FIG. 4A is a transmission electron micrographs (TEM) of a 3D nano carbon fibrous structure made by Hodogaya scientists for use in composites and inks.
Hodogaya Chemical Co., Ltd. (Tokyo, JP) Takayuki Tsukada and Jiayi Shan developed a three dimensional network of carbon fibrous structure. The structure includes a granular part formed by thermal decomposition of carbon in peripheral directions of a catalyst. The carbon fibers each having an outside diameter of 15-100 nm and are bound to the granular part and extend outwardly from the granular part. The an outside diameter of the granular part is larger than an outside diameter of each carbon fiber, and wherein the plurality of carbon fibers are fused together at the granular part during the formation of the carbon fibrous structure. The granular part may look like a knot of the plurality of carbon fibers. The carbon fibers may be tubular carbon fibers that are bound to the granular part, but are not entangled with each other.
The reason for restricting the outside diameter of the carbon fibers to a range of 15 nm to 100 nm is because when the outside diameter is less than 15 nm, the cross-sections of the carbon fibers cannot have polygonal figures. The carbon fibers are detailed in U.S. Patent Application 20100015444.
FIG. 1 is a scanning electron micrograph SEM photo of an intermediate for the carbon fibrous structure. By the CVD process, nano carbon fibrous structures were synthesized using toluene as the raw material.
The carbon fibrous structures according to embodiments of the present invention may have the following properties:
A) a low bulk density; B) a good dispersibility in a matrix such as resin; C) a high electrical conductivity; D) a high heat conductivity; E) a good slidability; F) a good chemical stability; G) a high thermal stability.
A) a low bulk density; B) a good dispersibility in a matrix such as resin; C) a high electrical conductivity; D) a high heat conductivity; E) a good slidability; F) a good chemical stability; G) a high thermal stability.
By combining carbon fibers with a resin, the resultant conductive resin and conductive resin molded body may be suitably used as wrapping material, gasket, container, resistance body, conductive fiber, electric wire, adhesive, ink, paint, and etc. Similar effects can be expected from composite materials in which the carbon fibers are added to an inorganic material, particularly, ceramic, metal, in addition to the composite with a resin.
The fine carbon fibrous structures, particularly structures that are composed of fine carbon fibers wherein each of the fibers is composed of tubular laminates of fine carbon sheets and has a varied configuration. The fibrous structures are suitable as additives to be added to solid materials, such as resins, ceramics, metals, and etc., to improve the physical properties of the solid materials, such as electrical, mechanical, or thermal properties, and also as additives to be added to liquid materials, such as fuels, lubricant oils, and etc., to improve the physical properties of the liquid materials, such as thermal property.
FIG. 5 is another scanning electron micrograph (SEM photo) of a carbon fibrous structure
FIG. 8 is an optical microphotograph of a composite material where a carbon fibrous structure is used.
