A method of forming a barrier to overcome lost circulation in a subterranean formation. The method includes injecting a polymer-sand nanocomposite into one or more lost circulation zones in the subterranean formation where the polymer-sand nanocomposite is formed from sand mixed with a polymer hydrogel. Further, the polymer hydrogel includes a hydrogel polymer, an organic cross-linker, and a salt. The sand additionally comprises a surface modification. The associated method of preparing a polymer-sand nanocomposite lost circulation material for utilization in forming the barrier is provided.

A process for the production of a geopolymer composite. The disclosure further relates to a geopolymer composite, and the use of a geopolymer, a geopolymer in combination with an athermanous additive, or the geopolymer composite in expanded vinyl polymer, preferably vinyl aromatic polymer. Furthermore, the disclosure relates to a process for the production of expandable vinyl aromatic polymer granulate, and expandable vinyl aromatic polymer granulate. Finally, the disclosure relates to expanded vinyl foam, preferably vinyl aromatic polymer, and to a masterbatch comprising vinyl polymer and a), b), or c).

An anti-forgery color conversion film includes a photonic crystal structure whose color is converted by an external stimulus such as a breath. The photonic crystal structure includes a first refractive index layer including a first polymer exhibiting a first refractive index; and a second refractive index layer which is alternately laminated with the first refractive index layer and includes a second polymer exhibiting a second refractive index. A consumer who purchases an article including the color conversion film may easily distinguish the authenticity of the article.

A polymerizable composition for forming an ion-exchange resin precursor, the polymerizable composition containing a monomer component and polyethylene particles in an amount of 50 to 120 parts by mass per 100 parts by mass of the monomer component, wherein the monomer component contains an aromatic monomer for introducing ion-exchange groups and a nitrogen-containing aliphatic monomer, the nitrogen-containing aliphatic monomer being present in an amount of 10 to 35% by mass in said monomer component. An ion-exchange membrane is produced by applying the polymerizable composition onto a polyolefin type filament base material and polymerizing the polymerizable composition to form an ion-exchange resin precursor and, thereafter, introducing ion-exchange groups into the precursor.

A method of forming a barrier to overcome lost circulation in a subterranean formation. The method includes injecting a polymer-sand nanocomposite into one or more lost circulation zones in the subterranean formation where the polymer-sand nanocomposite is formed from sand mixed with a polymer hydrogel. Further, the polymer hydrogel includes a hydrogel polymer, an organic cross-linker, and a salt. The sand additionally comprises a surface modification. The associated method of preparing a polymer-sand nanocomposite lost circulation material for utilisation in forming the barrier is provided.

An electrochemical compressor utilizes an anion conducting layer disposed between an anode and a cathode for transporting a working fluid. The working fluid may include carbon dioxide that is dissolved in water and is partially converted to carbonic acid that is equilibrium with bicarbonate anion. An electrical potential across the anode and cathode creates a pH gradient that drives the bicarbonate anion across the anion conducting layer to the cathode, wherein it is reformed into carbon dioxide. Therefore, carbon dioxide is pumped across the anion conducting layer. The compressor may be part of a refrigeration system that pumps the working fluid in a closed loop through a condenser and an evaporator.

The present disclosure provides an ion-exchange membrane that includes a supporting substrate impregnated with an ion-exchange material. The supporting substrate includes an imprinted non-woven layer, and the imprinting includes a plurality of deformations at a surface density of at least 16 per cm.sup.2. The supporting substrate may lack a reinforcing layer. In some examples, the supporting substrate may include only a single layer of the imprinted non-woven fabric.

The disclosure relates to polymers obtained by polymerizing in the presence of a Bronsted acid or a Lewis acid catalyst, a monomer comprising a 1,3-diisoalkenylarene, a 1,4-diisoalkenylarene, or mixtures thereof. The polymer comprises at least one of repeat units (A), (B), (C), and (D); wherein R.sup.1 is H or a C1-C8 alkyl group.

##STR00001##

The polymers have high T.sub.g and exhibit good solubility in non-polar solvents, forming substantially gel-free solutions. The polymers are useful for producing crosslinked materials having good physical properties. The crosslinked materials are valuable for further downstream uses, such as copper clad laminates.

An electrochemical compressor utilizes an anion conducting layer disposed between an anode and a cathode for transporting a working fluid. The working fluid may include carbon dioxide that is dissolved in water and is partially converted to carbonic acid that is equilibrium with bicarbonate anion. An electrical potential across the anode and cathode creates a pH gradient that drives the bicarbonate anion across the anion conducting layer to the cathode, wherein it is reformed into carbon dioxide. Therefore, carbon dioxide is pumped across the anion conducting layer. The compressor may be part of a refrigeration system that pumps the working fluid in a closed loop through a condenser and an evaporator.

A prepreg includes: a resin composition or a semi-cured product thereof; and a fibrous base material, wherein the resin composition contains a polymer having a structural unit expressed by the formula (1) in a molecule, and a curing agent each at a predetermined content rate. A cured product of the resin composition has a Dk of 2.6 to 3.8, and the fibrous base material includes a glass cloth having a Dk of 4.7 or less and a Df of 0.0033 or less. A cured product of the prepreg has a Dk of 2.7 to 3.8, and a Df of 0.002 or less.

##STR00001##

In the formula (1), Z represents an arylene group, R.sub.1 to R.sub.3 each independently represents a hydrogen atom or an alkyl group, and R.sub.4 to R.sub.6 each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.