Tuesday, August 6, 2019

Expensive but worth it

Battle of the Titans, attributed to Francesco Allegrini (Metropolitan Museum of Art)

      Cornwall, in the southwest of England, has sandy beaches, complete with surfing and, I was surprised to discover when I visited, palm trees..
      And in that sand, titanium, first noticed by one Rev. William Gregor in 1791, though he wasn't able to identity the black sand he had found, leaving it to a more skilled German scientist, Martin Heinrich Klaproth, who discovered the metal independently in 1795 and named it titanium, after the Titans of Greek mythology because, to him, the name had no meaning and therefore "could give no rise to any erroneous idea."
     If you're wondering what sent me down this particular rabbit hole, blame Jack, a reader—among hundreds who wrote in with their thoughts, experiences and good wishes last week during my three-part series on spine surgery, thank you all very much—who wrote:
      "Who knew element 22 would be your blessing."
      Element 22 is titanium, which I mentioned because it is a cool-sounding, Space Age metal. Which was all I knew about the substance, though that "22" reminded me that titanium, as opposed to, say, steel, is an element, with its own atomic number (any guesses? C'mon. Think hard. You've had a hint. . . Sigh: 22). 
     An atomic number, is you remember your high school physics, is the number of protons at the nucleus of an atom. Hydrogen has one proton, thus its atomic number is 1. And titanium has .... anybody? ... 22, putting it between scandium, 21, and vanadium, 23, on the Periodic Table. 
     It is indeed a cool substance. Stronger than steel but almost 50 percent lighter, titanium is used mostly in airplane parts—a Boeing 747 engine has 9,000 pounds of titanium—both  engines and airframes—about 66 percent of titanium processed—with the rest going into chemical plant pipes and valves, expensive wristwatches and, let's not forget, medical devices. 
      So how come did it come about to be used to shore up balky spines?
     "In the 1950s, surgeons noted that titanium metal was ideal for pinning together broken bones," notes my go-to reference on these matters, John Emsley's excellent, dare I say, invaluable book "Nature's Building Blocks: An A-Z Guide to the Elements" (Oxford: 2001). "It resists corrosion, bonds well to bone and is not rejected by the body. Hip and knee replacements, pace-makers, bone-plates and screws, and cranial plates for skull fractures, can be made of titanium and remain in place for up to 20 years."
     "Up to 20 years?" Sheesh, now they tel me. Nobody mentioned that before. You mean I have to go through this again, and in my late 70s at that? Oh well, I guess I'll worry about it in 2039.
      What else? That black sand that Rev. Gregor discovered wasn't pure titanium, of course, but titanium oxide—TiO2, or one atom of titanium bonded with two of oxygen, which are very useful in covering things up, thus is found in paint (where it replaced lead, fallen from favor after it was discovered to poison people) to lipstick to sunscreen. 
     Not to take anything away from Gregor, an amateur chemist, but someone was bound to find it: titanium is the 9th most common element on earth, making up .44 percent of the crust, and is found in most rocks, sand, clay not to mention most plants, animals and stars in the night sky. 
      Titanium shows up in some odd places: titanium tetrachloride is used in smokescreens and skywriting because it puts out dense smoke when mixed with water. The star in a blue star sapphire is due to titanium. 
    I should wind this up before I go completely into the weeds, but can't before I point out that Frank Gehry's masterwork, the Guggenheim Museum in Bilbao, Spain, is covered with 33,000 square meters of pure titanium. Local yokel that I am, my immediate thought was to wonder whether that means our own Pritzker Bandshell, also designed by Gehry, is also titanium. No such luck: stainless steel, no doubt as an economy move. And maybe a smart one. While prices vary according to grade, titanium, is very expensive to produce, roughly 100 times the cost of stainless steel. 
     "It's use has been thwarted by its cost," diplomatically noted Michigan's Titanium Processing Center. But not in my case: nothing but the best for my spine. 

