John, consider that under ideal conditions, 20 lbs of thermite will produce approximately ½ liter of liquid iron.
The amount of liquid metal seen streaming from the NW corner of WTC 2 was considerably more than 1/2 liter. if thermite was the source of that molten metal,, then one would have to conclude that there was greater than 20 lbs of thermite at work.
In your experiment, you observed that the reaction of 20 lbs of thermite “created an enormous, bright as the sun fireball.”
In looking at the pictures of the fires in the WTC towers, I can see the fire burning, but I can’t see any evidence of a “huge arc bright fireball resulted that was seen all over the desert..”
You state “After having successfully experimented with the stuff, I can tell you that I have a strong understanding of thermite’s violent effect on steel.” Can you justify this violent effect with t he neat, straight, diagonal cut lines on the columns that have been touted to be the result of thermite?
Sure Howard. I believe that military grade thermate cutter charges, (sol-gel thermate) were used in shaped fashion to bring down a portion of the main support columns in the interior of the building ....that's why we don't see it working, except for the cut remains in a few photos at ground zero later on. . Perhaps some charges were placed near the exterior supports as well. Thermate cuts faster and burns hotter than thermite. I was told by a demolition expert who I consulted with, that there are smaller and higher yield explosives than RDX, typically used in controlled demolitions. A combination of exotic incendiaries and explosives could have been used. I haven't experimented with thermite enough to calculate the optimum burn rate to quantity ratio. I work within the permit process.
Matthew, Steven Jones has found evidence in WTC 1&2 dust samples and slag from surviving steel, of thermite or thermate. Many firefighters had noted the presence of flowing metal in the lower levels of all 3 collapsed WTC buildings. Only an incendiary like thermite can do this to steel...raise it to its melting point of about 3000 F. Thermite and thermate don't make much of a sound when burned. My video will show that when I complete the project. I plan on melting through much thicker steel in future experiments. I'd like to try steel at the thickness of lower WTC support columns, which I believe were at least 4" thick or greater. There are patents for thermate cutter charges. Shaped RDX charges are routinely used by demo contractors. I developed a crude shaped thermite device and it worked very well. I believe I can make one that will cut vertically too. I don't doubt that now.
Don't let the lying trolls get you down John. You did something, which is a heck of a lot better than doing nothing. Perhaps your original plan can still be carried out in the future on private property, televised on the internet.
John, you state: “I believe that military grade thermate cutter charges, (sol-gel thermate) were used in shaped fashion”
OK, first of all, as it has been pointed out, the existence of a functional sol-gel thermate charge has not even been proven to exist, much less work the way you suppose it does.
It seems to me that you do not have a clear understanding on how shaped charges work. Shaped charge explosives are designed to that the shock wave of the blast focuses a jet of reactive gas (oxygen) in a narrow cone.
This process is incompatible with the thermite reaction. No oxygen is released by the thermite reaction, and it takes oxygen to cut through steel.
“. . . to bring down a portion of the main support columns in the interior of the building ....that's why we don't see it working, except for the cut remains in a few photos at ground zero later on.”
The photos that supposedly show a thermite cut are of columns at the very base of the building. If these were cut, leading to the collapse, then wouldn’t the collapse have started at the base and not the top of the building?
You then speculate: “Perhaps some charges were placed near the exterior supports as well.”
Then why didn’t we see evidence of these going off? Surely the bright light liberated by a thermite reaction would have been visible somewhere on the exterior of the building?
Furthermore, the photo that shows the molten aluminum or lead pouring out of the corner of the building is often cited as an example of the termite reaction. This was on the impact/ fire floor. I think it would be safe to say that at that point, most of the interior walls had been stripped away by the impact and fire. Why don’t we see the bright light then?
Anyway, John, best of luck to you, and I hope that when someday you realize that the 9/11 truth movement is based on political views and not science, that you will have no regrets over this. It sounds like you had fun trying and that is the most important thing.
