That is awesome! I am just now getting into small batch sonication in order to learn the ropes, but after I get the hang of the production and wrangle the taste issues in, I planned on building a flow cell in order to run larger batch sizes, sales and demand depending. If anyone has a line on a flow cell that would be compatible with the chinese horns, I would love to know!
See my edited post to see my small batch setup (up to about 2 gallons)
Thats a nice toy you got there 
. Never ran a heislher have you ran any others have any opinions on variances? I have access to a particle spectrum analyzer if you ever would like to test yours vs or sonomechanics version. Id be glad to see if eithers slight variance in frequency(if any) results in a smaller nm sizing
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Dude I totally dig your setup! I was envisioning something very similar for mine when I get to that point. My problem is that I could not justify the cost of the higher end equipment that are compatible with flow cells, and I am having a hard time finding a flow cell that would work with my chinese jobby. How does the flow cell mount to the probe/horn? Does it replace the probe or does it slip on and seal with an o-ring or something?
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Have you ran your batch setup without the homogenizer and seen if there was any comparable differences? I ran a larger continous setup but never considered plugging in a homogenizer during sonication. Only use it after to mix into our glycerin mix(helps a bit with flavor still bleh tho to be real) or when making the emulsifier
Look at your extraction process, minor fats and lipids are the cause most of the time for this issue. If you can minimize the amounts being processed there, it goes a LONG way.
Cheers
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I appreciate the tip. I am buying high purity isolate that generally has minimal fats/waxes in it. I will definitely keep an eye out for waxes in the future as we are running.
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Speak to your supplier, get some info on the extraction process if you can. All of this I am speaking from personal experience in this specific matter.
Happy extracting !
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I believe they are using CO2 which I understand will carry more waxes. I had a batch from them that was particularly waxy, but they swapped out the bucket and I havenāt had issues since. I am getting ready to place another order so I will double check with them.
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Sounds good hope it all works out for you!
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Working with hydroxy-propyl-beta-cyclodextrin always made an emulsion with a very bitter after taste for me. I used a 2:1 HPBCD:THC molar ratio. The thing is I always had lecithin in the solution as well, and Iām just now realizing that may have been the cause of the bitterness.
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Several items to respond to:
@Fyourmisinformation I have only used the hielscher for what Iām doing now. Most of my sonication experience in my previous life was lysing cells open for biochemistry purification and things of that nature. So I have certainly used several other manufacturers sonication devices. From my experience they all seem to work the same, itās more important that as long as you have a quality piece of equipment that your ability to hit certain frequencies or apply certain energy levels is met. I believe for nanoemulsification you want to be able to be at least 20khz or something like that? I canāt recall, could be incorrect with that number. Furthermore a big factor in getting a quality emulsion or proper particle size is really dependent on ensuring your batch size meets the size of your sonication horn and the depth of the horn is ideal to get proper cavitation. This is where the flow cell comes into play because I can, for all intents and purposes, create a batch size in volume that exceeds what my sonication probe can handle if I were sonicating the bulk formula. This way I can leverage the flow cell to get the entire batch sonicated and my trade off for a larger probe is just a longer processing time for the batch, which has yet to become so long itās an issue.
As for if I have run it without the homogenizer? I have in small enough batch sizes that my sonication probe can be immersed directly into the formulation. If I didnāt use the high shear homogenizer I would still be using a very large overhead stirrer with a rectangular impeller to ensure my solution is as mixed and homogenized as much as it can be prior to being exposed to sonication. My formulation contains some solids like citric acid, so I really just want to make sure everything is completely dissolved. I already had the homogenizer available so I decided to just combine the two techniques because I do feel that it does in fact reduce the amount of time I have to recirculate through the sonication flow cell.
@MedicineManHempCo Obviously cost is relative. I think this hielscher sonication probe, with the flow cell was maybe 9-11k all in? I canāt recall. In the grand scheme of lab equipment itās on the cheaper side of things. So I donāt really have a great answer for you, unless you had something custom fabricated, usually the flow cell somewhat matches the horn. Itās really a simple device if you think about it, two nipples, an open space and then some orings to seal the system around the horn. As you mentioned it slips around the horn and with the hielscher model there is a protruding disc shape a distance up from the bottom of the horn, and the flow cell tightens around that disc shape. So it may be difficult to just get any flow cell.
