摘要:
The present invention discloses the process of supplying high pressure (e.g., 30 atmospheres) CO that has been preheated (e.g., to about 1000° C.) and a catalyst precursor gas (e.g., Fe(CO)5) in CO that is kept below the catalyst precursor decomposition temperature to a mixing zone. In this mixing zone, the catalyst precursor is rapidly heated to a temperature that results in (1) precursor decomposition, (2) formation of active catalyst metal atom clusters of the appropriate size, and (3) favorable growth of SWNTs on the catalyst clusters. Preferably a catalyst cluster nucleation agency is employed to enable rapid reaction of the catalyst precursor gas to form many small, active catalyst particles instead of a few large, inactive ones. Such nucleation agencies can include auxiliary metal precursors that cluster more rapidly than the primary catalyst, or through provision of additional energy inputs (e.g., from a pulsed or CW laser) directed precisely at the region where cluster formation is desired. Under these conditions SWNTs nucleate and grow according to the Boudouard reaction. The SWNTs thus formed may be recovered directly or passed through a growth and annealing zone maintained at an elevated temperature (e.g., 1000° C.) in which tubes may continue to grow and coalesce into ropes.
摘要:
The present invention discloses the process of supplying high pressure (e.g., 30 atmospheres) CO that has been preheated (e.g., to about 1000° C.) and a catalyst precursor gas (e.g., Fe(CO)5) in CO that is kept below the catalyst precursor decomposition temperature to a mixing zone. In this mixing zone, the catalyst precursor is rapidly heated to a temperature that results in (1) precursor decomposition, (2) formation of active catalyst metal atom clusters of the appropriate size, and (3) favorable growth of SWNTs on the catalyst clusters. Preferably a catalyst cluster nucleation agency is employed to enable rapid reaction of the catalyst precursor gas to form many small, active catalyst particles instead of a few large, inactive ones. Such nucleation agencies can include auxiliary metal precursors that cluster more rapidly than the primary catalyst, or through provision of additional energy inputs (e.g., from a pulsed or CW laser) directed precisely at the region where cluster formation is desired. Under these conditions SWNTs nucleate and grow according to the Boudouard reaction. The SWNTs thus formed may be recovered directly or passed through a growth and annealing zone maintained at an elevated temperature (e.g., 1000° C.) in which tubes may continue to grow and coalesce into ropes.
摘要:
A carbon nanotube field emission device with overhanging gate fabricated by a double silicon-on-insulator process. Other embodiments are described and claimed.
摘要:
A method of forming a periodic array of nano-scale objects using a block copolymer, and nano-scale object arrays formed from the method are provided. The method for forming the arrays generally includes the steps of depositing a block copolymer of at least two blocks on a substrate to form an ordered meso-scale structured array of the polymer materials, forming catalytic metal dots based on the meso-scale structure, and growing nano-scale objects on the catalytic dots to form an ordered array of nano-scale objects.
摘要:
High-current density field emission sources using arrays of nanofeatures bundles and methods of manufacturing such field emission sources are provided. Variable field emission performance is provided with the variance in the bundle diameter and the inter-bundle spacing, and optimal geometries for the lithographically patterned arrays were determined. Arrays of 1-μm and 2-μm diameter multi-walled carbon nanotube bundles spaced 5 μm apart (edge-to-edge spacing) were identified as the most optimum combination, routinely producing 1.5 to 1.8 A/cm2 at low electric fields of approximately 4 V/μm, rising to >6 A/cm2 at 20 V/μm over a ˜100-μm-diameter area.
摘要翻译:提供了使用纳米尺寸束阵列的大电流密度场发射源和制造这种场致发射源的方法。 可变场发射性能具有束直径和束间距的变化,并且确定了用于光刻图案阵列的最佳几何形状。 将距离为5微米(边缘到边缘间距)的1μm和2μm直径的多壁碳纳米管束的阵列确定为最佳组合,通常在大约的低电场下产生1.5至1.8A / cm 2 4 V /μm,在直径约100μm的区域,以20 V /μm上升至> 6A / cm2。
摘要:
A method of forming a periodic array of nano-scale objects using a block copolymer, and nano-scale object arrays formed from the method are provided. The method for forming the arrays generally includes the steps of depositing a block copolymer of at least two blocks on a substrate to form an ordered meso-scale structured array of the polymer materials, forming catalytic metal dots based on the meso-scale structure, and growing nano-scale objects on the catalytic dots to form an ordered array of nano-scale objects.
摘要:
A nanofeature particulate trap comprising a plurality of densely packed nanofeatures, such as nanotubes, and a particulate detector incorporating the nanofeature particulate trap are provided. A method of producing a nanotrap structure alone or integrated with a particulate detector is also provided.