Howard, shaped thermite charges are in fact possible. My devices were shaped and directed the flow of thermite where I wanted it. The video will show this. Spectre Physics in Florida makes shaped thermite cutters. My project was primarily an art show. I went for safety based upon conditions at the time and the expense of possibly having to remove a large and extemely heavy 'fused' object from the desert.
Considering how violently the thermite burns in your "test", on a scale of 1 to ten, how likely do you think it is that thermite is capable of making a neat diagonal cut, seeing as you did not actually perform the demonstration of diagonal cutting charges in action.
If you are going to produce a giant steel sculpture with the words truth on it, tell everyone that you are going to cut it with thermite charges, cutting diagonally, to make NEAT cuts the way an oxy acetylene flame cutter would, then the least you can try and do, is actually keep to your word.
You didn't do that.
Therefore I asked a straightforward question:
Considering how violently the thermite burns in your "test", on a scale of 1 to ten, how likely do YOU think it is that thermite is capable of making a neat diagonal cut, seeing as you did not actually perform the demonstration of diagonal cutting charges in action.
john-- thank you for your amazing artwork on the playa! i loved it. i visited it and spent time with it, experiencing a deep gratitude for your existence, though i've never met you.
you are an inspiration to thousands.
thank you for your courage in general to stand for the truth in the face of such huge and powerful lies.
to the skeptics on this board: the 9-11 Truth Movement is largely comprised not of people who have precise answers, but of everyday people who know the official story not only smells fishy but is factually impossible. some of us are conducting mental or physical experiments to try to figure out what really did happen. others are dedicated to bringing about a real investigation, since 9-11 was never heard as a crime in any court of law; nothing about 9-11 was ever proven, no witnesses or evidence was ever presented. indeed the evidence was spirited away and those with the most to gain not only refused to testify but were empowered to fashion the crime narrative, to revise it, and to tell it countless times in the courtroom of public opinion. they have told their version of the story many times. it may be enough for you. it isn't for those of us in the movement for truth.
john created at burningman a wonderful work of art that not only was visually beautiful and inspiring, but in no uncertain terms asked the viewer to question for himself how steel could collapse neatly, perfectly, from asymmetric fires burning only hydrocarbons.
I think it is very telling when someone associated with a "truth" movement feels the need to delete comments that are essential polite but critical.
I suspect that you have no interest in truth at all. I know you'll delete this as well, but I hope you give some thought to what these actions should tell you about yourself.
Matthew, you consistently left a string of negative comments. If you have some useful insights to contribute, I'll leave them, otherwise expect the negative stuff to end up in the trash
The 'official' story is actually a consensus amongst thousands of trained structural engineers.
Steel begins losing tensile strength at just three hundred degrees C and carries on steadily losing strength up to 800 degrees C, after that the decrease in tensile strength continues at a slower rate.
At 600 degrees C steel has roughly half the tensile strength it would have at room temperature.
The structural integrity of the twin towers was comprimised by plane crashes and further weakened by fire.
The thermite theory is ridiculous. Metal is maleable, when metal gets hot it softens before melting.
Check this out: http://www.corusconstruction.com/en/design_and_innovation/structural_design/fire/steelwork_fire_resistance/
I'm a trained engineer, I've used flame cutters to cut steel. I've studied structural design principles such as bending moments.
I'm sorry Pete, Underwriters Labs and Kevin Ryan's testing of heat applied to similar to WTC steel supports and floor joists at excess of temps at actual event prove you wrong. See http://ae911truth.org
I am on the opposite side of the fence politically, but I do love TruthBurn. I'm sure glad you guys decided not to try to cut TRUTH off at the knees with your thermite.
Whatever looked like "molten metal" at the WTC is also seen at the Pentagon. http://thewebfairy.com/911/pentagon/thermite.htm
I expect some form of nanoparticle thermite was used in the fuel/air a-neutronic bombs that created the plane shape hole. The nuclear yellowtop fireball matches the one seen in the thermite video: http://thewebfairy.com/911/thermite Thanks. Your invocation to Truth is an inspiration on it's own.
