What are nanobubbles?
Bubbles in diameter smaller than the wavelength of light are called ultrafine bubbles, and they are too small to see. In general bubble with a diameter smaller than 200 nanometer are called ultrafine bubbles. Ultrafine bubbles have many other remarkable features that ordinary bubbles do not possess. For example, these bubbles can stay in a liquid for a long time, and are electrically charged, and are extra highly pressured as well. These special features of ultrafine bubbles have attracted attention from many industries such as agriculture, wastewater, fisheries, drinking water for animals, food, cosmetics, chemical, medical.
Links
Nanobubbles are gas filled cavities in water. The contact area between bubbles in water filled with tiny bubbles is much larger than water filled with bigger bubbles. The gas pressure inside a small bubble is higher than in a large bubble, therefore the surface tension of a small bubble is higher as well.
Nanobubbles are useful in accelerating the metabolism of living organisms, but the mechanism is not yet well understood. In a study, they investigated the production of reactive oxygen species (ROS) by Nano Bubbles and the effect on seed germination. The conclusion of the study was seeds in nanobubble water had a higher germination rate than all those submerged in the different other conventional used solutions.
Interested to know why nanobubbles are officially called ultrafine bubbles? In this article we explain the reasons why the ISO technical committee has decided to use the official name ultrafine bubbles instead of nanobubbles.
Nanobubbles can be measured by the same technology as measuring small particles. You can measure bubbles by camera (count pixel size) or laser (count blackout time), also as a simple method to know number index, you can refer information of turbidity. When you measure UFB, most common way is to analyze Brownian Motion.
Bubbles are all around us, in our foods, beer, pop drinks bread and cheese, but also in the bricks of our house. Bubbles are gas-filled cavities in water, the lifetime of a bubble is short at most a few minutes, only ultra-fine bubbles are stable for longer periods like months, that is making them very special and that enables us to change the properties of water.
Washing of surfaces and laundry is one of the promising areas were nanobubbles can make a difference in the application. Reducing the amount of detergent, has a positive effect by reducing pollution, washing laundry without detergent, would greatly benefit the environment. Nanobubbles can lower the surface tension of water, the large amounts of oxygen molecules in bubbles charge the water negative.
The electrical properties of gas bubbles are important in determining the interaction of nano-bubbles if and when they merge together and how they interact with other materials such as solid particles or oil droplets. Knowledge about this helps application development in for example, protein skimmers, froth flotation, food processing, washing surfaces and purification.