Fundamentals

When you focus sunlight with a magnifying glass, you can ignite paper or even wood. This works by amplifying the intensity of the light. The average intensity of sunlight reaching the earth ground is about 200 watts per square meter. A standard magnifying glass increases this intensity by a factor of 25 to 100. However, if you want to use light to not burn but vaporize hard materials such as metals or ceramics, you need intensities that are billions of times higher. Pulsed lasers are suitable for this purpose.

A compact microchip laser pulses in the chest of our machine. Its amplified light initiates the nanoparticle generation in a spontaneous evaporation event. We call this event ablation. The ablated matter is surrounded by a liquid medium, e.g. water, during the interaction with the laser light. This liquid has the important task of capturing the nanoparticles that form in the plume of ablated matter. During trapping, the liquid cools the particles and can even trigger chemical processes on their surface. The particles are thus protected from agglomeration and aggregation.

Finally, the particles float isolated from each other in the liquid. This state is called suspension or colloid. It represents the state of highest possible quality of nanoparticles, because their precious surface retains its unique properties. The nanoparticles leave our automated machine as a ready-to-use, high-quality colloid, without contamination by reactant residues, remaining reducing agents or unwanted surfactants.

Of course, this was only a very simplified short description of the synthesis method applied in the automated machine. If you want to dive deeper into the subject scientifically, we can recommend the following literature:

H. Zeng et al. 2012, Adv. Funct. Mater. 22, 1333-1353, DOI: 10.1002/adfm.201102295
D. Zhang et al. 2017, Chem. Rev. 117, 3990-4103, DOI: 10.1021/acs.chemrev.6b00468
A. Kanitz et al. 2019, Plasma Sources Sci. Technol. 28, 103001, DOI: 10.1088/1361-6595/ab3dbe

Materials

Theoretically, any solid substance can exist as a nanoparticle. However, nanoparticles cannot necessarily be produced from any solid substance. Or maybe they can? In fact, any light-absorbing solid can be processed into nanoparticles using our laser-based synthesis method. It may not have been shown for every substance yet, but there is already a long list covering all known classes of materials: light metals, heavy metals, alloys, oxides, nitrides, carbides, plastics, and organics.

Not only can the material of the nanoparticles be varied over a wide range, but also the dispersant. Our automated machine generates nanoparticles in many different liquids, which eliminates the need for phase transfer. The installed components of our machine set the limit of usable liquids and were chosen considering a broad and high chemical resistance. Keyword chemistry: while inert materials lead to very similar nanoparticles when synthesized in different dispersants, reactive materials interact with the dispersant. This opens up new possibilities in material development.

In terms of variation, however, we go one better. Given solubility in the desired dispersant, any stabilizer can be used. In some cases, it is even possible to work without a stabilizer or with only a small pinch of salt (sodium chloride, micromolar concentration).

Please contact us if you need information on the use of explicit nanoparticle materials, dispersants, stabilizers, and/or combinations.

Applications

The colloidal nanoparticles from our automated machine can be used in all common applications of such colloids. The machine simply allows much faster and more reliable access to the small particles than before. However, highest possible colloid purity and the option of sterile colloid production qualify the use of our machine especially in biomedical R&D. Furthermore, its use in the development of new catalysts is also of special interest because of the access to very small nanoparticles of diverse materials and the absence of surfactants.

In addition, we hope that the machine will accelerate the development of new applications. The wide range of possibilities in material development combined with the fast and easy access to colloidal nanoparticles will lay the foundation. In the future, we also want to make such new applications commercially viable with larger machines. Current laser technology already enables an increase in productivity from a few milligrams per hour (current laboratory machine) to a few grams per hour. Future laser technology will soon make the leap to hundreds of grams per hour possible.

If you want to test our automated machine in your application, we would be very pleased to organize a pilot use. Simply write us an e-mail or call us directly.