Thanks Rosalee. Check out this gov post about nano explosives:
ONE thousand years ago, black powder was prepared by grinding saltpeter, charcoal, and sulfur together into a coarse powder using a mortar and pestle. Since then, the equipment for making energetic materials-explosives, propellants, and pyrotechnics-has evolved considerably, but the basic process for making these materials has remained the same. That, however, is changing, thanks to an explosive combination of sol-gel chemistry and modern-day energetic materials research. At Livermore Laboratory, sol-gel chemistry-the same process used to make aerogels or "frozen smoke" (see S&TR, November/December 1995)—has been the key to creating energetic materials with improved, exceptional, or entirely new properties. This energetic materials breakthrough was engineered by Randy Simpson, director of the Energetic Materials Center; synthetic chemists Tom Tillotson, Alex Gash, and Joe Satcher; and physicist Lawrence Hrubesh. These new materials have structures that can be controlled on the nanometer (billionth-of-a-meter) scale. Simpson explains, "In general, the smaller the size of the materials being combined, the better the properties of energetic materials. Since these `nanostructures' are formed with particles on the nanometer scale, the performance can be improved over materials with particles the size of grains of sand or of powdered sugar. In addition, these `nanocomposite' materials can be easier and much safer to make than those made with traditional methods."
Energy Density vs Power, the Traditional Tradeoffs Energetic materials are substances that store energy chemically. For instance, oxygen, by itself, is not an energetic material, and neither is fuel such as gasoline. But a combination of oxygen and fuel is. Energetic materials are made in two ways. The first is by physically mixing solid oxidizers and fuels, a process that, in its basics, has remained virtually unchanged for centuries. Such a process results in a composite energetic material such as black powder. The second process involves creating a monomolecular energetic material, such as TNT, in which each molecule contains an oxidizing component and a fuel component. For the composites, the total energy can be much greater than that of monomolecular materials. However, the rate at which this energy is released is relatively slow when compared to the release rate of monomolecular materials. Monomolecular materials such as TNT work fast and thus have greater power than composites, but they have only moderate energy densities-commonly half those of composites. "Greater energy densities versus greater power—that's been the traditional trade-off," says Simpson. "With our new process, however, we're mixing at molecular scales, using grains the size of tens to hundreds of molecules. That can give us the best of both worlds-higher energy densities and high power as well."
Energetic Nanostructures in a Beaker To control the mix of oxidizer and fuel in a given material at the nanometer scale, Livermore researchers turned to sol-gel methodologies. Sol-gel chemistry involves the reactions of chemicals in solution to produce nanometer-size particles called sols. These sols are linked together to form a three-dimensional solid network or skeleton called a gel, with the remaining solution residing in the open pores of the gel. The solution can then be supercritically extracted to produce aerogels (highly porous, lightweight solids) or evaporated to create xerogels (denser porous solids). "A typical gel structure is extremely uniform because the particles and the pores between them are so small," notes Tillotson. "Such homogeneity means that the material's properties are also uniform. Our main interest in the sol-gel approach is that it will allow us to precisely control the composition and morphology of the solid at the nanometer scale so that the material's properties stay uniform throughout-something that can't be achieved with conventional techniques." Using these sol-gel-processing methods, the team derived four classes of energetic materials: energetic nanocomposites, energetic nanocrystalline materials, energetic powder-entrained materials, and energetic skeletal materials. Energetic nanocomposites have a fuel component and an oxidizer component mixed together. One example is a gel made of an oxidizer with a fuel embedded in the pores of the gel. In one such material (termed a thermite pyrotechnic), iron oxide gel reacts with metallic aluminum particles to release an enormous amount of heat. "These reactions typically produce temperatures in excess of 3,500 degrees Celsius," says Simpson. Thermites are used for many applications ranging from igniters in automobile airbags to welding. Such thermites have traditionally been produced by mixing fine powders of metal oxides and metal fuels. "Conventionally, mixing these fine powders can result in an extreme fire hazard. Sol-gel methods can reduce that hazard while dispersing extremely small particles in a