ense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown sing ther... more ense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown sing thermal chemical vapor deposition (CVD) from ethylene and hydrogen gases with wo or three independently controlled hot zones while introducing controlled flows of oxyen. Through preheating, oxygen and hydrogen reacted through a multi-step reaction to orm water, enabling the growth of tall CNT carpets. This process showed a large tolerance or variations of O2, H2, and C2H4. The measured water vapor produced was half the theoetical maximum. The residence time strongly affected the decomposition of the gases. The implicity and robustness of this CVD process provides a simpler alternative to direct addiion of water vapor for manufacturing tall carpets of aligned CNTs with a high level of ontrol. 2012 Elsevier Ltd. All rights reserved.
Dense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown using th... more Dense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown using thermal chemical vapor deposition (CVD) from ethylene and hydrogen gases with two or three independently controlled hot zones while introducing controlled flows of oxygen. Through preheating, oxygen and hydrogen reacted through a multi-step reaction to form water, enabling the growth of tall CNT carpets. This process showed a large tolerance for variations of O 2 , H 2 , and C 2 H 4 . The measured water vapor produced was half the theoretical maximum. The residence time strongly affected the decomposition of the gases. The simplicity and robustness of this CVD process provides a simpler alternative to direct addition of water vapor for manufacturing tall carpets of aligned CNTs with a high level of control.
Nanoparticles of the CuInTe(2) (CIT) and CuInSe(2) (CIS) alloys have been prepared using the micr... more Nanoparticles of the CuInTe(2) (CIT) and CuInSe(2) (CIS) alloys have been prepared using the microwave-assisted polyol method. In this simple and quick reaction the polyol is both the solvent and the reducing agent. XRD studies show that nanoparticles of CIT and CIS are formed in the body-centered tetragonal structure and their average diameters are approximately 94 and approximately 83 nm, respectively. Electron microscopy studies show that these formed particles are poorly aggregated with a mean diameter of 100 and 85 nm, respectively. The products have been characterized by different analytical techniques, and the electronic properties have been measured using photoacoustic spectroscopy (PAS).
Hoffman et al. contend that the peaks reported in our external reflection FTIR spectra are too in... more Hoffman et al. contend that the peaks reported in our external reflection FTIR spectra are too intense and that at least some of the peaks are pointed in the wrong direction.
The method of ultrasound irradiation is used for anchoring metallic nanocrystals (Ag, Au, Pd, and... more The method of ultrasound irradiation is used for anchoring metallic nanocrystals (Ag, Au, Pd, and Pt) onto the surface of polystyrene spheres. In former studies, almost all the sonochemically prepared, coated metallic nanomaterials were formed as amorphous nanoparticles (Pol, V. G.; et al. Langmuir 2002, 18, 3352; Pol, V. G.; et al. Chem. Mater. 2003, 15, 1111; Zhong, Z. Y.; et al. Chem. Mater. 1999, 11 (9), 2350; Pol, V. G.; et al. Chem. Mater. 2003, 15, 1378), which were coated on various substrates (silica spheres, carbon spherules, titania, and alumina). On the other hand, the noble metal nanoparticles deposited on polystyrene spheres via ultrasound irradiation yielded nanocrystalline Ag, Au, Pd, and Pt particles on the surface of polystyrene as as-synthesized materials. The sonochemical mechanism is proposed based on chemical interactions between the particles.
Nanoparticles of the Cd 1 2 x Zn x Se alloy with different stoichiometries (x~0.1, 0.2, 0.3) have... more Nanoparticles of the Cd 1 2 x Zn x Se alloy with different stoichiometries (x~0.1, 0.2, 0.3) have been prepared using the microwave-assisted polyol method. In this simple and quick reaction the polyol (ethylene glycol) is both the solvent and the reducing agent. XRD studies show that nanoparticles are formed in the wurtzite (hexagonal) form with an average diameter of the nanocrystals of 5-8 nm. Electron microscopy studies show that these particles form monodisperse spherical aggregates with a diameter of approximately 200 nm. Electronic properties of the as-prepared alloys have been studied using photoacoustic spectroscopy (PAS). Also, the particles have been characterized using TGA, DSC, XPS and EDS analysis. The results of these studies are presented in this paper.
Nanoparticles of the CuInTe(2) (CIT) and CuInSe(2) (CIS) alloys have been prepared using the micr... more Nanoparticles of the CuInTe(2) (CIT) and CuInSe(2) (CIS) alloys have been prepared using the microwave-assisted polyol method. In this simple and quick reaction the polyol is both the solvent and the reducing agent. XRD studies show that nanoparticles of CIT and CIS are formed in the body-centered tetragonal structure and their average diameters are approximately 94 and approximately 83 nm, respectively. Electron microscopy studies show that these formed particles are poorly aggregated with a mean diameter of 100 and 85 nm, respectively. The products have been characterized by different analytical techniques, and the electronic properties have been measured using photoacoustic spectroscopy (PAS).
Dense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown using th... more Dense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown using thermal chemical vapor deposition (CVD) from ethylene and hydrogen gases with two or three independently controlled hot zones while introducing controlled flows of oxygen. Through preheating, oxygen and hydrogen reacted through a multi-step reaction to form water, enabling the growth of tall CNT carpets. This process showed a large tolerance for variations of O 2 , H 2 , and C 2 H 4 . The measured water vapor produced was half the theoretical maximum. The residence time strongly affected the decomposition of the gases. The simplicity and robustness of this CVD process provides a simpler alternative to direct addition of water vapor for manufacturing tall carpets of aligned CNTs with a high level of control.
ense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown sing ther... more ense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown sing thermal chemical vapor deposition (CVD) from ethylene and hydrogen gases with wo or three independently controlled hot zones while introducing controlled flows of oxyen. Through preheating, oxygen and hydrogen reacted through a multi-step reaction to orm water, enabling the growth of tall CNT carpets. This process showed a large tolerance or variations of O2, H2, and C2H4. The measured water vapor produced was half the theoetical maximum. The residence time strongly affected the decomposition of the gases. The implicity and robustness of this CVD process provides a simpler alternative to direct addiion of water vapor for manufacturing tall carpets of aligned CNTs with a high level of ontrol. 2012 Elsevier Ltd. All rights reserved.
