A method for preparing a hydrogel includes forming a pre-gel comprising polymer and metal salt particles, unidirectionally-shrinking and dehydrating the pre-gel, and impregnating the unidirectionally shrunk and dehydrated pre-gel with an ion solution to crosslink and rehydrate the unidirectionally shrunk and dehydrated pre-gel to produce the hydrogel.

The invention relates to a method for reducing the viscosity of a nanofibrillar cellulose hydrogel, wherein the method comprises mixing a nanofibrillar cellulose hydrogel with an aqueous growth medium for cell culture, wherein the aqueous growth medium contains one or more salts and optionally one or more sugars, using shearing forces so that a homogeneous dispersion is formed. The invention further relates to a dispersion comprising a nanofibrillar cellulose hydrogel and an aqueous growth medium for cell culture and to a use of an aqueous growth medium.

The invention relates to a new method of preparation of a polynuclear iron compound stabilized by carbohydrates and/or humic acid or forming a complex with carbohydrates and/or humic acid using a pressure-driven filtration process.

Provided are printable gel or hydrogel compositions, methods of making printable gel or hydrogel compositions, uses of the printable gel or hydrogel compositions, objects formed from the printable gel or hydrogel compositions, and methods of using those objects. The printable gel or hydrogel compositions may be formed from a graphene component, a polymer component, and a carrier. The printable gel or hydrogel compositions may be used as inks in additive manufacturing techniques to 3D print a 3D object. The 3D object may be freeze-dried to form an aerogel. The aerogel may be used to remove contaminants from aqueous samples.

A process for treating a tailings stream comprising water, solids, and optionally polyacrylamide. The process involves (a) contacting the tailings stream with a silicate source for a pre-determined period of time to form a mixture; b) after a pre-determined period of time of at least 5 minutes, contacting the mixture with an activator to initiate gel formation, wherein the gel entraps the solids within the gel; and c) allowing the gel to strengthen and solidify; wherein the gel formation is delayed compared with a non-delayed process.

Disclosed herein is a method of preparing a silica aerogel. The silica aerogel is prepared by adding a first water glass solution and an acid catalyst to a reactor to form a first silica wet gel. The method further includes adding a second water glass solution and an acid catalyst to the first silica wet gel. The method further includes adding a surface modifier solution to the first silica wet gel to form a second silica wet gel. The method further includes drying a silica wet gel including the first silica wet gel and the second silica wet gel. The prepared silica aerogel has a tap density of 0.032 to 0.070 g/mL and a carbon content of 11.2 to 12.1 wt %.

In an aspect, a method for making a metal-containing material comprises steps of: forming a metal-containing hydrogel from an aqueous precursor mixture using a photopolymerization; wherein the aqueous precursor mixture comprises water, one or more aqueous photosensitive binders, and one or more aqueous metal salts; and thermally treating the metal-containing hydrogel to form the metal-containing material; wherein the metal-containing hydrogel is exposed to a thermal-treatment atmosphere during the step of thermally treating; wherein a composition of the metal-containing material is at least partially determined by a composition of the thermal-treatment atmosphere during the thermally treating step.

The invention provides a method for producing a heat insulating material composed of a hydrophobic aerogel, and the method includes the steps of: (1) mixing step; (2) hydrolysis step; (3) condensation step; (4) aging step; and (5) drying step. In the method, a siloxane compound, an inorganic gel, and a halogen-free surfactant are mixed and then a sol-gel process is performed to produce the aerogel heat-insulating material without water-washing. The produced heat-insulating material has preferable strength, smooth appearance, and low shrinkage and can overcome the powder-dropping problem. By the provided method, an aerogel heat-insulating board can be produced, or an aerogel cold-resisting and heat-insulating blanket can be produced by mixing with a fiber or a foam material.

The present invention concerns a method for producing a hydrogel comprising the following steps in succession: a first step (i) of providing at least one powder of an anionic polymer (A) and at least one chitosan powder (B) comprising amine functions (—NH.sub.2); a second step (ii) consisting in dry mixing at least the powders (A) and (B) from the first step in order to form a mixture of powders; a third step (iii) of suspending the mixture of powders obtained from the second step in an aqueous medium having a pH that can enable the anionic polymer (A) to be dissolved without dissolving the chitosan (B); a fourth step (iv) of adding an acid to the suspension obtained from the third step in order to form the hydrogel; or the third (iii) and fourth (iv) steps are replaced by a mixing fifth step (v), comprising mixing an acidified aqueous medium including at least one compound (C) comprising at least one unit of a hexose or a unit derived from a hexose, and/or at least one phosphate of said compound (C), with said mixture comprising at least the powders (A) and (B) obtained from the second step (ii).

The present disclosure relates to a method for preparing a restructured hydrogel, including forming a hydrogel containing a first polymer, unidirectionally shrinking and dehydrating the hydrogel, and additionally cross-linking and rehydrating the dehydrated hydrogel.