uniform way not possible through normal processing methods," adds Simpson. The Livermore team has successfully synthesized metal oxide gels from a myriad elements. At least in the case of metal oxides, sol-gel chemistry can be applied to a majority of elements in the periodic table. In energetic nanocrystalline composites, the energetic material is grown within the pores of an inert gel rather than mixed into it. One way to initiate the growth is to dissolve the energetic material in the solvent used to control the density of the resulting gel. After the gel is formed, the energetic material in the pore fluid is induced to crystallize within the pores. The Livermore team synthesized nanocrystalline composites in a silica matrix with pores containing the high explosive RDX or PETN. The resulting structures contain crystals so small that they do not scatter visible light and are semitransparent. In the powder-entraining method, a high concentration of energetic powders (90 percent by weight) is loaded within a support matrix (for example, silica) that takes up a correspondingly small mass. Highly loaded energetic materials are used in a variety of applications, including initiators and detonators. Manufacturing this type of energetic material using current processing technologies is often difficult. Producing detonators with pressed powders is a slow manufacturing process, mixing two or more powders homogeneously is difficult, and precise geometric shapes are not easy to produce. Also, pressing powders is a hazardous process. Many of these problems may be overcome with the sol-gel process. One result is that the sol-gel explosives formed by adding energetic powders are much less sensitive than those produced by conventional methods. "These results were surprising because conventionally mixed powders generally exhibit increased sensitivity when silica powders are added," says Simpson. "We're still exploring the reasons for this decreased sensitivity, but it appears to be generally true with sol-gel-derived energetic materials." The final class of energetic material produced by sol-gel methods is energetic skeletal materials. Basically, the sol-gel chemistry is used to create a skeletal matrix, which is itself energetic. Satcher thinks that it might also be possible to form a nanostructure made up of a fuel-oxidizer skeleton with precise stoichiometry (the numerical relationship of elements and compounds as reactants and products in a chemical reaction). "This is something we are still looking into," he adds. In addition to providing materials that have high energy density and are extremely powerful, sol-gel methodologies offer more safe and stable processing. For instance, the materials can be cast to shape or do not require the hazardous machining techniques required by materials that cannot be cast.
Future Looks Bright Right now, making energetic materials using the sol-gel technique is in the basic research stage, but results look promising. "Many compositions depend on a simple, inexpensive procedure that we can basically do in an ordinary chemistry beaker," says Tillotson. He notes that the practical advantages of these materials are encouraging. Some of the pluses are less sensitivity, safe mixing, low-temperature synthesis, safe handling, safe processing, and homogeneity leading to better performance. "We've just begun to explore the possibilities for these new materials and the methodologies that produced them," adds Simpson. "This approach is like a new baby—it has lots of potential. The ramifications are still largely unknown." —Ann Parker Key Words: aerogel, energetic materials, explosives, nanocomposites, PETN, propellants, pyrotechnics, RDX, sol-gel, xerogel. For more information contact Randy Simpson (925) 423-0379 (simpson5@llnl.gov). ________________________________________ Back to October 2000 // Science & Technology Review 2000 // Science & Technology Review // LLNL Homepage
furthermore you do not appear to have checked out the information on steel I gave you.
"Recent international research has shown, however, that the limiting (failure) temperature of a structural steel member is not fixed at 550ºC but varies according to two factors, the temperature profile and the load."
http://tinyurl.com/yzv6fp
Fire makes steel soft, but the load makes it sag, and fail.
fires have never brought down a steel frame building. Why should wtc be any different? Why not entertain the explosive demolition hypothesis? Previous comment deleted because of ad hominem attack and poor taste.
30 comments:
John, consider that under ideal conditions, 20 lbs of thermite will produce approximately ½ liter of liquid iron.
The amount of liquid metal seen streaming from the NW corner of WTC 2 was considerably more than 1/2 liter. if thermite was the source of that molten metal,, then one would have to conclude that there was greater than 20 lbs of thermite at work.
In your experiment, you observed that the reaction of 20 lbs of thermite “created an enormous, bright as the sun fireball.”
