Chemistry Blog

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!

Jan 10

The Hidden World of the PostDoc Interview

I thought I knew the process involved in a postdoc interview, but it is a unique experience that people don’t share enough.

Lesson #1
The one thing that was never made clear to me is that you should have an hour long talk ready to go. I was asked the night before my interview if I would be willing to give an institute wide 1-hour seminar while I was there. Unfortunately for my own professional development I politely chickened-out; I have some ACS talks of 20-25 min length but nothing prepared that would tell a cohesive story for a whole hour. Other postdocs that I have seen interview at Berkeley usually give a talk to the group they want to join, but not the big seminar talk.

Lesson #2
The interview is all day long. My day started at 9:00 am with a meeting with the professor I contacted followed by a presentation to his research group of my thesis work. Afterwards it was 1-on-1 talks with his postdocs and a lunch with the group. Which is what I expected. After lunch came meetings with the other professors in the department, an aspect of the process that I was not expecting and was more under prepared then I would have liked to be. The final meeting of the day was with the professor I initially contacted followed by more specifics on what aspects of his work was most interesting to me. The whole process ended after 5:00 pm with an early dinner.

Lesson #3
You need to wear a suit. Fortunately my friends got that into my head before the interview.

Lesson #4
The last step in the process is getting the funds. I need to apply for a fellowship to get started, but as the institute manages the fellowship program I am applying to, I was told not to worry too much about getting it.

The whole day went well, and I look forward to that next step in academia. If anyone else has gone through this process please share your experience in the comments.


Dec 22

Funny Flasks

During a recent group clean up, I came across these gems drying in an oven.  No one knew where they’d come from or how we obtained them:



Looks like the glass blower just capped some broken-off joints to make tiny flasks.  Although, I gotta say, if you’re going to do chemistry on that small of scale, why not just grab a 1 dram vial?

Merry Christmas, all!  Safe travels and well wishes in the new year :)

Dec 15

Silly Find from the Internets

Not much today. I saw this earlier and remembered having one of these moments back in G-chem that made me want to break the stupid buret. Actually, that happened on the last day of the semester, during checkout, after I washed it and was walking to the stockroom to return it. I forgot how long the damn thing was, and as I was walked out of the lab the door closed on it, cleaving it in two.

Why was this necessary for us learn in lab? Would have been much more useful to teach us how to make an electronic one instead.

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