The Physics of Storytelling

The living end of characters tells a story. As our eyes move from left to right across its sweep, the story's words leap translated into our imagination from start to finish. It's not just visual though. Read aloud, spoken stories too have living ends -- a beginning and an end heard just now.

Elvis-"Unchained Melody"

RIP (1935-1977)

"They're Gonna Put Y'all Back In Chains!"

I'm just being sardonic...[hope nobody saw that]

Zirconium Rhymes With Titanium

Zirconium has a long, illustrious history in jewelery. The element's name derives from an ancient word for the gemstone, zircon.  The element is more commonly found in cubic zirconia, which--thanks to the Soviet method for making it using the so-called skull process--is cheap and plentiful.

Zirconium rhymes with titanium. Often, such transition-metal family members mimic each other. Zirconium, like titanium, is a valuable catalyst for making plastics. I know--yawn. But catalysis is an intellectually interesting aspect of chemistry--one which has "real-life" analogy--much like status quo and change.

Catalysts are classified as "heterogeneous" or "homogeneous" depending on whether they mix freely with hoi polloi substrates. "Heterogeneous" means that the catalyst stays in a different phase than whatever it's working on--e.g., a catalytic converter working on gas phase exhaust. Homogeneous catalysts swim in a liquid phase like everything else around it--in a single phase.

First generation Ziegler-Natta catalysts were heterogeneous. Catalysis happened at the edges or face of a chunk or pellet.  Obviously, a lot of unused catalyst lies buried inside- and is wasted. Homogeneous catalysts are known for their "atom efficiency"-- a concept that becomes more important for rarer platinum group metals.

Amba Schooled Me (again)

Isambard Kingdom Brunel (1806-1859)

While on the topic, the man who built the SS Great Eastern (and the Great Western before her) was Isambard Kingdom Brunel.  There he is, pictured above, in a photo which might have stoked the rage and scorn of Dickensian socialists. Yet today, Brunel ranks highly in polls of "Greatest Britons."

I put this here to celebrate another wealth maker and also to note how Brunel exploited something which Amba schooled me on a few months ago: Surface area to volume ratio.  As a shipbuilder, Brunel understood that the carrying capacity of a ship increases by volume, while the water resistance (friction) only increases with the submerged area of its dimensions. This meant that large ships were intrinsically more fuel efficient, which was very important for long voyages across the Atlantic.

Sex, Blogs, and Videotapes

Most any lengthy composition has a sequence, including things as disparate as polymers, novels, films, or even a blog. All these different things are sequentially pieced together from smaller subunits. For polymers, the subunits are monomers, for novels they are alphabet characters, for films and videotapes, they are "frames," and for blogs, they are separate posts (which themselves comprise a smaller sequence of characters).

It might be fun to explore the mechanics of stringing together novels, films, and blogs, etc. For polymers, I already mentioned "step growth polymerization" back here, describing how Wallace Carothers mastered the art of making long-chain synthetic polymers like nylon and neoprene. One way for a non-chemist to visualize step-growth polymerization is to imagine a very large group of unattached people, each willing to reach out and join hands with another to begin forming a human chain. Imagine how this must work at the beginning of the process. All are separate. In a first step, two people get together, each joining just one hand to make a pair, but each leaving one hand free. Now that pair could get together with another like pair to make a chain of four, but it's unlikely to do so because in a sea of singletons it's far more likely that the first pair will just hook up with another single person to make a trio. Again, that's not a choice thing -- it's a statistical thing because the number of available singletons far exceeds the number of available pairs -- at first. Look at the chain growth profile labeled "step-growth" in this chart (the red curve): 

For step-growth polymerization, not until the very end of the coupling orgy do the relative amounts of already linked members far outnumber the available remaining singletons and the daisy-chaining really takes off because having consumed all the singletons, the short chains must join hands with the ends of other chains. In the graph, the step-growth mechanism is contrasted with the living chain growth mechanism (straight line) which grows steadily. An example of the living growth chain mechanism is the Zeigler-Natta mechanism mentioned back here. Comment threads on blogs are also like "living" polymers.