In looking at the pictures of the fires in the WTC towers, I can see the fire burning, but I can’t see any evidence of a “huge arc bright fireball resulted that was seen all over the desert..”
You state “After having successfully experimented with the stuff, I can tell you that I have a strong understanding of thermite’s violent effect on steel.” Can you justify this violent effect with t he neat, straight, diagonal cut lines on the columns that have been touted to be the result of thermite?
Sure Howard.
I believe that military grade thermate cutter charges, (sol-gel thermate) were used in shaped fashion to bring down a portion of the main support columns in the interior of the building ....that's why we don't see it working, except for the cut remains in a few photos at ground zero later on. . Perhaps some charges were placed near the exterior supports as well. Thermate cuts faster and burns hotter than thermite. I was told by a demolition expert who I consulted with, that there are smaller and higher yield explosives than RDX, typically used in controlled demolitions. A combination of exotic incendiaries and explosives could have been used. I haven't experimented with thermite enough to calculate the optimum burn rate to quantity ratio. I work within the permit process.
Matthew, Steven Jones has found evidence in WTC 1&2 dust samples and slag from surviving steel, of thermite or thermate. Many firefighters had noted the presence of flowing metal in the lower levels of all 3 collapsed WTC buildings. Only an incendiary like thermite can do this to steel...raise it to its melting point of about 3000 F. Thermite and thermate don't make much of a sound when burned. My video will show that when I complete the project. I plan on melting through much thicker steel in future experiments. I'd like to try steel at the thickness of lower WTC support columns, which I believe were at least 4" thick or greater.
There are patents for thermate cutter charges. Shaped RDX charges are routinely used by demo contractors. I developed a crude shaped thermite device and it worked very well. I believe I can make one that will cut vertically too. I don't doubt that now.
Er, I thought you were going to try cutting the sculpture, in two places, not burn thermite underneath it !
Never mind distracting people with 911 'truth' video's afterwards, your own project has debunked the thermite theories lol
Don't let the lying trolls get you down John. You did something, which is a heck of a lot better than doing nothing. Perhaps your original plan can still be carried out in the future on private property, televised on the internet.
John, you state: “I believe that military grade thermate cutter charges, (sol-gel thermate) were used in shaped fashion”
OK, first of all, as it has been pointed out, the existence of a functional sol-gel thermate charge has not even been proven to exist, much less work the way you suppose it does.
It seems to me that you do not have a clear understanding on how shaped charges work. Shaped charge explosives are designed to that the shock wave of the blast focuses a jet of reactive gas (oxygen) in a narrow cone.
This process is incompatible with the thermite reaction. No oxygen is released by the thermite reaction, and it takes oxygen to cut through steel.
John, you state:
“. . . to bring down a portion of the main support columns in the interior of the building ....that's why we don't see it working, except for the cut remains in a few photos at ground zero later on.”
The photos that supposedly show a thermite cut are of columns at the very base of the building. If these were cut, leading to the collapse, then wouldn’t the collapse have started at the base and not the top of the building?
You then speculate: “Perhaps some charges were placed near the exterior supports as well.”
Then why didn’t we see evidence of these going off? Surely the bright light liberated by a thermite reaction would have been visible somewhere on the exterior of the building?
Furthermore, the photo that shows the molten aluminum or lead pouring out of the corner of the building is often cited as an example of the termite reaction. This was on the impact/ fire floor. I think it would be safe to say that at that point, most of the interior walls had been stripped away by the impact and fire. Why don’t we see the bright light then?
joy - What is the definition of a troll? Someone who calls someone else a liar without evidence.
Anyway, John, best of luck to you, and I hope that when someday you realize that the 9/11 truth movement is based on political views and not science, that you will have no regrets over this. It sounds like you had fun trying and that is the most important thing.
Howard, shaped thermite charges are in fact possible. My devices were shaped and directed the flow of thermite where I wanted it. The video will show this. Spectre Physics in Florida makes shaped thermite cutters. My project was primarily an art show. I went for safety based upon conditions at the time and the expense of possibly having to remove a large and extemely heavy 'fused' object from the desert.
