Invisibility Cloaks & Tomato Juice – Two Videos About Light & Color

Last month we posted “Light Can Do Way More Than Bend: Part 2,” in which we talked about using lasers to create a particular type of metamaterial from gold nanoparticles. One exciting application for metamaterials research is the development of invisibility technology, and now the ACS Reactions team has produced a great little video explaining more about this topic: “Are Invisibility Cloaks Possible?”

Another recent video relevant to our blog is the very first episode of Chem-Lapsed, a new time-lapse video series from C&E News. In “How the Fruits Got Their Colors,” we described the importance of the molecule lycopene in the red color we see in tomatoes. In their “Tomato Juice Rainbow” demo, Chem-Lapsed shows how the interaction between bromine water and lycopene can produce  a rainbow of colors:

Videos like these can help illuminate (ha!) how we perceive light and color, which involves phenomena that are much too small to see with the naked eye. Molecules like lycopene are even smaller than a nanometer, and visible light wavelengths are about 400-700 nanometers, which is why nanoscience research is so relevant to the development of metamaterials and other cutting-edge technologies.

Do you have any favorite videos or activities for demonstrating how we see light and color?

Publication Summary: How do different kinds of bacteria interact with different kinds of nanoparticles?

This post is part of our ongoing series of public-friendly summaries describing research articles that have been published by members of the Center for Sustainable Nanotechnology. Vivian Feng, a chemistry professor at Augsburg College, is the first author of this paper, which was a collaboration with undergraduate and graduate students as well as other CSN faculty members. Vivian says, “Understanding the impact of nanomaterial toxicity on the environment is a highly interdisciplinary task. I really valued the team effort while working on this manuscript, especially for my undergraduate students to experience it. The boundaries between disciplines of chemistry, biology and physics were blurred when we all put our heads together to solve the same problem – that’s the beauty of a collaboration.”

The article was first published online in June 2015 in the journal Chemical Science.1

Bacillus and gold nanoparticles

Gold nanoparticles (indicated by the arrow) binding to the surface of a Bacillus bacterium cell. Image from Feng et al., 2015,1 published by the Royal Society of Chemistry.

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What Can One Hotel Do to Be Sustainable?

Let’s face it, staying in a hotel can be pretty wasteful. All those take-out containers for food, those little soaps in cardboard boxes (or plastic wrap!) that get used three times before they’re replaced with a new one, and hard-to-control thermostats that lead to ice-box air conditioning even when no people are around to enjoy it.

This week the Center for Sustainable Nanotechnology had one of our rare in-person meetings where we gathered from all around the country to talk science (and blogging!). We met at the University of Wisconsin-Madison, and many of us stayed at the Wisconsin Union Hotel, just down the road from the Chemistry Department. It turned out to be a good fit philosophically as well as geographically for our CSN meeting: the hotel had the most comprehensive approach to sustainability that I personally have ever experienced.

You literally cannot walk into your room at the hotel without noticing their sustainability efforts: the lights won’t operate unless you put your room key in a slot by the door!


Want lights on in your room? Put your key card in the slot first.

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How the Fruits Got Their Colors

It’s Sunday night and I am watching one of my favorite shows, which of course revolves around food. In this particular episode, competitors were challenged to incorporate blue into their baked delights without using artificial coloring. That may not seem to be much of a challenge, but there are actually very few naturally occurring blue foods. Many challengers reached for blueberries as their blue ingredient, but blueberries seem to be closer to purple than blue to me. (I guess because blue is in the name, we can just consider it close enough to blue to pass. But how many other blue fruits or vegetables can you think of?) Fruit and vegetable colors seem to be dominated by greens, yellows, oranges and reds. With my interest piqued, I set out to explore and better understand how the fruits (and vegetables) got their colors.


Figure 1. Blueberries: blue, or purple? Image by Jeff Kubina

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Who Reads Sustainable Nano?

Who reads Sustainable Nano? You do!  And we’d love to know a little more about you!

Instead of reading a new blog post this week, please take a few minutes to fill out our first ever Sustainable Nano Reader Survey!


When you’re done, you may enjoy celebrating the U.S. Fourth of July holiday by re-reading our post about nanomaterials making their way into fireworks; or check out this infographic from Compound Interest about the Chemistry of Sparklers:

The Chemistry of Sparklers

Infographic by Compound Interest

Thanks so much for reading Sustainable Nano – we look forward to hearing from you!

The Green Nanotechnology Revolution

When we talk about sustainability in chemistry, one thing we have to think about is how the chemicals we use in our experiments may affect the environment. The traditional production of nanoparticles frequently involves the use of toxic materials such as harsh solvents and surfactants to synthesize a diverse array of nanoparticles that range from metals through metal oxides.1 A big concern is that disposal of these toxic materials in the environment may directly affect all organisms living in it, and subsequently change the ecological equilibrium of a particular ecosystem.

At this point you may wonder if there are any sustainable ways to produce nanoparticles. I have some good news: a new way to prepare nanoparticles has slowly made its way into nanotechnology, and it uses plants!

Plants!      image source

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Publication Summary: Sustainable Nano on Open Access Sustainably

This post is part of our ongoing series of public-friendly summaries describing research articles that have been published by members of the Center for Sustainable Nanotechnology. Dr. Rigoberto Hernandez (one of the co-authors of the article) wrote this description for his blog, Everywhere Chemistry, and kindly agreed to let us cross-post here at Sustainable Nano. 
The article was first published online in June 2015 in ACS Central Science.1

Cartoon of a nanoparticle interacting with a cell membrane. Modified from Murphy et al. (2015)1

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