Taking a closer look at the handholding analogy, it's a sanitized whitewash of what's really going on. The monomers in nylon are really "gendered" i.e. there are two types of monomers being joined: there is a "male" monomer, 1,6-diaminohexane which looks like this:

and a female monomer, 1,6-dicarboxyhexane (also called adipic acid) which looks like this:

I've already called attention to the "male" nature of amines, and the "female" nature of acids here. If that analogy bothers you, think instead of plugs and sockets or hands and gloves.

Thanks Again, Carol!

Carol Herman wrote in the comments here:

I guess chemists mistake the fact that you can line elements up in a row ... with the same sort of detail you could do with human beings.

I don't see it as a mistake--just being very analytical with the world. No more harm than taking the letters of a sentence and reordering them. For example, the letters of "SEE SPOT RUN" become E₂NOPRS₂TU

The converse of analysis in chemistry is synthesis, but reverse engineering "E₂NOPRS₂TU" back into SEE SPOT RUN requires creativity, insight (and the use of spaces).

A novel's story is defined by a very long sequence of characters set down neatly on a series of pages. A chemist could chop that novel up into a "formula" having just 24 unique characters. Each novel would have a unique formula.

Humans are analytically defined by their DNA, which also is a sequence of encoded information, like a series of characters in a book. But humans are much, much more than just their sequence of base pairs, don't you think?

Ironically, it is a very "Jurassic" question.

Added: Jason, in the comments, pointed out that I neglected the "T" in my formula, so I fixed it.

Blessed Are The Wealth Makers

Wallace Hume Carothers (1896-1937)

DuPont made a fortune selling things like gunpowder and nitrocellulose to warring governments (mainly to our own) up through and including the First World War. During the roaring 1920s (and flush with cash before the crash) they decided to pursue pure research into material science and established a new division at their fledgling Experimental Station located near Wilmington, Delaware.

The company hired a young PhD chemist named Wallace Carothers to start up a new group. Carothers was fascinated by long chain macromolecules ubiquitous in nature but which had only recently been recognized as "polymers." With the exception of Bakelite, the first synthetic plastic,* other synthetic polymers were unheard of, let alone commercially successful.

DuPont's research gamble paid off and Carothers and his group brought the company enormous success, first with the serendipitous discovery of neoprene, the first synthetic rubber, and then with nylon. Neoprene and nylon were tangible wealth creation: making things of value from what were, at the time, essentially waste products.

Nylon was Carothers' baby. Not only did he invent a synthetic replacement for silk, he purposefully developed a new method of making polymers called step-growth polymerization. He used the same durable type of linkages used by proteins (amide bonds), mimicking nature. Nylon was the first synthetic fabric and was commercialized around 1938, just in time to replace Asian silk which, along with natural rubber, went missing during the Second World War.

We have a lot to thank Carothers for but he didn't stick around. He checked out early, killing himself in 1937.
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* I have two items made from Bakelite: One is a late 1940's era Viewmaster device and the other is my father's old Kit-Cat clock which I described here. Both of these items have the characteristic fragility and tendency to chip common to Bakelite.

Meet the Priest who invented Flubber

Remember the storyline from Walt Disney's The Absent Minded Professor(1961)?  Fred MacMurray played a small Midwestern college chemistry professor who invented a miraculous substance which he named Flubber. He saved the football team and got the girl in the end. I think I found the real-life embodiment-well, forget the getting the girl part and focus on the chemistry and small midwestern university parts.

Reverend Julius Nieuwland (1878-1936)

I ran across the name Julius Nieuwland recently. Nieuwland was a priest and professor at Notre Dame University. As part of his Ph.D research, Nieuwland discovered Lewisite which was produced in tonnage quantitites by the U.S. during World War I as a poison gas.  Nieuwland had nothing to do with this application and distanced himself from the molecule (it's named for an enthusiastic supporter of gas warfare, named Lewis). Later, as a professor of organic chemistry at Notre Dame, Nieuwland successfully polymerized acetylene into divinylacetylene, laying the groundwork for the discovery of neoprene by Du Pont.

One of Nieuwland's more famous students was Knute Rockne, which even explains the football part of the otherwise bizarre Flubber story.