Dense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown using th... more Dense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown using thermal chemical vapor deposition (CVD) from ethylene and hydrogen gases with two or three independently controlled hot zones while introducing controlled flows of oxygen. Through preheating, oxygen and hydrogen reacted through a multi-step reaction to form water, enabling the growth of tall CNT carpets. This process showed a large tolerance for variations of O 2 , H 2 , and C 2 H 4 . The measured water vapor produced was half the theoretical maximum. The residence time strongly affected the decomposition of the gases. The simplicity and robustness of this CVD process provides a simpler alternative to direct addition of water vapor for manufacturing tall carpets of aligned CNTs with a high level of control.
Nanoparticles of the CuInTe(2) (CIT) and CuInSe(2) (CIS) alloys have been prepared using the micr... more Nanoparticles of the CuInTe(2) (CIT) and CuInSe(2) (CIS) alloys have been prepared using the microwave-assisted polyol method. In this simple and quick reaction the polyol is both the solvent and the reducing agent. XRD studies show that nanoparticles of CIT and CIS are formed in the body-centered tetragonal structure and their average diameters are approximately 94 and approximately 83 nm, respectively. Electron microscopy studies show that these formed particles are poorly aggregated with a mean diameter of 100 and 85 nm, respectively. The products have been characterized by different analytical techniques, and the electronic properties have been measured using photoacoustic spectroscopy (PAS).
Hoffman et al. contend that the peaks reported in our external reflection FTIR spectra are too in... more Hoffman et al. contend that the peaks reported in our external reflection FTIR spectra are too intense and that at least some of the peaks are pointed in the wrong direction.
The method of ultrasound irradiation is used for anchoring metallic nanocrystals (Ag, Au, Pd, and... more The method of ultrasound irradiation is used for anchoring metallic nanocrystals (Ag, Au, Pd, and Pt) onto the surface of polystyrene spheres. In former studies, almost all the sonochemically prepared, coated metallic nanomaterials were formed as amorphous nanoparticles (Pol, V. G.; et al. Langmuir 2002, 18, 3352; Pol, V. G.; et al. Chem. Mater. 2003, 15, 1111; Zhong, Z. Y.; et al. Chem. Mater. 1999, 11 (9), 2350; Pol, V. G.; et al. Chem. Mater. 2003, 15, 1378), which were coated on various substrates (silica spheres, carbon spherules, titania, and alumina). On the other hand, the noble metal nanoparticles deposited on polystyrene spheres via ultrasound irradiation yielded nanocrystalline Ag, Au, Pd, and Pt particles on the surface of polystyrene as as-synthesized materials. The sonochemical mechanism is proposed based on chemical interactions between the particles.
Nanoparticles of the Cd 1 2 x Zn x Se alloy with different stoichiometries (x~0.1, 0.2, 0.3) have... more Nanoparticles of the Cd 1 2 x Zn x Se alloy with different stoichiometries (x~0.1, 0.2, 0.3) have been prepared using the microwave-assisted polyol method. In this simple and quick reaction the polyol (ethylene glycol) is both the solvent and the reducing agent. XRD studies show that nanoparticles are formed in the wurtzite (hexagonal) form with an average diameter of the nanocrystals of 5-8 nm. Electron microscopy studies show that these particles form monodisperse spherical aggregates with a diameter of approximately 200 nm. Electronic properties of the as-prepared alloys have been studied using photoacoustic spectroscopy (PAS). Also, the particles have been characterized using TGA, DSC, XPS and EDS analysis. The results of these studies are presented in this paper.
Nanoparticles of the CuInTe(2) (CIT) and CuInSe(2) (CIS) alloys have been prepared using the micr... more Nanoparticles of the CuInTe(2) (CIT) and CuInSe(2) (CIS) alloys have been prepared using the microwave-assisted polyol method. In this simple and quick reaction the polyol is both the solvent and the reducing agent. XRD studies show that nanoparticles of CIT and CIS are formed in the body-centered tetragonal structure and their average diameters are approximately 94 and approximately 83 nm, respectively. Electron microscopy studies show that these formed particles are poorly aggregated with a mean diameter of 100 and 85 nm, respectively. The products have been characterized by different analytical techniques, and the electronic properties have been measured using photoacoustic spectroscopy (PAS).
Dense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown using th... more Dense millimeter-tall carpets of vertically aligned carbon nanotubes (VACNTs) were grown using thermal chemical vapor deposition (CVD) from ethylene and hydrogen gases with two or three independently controlled hot zones while introducing controlled flows of oxygen. Through preheating, oxygen and hydrogen reacted through a multi-step reaction to form water, enabling the growth of tall CNT carpets. This process showed a large tolerance for variations of O 2 , H 2 , and C 2 H 4 . The measured water vapor produced was half the theoretical maximum. The residence time strongly affected the decomposition of the gases. The simplicity and robustness of this CVD process provides a simpler alternative to direct addition of water vapor for manufacturing tall carpets of aligned CNTs with a high level of control.
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