Nanoparticle dispersion is most effectively accomplished using ultrasound, where the power of ultrasonic cavitation is used to break up nanoparticle aggregates suspended in solution.
Ultrasonic horns have been used for small-scale nanoparticle dispersion (such as down to 0.3 ml) but in selecting equipment for the task it may be essential that the horn does not in any way physically contact and potentially contaminate the samples. To solve this consider a sonicator cup horn such as offered by Tovatech for small-scale nanoparticle dispersion.
The Ultrasonic Horn as a Mini Ultrasonic Bath
Sonifier horns, also called ultrasonic cell disruptors, operate on the same principal as using a benchtop ultrasonic cleaner for larger batch processing. In this case, however, the bath is replaced by an assembly consisting of an acrylic sleeve that is fitted over a cup horn available in 2 or 3 inch diameters. The horn is attached to a converter that delivers 20 kHz frequency ultrasonic vibration. Coolant such as cold water can be continually circulated through the acrylic sleeve via a lower inlet and upper outlet to avoid heat damage to the samples.
Samples to be treated are placed into small sealed vials or test tubes. These are fitted into grid that fits snugly over the top of the acrylic tube and are partially immersed in the coolant. The nanoparticle dispersion is ready to begin. Because the ultrasonic treatment is indirect, the processing time to disaggregate the nanoparticles will be longer than direct placement of the ultrasonic horn into the sample solution. Use of the cup horn precludes titanium migration from the horn into the samples and allows treatment of multiple small samples simultaneously without cross contamination.
Units are available with analog controls or digital controls including a membrane switch for easy data entry, a 10-hour timer, digital wattmeter, and an 80 character LCD display to monitor parameters. Digital units offer a parallel printer interface and RS-232C serial computer interface to provide record-keeping capability. An input/output permits remote start/stop control and the ability to view temperature, amplitude, and power values during experiments.
As with dispersion processes employing powerful ultrasonic cleaners, cavitation action penetrates the glass walls of the test tubes and acts on the nanoparticle suspension.
Rely on the scientists at Tovatech for expert information on dispersing nanoparticles.