HOW TO SEE NANO
Things which are nano-sized cannot be seen with your eye. They are simply too small so special tools are required. These tools include specialty microscopes and laser light scattering devices. These techniques permit you to acquire information about the nanoparticles in your CBD concentrates without having to add any chemicals or processing.
The microscopes used to see nano-sized objects don’t use regular light, but rather beams of electrons. They are very expensive and have to be maintained in specialized facilities, operated by trained professionals. Their advantage is that they provide a picture of a single nanoparticle in your specimen. However, their disadvantage is that it is still hard to get a complete picture of all the nanoparticles in your specimen. In other words, the one you see might be perfect, but you have no idea what is happening with all the other particles. Laser light scattering tools can’t provide a picture of 100% of the nanoparticles. But, they can deliver you information about what is happening with most of them, their average size, and how “clean” or “uniform” the size is.
There are many kinds of machines that use the laser light scattering method. Some have a small tube through which the specimen flows. Every time a nanoparticle passes through a viewing window, a little bit of the light is reflected. The bigger the particle the more light is reflected back, and the longer it can be seen in the viewing window. A computer algorithm then analyzes these bits of reflected light and reports the particle size. The flow through system is limited on what it can tell you about whether the nanoparticles are interacting with each other, since the force of the flowing liquid disrupts how they speak with one another.
A different kind of tool holds your nanoparticle-containing specimen in a small glass holder. The nanoparticles are free to move around as they like. If they like to stick to each other, they will; if they like to stay apart they are free to do that, too. If the nanoparticles become unstable, and start to fuse together into larger sizes, they will start to either fall to the bottom, or float to the top. In each case, the small blips of reflected laser light will have a unique pattern. This type of laser light scattering is called Dynamic Light Scattering because it can tell you in real time what the nanoparticles are doing – in addition to their average size.
Dynamic Light Scattering is a very useful scientific tool for developers of nanoparticle-containing products. It helps developers understand when a formula is unstable and how to optimize formulas to halt the instability. It can be used to either test the effects of salts, sugars or other additives that may be desired in a nanoparticle-containing product. There is a limit to all laser light scattering methods. If the sample is too concentrated or colored then the laser light gets lost in the sample and no measurements are possible. So to get the information necessary, great care must be used in how the measurements are performed.
A TIME PROVEN PROCESS
Dynamic Light Scattering has been used for about 40 years. Scientifically, it is based on the Brownian motion of dispersed particles. When particles are dispersed in a liquid they move randomly in all directions. The relation between the speed the particles move and the particle size is given by the Stokes-Einstein equation. The equation includes the viscosity of the dispersant and the temperature because both parameters directly influence particle movement. A basic requirement is that the movement of the particles has to be random. If there is sedimentation or agglomeration, there is no random movement.
Below are typical data seen in the machine for large and small particles, and typical data for gold and silver nanoparticles. The mixture signal is a weighted average of the two, assuming the particles have no interaction. If there is, then the resulting signal carries information about that interaction as well, and the analysis becomes more complicated.