HiPco method high pressure

SWNTs were prepared by high-pressure CO decomposition over the Fe catalyst (HiPco method [13]) at Carbon Nanotechnologies Inc. Houston, Texas, USA. The raw sample was purified by controlled thermal oxidation in air followed by sonication in HC1. The purity estimated by elemental analysis, TGA, XRD and TEM gave in result 99% content of SWNT in the samples studied [4],... 

The polyaniline was prepared by emulsion polymerization following the procedure outlined in US patent 5,863,465 with DNNSAused as a dopant [22]. Carbon Nanotubes (CNI) manufactured the nanotubes used in the work either by a high-pressure fabrication method (Hipco SWNT) or via laser ablation (Laser SWNT). We found that excellent dispersions of the nanotubes in PANI could be produced by two different procedures. The nanotubes could either be directly sonicated into the PANI solution or first sonicated into xylene and that dispersion afterwards sonicated into the DNNSA-PANI solution. 

The preparation of single-walled nanotubes succeeds more easily by the so-called HiPCo-process that was published for the first time in 1998. The name is deduced from high-pressure carbon monoxide and signifies a crucial aspect of the method Here the carbon source is not a hydrocarbon, but carbon monoxide that does not suffer pyrolysis at the relevant temperatures. The formation of carbon material is based on the Boudouard equilibrium (3.9) ... 

A well-known floating catalyst method developed at Rice Uruversity is the so-called HiPCO (high-pressure CO) method. In this case, the growth of SWNTs is realized by disproportionation of CO catalyzed by Fe clusters generated in situ by decomposition of Fe(CO)s in continuously flowing CO at high pressure and elevated temperature (79). A mixture of the Fe precursor and CO is injected into the reactor... 

High-pressure CO conversion (HiPCO) is a new method for the bulk production of SWCNTs under high-pressure, high-temperature flowing CO on catalytic clusters of Fe. Fe catalyst is formed in situ by thermal decomposition of iron pentacarbonyl (i.e., Fe(CO)j) which is delivered intact within a cold CO flow and then rapidly mixed with hot CO in the reaction zone. Upon heating, the FefCO) decomposes into atoms that condense into larger clusters. SWCNTs nucleate and grow on these particles in the gas phase via CO disproportionation CO-i-CO (catalyzed) CO -i-C(SWCNT) [14,15],... 

While both SWNT and MWNT existed in small quantities from the first wood fires at the dawn of Earth s history, their discovery and methods of preparation are only recent, as described above. Briefly, some synthetic methods include nickel catalyzed pyrolysis of methane at bOO C (64) for MWNT, and the so-called HiPCO (high pressure carbon monoxide) process for SWNT.This latter involves thermal decomposition of iron pentacarbonyl in a flow of CO at 800-1200°C (65). 

CNT s are fabricated by a number of different methods including arc discharge, CVD, high pressure carbon monoxide (HiPco), and laser ablation. Laser ablation mainly produces SWNTs but is more expensive than the CVD and arc discharge techniques [51]. Alternatively, CVD methodology allows... 

CoMoCAT (fluidized-bed CVD) and HiPCO (high-pressure CO CVD), have recently been developed for the commercial production of SWNTs (Figure 6.79). Though the experimental setup of these methods are significantly more complex than standard hot-walled CVD, these techniques are still considered an extension of... 

SWNTs for the flammability study of PMMA-SWNT nanocomposites were synthesized by the high-pressure carbon monoxide method (HiPCO) and the coagulation method was used to produce PMMA-SWNT nanocomposites in... 

A number of methods have been developed to produce single- and multiple-wall carbon nanotubes. The most prominent are laser ablation, arc discharge, and catalytic growth (vapor deposition (CVD) and high pressure carbon monoxide (HipCO) process). 

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