United States Patent Application: 0100187172
We have several times documented the extraordinary technology that has been developed at Penn State University, which would enable us to begin treating Carbon Dioxide, as it is co-produced in only a small way, relative to natural sources of emission such as volcanoes, from our economically vital and essential use of Coal in the generation of electrical power, for what it truly is:
A freely-available natural raw material resource which we can harvest and then convert into anything, almost quite literally anything, we now indenture ourselves to the somewhat inimical alien nations of OPEC for the supply of.
Carbon Dioxide can be seen and treated, in fact, as the Natural Gas we don't have to drill and frack for.
Our reports concerning the CO2-recycling technologies developed by Penn State University sort of culminated in, as accessible on the West Virginia Coal Association's web site:
West Virginia Coal Association | Penn State Seeks CO2 Recycling Patent | Research & Development; concerning: "United States Patent Application 20100213046 - Nanotube ... Photocatalytic Conversion of Carbon Dioxide; 2010; Inventors: Craig Grimes, et. al., PA; Assignee: The Penn State Research Foundation; Abstract: Nitrogen-doped titania nanotubes exhibiting catalytic activity on exposure to any one or more of ultraviolet, visible, and/or infrared radiation, or combinations thereof are disclosed. The nanotube arrays may be co-doped with one or more nonmetals and may further include co-catalyst nanoparticles. Also, methods are disclosed for use of nitrogen-doped titania nanotubes in catalytic conversion of carbon dioxide alone or in admixture with hydrogen-containing gases such as water vapor and/or other reactants as may be present or desirable into products such as hydrocarbons and hydrocarbon-containing products, hydrogen and hydrogen-containing products, carbon monoxide and other carbon-containing products, or combinations thereof".
And, being as how no one could rightfully expect any of us snuff-dipping miners of Coal to have the foggiest notion of what "Nitrogen-doped titania nanotubes" might be, we wanted herein to explain them a bit; and, to assure everyone that they do exist; can be, and are being, manufactured; and, that Penn State University knows exactly how to put them together so that they can accomplish their desired task of helping to effect the "catalytic conversion of carbon dioxide ... into products such as hydrocarbons".
First, there are some different varieties of "nanotubes", as can be learned via:
Inorganic nanotube - Wikipedia, the free encyclopedia; "An inorganic nanotube is a cylindrical molecule often composed of metal oxides, and morphologically similar to a carbon nanotube. Inorganic nanotubes have been observed to occur naturally in some mineral deposits. Typical inorganic nanotube materials are 2D layered solids such as tungsten sulfide (and) have been synthesized in macroscopic amounts. However, traditional ceramics like titanium dioxide ... also form inorganic nanotubes. Inorganic nanotubes are an alternative material to better-explored carbon nanotubes, showing advantages such as easy synthetic access and high crystallinity, good uniformity and dispersion, predefined electrical conductivity depending on the composition of the starting material and needle-like morphology, good adhesion to a number of polymers and high impact-resistance. They are therefore promising candidates as fillers for polymer composites with enhanced thermal, mechanical, and electrical properties. Target applications for this kind of composites are materials for ... photovoltaic elements"; and:
Carbon nanotube - Wikipedia, the free encyclopedia; "Carbon nanotubes are allotropes of carbon with a cylindrical nanostructure. Nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger than for any other material. These cylindrical carbon molecules have unusual properties, which are valuable (in the) fields of materials science and technology. Techniques have been developed to produce nanotubes in sizeable quantities (and) advances in catalysis and continuous growth processes are making CNTs more commercially viable".
Even more can be learned via:
Nanostructure - Wikipedia, the free encyclopedia; "A nanostructure is an object of intermediate size between molecular and microscopic (micrometer-sized) structures".
So, even though "nanotubes" are a tad on the teensy side, we do know how to make, handle and use them.
Also note, in all the above, and in the following, that, as related in:
Titanium Dioxide - Titania ( TiO2); the labels "titania" and "titanium dioxide" are synonymous.
That said, following, in excerpts from the initial link in this dispatch, Penn State University tells us precisely how to go about making the "nanotubes" that, in the process of their above-cited "United States Patent Application 20100213046 - Nanotube ... Photocatalytic Conversion of Carbon Dioxide", are a key component of the "methods ... disclosed for (the) catalytic conversion of carbon dioxide ... into ... hydrocarbons":
"United States Patent Application 20100187172 - Highly Ordered Titania Nanotube Arrays
Date: July, 2010
Inventors: Maggie Paulose, ... Craig Grimes, et. al.
Assignee: The Penn State Research Foundation
Abstract: Fabrication of self-aligned closed packed titania nanotube arrays in excess of 10 .mu.m in length and aspect ratio .apprxeq.10,000 by potentiostatic anodization of titanium is disclosed. Conditions for achieving complete anodization and absolute tailorability of Titanium foil samples resulting in a self-standing mechanically robust titania membrane in excess of 1000 .mu.m are also disclosed.
(Some explanation seems necessary. First of all, "aspect ratio", just means the length of the nanotube relative to it's diameter. They are, thus, roughly,"10,000" times longer than they are thick; with the shorthand "apprxeq" just meaning "approximately equal to". And, the enigmatic ".mu.m" is just metric shorthand, we believe, for the "micrometer", or, so it's not confused with the measuring tool, just "micron"; a length of measure that is one millionth of a meter; i.e., one thousandth of a millimeter. As we said, they are teensy, but not unmanageably so. Products and structures on the micron scale are commonly dealt with by the semiconductor industry out in Silicon Valley. The point being, in conjunction with our introductory comments about nanotubes and titania and such, that, this is all stuff some specialists among us know about, know how to get, and know how to utilize. There's nothing called for herein that we have to strap on gossamer wings, fly to the moon and gather into little silk bags. It is all stuff we can get, make and deal with right here, and right now.)
