Abstract: A process for growth of boron-based nanostructures, such as nanotubes and nanowires, with a controlled diameter and with controlled chemical (such as composition, doping) as well as physical (such as electrical and superconducting) properties is described. The boron nanostructures are grown on a metal-substituted MCM-41 template with pores having a uniform pore diameter of less than approximately 4 nm, and can be doped with a Group Ia or Group IIa electron donor element during or after growth of the nanostructure. Preliminary data based on magnetic susceptibility measurements suggest that Mg-doped boron nanotubes have a superconducting transition temperature on the order of 100 K.

Abstract: A metal-substituted mesoporous oxide framework, such as Co-MCM-41, are disclosed which includes more than one ion species with different reduction kinetics. The reducibility correlates strongly with the pore radius of curvature, with the metal ions incorporated in smaller pores more resistant to complete reduction. The metal-ion substituted oxide framework improves catalytic processes by controlling the size of the catalytic particles forming in the pores. The metal-substituted mesoporous oxide framework can be employed in selective hydrogenation of organic chemicals, in ammonia synthesis, and in automotive catalytic exhaust systems.

Abstract: A process for growth of boron-based nanostructures, such as nanotubes and nanowires, with a controlled diameter and with controlled chemical (such as composition, doping) as well as physical (such as electrical and superconducting) properties is described. The boron nanostructures are grown on a metal-substituted MCM-41 template with pores having a uniform pore diameter of less than approximately 4 nm, and can be doped with a Group Ia or Group IIa electron donor element during or after growth of the nanostructure. Preliminary data based on magnetic susceptibility measurements suggest that Mg-doped boron nanotubes have a superconducting transition temperature on the order of 100 K.

Abstract: A process for growth of boron-based nanostructures, such as nanotubes and nanowires, with a controlled diameter and with controlled chemical (such as composition, doping) as well as physical (such as electrical and superconducting) properties is described. The boron nanostructures are grown on a metal-substituted MCM-41 template with pores having a uniform pore diameter of less than approximately 4 nm, and can be doped with a Group Ia or Group IIa electron donor element during or after growth of the nanostructure. Preliminary data based on magnetic susceptibility measurements suggest that Mg-doped boron nanotubes have a superconducting transition temperature on the order of 100 K.

Abstract: Transition metal-substituted MCM-41 framework structures with a high degree of structural order and a narrow pore diameter distribution were reproducibly synthesized by a hydrothermal method using a surfactant and an anti-foaming agent. The pore size and the mesoporous volume depend linearly on the surfactant chain length. The transition metals, such as cobalt, are incorporated substitutionally and highly dispersed in the silica framework. Single wall carbon nanotubes with a narrow diameter distribution that correlates with the pore diameter of the catalytic framework structure were prepared by a Boudouard reaction. Nanostructures with a specified diameter or cross-sectional area can therefore be predictably prepared by selecting a suitable pore size of the framework structure.

Abstract: A transition metal substituted, amorphous mesoporous silica framework with a high degree of structural order and a narrow pore diameter distribution (±0.15 nm FWHM) was synthesized and used for the templated growth of single walled carbon nanotubes (SWNT). The physical properties of the SWNT (diameter, diameter distribution, electronic characteristic) can be controlled by the template pore size and the pore wall chemistry. The SWNT can find applications, for example, in chemical sensors and nanoscale electronic devices, such as transistors and crossbar switches.

Abstract: A transition metal substituted, amorphous mesoporous silica framework with a high degree of structural order and a narrow pore diameter distribution (±0.15 nm FWHM) was synthesized and used for the templated growth of GaN nanostructures, such as single wall nanotubes, nanopipes and nanowires. The physical properties of the GaN nanostructures (diameter, diameter distribution, electronic characteristic) can be controlled by the template pore diameter and the pore wall chemistry. GaN nanostructures can find applications, for example, in nanoscale electronic devices, such as field-emitters, and in chemical sensors.

Abstract: A transition metal substituted, amorphous mesoporous silica framework with a high degree of structural order and a narrow pore diameter distribution (±0.15 nm FWHM) was synthesized and used for the templated growth of GaN nanostructures, such as single wall nanotubes, nanopipes and nanowires. The physical properties of the GaN nanostructures (diameter, diameter distribution, electronic characteristic) can be controlled by the template pore diameter and the pore wall chemistry. GaN nanostructures can find applications, for example, in nanoscale electronic devices, such as field-emitters, and in chemical sensors.

Abstract: A process for growth of boron-based nanostructures, such as nanotubes and nanowires, with a controlled diameter and with controlled chemical (such as composition, doping) as well as physical (such as electrical and superconducting) properties is described. The boron nanostructures are grown on a metal-substituted MCM-41 template with pores having a uniform pore diameter of less than approximately 4 nm, and can be doped with a Group Ia or Group IIa electron donor element during or after growth of the nanostructure. Preliminary data based on magnetic susceptibility measurements suggest that Mg-doped boron nanotubes have a superconducting transition temperature on the order of 100 K.

Abstract: A transition metal substituted, amorphous mesoporous silica framework with a high degree of structural order and a narrow pore diameter distribution (±0.15 nm FWHM) was synthesized and used for the templated growth of GaN nanostructures, such as single wall nanotubes, nanopipes and nanowires. The physical properties of the GaN nanostructures (diameter, diameter distribution, electronic characteristic) can be controlled by the template pore diameter and the pore wall chemistry. GaN nanostructures can find applications, for example, in nanoscale electronic devices, such as field-emitters, and in chemical sensors.

Abstract: Transition metal-substituted MCM-41 framework structures with a high degree of structural order and a narrow pore diameter distribution were reproducibly synthesized by a hydrothermal method using a surfactant and an anti-foaming agent. The pore size and the mesoporous volume depend linearly on the surfactant chain length. The transition metals, such as cobalt, are incorporated substitutionally and highly dispersed in the silica framework. Single wall carbon nanotubes with a narrow diameter distribution that correlates with the pore diameter of the catalytic framework structure were prepared by a Boudouard reaction. Nanostructures with a specified diameter or cross-sectional area can therefore be predictably prepared by selecting a suitable pore size of the framework structure.

Abstract: A transition metal substituted, amorphous mesoporous silica framework with a high degree of structural order and a narrow pore diameter distribution (±0.15 nm FWHM) was synthesized and used for the templated growth of single walled carbon nanotubes (SWNT). The physical properties of the SWNT (diameter, diameter distribution, electronic characteristic) can be controlled by the template pore size and the pore wall chemistry. The SWNT can find applications, for example, in chemical sensors and nanoscale electronic devices, such as transistors and crossbar switches.