11 comments:

  1. Thanks for the interesting article. Seems like titanium is some amazing stuff with lots of interesting applications. A couple science notes for you:

    Protons along with neutrons actually make up the nucleus of an atom. It is electrons that orbit the nucleus. Protons and electrons have equal but opposite charges and in a neutral atom the number of electrons equals the number of protons.

    It's not clear to me whether you are claiming that titanium is found in most stars in the night sky, but as far as I know such a claim would be inaccurate. For most a star's life cycle, it fuses hydrogen into helium. For stars with the lowest mass that's it. For stars of mass similar to our sun, they will eventually go on to fuse helium into carbon and then oxygen before they expire. Massive stars go on to fuse carbon into heavier elements including titanium and up to iron (atomic number 26). Compared to how long it takes to fuse the hydrogen into helium, the time span where titanium and ultimately iron are fused is over in the blink of an eye. Elements heavier than iron are only formed by super nova.

    The upshot is that while there is titanium in some stars, it would only be found in massive stars at the very end of their life. If this subject is of further interest to you, there is an excellent YouTube series called Crash Course Astronomy that explains it all and more in a straightforward manner for the layman. Episode 31 on High Mass Stars is particularly pertinent to the stellar fusion of elements.

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    1. I'm not quite following you. I left out neutrons because they aren't germane. The definition of the atomic number is the number of protons orbiting the nuclear. I believe the number of neutrons is the same, but didn't feel like sailing off in that direction.

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    2. It is true that the atomic number of an atom is given by the number of protons in one of its atoms. My point is that protons along with neutrons are the components that make up the nucleus of the atom. Protons do not orbit the nucleus because protons along with neutrons are the nucleus.

      It is an atom's electrons that are said to orbit its nucleus. The protons and neutrons are held together in the nucleus by the strong nuclear force. The negatively charged electrons are attracted to the positively charged nucleus by electromagnetic force. The space taken up by the nucleus is a small fraction of the size of an atom - on the order of 1/100,000.

      After further investigation, I did find that protons could be said to "move" within the nucleus. Though movement within an atom is really described by quantum physics (not a strong suit of mine) so concepts like a physical position in space or an orbital path are not exactly precise or analogous to our observable world.

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    3. I have rethought my comments on the claim that most stars contain titanium. Stars that formed at the beginning of the universe did consist of mostly hydrogen and helium. Apparently lithium and trace amounts of beryllium would also be present. There would not be titanium because that has to be formed at the end of the life cycle of massive stars like I described.

      That said, not all stars were formed at the beginning of the universe. Stars are still forming today wherever large clouds of gas and dust are pulled together by gravity. Some of the dust would contain heavier elements including titanium produced by earlier generation stars and then spread into the universe when those stars violently explode in a supernova. Our sun is such a later generation star that has a relatively high metal content. As you sometimes write in other columns, "we regret the error."

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  2. I is remembering High School chemistry where we were taught electrons orbited the nucleus, the number of protons in the nucleus is the atomic number, and the number of neutrons plus protons was an approximation of the atomic weight. Now if you ever had an MRI, or been present when one was being conducted, you may recall a strict regimen of removing metallic items, to prevent people and machine from being torn asunder. Don't worry, titanium is non magnetic, so as long as your implant is pure titanium and has no impurities, everything will be okay.

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  3. A good science class refresher.

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  4. The SR-71 spy plane, designed to fly over the Soviet Union is mostly titanium. Ironically, the best part is that the titanium came from the then Soviet Union, although the Soviets didn't know that. It was Lockheed that figured out how to make the metal useful, as no one had ever made anything large with titanium before that.

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  5. Have two titanium heart valves installed in 1992, said to last 15 years, 26 years later still strong. You won't be going through that again. And neither will I.

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  6. Hey, while we're talking metallurgy, some stainless steels are magnetic while others are not. You need to be sure which one is implanted in/worn on your body prior to rude happenings in an MRI.

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  7. Most importantly. ..you wont set off airport alarms and can get MRIs

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  8. Needs to send some of that DMA over to the Cubs.

    john

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