Government Interests: This invention was developed with government support under Grant No. DE-FG02-06ER15772, awarded by The Department of Energy, and under Grant No. CTS-0518269 awarded by the National Science Foundation. The government has certain rights in this invention.
Claims: A method of forming a vertically oriented titania nanotube array using electrochemical oxidation, the method comprising: providing a two-electrode configuration having a working electrode and a counter electrode; and anodizing the working electrode in a polar organic electrolyte for providing fluoride ions, the polar organic electrolyte optimized to maintain dynamic equilibrium between growth and dissolution processes to promote growth of the nanotube array by providing sustained chemical oxidation of the working electrode and pore growth by dissolution of formed oxides.
The method ... wherein the polar organic electrolyte is ethylene glycol or a polar organic electrolyte consisting of a formamide, a dimethyl sulfoxide, a dimethylformamide or a N-methylformamide for providing fluoride ions.
(The "ethylene glycol" is just the main ingredient in some brands of automotive antifreeze; and, it might interest some to know that it was first made commercially in the United States back in the 1920's, at a factory operated by a company that later became a part of Union Carbide, in South Charleston, West Virginia. The "dimethyl sulfoxide" is better known as just "DMSO", a miraculous pain reliever for muscles and joints that some achy old Coal miners might have once used, but, which they're no longer allowed to buy; though it is still used in veterinary liniments to reduce inflammation in the legs of horses. The main point being that these are other things we can easily, at reasonable cost, make plenty of.)
The method ... wherein the working electrode is a titanium foil having a thickness sufficient to provide synthesis of self-aligned closely packed nanotube arrays of in excess of 10 .mu.m in length.
The method ... wherein the working electrode is a titanium foil having a thickness sufficient to provide synthesis of self-aligned closely packed nanotube arrays of at least 134 .mu.m in length.
The method ... wherein the working electrode is a titanium foil having a thickness sufficient to provide synthesis of self-aligned closely packed nanotube arrays in excess of 1000 .mu.m in length.
The method ... wherein the polar organic electrolyte is an ethylene glycol containing ... NH4F and ...H2O.
The method ... wherein the polar organic electrolyte is a fluoride containing organic electrolyte of DMSO containing hydrofluoric acid, potassium fluoride, or ammonium fluoride.
(The "ammonium fluoride" is the "NH4F" previously mentioned. It has several commercial uses already; and, if we don't make any of it in the US, we can import it from India. We can make, if we understand the literature correctly, "hydrofluoric acid" by reacting the mineral "fluorite", of which there are many exploitable deposits in the US and Canada, with Sulfuric Acid, which is so widely used in a number of industries that it is, in essence, an inexpensive industrial commodity. The "potassium fluoride" can and is made by reacting "hydrofluoric acid" with Calcium Carbonate, CaCO3; which we can obtain by reacting a little inexpensive Calcium Hydroxide with, somewhat serenditously, --- Carbon Dioxide.)
The method ... further comprising the step of optimizing the electrolytic composition of the fluoride containing organic electrolyte and duration of oxidation to provide complete anodization of the working electrode and control of the length of the nanotube array.
The method ... wherein the counter electrode comprises a platinum foil.
(Yeah, "platinum foil" would be expensive; but, serving just as an electrode and not as a reactant, it wouldn't get used up or consumed to any appreciable extent in the process.)
A method for forming a vertically oriented nanotube array using electrochemical oxidation, the method comprising: providing a two-electrode configuration having a working electrode and a counter electrode; anodizing the working electrode in an electrolyte having fluoride ions to assist in providing a formed oxide; dissolving the formed oxide to form the nanotube array; maintaining dynamic equilibrium between growth and dissolution processes by controlling one or more anodization variables; and growing the nanotube array to a total length to form to the nanotube array by sustained oxidation of the working electrode.
The method ... wherein the working electrode comprises a titanium foil.
The method ... wherein the counter electrode comprises a platinum foil.
(There is more to the "Claims" section; but, it's all just variations on the same theme.)
Field and Summary: The present invention concerns fabrication of highly-ordered TiO2 nanotube-arrays of great length and more particularly concerns vertically oriented titanium oxide nanotube arrays exhibiting array lengths from 10 .mu.m and in excess of 1000 .mu.m.
Vertically oriented, highly ordered TiO2 nanotube arrays made by anodization of Ti thin or thick films are of increasing importance due to their impressive properties in variety of applications including dye sensitized solar cells, hydrogen generation by water photoelectrolysis (and) photocatalysis".
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And, although Carbon Dioxide, and it's recycling into hydrocarbons, as in the above-cited "United States Patent Application 20100213046 - Nanotube ... Photocatalytic Conversion of Carbon Dioxide", isn't mentioned specifically, we submit that it is the above "photocatalysis" function for which the "Highly Ordered Titania Nanotube Arrays" of our subject herein, "United States Patent Application 20100187172", are most intended.
And, that couples perfectly with the above-specified "hydrogen generation by water photoelectrolysis"; all which lead to the recombination of the of the Hydrogen and the Carbon Dioxide, as in "United States Patent Application 20100213046 - Nanotube ... Photocatalytic Conversion of Carbon Dioxide", "into products such as hydrocarbons and hydrocarbon-containing products".