Abstract:
A porous cellulose aggregate characterized by having a secondary aggregate structure resulting from aggregation of primary cellulose particles, having a pore volume within a particle of 0.265 to 2.625 cm3/g, containing I-type crystals and having an average particle size of over 30 to 250 μm, a specific surface area of 0.1 to less than 20 m2/g, a repose angle of 25° to less than 44° and a swelling degree of 5% or more, and characterized by having the property of disintegrating in water.
Abstract:
The invention relates to a microporous and mesoporous carbon xerogel and organic precursors thereof based on a phenol-formaldehyde xerogel. A characteristic parameter common to carbon xerogels is a peak in the mesopore size distribution determined by the BJH method (Barrett-Joyner-Halenda) from nitrogen absorption measurements at 77 K in the range from 3.5 nm to 4 nm. The production process is characterized firstly by the low starting material costs (use of phenol instead of resorcinol) and secondly by very simple and cost-effective processing; convective drying without solvent exchange instead of supercritical drying or freeze drying. The carbon xerogels and their organic phenol-formaldehyde xerogel precursors have densities of corresponding to a porosity of up to 89%, and the xerogels can also have a relevant mesopore volume. The carbon xerogels obtained from the phenol-formaldehyde xerogels are also microporous.
Abstract:
The invention relates to a process for the production of alginate-containing porous or sponge-like moulded articles, and to the moulded articles obtainable thereby and their use.
Abstract:
A process that results in a flexible dissolvable porous solid article that can be used as a personal care composition or a fabric care composition.
Abstract:
Foams composed of water-absorbing basic polymers, obtainable by (I) foaming a crosslinkable aqueous mixture including (a) at least one basic polymer whose basic groups have optionally been neutralized, (b) at least one crosslinker, (c) at least one surfactant, (d) optionally at least one solubilizer, (e) optionally thickeners, foam stabilizers, fillers, fibers and/or cell nucleators, and (f) optionally particulate water-absorbing acidic polymers, by dissolving a gas which is inert toward free radicals in the crosslinkable aqueous mixture under a pressure from 2 to 400 bar and subsequently decompressing the crosslinkable aqueous mixture to atmospheric or by dispersing fine bubbles of a gas which is inert toward free radicals, and (II) crosslinking the foamed mixture to form a hydrogel foam and if applicable adjusting the water content of the polymer foam to 1-60% by weight. Preparation of the foams by application of the abovementioned measures (I) and (II) and use of the thus obtainable foams in hygiene articles to absorb body fluids, in dressing material to cover wounds, as a sealing material, as a packaging material, as a soil improver, as a soil substitute, to dewater sludges, to absorb aqueous acidic wastes, to thicken waterborne paints or coatings in the course of disposing of residual quantities thereof, to dewater water-containing oils or hydrocarbons or as a material for filters in ventilation systems.
Abstract:
By reaction of one or more epoxy resins with an amphiphilic epoxy resin hardener in water in a phase inversion polymerization, nanoporous polymer foams are obtained. These foams are suitable as filter materials.
Abstract:
The present invention provides for concentrated aqueous silk fibroin solutions and an all-aqueous mode for preparation of concentrated aqueous fibroin solutions that avoids the use of organic solvents, direct additives, or harsh chemicals. The invention further provides for the use of these solutions in production of materials, e.g., fibers, films, foams, meshes, scaffolds and hydrogels.
Abstract:
The present invention provides for concentrated aqueous silk fibroin solutions and an all-aqueous mode for preparation of concentrated aqueous fibroin solutions that avoids the use of organic solvents, direct additives, or harsh chemicals. The invention further provides for the use of these solutions in production of materials, e.g., fibers, films, foams, meshes, scaffolds and hydrogels.
Abstract:
The invention provides a method of producing a gelled foam comprising the steps of:forming a dispersion by mixing i) a solution comprising a soluble polysaccharide and a plasticizer and adding a polysaccharide/gel-forming ion particles or ii) a soluble, preferably immediately soluble, polysaccharide, preferably an alginate, a polysaccharide/gel-forming ion particles, and adding a solvent, said dispersion (ii) further comprising a water soluble plasticizer to make the dispersion and then aerating the dispersion to form the foam. The foam may be inhomogeneous in structure which is useful in providing improved delivery of a component carried in the foam and in degradation.
Abstract:
The present invention relates to a method for producing a porous material comprising the steps of; (a) providing a C/W emulsion comprising an aqueous phase, a matrix building material, a surfactant and liquid CO2 phase; (b) at least partially freezing the aqueous phase; (c) gasifying CO2 from the liquid CO2 phase to form an intermediate porous material; (d) venting gasified CO2 from the intermediate porous material; and (e) freeze drying the intermediate porous material at least substantially to remove the aqueous phase and form the porous material. The present invention also relates to a porous material obtainable by the method.