Considering how violently the thermite burns in your "test", on a scale of 1 to ten, how likely do you think it is that thermite is capable of making a neat diagonal cut, seeing as you did not actually perform the demonstration of diagonal cutting charges in action.
http://www.spectreenterprises.net/contactUs.htm
thats not an answer...
Pete. That is an answer, do you want me to do all the work for you? Call them and find out for yourself.
If you are going to produce a giant steel sculpture with the words truth on it, tell everyone that you are going to cut it with thermite charges, cutting diagonally, to make NEAT cuts the way an oxy acetylene flame cutter would, then the least you can try and do, is actually keep to your word.
You didn't do that.
Therefore I asked a straightforward question:
Considering how violently the thermite burns in your "test", on a scale of 1 to ten, how likely do YOU think it is that thermite is capable of making a neat diagonal cut, seeing as you did not actually perform the demonstration of diagonal cutting charges in action.
john--
thank you for your amazing artwork on the playa! i loved it. i visited it and spent time with it, experiencing a deep gratitude for your existence, though i've never met you.
you are an inspiration to thousands.
thank you for your courage in general to stand for the truth in the face of such huge and powerful lies.
to the skeptics on this board: the 9-11 Truth Movement is largely comprised not of people who have precise answers, but of everyday people who know the official story not only smells fishy but is factually impossible. some of us are conducting mental or physical experiments to try to figure out what really did happen. others are dedicated to bringing about a real investigation, since 9-11 was never heard as a crime in any court of law; nothing about 9-11 was ever proven, no witnesses or evidence was ever presented. indeed the evidence was spirited away and those with the most to gain not only refused to testify but were empowered to fashion the crime narrative, to revise it, and to tell it countless times in the courtroom of public opinion. they have told their version of the story many times. it may be enough for you. it isn't for those of us in the movement for truth.
john created at burningman a wonderful work of art that not only was visually beautiful and inspiring, but in no uncertain terms asked the viewer to question for himself how steel could collapse neatly, perfectly, from asymmetric fires burning only hydrocarbons.
Thanks Tony. It was a lot of hard work and it has another life as well
I think it is very telling when someone associated with a "truth" movement feels the need to delete comments that are essential polite but critical.
I suspect that you have no interest in truth at all. I know you'll delete this as well, but I hope you give some thought to what these actions should tell you about yourself.
Matthew, you consistently left a string of negative
comments. If you have some useful insights to contribute, I'll leave them, otherwise expect the negative stuff to end up in the trash
The 'official' story is actually a consensus amongst thousands of trained structural engineers.
Steel begins losing tensile strength at just three hundred degrees C and carries on steadily losing strength up to 800 degrees C, after that the decrease in tensile strength continues at a slower rate.
At 600 degrees C steel has roughly half the tensile strength it would have at room temperature.
The structural integrity of the twin towers was comprimised by plane crashes and further weakened by fire.
The thermite theory is ridiculous.
Metal is maleable, when metal gets hot it softens before melting.
Check this out:
http://www.corusconstruction.com/en/design_and_innovation/structural_design/fire/steelwork_fire_resistance/
I'm a trained engineer, I've used flame cutters to cut steel. I've studied structural design principles such as bending moments.
link to corus steel website was too long I've shortened it:
http://tinyurl.com/yzv6fp
Check out this info on steel.
I'm sorry Pete, Underwriters Labs and Kevin Ryan's testing of heat applied to similar to WTC steel supports and floor joists at excess of temps at actual event prove you wrong.
See http://ae911truth.org
I am on the opposite side of the fence politically, but I do love TruthBurn. I'm sure glad you guys decided not to try to cut TRUTH off at the knees with your thermite.
Whatever looked like "molten metal" at the WTC is also seen at the Pentagon.
http://thewebfairy.com/911/pentagon/thermite.htm
I expect some form of nanoparticle thermite was used in the fuel/air a-neutronic bombs that created the plane shape hole. The nuclear yellowtop fireball matches the one seen in the thermite video:
http://thewebfairy.com/911/thermite
Thanks.
