Chemistry Blog

Jan 27

Boiling in Space: What Happens in the Absence of Gravity?

(for other entries in the Chemistry in Space series, click here)

Who knew boiling a liquid was so complicated?  When you put a pot of water on the stove or heat your reaction-in-toluene solution in an oil bath several things happen.  The liquid closest to the heating element starts to get hot.  Convection circulates the hot liquid up and the cold liquid down due to the density differences of hot and cold liquids.  Eventually, the liquid near the heating element becomes hot enough to move into the vapor phase and bubbles start to form.  Buoyancy causes the bubbles to float to the surface and pop, while more convection continues to circulate the water.  Eventually, you get a rolling boil.

Everything changes in the microgravity environment of space.  Buoyancy and convection no longer play a role.  The heated fluids no longer circulate and the bubbles no longer naturally rise to the surface.  So what happens when you try to heat a liquid to boil in microgravity?  Astronauts tested this during the course of several space shuttle missions during the 1990s.  They arrived at some very interesting conclusions.

First, the liquid nearest the heating element starts to get hot, just as it does on Earth.  But it doesn’t rise and circulate due to convection.  It just gets hotter and stays next to the heating element.  It eventually gets hot enough to move into the vapor phase, just as it does on Earth, but the bubbles don’t rise to the surface and pop.  Instead, they stay next to the heating element and coalesce into one giant bubble.  Eventually, the size of the bubble becomes larger than the heating element and there is no longer any liquid in contact with the heating element.  This insulates the liquid from the heating element and leads to a “dry out” where there is no more boiling and the temperature of the heating element “begins to soar.”

(click on the image to go to the NASA page describing Zero G Boiling and to see an awesome movie of boiling in action)

All of this is predicted by theory, but it’s nice to have the chance to do some of those proof of principle experiments for the first time ever.  It reminds me of what some of the pioneers of science must have felt when working out some of the fundamental theories of chemistry and physics that we don’t even realize we take for granted today.

An interesting variation of this experiment was conducted impromptu by an astronaut on the International Space Station in 2003.  Don Pettit* was performing repair operations using a soldering iron.  He decided to put a few milliliters of water on the hot surface.  The water droplet formed a blob around the soldering iron and kinda wobbled there.  As expected, the water heated up and began to boil.  Surprisingly, though, this time the boiling looked much similar to boiling on Earth.

My working theory is the small amount of water and the inherent jostling of the system (the soldering iron looks like it was held by hand in front of the camera) caused enough motion in the water to move the bubbles around.  The bubbles could bump into each other and coalesce.  The size of the bubbles quickly reached the surface (unlike the bulk boiling experiment described above) and were allowed to pop.  Thus, it is by accident, in my opinion, that the boiling looks like it would on Earth.  It’d be interesting to repeat the experiment with the soldering iron held steady by vice grips or something.

(click on the image to go to the NASA page on the soldering iron boiling experiment and to see an awesome movie of this microgravity microboiling in action)

Here’s an overview page of boiling in space.
Here’s the NASA page on the 1990s boiling experiments.
Here’s the NASA page on the impromptu soldering iron boiling experiment.

*Also inventor of the super awesome zero-g coffee mug.

Jan 26

DuPont Phosgene Death

Carl Daniel Fish
Carl Daniel Fish

Carl “Dan” Fish, a worker at the DuPont plant in Belle West Virginia, died this past Sunday due to phosgene exposure. Only scant details about the incident have been released by DuPont thus far, but this is what we have been told.

On Saturday afternoon a site employee was exposed to Phosgene from a leaking transfer hose. The hose was not in service when the leak occurred but did contain a small amount residual Phosgene from an earlier use. The employee was transported to the hospital by the Kanawha County Ambulance Authority for treatment and observation as part of the standard protocol for exposure to this material.

Unlike previous chemistry related deaths this has gotten the attention of Washington. Senator Rockefeller (D-WV) released a statement Monday, Rockefeller Statement on Incidents at DuPont Chemical Plant, calling for a thorough investigation of the incident. Since Rockefeller is the chairman of the Senate Commerce Committee, the committee with oversight of the facility, and being a senator from West Virginia Dupont can look forward to being under intense scrutiny.

