RobboAU
Forum Replies Created
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Does it happen immediately upon dissolving when mixing in plain water?
Aqueous copper ions form colourful complex ions with anions. Cu2+ and Cl- famously make a green solution.
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I use the mixer with the digital display and use it to mix shampoo, conditioner and hair styling emulsions. It suffices for lab volumes of 100-800 mL.
I primarily use a pitched blade axial flow impeller (from eBay), which I was advised to use instead of the marine propellor/screw that comes with the unit. If anyone can tell me why, that would be great!
For dispersion/wetting, I also got a few different sizes of cowles/dispersion blades (also from eBay). One of those at 2000 RPM for 30 seconds can really tear things up.
Overall it’s a pretty cheap system that gets the job done, and allows you to safely leave something mixing for hours.
The clamp that is meant to hold your beaker in position is absolutely useless though.
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Just for fun, I decided to try the OpenAI chatbot that’s making social media news recently. I was rather impressed with the result it generated.
“Clean beauty is a term used to describe cosmetics and personal care products that are made with ingredients that are considered safe, non-toxic, and environmentally friendly. Clean beauty products often avoid the use of certain chemicals and synthetic ingredients that are believed to be harmful or potentially harmful to human health or the environment.
Some of the key principles of clean beauty include:
- Using natural, plant-based ingredients whenever possible
- Avoiding synthetic chemicals and preservatives
- Avoiding known irritants and allergens
- Using minimal and safe synthetic ingredients
- Avoiding animal testing
- Using sustainable and environmentally friendly packaging
The term “clean beauty” is not officially defined or regulated, so different companies and organizations may have different criteria for what constitutes a clean beauty product. Generally, clean beauty products are those that prioritize the use of ingredients that are considered to be safe and non-toxic, while also being mindful of environmental impact.
It’s important to mention that there’s no standard definition of clean beauty, so different companies and organizations may have different criteria for what constitutes a clean beauty product. Also, some certifications can help consumers identify clean beauty products, but it’s important to read the labels and make an informed decision.”
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Microformulation said:Cocoa Butter was also used a great deal in Pharmaceutical Compounding as well. To this day whenever I smell it, I can recall making hundreds of suppositories in the Pharmacy back in the early 80s.
Interesting, does that mean I’ve been taking chocolate the wrong way this hole time?
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ketchito said:@RobboAU I don’t think I made a disrespectful reply to your comment, and I didn’t know one can’t make a mistake without being mocked, but well, you always meet different types of people.
My comment was correct, except for the molecular weight of the Dimethicone 350 (wrong source of information, my bet). And as @Pharma mentioned, there’s no linear correlation between a polymer’s viscosity and its molecular weight -# of repeating units, if we were to talk ideally about linear molecules- (there’s a relationship, of course, but not linear).
You weren’t disrespectful at all, I had completely misunderstood the 350 due to assuming it had the same meaning as the numbers in D4-6 cyclomethicones.
The formulation I’m working on wanted a thicker aesthetic and a silicone after-feel, for which I was turning to 350 on mistaken logic. I’d rather find out now than weeks later!
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Good lordketchito said:
RobboAU said:Dimethicone comes in various sizes, based on how many Si-O units it has.D5 is as Graillotion described. D350 has 350 repeating units and is therefore much bigger. It does not evaporate quickly (if at all) when heated to normal process temperatures.
More Si-O units means bigger molecules, which trends with greater viscosity, higher boiling points and thicker aesthetics.
The 350 in Dimethicone 350 is referred to its (kinematic) viscosity -which is 350 cSt- and not to the number of repeating units. If you asume 350 repeating units, then your dimethicone 350 would have a molecular weight close to 27k g/mol, which is way higher than the value you can find from different suppliers, which is no higher than 300 g/mol.
Wow, I’m just about to start a formulation with 350 too!
I wonder if my fragrance supplier can tailor a hot baked humble pie fragrance for me
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Dimethicone comes in various sizes, based on how many Si-O units it has.
D5 is as Graillotion described. D350 has 350 repeating units and is therefore much bigger. It does not evaporate quickly (if at all) when heated to normal process temperatures.
More Si-O units means bigger molecules, which trends with greater viscosity, higher boiling points and thicker aesthetics.
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Graillotion said:I like the other two you mentioned better. To me…68 feels more unctuous. So if that is your goal….have at it.
Curious, I went the opposite way.
I love 68 (technically the BASF equivalent) and found 202 unpleasant in comparison.
I had to do a label copy of a popular hair styling product that used 68, but only had access to 202. I found the rub-in and spread of 202 was not as uniformly smooth and creamy, and was prone to beading and pilling. In contrast, I couldn’t stop playing with the 68 version - but it is “heavy”.
68 is also cheaper than 202, so I reckon that’s worth trying
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You’re welcome, hope it helps. Keep in mind that whilst this is helpful for lab-size batches, scaling it up beyond the 1 kg range can be challenging and expensive.
Let us know how it goes!
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sweetflakes said:Hi @ketchito & @ariepfadli, you’re absolutely right. I tried adding a little bit of silica dimethyl silylate and it keeps the pigments from settling. I had no previous experience with silica dimethyl silylate though so it wasn’t a smooth dispersion. What’s the correct way to disperse it in oil? Do I need a rotor/stator homogenizer or would a 4-bladed overhead mixer suffice?
You can use an overhead mixer, but get a dispersion blade for it (which is also called a Cowles blade). They’re very simple to manufacture, so grabbing a cheap one ebay for your overhead is fine.
I would recommend batch sizes greater than 400 g and 1500-2000 RPM when using it.
For reference: https://fusionfluid.com/products/mixing-impellers/cowles-disperser-multi-blade-stx
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You could try using something like Dermofeel Viscolid to thicken your oil phase.