Your invocation to Truth is an inspiration on it's own.
Thanks Rosalee. Check out this gov post about nano explosives:
ONE thousand years ago, black powder was prepared by grinding saltpeter, charcoal, and sulfur together into a coarse powder using a mortar and pestle. Since then, the equipment for making energetic materials-explosives, propellants, and pyrotechnics-has evolved considerably, but the basic process for making these materials has remained the same. That, however, is changing, thanks to an explosive combination of sol-gel chemistry and modern-day energetic materials research.
At Livermore Laboratory, sol-gel chemistry-the same process used to make aerogels or "frozen smoke" (see S&TR, November/December 1995)—has been the key to creating energetic materials with improved, exceptional, or entirely new properties. This energetic materials breakthrough was engineered by Randy Simpson, director of the Energetic Materials Center; synthetic chemists Tom Tillotson, Alex Gash, and Joe Satcher; and physicist Lawrence Hrubesh.
These new materials have structures that can be controlled on the nanometer (billionth-of-a-meter) scale. Simpson explains, "In general, the smaller the size of the materials being combined, the better the properties of energetic materials. Since these `nanostructures' are formed with particles on the nanometer scale, the performance can be improved over materials with particles the size of grains of sand or of powdered sugar. In addition, these `nanocomposite' materials can be easier and much safer to make than those made with traditional methods."
Energy Density vs Power, the Traditional Tradeoffs
Energetic materials are substances that store energy chemically. For instance, oxygen, by itself, is not an energetic material, and neither is fuel such as gasoline. But a combination of oxygen and fuel is.
Energetic materials are made in two ways. The first is by physically mixing solid oxidizers and fuels, a process that, in its basics, has remained virtually unchanged for centuries. Such a process results in a composite energetic material such as black powder. The second process involves creating a monomolecular energetic material, such as TNT, in which each molecule contains an oxidizing component and a fuel component. For the composites, the total energy can be much greater than that of monomolecular materials. However, the rate at which this energy is released is relatively slow when compared to the release rate of monomolecular materials. Monomolecular materials such as TNT work fast and thus have greater power than composites, but they have only moderate energy densities-commonly half those of composites. "Greater energy densities versus greater power—that's been the traditional trade-off," says Simpson. "With our new process, however, we're mixing at molecular scales, using grains the size of tens to hundreds of molecules. That can give us the best of both worlds-higher energy densities and high power as well."
Energetic Nanostructures in a Beaker
To control the mix of oxidizer and fuel in a given material at the nanometer scale, Livermore researchers turned to sol-gel methodologies. Sol-gel chemistry involves the reactions of chemicals in solution to produce nanometer-size particles called sols. These sols are linked together to form a three-dimensional solid network or skeleton called a gel, with the remaining solution residing in the open pores of the gel. The solution can then be supercritically extracted to produce aerogels (highly porous, lightweight solids) or evaporated to create xerogels (denser porous solids).
"A typical gel structure is extremely uniform because the particles and the pores between them are so small," notes Tillotson. "Such homogeneity means that the material's properties are also uniform. Our main interest in the sol-gel approach is that it will allow us to precisely control the composition and morphology of the solid at the nanometer scale so that the material's properties stay uniform throughout-something that can't be achieved with conventional techniques."
Using these sol-gel-processing methods, the team derived four classes of energetic materials: energetic nanocomposites, energetic nanocrystalline materials, energetic powder-entrained materials, and energetic skeletal materials.
