Ultrasonic Nozzle Systems for Nanotechnology Coating Applications
Nanotechnology coatings is a fast growing field for ultrasonic spray technology. Sono-Tek ultrasonic nozzles are ideally suited to depositing nanotechnology coatings containing functional nanoparticles and are increasingly being used in research as well as production volume spray processes.
The two main focuses of nanotechnology coatings for ultrasonic spray nozzles are:
- Depositing uniform nanolayers of solutions onto any size or width substrate (including moving webs of material).
- Dispersing nanosuspensions homogenously onto a substrate (including suspensions that tend to agglomerate easily). Ultrasonic nozzles continuously break apart agglomerations during the coating process due to the mechanical vibration of the nozzle.
Sono-Tek ultrasonic spray technology is used for depositing nanolayer thickness uniform coatings across any width substrate. The ability to create these very thin coatings with high uniformity, even across very wide widths, makes ultrasonic spray technology uniquely suited to many precision nanotechnology spray applications. Shown on the left is Sono-Tek’s WideTrack spray system for depositing nanolayer coatings onto glass ribbons during continuous float glass manufacturing.
Some common nanolayer deposition applications include:
- Anti-reflection coatings onto solar glass
- Anti-stain or other protective coatings onto float glass
- Anti-scratch coatings onto eyeglass or other lenses
Ultrasonic nozzles, by design, continuously break apart agglomoerated particles held in suspension. This is due to the ultrasonic vibration of the nozzle. High frequency sound waves are used to create capillary waves in the liquid as it travels to the atomizing tip of the nozzle. As a result the suspension is subjected to high frequency vibrations during the atomization process. This is shown in the illustration on the left, where the ultrasonic action breaks apart agglomerates as they pass through the nozzle and particles are dispersed evenly into a fine atomized spray of uniform droplets. Air spray nozzles, in comparison, cannot disperse agglomerates, and clog easily. For more information on the unique properties of ultrasonic spray nozzles, go to http://www.sono-tek.com/how-ultrasonic-nozzles-work/
Ultrasonic nozzles are especially well suited to nanosuspension dispersion applications such as:
- Depositing carbon nanotubes and nanowires in uniform thin coatings for alternative energy, electronics, semiconductor, or medical applications
- Spraying catalyst inks such as carbon black in fuel cell manufacturing
- Coating solar cell substrates with active layer chemistries containing metal oxides
- Spraying Transparent Conductive Oxide (TCO) chemistries in touch screen manufacturing processes
- Depositing uniform thin films of nanowires or graphene in advanced electronics applications
Right: CNT’s agglomerated prior to ultrasonic dispersion.
Left: Evenly dispersed CNT’s following ultrasonic disepersion.
The soft nature of the atomized spray will not break delicate carbon nanotube structures.
Sono-Tek also offers unique liquid delivery systems for use with suspensions, including the SonicSyringe ultrasonic dispersion syringe pump and the CSP Flow, a continuous ultrasonic dispersion syringe pump.
With proven expertise in many emerging applications where uniform dispersion of nanoparticles is key to creating successful functional coatings, Sono-Tek offers full coating solutions, from our ExactaCoat R&D tabletop spraying systems to our WideTrack wide area continuous web coating systems. All Sono-Tek systems employ the same ultrasonic nozzle technology, enabling our equipment to be easily scaled up from R&D to high volume production.