This study reports on the synthesis of N-doped carbon spheres (N-CSs) by a simple synthetic
procedure. A horizontal CVD type reactor was used to synthesize N-CSs from pyridine.
Depending on the dilution of the pyridine with toluene, a nitrogen content of 0.13-5 mol % was
obtained. The use of a vertical CVD reactor gave N-CSs with a N-content of 0.19-3 mol % when
an ammonium solution and acetylene were used as reactants. The diameters of carbon spheres
were found to be in the range of 40 nm to 1000 nm for both CVD reactors. The diameter can be
controlled by varying the flow rate, temperature, time, concentration and the reactor type. The
samples were characterized by TEM, HRTEM, elemental analysis, Raman spectroscopy, TGA,
PXRD and ESR.
We have demonstrated that unsubstituted thiophene can be polymerized by Fe3+-catalyzed
oxidative polymerization. The average particle size was about 50 nm, within a narrow particlesize
distribution. The undoped carbon spheres (CSs) were reacted with thiophene to give
polymer/carbon composites containing polythiophene and carbon nanospheres via chemical
oxidative polymerization reaction. Polythiophene molecules were either chemically bonded or
physically adsorbed to the surface of carbon spheres. The microstructure and properties of the
two types of composites were compared. The thermogravimetric analysis data confirmed that the
presence of CSs in the polymer\carbon composites is responsible for the higher thermal stability
of the composite material in comparison with pristine polythiophene. The FTIR analysis showed
that covalent functionalized nanocomposites exhibit a high intensity of a C-S bond This study reports on the synthesis of N-doped carbon spheres (N-CSs) by a simple synthetic
procedure. A horizontal CVD type reactor was used to synthesize N-CSs from pyridine.
Depending on the dilution of the pyridine with toluene, a nitrogen content of 0.13-5 mol % was
obtained. The use of a vertical CVD reactor gave N-CSs with a N-content of 0.19-3 mol % when
an ammonium solution and acetylene were used as reactants. The diameters of carbon spheres
were found to be in the range of 40 nm to 1000 nm for both CVD reactors. The diameter can be
controlled by varying the flow rate, temperature, time, concentration and the reactor type. The
samples were characterized by TEM, HRTEM, elemental analysis, Raman spectroscopy, TGA,
PXRD and ESR.
We have demonstrated that unsubstituted thiophene can be polymerized by Fe3+-catalyzed
oxidative polymerization. The average particle size was about 50 nm, within a narrow particlesize
distribution. The undoped carbon spheres (CSs) were reacted with thiophene to give
polymer/carbon composites containing polythiophene and carbon nanospheres via chemical
oxidative polymerization reaction. Polythiophene molecules were either chemically bonded or
physically adsorbed to the surface of carbon spheres. The microstructure and properties of the
two types of composites were compared. The thermogravimetric analysis data confirmed that the
presence of CSs in the polymer\carbon composites is responsible for the higher thermal stability
of the composite material in comparison with pristine polythiophene. The FTIR analysis showed
that covalent functionalized nanocomposites exhibit a high intensity of a C-S bondThis study reports on the synthesis of N-doped carbon spheres (N-CSs) by a simple synthetic
procedure. A horizontal CVD type reactor was used to synthesize N-CSs from pyridine.
Depending on the dilution of the pyridine with toluene, a nitrogen content of 0.13-5 mol % was
obtained. The use of a vertical CVD reactor gave N-CSs with a N-content of 0.19-3 mol % when
an ammonium solution and acetylene were used as reactants. The diameters of carbon spheres
were found to be in the range of 40 nm to 1000 nm for both CVD reactors. The diameter can be
controlled by varying the flow rate, temperature, time, concentration and the reactor type. The
samples were characterized by TEM, HRTEM, elemental analysis, Raman spectroscopy, TGA,
PXRD and ESR.
We have demonstrated that unsubstituted thiophene can be polymerized by Fe3+-catalyzed
oxidative polymerization. The average particle size was about 50 nm, within a narrow particlesize
distribution. The undoped carbon spheres (CSs) were reacted with thiophene to give
polymer/carbon composites containing polythiophene and carbon nanospheres via chemical
oxidative polymerization reaction. Polythiophene molecules were either chemically bonded or
physically adsorbed to the surface of carbon spheres. The microstructure and properties of the
two types of composites were compared. The thermogravimetric analysis data confirmed that the
presence of CSs in the polymer\carbon composites is responsible for the higher thermal stability
of the composite material in comparison with pristine polythiophene. The FTIR analysis showed
that covalent functionalized nanocomposites exhibit a high intensity of a C-S bond at 695 cm-1 ,
which is not observed in the noncovalent functionalized nanocomposites
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:wits/oai:wiredspace.wits.ac.za:10539/7709 |
| Date | 17 March 2010 |
| Creators | Kunjuzwa, Nikiwe |
| Source Sets | South African National ETD Portal |
| Language | English |
| Detected Language | English |
| Type | Thesis |
| Format | application/pdf |
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