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bernpfenn t1_irpojn2 wrote

You are correct. Smaller bubbles rise slower. My specialty are nano bubbles. They don’t rise at all and stay in the water for weeks with a Brownian motion. They have high inner pressures and a strong zeta potential. Sizes are 10-80nm

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seeingeyefish t1_irq5sua wrote

What kind of applications does this bubblology have?

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evonix420 t1_irqhxyo wrote

I don‘t know about nanobubbles, but microbubbles are used in contrast enhanced ultrasound. Basically overcoming the resolution limit of conventional ultrasound systems to create an image of your microvessels for medical diagnostics.

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RedditWojak t1_irrz84s wrote

That's interesting. Why aren't they deleterious to the ultrasound resolution due to the constant refraction from the medium shift? Does that refraction change act like dithering in astronomical images?

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PresumedSapient t1_irr3ky7 wrote

Not the person you asked, but I think 'bubblology' (thank you for that word by the way) would have relevance in micro-fluidics, which relates to lab-on-a-chip applications and microbiology and cellular biology. It may also have mechanical engineering relevance through hydro-dynamics in (micro-)pumps, injectors, and carburetors. Maybe even drug delivery systems.

Edit: and according to this link it's also very useful for water aeration, which is needed for hydroponics, hydro-culture, and general water treatment.
In general for nano: lots of surface interaction, so great if you want to a lot of chemical or physical interaction between your nano-something and whatever substance you put it in.

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bernpfenn t1_irssrxx wrote

yes, Moleaer is THE leading company developing nano bubble generators for industrial volumes. I use a 200 GPM unit for removing algae from a 75,000 m3 lake. It is quite a spectacular transformation to see clear, transparent water in a tropical lake. The fish loved it. Oxygen levels rose to 8 mg/L.

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Gaothaire t1_irr4wly wrote

A nice fuzzy soda pop. The way the bubbles of a McDonald's Sprite tickle your 'buds.

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kerbalsdownunder t1_irr5n0a wrote

Russell Wilson once claimed nanobubbles protect him from concussions. He's also a complete weirdo

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PerspectivePure2169 t1_irpz2z0 wrote

Oh this is fascinating, please expand on these! It's crazy to think they can survive that long, what's the predominant force at that scale that keeps them from collapsing or dissolving?

Also, is this a significant source of dissolved oxygen in water for fish etc?

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rdsd1124 t1_irqi06t wrote

At ambient temperature and pressure too high of an energy barrier exists for the dissolution of the bubble's contained gas. This is b/c small bubbles have a large internal pressure (scales w/ 1/r) and a high chemical potential, just like bernpfenn mentioned. Here's a cool paper showing the math behind this (doi.org/10.1021/acsomega.0c05384)

u/bernpfenn would probably know better if a more updated source exists.

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bernpfenn t1_irsg3hi wrote

Immediate benefits of nano-bubble aeration

Saturates water with up to 79,000x more oxygen than traditional aeration

Can remain within the water column for 2-3 months
Sustains the rapid growth of beneficial bacteria and desirable microbes

Prevents accumulation of anaerobic bottom muck and sediments

Helps reduce the impact of nutrients responsible for fueling weeds and algae

Provides cyanotoxin control as demonstrated in laboratory settings

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bernpfenn t1_irsorug wrote

>oi.org/10.1021/acsomega.0c05384

That was a nice dive into the theory.
In essence, to dissolve gas into liquids, smaller bubbles have a longer time in contact with the liquid due to the mentioned stability and surface in contact with the liquid multiplied with the time.

Size, there are nanobubble generators with 1000 GPM water flow. These generators require 100 psi gas pressure and 3.3 m3 gas per hour.

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bernpfenn t1_irsgti5 wrote

Gas bubbles having such a small diameter shrink in water due to ions existing at the interface between gas and liquid, which in turn increases the ion concentration at the interface and raises the inner pressure and temperature of the bubbles, causing various phenomena to occur.
We think that taking advantage of these phenomena will provide many different possibilities.

In recent years, it was revealed that the micro-nano bubbles have a lot of useful properties. These include the following capabilities:

Sterilization capability:The agglomeration and collapse process of the micro-nano bubbles converts oxygen in the air into active oxygen, creating bactericidal molecules including OH and O3.

Cleaning capability: Ions existing at the gas-liquid interface of the micro-nano bubbles decompose and adsorb oil and fat contamination, which allows removal of the contamination without the need for cleaning agents.

Bio-activation capability: It has been proven that the micro-nano bubbles penetrate deep into biological cells and enhance the immunity of the cells. This has allowed elimination of the need for antibiotics or reduction of the amount of antibiotic usage.

Growth promotion capability: It has been verified that using the micro-nano bubbles allows fish, crustacea and plants to be grown 20 to 30 percent larger than those grown in an ordinary manner.

Cell protection capability: It has been found that oysters grown with the micro-nano bubbles remain alive even if they are frozen to minus 20°C. This is likely because the micro-nano bubbles protect oysters’ cells against damage due to freezing.

Heat transfer capability: The micro-nano bubbles can be used to raise or lower the temperature of a liquid rapidly and effectively.

Vaporization promotion capability: It has been proven that the micro-nano bubbles contained in a liquid promote vaporization of the liquid. Applications based on this effect include highly efficient water-cooled cooling towers and evaporation based desalination systems.

Environmental purification capability: The micro-nano bubbles help restore the biological balance in lakes, rivers or seas and remove odors and toxic substances produced by anaerobic bacteria. This effect stays for a long time even in a large water body such as oceans and seas.

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