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I really appreciate the info! Yeah man, I spent 2500$ out the door on my chinese sonicator. It surprisingly worked well for the first batch that I did. I have my hands in a lot of different pies, and if I bought the mack daddy for everything we are doing, weād be insolvent. Basically my MO is to find the cheapest way to get the job done, and improve/upgrade from there. I am interested in having something like that fabricated. I may hit up indofab and see what they could come up with. Now knowing that it can slip over the probe with an oring to seal, it should be fairly easy to design the rest. Iāve seen some that thread into the horn and have more complicated designs.
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It would certainly be interesting to see the difference between manufacturers who are providing a device to meet the same end goal, with similar but maybe not equivalent specs. I think there are a lot of variables we would have to make sure were constant to be sure weāre only evaluating the device itself, could get tricky to coordinate between two different facilities haha.
I hear you - Iām usually Macgyvering a lot of the things we do as well to keep costs low. With that in mind, the old adage of āyou get what you pay forā tends to be more and more true for more intricate and technical pieces of equipment. So I like to spend a little here or there where I feel it would be well spent.
Even with that, the sonicator comes with a temperature probe but when you install the flowcell there is no place to put the probe. So I had to put together a little swagelock three way tee that was positioned right after the flowcell, so I could try to measure the temperature of the solution at the horn as best I could to ensure I wasnāt going over my target temperature ceiling. This is why it might look so strange that I have a random temperature probe just hanging out in a random spot. So I guess even spending the money doesnāt always solve the problem haha.
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It is classified as GRAS. Iāve never seen anything restricting itās use in the past and canāt find anything on the web after a quick search. Only thing I can think of is the LD 50 which is around 18g / kg in rats
Loving your setup too. The flow cell with a jacketed cooler is whatās up!!!
Fact: All parent cyclodextrins are accepted as food additives and āgenerally recognized as safeā (GRAS).
As dietary supplement, the total daily oral dose of Ī±-CD may reach 6000 mg/day, for Ī²-CD 500 mg/day and for Ī³-CD 10 000 mg/day, and for HP-Ī²-CD as oral pharmaceutical 8000 mg/day (Ref: Loftsson, T., Brewster, M.E., āPharmaceutical applications of cyclodextrins: basic science and product developmentā, J. Pharmacy and Pharmacology, Vol. 62, 2010, p. 1607-1621).
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Dude I saw that tee and thought that was a pretty slick way to do it! My sonicator came with a thermocouple, but itās not removable, and itās a pain in the ass to get it to say down in the beaker. At some point Iāll get in there and change it out with a socket and plug so that I can use different probes.
It may be worth trying 1,3-propanediol at a higher concentration by adding it at 2%, 3%, and 4% calculated by weight/weight. Then use the lowest effective concentration. Per FDA GRAS notice GRN. 302, the maximum concentration in an alcoholic beverage is 5%. That would also be at least the maximum concentration for non-alcoholic beverages.
Also, someone may have mentioned this, but temperature control is essential. I have found bitterness increases under higher temperature processes liquid.
Are you sterile filtering your nanoemulsion?
All grades of polysorbates are generally going to have bitterness, IME. Have you found otherwise? Itās too bad synthetic surfactants and emulsifiers are not an option for people who want to make a clean label product because they work so well.
Thatās interesting! I use an overhead impeller mixer in the process tank tank for agitatation and use a high-shear roto-stator for the rough emulsion stage. I havenāt thought about using a high-shear rotor-stator homogenizer instead. Compared to the impeller mixer you wrote about, does the roto-stator improve your process?
A few questions:
- What is the throughput of your hybrid system to produce a transparent emulsion, what is your flow rate, and what is your oil load?
- Does the rotor-stator mixer increase the process liquid temperature?
