Synthesis tips101. Make your condition inert!

water and oxygen. oh, water and oxygen...

Water and oxygen. These are the two most necessary molecules to human beings. For those who synthesize nanocrystals in oils, like me, or like you, water and oxygen could be detrimental.

When you talk about synthetic skills, the dewater and drying process are the most important skills. Some reactions that go well under a pure inert condition would produce just a piece of junk under a small amount of oxygen or water. By just knowing little tips to make your reaction conditions better, you will be recognized as a chemist with an excellent synthetic skill!

Synthesis! That is what I am talking about here!

Here, I listed several techniques that have been useful to me when synthesizing inorganic nanomaterials.

(1) Adaptor with a stopcock 

I am always surprised that adaptors with a stopcock are so less known.  People should use a stopcock adaptor!
You can buy it in here

For example, when you want to use your dried solution for the next week and you do not want to keep it with the Schlenk line for a long time, this works better.  Even normal molecules like oleic acid or oleylamine, I dry under vacuum and use it for later when necessary.  

(2) Glove box

The glove box is the must when you handle very oxygen- or water-sensitive chemicals.

(3) freeze-pump-thaw

The freeze-pump-thaw is good when you wanna dry low boiling point solvent! This is a nice SOP. https://depts.washington.edu/eooptic/linkfiles/Freeze_Pump_Thaw.pdf

Or if you like a video here is an excellent YouTube video

There are more techniques, such as molecular sieves, distillation, and recrystallization of chemicals. I hope this post would be a good starting point for your explore for further reaction tips!

Good luck with a pure reaction!

XRD for nanocrystals

Cool XRD instrument

Humans can perceive 400–700 nm electromagnetic waves. We call it “see.” Although humans cannot see the circulation of light, some insects can see the polarity of light. I am wondering who is the sexiest person if we could see the circulation of light, or if we have different ranges of wavelengths. Probably the sexiest person in human society might not be so sexy in a world where the circulation of light can be seen. The perspective of our lives will be literally changed.

If we could see X-ray, we may not have to use X-ray scanning at hospitals. Although we cannot see X-rays with our eyes, we can detect them using a detector to see the molecular structures and nanostructures. The physics behind X-ray techniques are surprisingly easy compared with its benefits.

Although I cannot lecture how it works in this blog post, I listed famous things that you need to master and the important papers that you want to read if you study the nanochemistry field.

10 Important Concepts to Know

Bragg equation, Scherrer equation, 2theta-theta, instrumental factors, basics of powder XRD, crystallography, right-hand rules, space group selection rules, diffraction intensity, atomic scattering factor:

Five Selected Papers

1)             Forster S. et al. J. Phys. Chem. B 2005, 109, 1347-1360


2)             Brown, P. J. et al. International Table of Crystallography 2006. 6.1 Intensity of DiffractedIntensity Form factor, structural factor, GISAXS, single crystallography

3)             Jones, M. R.; C. Mirkin., et al. Nature Materials 9, 913–917 (2010).

4)             Förster, S. et al. Nature Materials 6, 888 – 893 (2007).

5)             Cameron F. Holder and Raymond E. Schaak. ACS Nano 20191377359-7365

Good luck on your better perspective of your materials!

Figure Balance “Casual and Classy” and Color Contrast

When you make a figure, you need to aim at a good balance point between formal and casual. Not too casual, not too formal, and be neat. The image is from here.

Here is a question: What makes a good figure?

I would say there are three factors: (1) informative; (2) intuitively understandable; (3) slick design. They are intermingled. When crafting your figures, if you put too much information without caring about  the balance, factors (2) and (3) may be lost. Just like, even though you know that broccoli is good for your health, if you only eat broccoli without caring for nutrient balance, such a diet may end up jeopardizing your health and beauty. “Balance” is the keyword here.

I was poor at creating balanced figures. I once believed that figure-making was something you need a sense or talent for—and I had neither. I knew my figures did not look good, but I did not how to improve them. I read books of design methodology or color coordination, but none of them improved my figure-making skills.

I read an article about fashion that talked about the balance between being casual and being formal. It struck my mind, and I realized that, when one designs a figure, a similar method can be applied.

Here, I introduced the concept of balance using “casualty factor” and “classy factor.” If you think there is too much classy factor in your figure, you can balance that out by adding components of casualty factor.

Examples of Casualty and Classy Factors

Casualty factor: Colorful, bold, asymmetry, rectangular, round, vivid, space

Classy factor: Black and white, thin, symmetry, square, sharp, much information

Tune the casualty/classy parameter to hit the sweet point.  But be always neat.

An easy example is a TEM image, which is a black and white result. When I use a TEM image, I trim the image into a rectangular shape not a square because “black and white” + “square” is going to be a little too formal, possibly boring. This is an easy example, but this is my thought process when crafting figures. Similarly, when making big figures (see below), it usually involves big information. Conveying a good amount of information is good, but if you make it only black and white with a sharp shape, your reader might tire from attempts to understand what’s going on. Then, you probably want to add more color into your figures.

 

The left one is clearly clearer than the right one. Color contrast is important.

Good luck on having a nice balance point!