Update 1: The senior senator from West Virginia, Robert Byrd (D-WV), has released his own statement: Byrd statement on incident at DuPont chemical plant

Update 2: It took DuPont 20 minutes to identify the chemical exposure to Metro 911 services after the initial call for an ambulance: DuPont calls: ‘Can you give me some more information?’
Audio Files: 1st Call from Dupont Advising Medical Emergency, Cpt Wallace Contacting Dupont for more info (The Charleston Gazette)

Update 3: The U.S. Chemical Safety Board voted to investigate the incident that caused a braided steel hose connected to a one-ton capacity phosgene tank to suddenly rupture. The lead investigator will be Johnnie Banks and the CSB team will arrive Tuesday at DuPont: Board Votes to Initiate Investigation on Accidents at DuPont Chemical Facility in Belle, West Virginia (CSB)

Update 4: Obituary

Update 5: From an anonymous source that I can not verify.

From what I’m told, he and another employee were walking by the tube when he heard it getting ready to bust and he shoved the other employee out of the way and he took the full brunt of it to the face and chest himself. I’m surprised they don’t mention those heroics in their statements. BTW, he was in his 50’s. He worked at that plant for 32 yrs.

Update 6: Senator Rockefeller called for a full CSB investigation into DuPont’s safety infrastructure and the facility’s compliance with emergency notification requirements to Metro 911 and federal agencies. In addition he asked for $1.6 million to create a new CSB team to alleviate the current workload and allow a concentrated effort for CSB to examine DuPont: Chemical Safety Board Must Have Resources To Review and Investigate All Current Cases Simultaneously (Press Release, Jan 27th 2010)

Update 7: “[During a briefing at a Charleston hotel] CSB lead investigator Johnnie Banks said the hose that sprayed phosgene onto Fish showed signs of “fraying” and “wear.” …another Kanawha Valley chemical company that uses phosgene, Bayer CropScience, utilizes only solid steel piping for transfers of the chemical. Banks described the hose as an 18-inch-long quarter-inch hose, with woven stainless steel on the outside and Teflon inside. It was damaged badly enough that investigators could see its Teflon lining through a small hole”. From: CSB: DuPont phosgene hose showed signs of ‘fraying’ (The Charleston Gazette, Jan 28th 2010)

Mitch (Our best thoughts from everyone at Chemistry Blog goes to his family and friends at this time)

Jan 25

SPIE – San Francisco 2010: Day 2

SPIE an international society focused on all things light-based is having their big photonics conference in San Francisco this week. I had the opportunity to sit in the professional development speaker series and thought I would share some of the speakers’ insights.

Andrea Armani a 2nd year assistant professor at USC in chemical engineering spoke on Leading a Well-Adjusted Research Group. She stated that she gives her students Fridays off from their main research endeavor and allows them to tackle any question they want; which is a very new generation Google-esque approach to student mentoring. She also explicitly establishes that a particular older graduate student will mentor a younger graduate student in the lab, so that the younger student will always have someone to answer their questions. The most interesting story told was how she deftly managed to diffuse the amorous advances of a student, a very awkward position indeed, and a situation not covered in the manual.

Thomas Tongue gave a talk on Peaks and Pitfalls of Professional Communication, but it mainly focused on how to deliver what he calls The Elevator Pitch. He says that in scenarios where you would like to collaborate with an other scientist, or a scenario where you feel you could contribute to a team in the company if only you were placed on it, that you essentially have 60-90 s with that collaborator or vice-president to make your best pitch. The pitch has to be clear, compelling, conceptual (not bogged down in technical jargon), concrete (a specific quantifiable metric should be given), consistent (story should flow well), customized for the the target audience, and always given in a conversational tone. His advice is similar in nature to what Peggy Klaus advocates in her book The Art of Tooting Your Own Horn without Blowing It but she terms them brag-a-logs. Peggy Klaus’s book is a good read for those interested in professional development and especially for those that have problems vocalizing their contributions.