- It looks like youāre using the top port on the reactor chamber as the inlet. If so, have you tried using the bottom port as the inlet? I ask because itās generally preferred to have the process liquid flowing toward the sonotrodeās horn tip to increase cavitation and mixing within the chamber.
What are the dimensions of your sonotrodeās (aka probeās) horn? You should post a picture so we can see what youāre using. An off-the-shelf flow cell reactor vessel may work for you. I know someone on the forum who has a custom fabrication machine shop that Iām using for custom machine SS tubes. LMK if you want his info. To save money, you could use an in-line tube heat exchanger rather than a jacketed flow cell reactor vessel.
Are you using a jacketed batch reactor vessel now?
Youāre correct; the ultrasonic transducer/converter frequency should be 20 kHz, and ideally, the sonotrodeās (probe) amplitude at full power is 120 Ī¼m (a minimum of 100 Ī¼m).
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So, I personally think that the super refined polysorbate that I use is less bitter than other options. I agree that it will probably never be completely devoid of bitterness, but I would say I felt the impact was a bit more mild using a super refined version. I source my super refined polysorbate 80 from Croda, so there may be variations between manufacturers or suppliers and Iām sure itās one of those YMMV situations, especially because everyone has such a different perspective on taste.
I do feel that using the high shear homogenizer as my initial mixing and homogenizing apparatus does reduce the amount of time I need to recirculate the formulation through the flow cell for a consistent and reproducible particle size of my final product. I also think that the high sheer homogenizer does a much better job of mixing my bulk formulation to begin with vs an impeller. Now as I mentioned, the formulation that I normally use contains water, liquid coconut (mct) oil and glycerin as the formulation base. These three liquids are already a bit more difficult to mix together as it is, and thatās not even getting into the dissolution of the solid ingredients that I have to add as well. So based on visual observations and my own non-data based assessment, the high shear homogenizer does provide me an overall better formulation experience vs an impeller.
Here are my answers:
1). Right now I can run about 6kg of my formulation and I run my peristaltic pump at ā50ā. I would have to go back and double check what that means as I donāt think itās really a specific unit of measurement, itās a value that will equate to a certain flow rate. I just donāt know what that actually is. With that in mind, Iāve found that after about 20-25min max of recirculation, I have been able to get a very consistent particle size result. My formulation is a concentration of 1% w/w D9 and I often use oil between 85-90% D9 purity. Keep in mind that my product is not designed to be an aqueous product and must have a water activity level below 0.85, so this formulation does NOT produce a transparent emulsion, but it looks like milk. Even with that in mind, you can see below that my particle size is still below 200um, I have a very smooth particle size distribution curve, and a consistent zeta potential (although I donāt believe the zeta potential means much in this case because I am using non-ionic surfactants, so the value itself may not necessarily dictate stability). I have posted the results I normally obtain from my finished product below.
With all of that in mind, when I was making solely aqueous based nanoemulsions, I was always doing small batch sizes and I havenāt run that type of formulation on this setup. I would have to dig through my data but Iāve been able to create some formulation mixtures that are transparent/translucent at about 20mg/mL but this is using a high energy method and I never really tried to go above that because I never needed to for any R&D application I was doing. So I am unfortunately not able to really comment on or describe how well my system works with a fully aqueous based =< 50um particle size formulation.
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I have not found that the high sheer homogenizer has as big of an impact on temperature increase as the circulation through the sonication horn does. I do get some heat generation from the homogenizer, absolutely, but I never really get close to my 50C upper limit until I turn on the sonication horn and itās been running for a few minutes. Luckily the flow cell is jacketed so I can help control the temperature a bit more directly at the flow cell, but in general I rarely ever hit my upper temperature limit unless I let the horn run for like 10min non-stop and it starts to produce more heat than the jacket can offset.
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So I pump from the bottom port of my batch mixing vessel into the top port of my flow cell, which means the liquid should be running from the top of the horn down to the tip, as you described. Maybe Iām a bit confused? In any event, I can certainly play around with the flow direction setup, itās not something I really considered.
edit minor grammar and sentence correction
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