural element to remove surface contamination; applying a graphene-enhanced coating to the structural element; and encasing the structural element in a graphene-enhanced primary building material.