The chair of the session was Dirk Fabian from SPIE Student Services and I’m glad they were able to put together a good mix of speakers; as this type of information can be hard to extract from PIs.


Jan 16


Stephen J. Ebbens

Jonathan Howse

The current state of the art in nanopropulsion devices was recently reviewed by Ebbens and Howse in an article last Friday.[SoftMatter] A short summary of the nano- systems is presented below with video action shots when I could find them.

The Whitesides

Catalyst: Pt
Fuel: H2O2
Propulsion: Bubble propulsion
Terrain: Aqueous meniscus
Max Speed: 2 cm/s
Mitch’s Name: The Karl Benz (since it was the first)
Article: Autonomous Movement and Self-Assembly

The Sen-Mallouk-Crespi

Catalyst: Pt
Fuel: H2O2
Propulsion: Self electrophoresis/Interfacial tension
Terrain: Settled near boundary in aqueous solution
Max Speed: 6.6 um/s
Mitch’s Names: The Ford Mustang of nanopropulsion. (It is a hot rod, get it?)
Article: Catalytic Nanomotors: Autonomous Movement of Striped Nanorods

The Jones-Golestanian

Catalyst: Pt
Fuel: H2O2
Propulsion: Pure self diffusiophoresis
Terrain: Free aqueous solution
Max Speed: 3um/s
Mitch’s Name: The Volkswagen Beetle
Article: Self-Motile Colloidal Particles: From Directed Propulsion to Random Walk

The Mano-Heller

Catalyst: Glucose oxidase and Biliruben oxidase
Fuel: Glucose
Propulsion: Self electrophoresis
Terrain: Aqueous meniscus
Max Speed: 1 cm/s
Mitch’s Name: The Komatsu Truck (because it is huge)
Article: Bioelectrochemical Propulsion

The Feringa

Catalyst: Synthetic catalse
Fuel: H2O2
Propulsion: Bubble/interfacial
Terrain: Acetonitrile solution
Max Speed: 35 um/s
Mitch’s Name: The F150 (has some exhaust issues)
Article: Catalytic molecular motors: fuelling autonomous movement by a surface bound synthetic manganese catalase

The Sen-Mallouk

Catalyst: Pt (CNT) (+cathodic reactions at Au)
Fuel: H2O2/N2H4
Propulsion: Self electrophoresis
Terrain: Settled near boundary in aqueous solution
Max Speed: 200 um/s
Mitch’s Names: The Ford Mustang GT (has more kick than the regular version)
Article: Bipolar Electrochemical Mechanism for the Propulsion of Catalytic Nanomotors in Hydrogen Peroxide Solutions

The Feringa v2

Catalyst: Glucose oxidase and catalse
Fuel: Glucose
Propulsion: Local oxygen bubble formation
Terrain: Free aqueous buffer solution
Max Speed: 0.2–0.8 um/s
Mitch’s Name: The Chevrolet Nova (more hot rod action)
Article: Autonomous propulsion of carbon nanotubes powered by a multienzyme ensemble

The Gibbs-Zhao

Catalyst: Pt
Fuel: H2O2
Propulsion: Bubble release mechanism
Terrain: Aqueous solution
Max Speed: 6 um/s
Mitch’s Name: The Rover
Article: Autonomously motile catalytic nanomotors by bubble propulsion

The Bibette

Engine: External magnetic field
Propulsion: Flagella
Terrain: Aqueous solution
Max Speed: unknown
Mitch’s name: The BMW Mini E (because there is no such thing as a magnetic car)
Article: Microscopic artificial swimmers

The Sagués

Engine: External magnetic field
Propulsion: Doublet rotation coupling with boundary interactions
Terrain: Settled near boundary in aqueous solution
Max Speed: 3.2 um/s
Mitch’s Name: The Smart ED
Article: Magnetically Actuated Colloidal Microswimmers

The Fischer

Engine: External magnetic field
Propulsion: Propeller drive
Terrain: Aqueous solution
Max Speed: 40 um/s
Mitch’s Name:
Article: Controlled Propulsion of Artificial Magnetic Nanostructured Propellers