How Titanium Gets All Touchy-Feely with Carbon

A titanium chloride catalyst holds one end of the growing polymer chain. The same titanium atom simultaneously binds another incoming ethylene and stabilizes the contortions leading to the insertion of the next link into the growing chain. Titanium does this by polarizing ethylene's electrons while stabilizing a migration:



Original is here


Polarization, followed by attack, followed by depolarization...polarization, followed by attack, followed by depolarization...polarization, followed by attack, followed by depolarization... link

Karl Ziegler: "Consequences and Development of an Invention"

Karl Ziegler, German chemist (1898-1973)

Karl Ziegler, then director of the Max-Planck-Institute-for Coal Research, describing what he and co-workers discovered ten years prior to winning the 1963 Nobel Prize in Chemistry:

The catalyst is prepared simply by simultaneously pouring, with exclusion of air, two liquid materials into about two liters of a gasoline-like hydrocarbon, after which ethylene is introduced, while stirring. The gas is absorbed quickly; within an hour one can easily introduce 300-400 liters of ethylene into the two liters of liquid. At the same time, a solid substance precipitates, and can scarcely be stirred anymore. If the brown catalyst* is then destroyed, by the addition of some alcohol and by the introduction of air, the precipitate becomes snow-white and can be filtered off. In its final state it will accumulate in amounts of 300-500 g, as a dry, white powder.

~Karl Ziegler "Consequences and development of an invention"

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*The two co-catalysts were titanium and aluminum chlorides

Polyethylene had been known earlier. A British company, ICI, held patents for what they called "polythene" (hmm, maybe related to the Beatles' "plasticene"?), but ICI's polyethylene was different animal than Ziegler's polyethylene. The difference is at the atomic level. Though both plastics were polymers of ethylene, the older, inferior product was highly branched:

Ziegler's new process for making polyethylene essentially made perfectly linear chains of polymer with very little branching. The bulk properties of the two were markedly different. The density differences are akin to what one expects from trying to pack together a bunch of branches versus bunches of straight sticks.

Ziegler and his Institute became independently wealthy as the plastic age began in earnest.

Get Your Carbs Here!

A single blogpost will just not cut it for carbon, the 6th element. There are so many interesting little sub-topics to cover like diamonds, graphite, buckyballs, and nanotubes. But that wouldn't even begin to touch on compounds, e.g., the hydrocarbons, which give us energy and which also fuel human conflicts past, present and future. And then there's carbon combining with other elements that I haven't reached yet- elements like nitrogen and oxygen: hello, CO₂ anyone? Of course that wouldn't get us to carbohydrates or even amino acids, let alone to proteins and things that make up living creatures. I'll probably end up doing several blog posts on carbon, but also keep moving ahead.

Many chemists fall so in love with carbon that they never get past it. Those chemists are called organic chemists. To help understand why carbon is so special, consider a "carbo-centric" version of the periodic table which any Organiker should love:

original

That chart used to be standard fare at German universities (and let's face it: until the end of WW II, the Germans were organic chemistry). Notice how carbon sits dead center in a row of nine elements, having an equal number of elements to its right and to its left. Here is that first row or period again, pulled out of the chart:

    He     Li    Be     B      C      N     O     F     Ne

Carbon is the first element beyond helium that is found (practically) pure in the elemental state. In general, when commingling, elements tend to gain or lose valence electrons to resemble the nearest noble gas: elements to the left of carbon (e.g., Li⁺, Be²⁺) achieve the electronic nobility of helium by doffing one or two electrons respectively; elements to the right (O^2-, F^-) achieve the nearest noble gas configuration of neon by gaining one or two electrons; elements in the middle (B, C, N) tend to neither completely gain nor to lose electrons, but rather, to share electrons with other elements. These tendencies are a consequence of electronegativity. Carbon also forms so many compounds because of catenation. Catenation is just a fancy latinate word for "linking together"-something that carbon is good at doing, especially with itself.

Returning to the carbo-centric periodic table above, note that there is a similar row or period centered around silicon:

    Ne    Na     Mg    Al     Si      P      S      Cl    Ar

One might ask whether a similarly rich silicon chemistry exists. The short answer is no, because silicon can't self-catenate like carbon can.  Silicone polymers require the insertion of one oxygen atom between silicon "monomers." But some might argue that silicon-based life, created in our own image, has just begun to evolve--it just finds our oxygen-rich environment too hostile.