It doesn’t give you a clear product, but 5% is apparently enough to gel sunflower oil. The TDS on prospector gives a good overview.
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Abdullah said:RobboAU said:700 ppm is 0.7 g/L (0.07% w/w) of total dissolved solids, some of which will be CaCO3.
If we assume that all the TDS is metal cations that EDTA/STPP complexes with, then 2% is more than triple the amount you need. It’s also a lot of Na+ ions.
To quote the famous cosmetic chemist, Lil Jon: that EDTA concentration needs to Get Low. (citation needed)
2% EDTA/STPP is 2% when it is in Product, when it is in wash water, it gets diluted many time.
For example, in a wash cycle in automatic machine, i added 150g of liquid detergent, when wash water came out, it was around 17kg water.
It means that 150g detergent has been diluted with 17kg of hard water.
So if the detergent had 2% STPP, during washing it has only 0.017%. is this amount enough to make that hard water soft?I didn’t realise you were adding it to soften the water in the washing machine.
In that case I am skeptical that is practical or feasible. 17 kg of water at 700 ppm is about 12 g of dissolved solids. A 150 g dose of detergent would need 20 grams of Na2EDTA to bring that water down to “soft”, with some very big assumptions. You will not create a stable liquid detergent under those conditions.
Ketchito has suggested the best solution - mixed micelles - to address detergent functionality in very hard water.
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700 ppm is 0.7 g/L (0.07% w/w) of total dissolved solids, some of which will be CaCO3.
If we assume that all the TDS is metal cations that EDTA/STPP complexes with, then 2% is more than triple the amount you need. It’s also a lot of Na+ ions.
To quote the famous cosmetic chemist, Lil Jon: that EDTA concentration needs to Get Low. (citation needed)
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Do you have a measure of your water hardness?
The US Geological Survey defines very hard water as having a CaCO3 concentration greater than 180 mg/L. Converting to mol/L, that’s 0.018 mol/L.
To treat that you’d need 0.018 mol/L of disodium EDTA, which is 6 g/L. That’s about 0.6% by weight.
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Abdullah said:ketchito said:@Abdullah That’s too much precipitate to be the CMC. Maybe you’re salting out your surfactants. Could you try reducing the STPP?
What is “salting out” of surfactant?
What percentage of STPP do you suggest?
Salting out is the practice of reducing the solubility in water of a compound by increasing the ionic strength, i.e. adding more Na+ ions.
My suspicion is that 5% STPP is a lot of Na+, the back of my napkin says it’s equivalent to 4% NaCl.
With 7.5% active SLS, 4% equivalent of NaCl is going to push a lot of that SLS back into the associated state.
Like Ketchito said, try without the STPP.
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The ABS numbers are a measure of how much light with a wavelength of 500 nm is absorbed by the sample.
I’m assuming that sebum oil has particular carbon chemistry that absorbs light in the 500 nm region. The sample that absorbs more light therefore has more of the absorbing compound, which we are lead to believe is sebum.
Without knowing a lot more about emulsion science and the details of the test, I remain skeptical that the graph actually demonstrates that LHS has indeed emulsified more sebum than CAPB in an identical situation.
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Fantastic, thank you both!
I haven’t got any confirmation on the manufacturing process (nor do I expect it), but industry standard is apparently to run the polymerisation in an ethanol solvent.
When you say that it may aspirate, do you mean that ethanol vapours from the bulk powder may condense at the top and create a gummy-glue residue?
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I’d also suggest trying a fatty alcohol, but more specifically a blend like Montanov 68 or Emulgade PL 68/50 (cetearyl alcohol & cetearyl glucoside).
They should help improve the rinse-out if you’re using them around 3-4%.
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As a first timer that has used the search feature many times, I find it particularly ineffective.
It’s okay for searching for a single word, such as “process”, but if I’m searching for “Hot process” I will get anything and everything with either “Hot” or “Process” in it.
The way the results are displayed is also a little inconvenient, with it being sorted by time. It would be helpful if results were grouped to discussion heading rather than all listed out by date posted.
Overall I’d say I’m quite cold on the current search process.
I’m hot for a like function on replies, but I do not think a dislike function will benefit this site.
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I’d recommend going with their dispersions for ease of manufacturing and formulating. MicNo® DCC-N or MicNo® DAB. You can combine dry powder with the dispersions if you want, but it will make for a more challenging scale-up beyond lab bench batches. Remember, the dry powder will do nothing if it isn’t wet, dispersed and suspended properly.
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They’re saying non-nano their website but doesn’t mean much without knowing which definition of nano they’re using. Nano definitions used to be pretty vague and varied, I know of a USP-grade ZnO powder that was non-nano according to a specific French decree but nano according to EC 1223. That’s two contrary claims inside the EU!
Generally speaking, ZnO’s provides SPF by scattering UV rays and to a lesser extent, absorbing and emitting it as thermal radiation. The smaller and more numerous the particles, the greater your scattering power for the same total weight. Achieving 2 SPF units per % of ZnO is quite challenging and I’d be highly skeptical of a truly “non-nano” powder achieving this.
In regards to it being easy to get that level of protection with ZnO… yes and no. If you are working with a dry powder then you need to wet, disperse and suspend the particles. When the particles are not evenly dispersed you won’t get scattering and your SPF will be zilch. Achieving this can be very challenging, even for industry veterans.
Using a pre-dispersed grade of ZnO in a common oil like CCT will solve the wetting and dispersing problem, so you can simply pour it into your oil phase. Now all you need to do is ensure the mixture is homogenous and has enough viscosity to prevent ZnO agglomeration.
Get all of the above right and you’ve got a 50/50 of the in-vivo SPF being… in the ballpark.
