Carbon Based Hierarchical Micro- And Nano- Structures

Carbon Based Hierarchical Micro- And Nano- Structures

Introduction

Carbon, because of its unique properties of bonding chemically, is the greatly resourceful constituents in the periodic chart. It executes its part like a bone of every well-versed life in natural history. There are a number of allotropic forms of carbon that exist in the shape of naturally taking place diamond, graphite, to the nano-tubes that are synthesized in the lab, fullerenes (C60) and so on. Furthermore, one more classification of the materials of carbon is there, called “Amorphous Carbon” that does not reveal any order of the extensive range or crystallinity. Although, this amorphous carbon takes in two additional categories that include glassy carbon and diamond-like carbon derived from numerous percentage of the crystallites of diamond and graphite. For this report, the emphasis will be more on the glassy carbon that is utilized in a number of appliances taking in the carbon micro-electro-mechanical systems (C-MEMS). This glassy carbon is a hard (non-graphitizing) form of carbon that has power over the glassy characteristics for example resistance to high temperature and a lower concentration. In general, this glassy carbon is created in the form of bulk by treatment of heat of a lot of polymers, known as “polymeric predecessors” to carbon as well. These polymeric precursors include coal, wood, organic compounds, lignite and so on. When these predecessors are heated up in a static atmosphere in excess of 800 °C, the non-carbon substance of these precursors break out in the shape of yield carbon and in gaseous form. This procedure is known as carbonization or pyrolysis. Various polymers, for instance, cellulose, phenolic resins, polyvinyl alcohol, poly-acrylonitrile (PAN), epoxy resins, coal tar pitch, polyamides and so forth have been employed to manufacture the pyrolytic carbon by the help of the process of carbonization. With the exception of the synthesis of bulk, thin film of the materials of carbon could be formulated by a number of other techniques for example the chemical deposition of vapor, evaporation of electron beam, spluttering, and the polymeric thin films' pyrolysis (Chandra S. Sharma. et al. 2010).

Relying on the chemical configuration of the precursor of polymer and the conditions of heating, the materials of carbon with extensive variety of characteristics could be amalgamated. The carbon yields of numerous precursors of polymer have been reported by Jenkins et al. whereas different attributes of a lot of materials of carbon were recapitulated by McCreery, as these carbon materials were utilized as the materials of electrode. Because the glassy carbon takes in little resistance to electricity and is secure chemically and thermally as well, it is extensively utilized in electro-chemistry.

Our goal is to introduce carbon nano-tubes vertically aligned (CNT), which are referred to as CNT "forest", as material for new micro fabrication. We present the details of a series of related methods recently developed by our group: manufacture of CNT forest microstructures by thermal CVD film of catalyst lithographically fantasy thin, self-directed elasto-capillary densification of CNT microstructures, and ...