The Najafi-Golestanian

Engine: Conformation changes in linking units
Propulsion: Time irreversible translations
Terrain: Free solution
Max Speed: ?
Mitch’s Name: The Eternal Concept Car
Article: Propulsion at low Reynolds number

Some devices that were not included by the authors of the review article, but should definitely be included in any list like this are below:

The Gracias

Engine: External magnetic field
Propulsion: Brute Force
Terrain: Aqueous solution
Max Speed: ?
Mitch’s Name: The Truck Cranes
Article: Tetherless thermobiochemically actuated microgrippers

Tetherless Microgrippers Grabs Tissue SampleWatch today’s top amazing videos here

The Nelson

Engine: External electromagnetic fields
Propulsion: Flagella
Terrain: ?
Max Speed: 18 um/s
Mitch’s Name: The Tesla Roadster (simply awesome)
Article: Characterizing the Swimming Properties of Artificial Bacterial Flagella

Artificial SpermWatch more funny videos here

Link to Review Article: In pursuit of propulsion at the nanoscale


Jan 14

Chemical Vitae

As chemists we are members of the professional class, whatever that means, and are required to keep an updated curriculum vitae on hands for all occasions. As job hunting has brought this into focus for me recently I felt the need to share some of my insights.

Pronounciation and Origins
Curriculum is Latin for course. Vitae is Latin for life (technically the plural of life, unless you’re in second declension genitive). Put it together and it translates to course of life. As vitae is loaned from Latin it can be very confusing to pronounce. has the correct pronunciation of vitae as vigh-tee. This is a little irking since scientists know how to pronounce Latin words and in Latin vitae would be pronounced vee-tigh (more-or-less).

Now to the point. It would be great if there was a place online for the chemical class to keep their CVs. As you develop more work experience it would be nicer to update one centralized CV than to update your word file and then redistribute your CV. Imagine having a link to your CV on your business card, it would be more employer friendly than having them hold onto your business card + several printed pages of CV. To that end, I made a website for that purpose.

I have been using it solely for my personal use, but if there was interest from other chemists I’ll be willing to open it up to a larger audience. Link below…

Mitch’s CV:

The template is based on Paul Bracher’s CV template that he posted about oh-so many years ago. As I alluded to above, if you want one leave a comment and if there is enough demand I’ll open it up to public registrations. If demand is but a twinkle, I’ll setup the site with a lot less bells-and-whistles and keep registration limited only to the commenteers.

For those chemists that are worried about having too much information about themselves visible on the internet, I can block search-engines from visiting/indexing your profile. So only the people that you have given a link to your CV will be able to find it. Let me know what you guys think.


Edit: Fixed some Latin grammar.

Jan 11

Sodium Chloride

(for other entries in the Chemistry in Space series, click here)

The below picture is of sodium chloride crystals.  I’ve made them dozens of times in left over aqueous layers that have been in my hood so long that all the water evaporated.

Crystalline sodium chloride is one of my favorite crystals to grow.  Very easy (although it takes a while), the crystals can get quite large and beautiful.  And they have the characteristic X running through them.  Especially awesome to me, because I did my undergrad at Xavier University.  It’s nice to know that even my chemistry loves XU :)

What makes this picture so cool, though, is the crystals were grown in space.  The picture is from NASA’s Image of the Day.  The crew aboard the International Space Station‘s Destiny lab grew the crystals in a water bubble as part of the program to do chemistry in space.  From NASA:

Looking for all the world like a snowflake, this is actually a close up view of sodium chloride crystals. The crystals are in a water bubble within a 50-millimeter metal loop that was part of an experiment in the Destiny laboratory aboard the International Space Station and was photographed by the Expedition 6 crew.

Space has long fascinated me, and I’ve been trying to get the info and motivation to start a miniseries on chemistry in space.  So I guess today’s IotD is a good way to begin.  Stay tuned over the next several weeks to hear more about awesome chemistry in space!

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