The present disclosure provides scalable nanotube fabrics and methods for controlling or otherwise adjusting the nanotube length distribution of a nanotube application solution in order to realize scalable nanotube fabrics. In one aspect of the present disclosure, one or more filtering operations are used to remove relatively long nanotube elements from a nanotube solution until nanotube length distribution of the nanotube solution conforms to a preselected or desired nanotube length distribution profile. In another aspect of the present disclosure, a sono-chemical cutting process is used to break up relatively long nanotube elements within a nanotube application solution into relatively short nanotube elements to realize a pre-selected or desired nanotube length distribution profile.

A gas diffusion layer for proton exchange membrane fuel cell and preparation method thereof are provided. The preparation method is to papermake and dry carbon fiber suspension mainly composed of a fibrous binder, water, a dispersant and carbon fibers with different aspect ratios to obtain a carbon fiber base paper, and then carbonize and graphitize under the protection of nitrogen or inert gas to obtain a gas diffusion layer for proton exchange membrane fuel cell; where the fibrous binder is a composite fiber or a blend fiber composed of a phenolic resin and other resin; where the prepared gas diffusion layer for proton exchange membrane fuel cell has a pore gradient, and the layer with the smallest pore size is an intrinsic microporous layer.

A gas diffusion layer for proton exchange membrane fuel cell and preparation method thereof are provided. The preparation method is to papermake and dry carbon fiber suspension mainly composed of a fibrous binder, water, a dispersant and carbon fibers with different aspect ratios to obtain a carbon fiber base paper, and then carbonize and graphitize under the protection of nitrogen or inert gas to obtain a gas diffusion layer for proton exchange membrane fuel cell; where the fibrous binder is a composite fiber or a blend fiber composed of a phenolic resin and other resin; where the prepared gas diffusion layer for proton exchange membrane fuel cell has a pore gradient, and the layer with the smallest pore size is an intrinsic microporous layer.

A transfer method for carbon nanotube array is provided. A carbon nanotube array is located on a first substrate. A pressure is applied to the carbon nanotube array to form a carbon nanotube paper. A second substrate with a bonding layer is placed on the carbon nanotube paper, and the bonding layer is located between the second substrate and the carbon nanotube array. The second substrate is peeled off, and the carbon nanotubes of the carbon nanotube paper vertically aligned and form the carbon nanotube array under forces of the first substrate and the second substrate. The carbon nanotubes of the carbon nanotube array are substantially perpendicular to the surface of the second substrate.

A transfer method for carbon nanotube array is provided. A carbon nanotube array is located on a first substrate. A pressure is applied to the carbon nanotube array to form a carbon nanotube paper. A second substrate with a bonding layer is placed on the carbon nanotube paper, and the bonding layer is located between the second substrate and the carbon nanotube array. The second substrate is peeled off, and the carbon nanotubes of the carbon nanotube paper vertically aligned and form the carbon nanotube array under forces of the first substrate and the second substrate. The carbon nanotubes of the carbon nanotube array are substantially perpendicular to the surface of the second substrate.

A reinforced paper includes a nonwoven fibrous mat impregnated with a polyetherimide composition. The nonwoven fibrous mat includes a reinforcing fiber, a high strength toughening fiber, or a combination thereof. The polyetherimide composition includes a polyetherimide having repeating units as defined herein. A method of making a reinforced paper is also disclosed. The method includes contacting at least a portion of a nonwoven fibrous mat with a composition to form a pre-preg, and heating under conditions effective to provide the reinforced paper. Articles including the reinforced paper are also described.

A reinforced paper includes a nonwoven fibrous mat impregnated with a polyetherimide composition. The nonwoven fibrous mat includes a reinforcing fiber, a high strength toughening fiber, or a combination thereof. The polyetherimide composition includes a polyetherimide having repeating units as defined herein. A method of making a reinforced paper is also disclosed. The method includes contacting at least a portion of a nonwoven fibrous mat with a composition to form a pre-preg, and heating under conditions effective to provide the reinforced paper. Articles including the reinforced paper are also described.

A porous electrode substrate has a form of a tape material and contains a structure made of carbon fibers and a carbon matrix. A specific surface area, porosity, and pore distribution are determined by the carbon matrix. The carbon matrix contains carbon particles including activated carbon with a high specific surface area and a carbonized or graphitized residue of a carbonizable or graphitizable binder.

A porous electrode substrate has a form of a tape material and contains a structure made of carbon fibers and a carbon matrix. A specific surface area, porosity, and pore distribution are determined by the carbon matrix. The carbon matrix contains carbon particles including activated carbon with a high specific surface area and a carbonized or graphitized residue of a carbonizable or graphitizable binder.

In a method of making a conductive structure, a reducing agent is applied to a region of a sheet of graphene oxide composite paper for a predetermined amount of time. The reducing agent is removed after the predetermined amount of time so as to expose a region of reduced graphene oxide disposed in the sheet of graphene oxide composite paper. A conductive structure includes a sheet of graphene oxide composite paper. At least one region on the sheet of graphene oxide composite paper includes reduced graphene oxide.