The Future Potential of Nanobubbles

Welcome back to our final and seventh episode in our Nanobubbles 101 podcast exploration, if you like, of Nanobubbles Science and Engineering. Once again, I'm Niall English, your host. I'm the co-founder and CTO at AquaB, as well as a professor in chemical engineering at UCD in Ireland.

In this last session, we're going to explore what I believe are key drivers in the Nanobubbles area of fundamental science. What I believe are key challenges and progress yet to be made, and hopefully involving some original and powerful discoveries and maybe some spinoff technologies of their own right, which would really help us to make environmental and scientific and indeed commercial progress. So really, what I'm trying to do in my ERC project called Nimble is to engineer and manipulate at will both the lifetime and population of Nanobubbles for different situations, different strokes for different folks, as it were.

For example, agriculture, carbon capture, water treatment, fish farms, fermentation, etc., etc. Oil and gas, of course, but they all have their own different sweet spots or goldilocks zones where a shorter, longer Nanobubble lifetime might be the order of the day.

Can we try to control the density of the Nanobubbles, the fixed law release rate, into the regularly dissolved phase? Where again, just to remind you, we just have a single solitary gas molecule surrounded by the solvent molecule, for example, water, perhaps petrol. So can we effectively dial up the lifetime, whether it be short or long, and the population, bearing in mind sort of natural upper limits, typically of the order of about 10 to the 9 bubbles per milliliter, where we start to see mutual electrostatic shielding effects and the Nanobubbles sort of see each other in inverted commas.

In each other's electrostatic and electric field orbits that they project in space. Are there ways to sidestep some of these, to reach larger populations, perhaps with smaller bubble sizes? So these are some burning questions of a fundamental nature that will really allow us to become more skilled in the art of Nanobubble engineering from a very fundamental point of view.

And they'd be able to apply that to different environments, different ecosystems, different media, if you will, where we want faster, slow Nanobubbles. We want many of them or fewer of them, depending upon them. We want to manipulate their electrostatic adsorption properties for more or less nutrients or surfactants, et cetera, to be adsorbed there too.

So really, I'm quite optimistic. I'm quite upbeat. And I think that there are many ways that we can manipulate electric field pulse trends, the frequencies that are applied, the pulse width modulation that is applied in the electric field signals, in the case of electric field generated Nanobubbles.

I think that there's much we can do in terms of the recirculation and residence times that expose liquids and gases under the influence of the electric field. So being able to manipulate recirculation times inside a generator to increase the population, if that's what's desired, we can of course increase or decrease the flow rate and turbulence profile to influence the level of turbulence and mesoscale bubble conversion into Nanobubbles as well. By playing games with that, in terms of aerosolization, for example, if we produce a mist inside the engine block of an engine, we can manipulate the size of the fuel micro droplets to maybe make them larger or smaller to ensure that the Nanobubble population burns them effectively from the inside to the out, as well as from the air in the cylinder block from the outside inwards.

So we can play with the flame propagation temperature by doing effectively some aerosol engineering there. So there's a wide range of games that can be played as well. We can manipulate the internal electric field inside water and solvents by playing games with the pH as well, and perhaps any aspects of magnetic field exposure, static field buildup, etc.

There's games that can be played as well with the surface coatings in terms of flow patterns inside flow-based generators. And indeed, we can go towards mesoscale and microscale fluidics as well to treat much smaller size nanobubbles. For example, in smaller engines, motorcycle engines, or indeed in consumer-level nanobubble generators for aqueous systems, such as in perhaps washing machines and consumer-grade systems.

So there's really a wide variety of things that can be done, but it really boils down to the two sacred principles of can we engineer the population of nanobubbles? Can we manipulate the lifetime of the nanobubbles? And other corollaries soon follow, such as can we therefore manipulate with the electrostatic potential, the electric field environment, the pulse rate of the applied electric field?

Can we influence the level of reactive species that would, for example, make short work of, in other words, oxidize, ammonia, for example, or other reactive forms of sulfur, hydrogen sulfide, et cetera? So really, there's so much to be done in terms of nanobubble engineering and the associated electric field engineering, that there's many, many things that could be done at the generator level. And then this begs the question, well, how can we expand in terms of applications?

What new applications are there out there that we might not yet have thought of? And, you know, in a sense, that's a difficult question to answer, because there's always new applications coming along that haven't been anticipated of nanobubbles with this platform-wide technology. If we talk about how electric field generators have liberated us from the tyranny, if you like, of membranes, I can see some important emerging trends in the future.

That would be the solar vision and solar agenda. I haven't spoken too much about this in previous episodes, but I will now. Having floating offshore or indeed onshore solar with batteries, because night follows day, as soon as Christmas comes and goes, night comes and goes, so we can connect those up with batteries to give us a good level of resiliency for when the sun ain't shining or when the level of solar radiance has gone below its established watts per square meter, for example, under diffuse light conditions or under prolonged winters.

So we can really dial up and tune what level of solar capacity with associated backup batteries and any inverters we might want to install there on for if there's any particular AC aspects of the primarily DC setup that we want to have. And we can really go off grid, whether on land or on water. So we can have submerged bubble generators on reservoirs, lakes.

We can really go off grid in terms of land-based nanobubble generators, say for irrigation header tanks. We can bring great advances to isolated communities, especially in many parts of Asia and Africa, and to groups and tribes of people who depend upon irrigation header tanks, upon clean water, which is a human right. And we can really make a difference to the world.

And that's something very important and dear to my heart. And if you ask me what my biggest hope for the legacy of Nanobubbles is done using the electric field approach, for example, using solar off-grid, I think it's really to help alleviate problems in water treatment and problems in clean water where it's needed the most in the Global South. And that is what I think is most important about the future.

I've told you about some of my technical visions, but I think that helping those who are more disadvantaged than us in the Global South who really need clean water is what is really, really important. And that's a moral imperative. So that's how I think Nanobubbles will really change the world.

Forget the economics, forget the energy savings, forget the finance, forget the maintenance. It's really about helping people. Because if we don't help people, where are we?

Who are we? Think about that. Anyway, thank you so much for joining me on this final episode where I've laid out some of my future thoughts.

And we've discussed some technical advances that can be made in nanobubble generation at the molecular level. We've discussed how this can be commercially and environmentally exciting. And we've discussed how nanobubbles combined with solar off-grid can really do so much to help the world, especially to those in areas where electricity isn't readily available, to really, really improve their quality of life.

Because the world is nothing without clean water, and it's a human right. So thank you very much. It's been a pleasure to explore these issues with you over these past seven episodes.

And I wish you every success in your further exploration of the nanobubbles area in terms of science, engineering, business, commercial activities, general applications. Good day to you.