Passing a high powered laser beam across a slab of gold releases a foam of red gold nanoparticles


Passing a high powered laser beam across a slab of gold releases a foam of red gold nanoparticles


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About the Author: livescience

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  1. **Explanation**

    The effect shown in this video is called [laser ablation](https://en.wikipedia.org/wiki/Laser_ablation). The key idea is that a high power laser beam can pack enough of a punch to strip of small particles from a slab of solid metal, in this case gold [as shown in this cartoon](https://i.imgur.com/zeUdgzv.png). In this case the particles are so small that they fall in the nanometer size, hence the term nanoparticles. The interesting thing about this size range is that the optical properties of these particles will depend on their size [as shown here](https://i.imgur.com/ojVNhu0.png). For this particular size range the particles produce solutions that look red to our eyes as shown in this clip.

    P.S. if you are curious about the color of the solution, it is due to an effect called a [surface plasmon resonance (SPR).](https://en.wikipedia.org/wiki/Surface_plasmon_resonance) To put it simply, these SPR’s show how a sea of electrons in a metal interact with light when you squeeze the metal into a small particle or a thin film. It is this effect that largely explains the [vivid color of stained glass windows in old churches such as Notre Dame de Paris.](http://i.imgur.com/9L1aYmW.jpg)

    ___
    Source for the GIF: [This video](https://www.youtube.com/watch?v=XxMA3dSblek)

  2. What size are the created particles?

    Does this work with silver?

    And is it expensive? The lab I work in does a lot of work with silver nanoparticles and we haven’t quite nailed synthesis yet. Also, silica coated silver is hella costly.

  3. *Lucy Ashton’s Song*

    Look not thou on beauty’s charming,

    Sit thou still when kings are arming,

    Taste not when the wine-cup glistens,

    Speak not when the people listens,

    Stop thine ear against the singer,

    From the red gold keep thy finger;

    Vacant heart and hand and eye,

    Easy live and quiet die.

    (Sir Walter Scott)

  4. Kinda unrelated but this reminds me of when I used to work as a contractor for Boeing. They spray gold paint on certain parts because it won’t ever rust. the cool thing was that it is cherry red when they spray it on the parts and after it is baked it turned bright chrome gold. One little glass of paint was $10,000 too

  5. Burning gold and silver into a vapor is how glass blowers get that purple, blue and yellow effect. I wonder if they used lasers they could better control the colors and patterns? They currently use various types of torches and can control the flame size and gas/oxygen levels.

  6. Can you compress these particles in a small tube that is designed to generate electricty and then shake the tube to make electricity or something? since they are in the air i would imagine that violently moving them in a tube might do something or something? i donno man can someone elaborate what the point of these nano particles are?

  7. Interestingly, when you can decrease the separation distance between these nanoparticles they go from a deep red colour to bright blue. Makes them really useful as visual markers for certain bio-reactions.

  8. I (almost) fully understand the “how”, but WHY do this? What are gold nana party kills used for?

    Edit: *nanoparticles. Damn voice recognition!

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