HiPcO High Pressure Carbon

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). 

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) ... 

In the same line, high-Pressure carbon monoxide (HiPco) SWCNTs were functionalized along their sidewalls with hydroxyalkyl groups using a radical addition scheme.These moieties were found to be active in the polymerization of acrylic acid from the surface of the nanotubes by a redox radical mechanism. In Figure 9.4 (left-hand panel) the Raman response of pristine, ethanol-treated and polymer-modified samples is illustrated. Compared with... 

Blocky VA/AA copolymer (Fig. 4.6.5) was sonicated with high-pressure carbon monoxide based single-walled carbon nanombes (HiPco SWCNT) in THF (Caneba... 

CNTs can be made by means of arc-discharge, laser ablation, high pressure carbon monoxide decomposition (HiPCO), and chemical vapor decomposition (CVD) processes. The HiPCO process delivers high quality SWCNTs but the upscaling is difficult. Arc-discharge, laser ablation and CVD systems are currently used to produce SWCNTs as well as MWCNTs in laboratory scales. However, until now only CVD processes have been upscaled successfully to produce MWCNTs in commercially relevant amounts. For this purpose the synthesis is usually performed in fluidized beds [10-12]. Currently (2011), industrial grades of MWCNTs can be purchased for less than 130 USD/kg. 

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... 

Acronyms and variables cold crystalhzation (CC) cobalt molybdenum catalyst (CoMoCAT) chemical vapor deposition (CVD) dichlorobenzene (DCB) high-pressure carbon monoxide (HiPCO) isotactic polypropylene (iPP) melt crystalhzation (MC) melt flow index (MFl) poly( -caprolactone) (PCL) polydispersity index (PDD polyethylene (PE) polyethylene oxide (PEO) poly (ethylene-propylene-diene) [P(E-PP-diene)] poly(ethylene 2,6-naphthalate) (PEN) poly(ethylene terephthalate (PET) poly(L-lactic acid) (PLLA) poly(trimethylene terephthalate (PTMT) poly(vinyl alcohol) (PVA) 1,1,2,2-tetrachloroethane (TCE) tetrahydrofuran (THE) weight-average molecular weight = ] number-average molecular weight Avrami exponent for neat polymer = Avrami exponent for CNT composite = Avrami rate constant for neat polymer = Avrami exponent for composite = neat polymer crystalhzation... 

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). 

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. 

Ceo = Fullerene SWNTs = Single-walled carbon nanotubes MWNTs = Multiwalled carbon nanotubes DWNTs = Double-walled carbon nanotubes CNTs = carbon nanotubes TEM = Transmission electron microscopy HRTEM = High-resolution transmission electron microscopy SEM = Scanning electron microscopy AFM = Atomic force microscopy Ch = Chiral vector CVD = Chemical vapor deposition HiPco process = High-pressure disproportionation of CO RBM = Radical breathing vibration modes DOS = Electronic density of states. 

---