Energetic nanocomposites have a fuel component and an oxidizer component mixed together. One example is a gel made of an oxidizer with a fuel embedded in the pores of the gel. In one such material (termed a thermite pyrotechnic), iron oxide gel reacts with metallic aluminum particles to release an enormous amount of heat. "These reactions typically produce temperatures in excess of 3,500 degrees Celsius," says Simpson. Thermites are used for many applications ranging from igniters in automobile airbags to welding. Such thermites have traditionally been produced by mixing fine powders of metal oxides and metal fuels. "Conventionally, mixing these fine powders can result in an extreme fire hazard. Sol-gel methods can reduce that hazard while dispersing extremely small particles in a uniform way not possible through normal processing methods," adds Simpson. The Livermore team has successfully synthesized metal oxide gels from a myriad elements. At least in the case of metal oxides, sol-gel chemistry can be applied to a majority of elements in the periodic table.
In energetic nanocrystalline composites, the energetic material is grown within the pores of an inert gel rather than mixed into it. One way to initiate the growth is to dissolve the energetic material in the solvent used to control the density of the resulting gel. After the gel is formed, the energetic material in the pore fluid is induced to crystallize within the pores. The Livermore team synthesized nanocrystalline composites in a silica matrix with pores containing the high explosive RDX or PETN. The resulting structures contain crystals so small that they do not scatter visible light and are semitransparent.
In the powder-entraining method, a high concentration of energetic powders (90 percent by weight) is loaded within a support matrix (for example, silica) that takes up a correspondingly small mass. Highly loaded energetic materials are used in a variety of applications, including initiators and detonators. Manufacturing this type of energetic material using current processing technologies is often difficult. Producing detonators with pressed powders is a slow manufacturing process, mixing two or more powders homogeneously is difficult, and precise geometric shapes are not easy to produce. Also, pressing powders is a hazardous process.
Many of these problems may be overcome with the sol-gel process. One result is that the sol-gel explosives formed by adding energetic powders are much less sensitive than those produced by conventional methods. "These results were surprising because conventionally mixed powders generally exhibit increased sensitivity when silica powders are added," says Simpson. "We're still exploring the reasons for this decreased sensitivity, but it appears to be generally true with sol-gel-derived energetic materials."
The final class of energetic material produced by sol-gel methods is energetic skeletal materials. Basically, the sol-gel chemistry is used to create a skeletal matrix, which is itself energetic. Satcher thinks that it might also be possible to form a nanostructure made up of a fuel-oxidizer skeleton with precise stoichiometry (the numerical relationship of elements and compounds as reactants and products in a chemical reaction). "This is something we are still looking into," he adds. In addition to providing materials that have high energy density and are extremely powerful, sol-gel methodologies offer more safe and stable processing. For instance, the materials can be cast to shape or do not require the hazardous machining techniques required by materials that cannot be cast.
Future Looks Bright
Right now, making energetic materials using the sol-gel technique is in the basic research stage, but results look promising. "Many compositions depend on a simple, inexpensive procedure that we can basically do in an ordinary chemistry beaker," says Tillotson. He notes that the practical advantages of these materials are encouraging. Some of the pluses are less sensitivity, safe mixing, low-temperature synthesis, safe handling, safe processing, and homogeneity leading to better performance.
"We've just begun to explore the possibilities for these new materials and the methodologies that produced them," adds Simpson. "This approach is like a new baby—it has lots of potential. The ramifications are still largely unknown."
—Ann Parker
Key Words: aerogel, energetic materials, explosives, nanocomposites, PETN, propellants, pyrotechnics, RDX, sol-gel, xerogel.
For more information contact Randy Simpson (925) 423-0379 (simpson5@llnl.gov).
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Back to October 2000 // Science & Technology Review 2000 // Science & Technology Review // LLNL Homepage
furthermore you do not appear to have checked out the information on steel I gave you.
"Recent international research has shown, however, that the limiting (failure) temperature of a structural steel member is not fixed at 550ºC but varies according to two factors, the temperature profile and the load."
http://tinyurl.com/yzv6fp
Fire makes steel soft, but the load makes it sag, and fail.
fires have never brought down a steel frame building. Why should wtc be any different? Why not entertain the explosive demolition hypothesis?
Previous comment deleted because of ad hominem attack and poor taste.
"fires have never brought down a steel frame building. Why should wtc be any different"
How many buildings have been hit by commercial jets with a full tank of fuel?
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