[Bill_Toge]

ngarayeva001 said:

I noticed that polysorbates can lead to a decrease of viscosity when added to shampoo. The caveat is that I only observed that in sulfate-free shampoos.

this is true in structured surfactant systems generally; highly soluble non-ionic surfactants like polysorbate 20 compete with the structured surfactant system for the available water, and cause the latter to thin

a manufacturer I used to work for used to use PS20 to thin surfactant-based products, until they realised hexylene glycol was more flexible (easier to re-thicken the product if they overshot the bottom of the spec) and was cheaper

[Bill_Toge]

what you call the ‘binding power’ of a salt is its solubility in a given solvent - there are many methods to determine this, simple and sophisticated, and solubilities of relatively common substances are widely published

when the term ‘binder’ is applied to cosmetics and other formulated mixtures, it is typically used to mean a substance which acts to keep the mixture physically homogeneous; it is an entirely separate meaning which has nothing to do with the substance’s power to solvate

[Bill_Toge]

whatever you use, a mixture of two or more different types will be most effective, particularly as face masks carry a relatively high risk of contamination

[Bill_Toge]

sounds like there’s a lot of residual ammonia in it; when I used to use BTMS-50 it always had a hint of ammonia, but the smell was mostly fat-like

[Bill_Toge]

should be if you have a high enough dose - try it and see

1,2-diols are antimicrobial by nature, and their activity increases as the chain length gets longer

[Bill_Toge]

the fundamental problem is that the two phases in your product have different densities, and your product is a Newtonian fluid (has no viscosity at zero shear), which causes them to separate over time

your best bet is adding a rheology modifier to the water phase, e.g. a carbomer of some kind, which renders your product pseudoplastic (i.e. immobile at zero shear) and physically prevents the phases from separating

[Bill_Toge]

either for cleaning, but 70% works better for disinfection as it evaporates more slowly, so the contact time is longer

[Bill_Toge]

in my experience, low acyl gellan gum can form very carbomer-like gels at low concentrations - the relatively minor down side is that it can be more fiddly to work with than carbomer

[Bill_Toge]

if you have the budget, consider investing in a chroma meter - this will allow you to measure colour quantitatively

to ensure your results are reproducible, always measure your samples in the same lighting conditions; a light booth will help enormously

[Bill_Toge]

for what it’s worth, polysorbate 60 or 80 at that level will render most preservatives useless

[Bill_Toge]

for what it’s worth, hot-fill styling products are some of the most complicated products on the market in terms of formulation

[Bill_Toge]

in the UK at least, perhaps it’s for the best that bench work is kept to a minimum

there were at least two infamous examples of ham-fisted formulation from my previous employment in a contract manufacturer, in which the manufacture and filling of some major then-new Alberto Culver hot-fill styling products was subcontracted to us, because the sheer size of their reaction vessels combined with their R&D department’s lack of attention to detail made it impossible to produce those products on their own site

there were 12 people employed in that R&D department, none of them could figure out why their formulas went tits-up in production, and blamed their production and manufacturing departments for their failure; given that the two chemists on our site figured out the reasons within hours (one had a fundamentally unstable emulsion that separated under filling conditions, the other contained a resin that became insoluble 10 degrees below the product’s filling temperature, making it gritty), it’s little wonder the former were eventually made redundant

as far as I could tell, most of them were well-spoken and politically OK, but as much use as a glass hammer when it came to anything practical - yet another triumph of British university education!

[Bill_Toge]

in my experience they tend to make minor modifications to existing formulas, or adapt formulas from ingredients suppliers, and generally keep the bench work to a bare minimum

your mileage may vary

[Bill_Toge]

they’re as different as chalk and cheese

[Bill_Toge]

at sufficiently high concentrations, chlorhexidine will basically nuke microorganisms from orbit, which is why it’s used as a surgical disinfectant

and for what it’s worth, Dettol is sold in the USA, but under the brand name Lysol

[Bill_Toge]

how big are your batches?

if they’re more than a few hundred grams, the effect is insignificant

[Bill_Toge]

also, if the ingredients list is accurate, the product is missing a low-HLB emulsifier, and going by its appearance, it appears to be a highly concentrated surfactant gel rather than a conventional emulsion

[Bill_Toge]

I’ve seen it argued that the alkaline pH of soaps helps soften the hair prior to shaving; however, as I have very thick, coarse, product-resistant facial hair I can’t personally confirm or deny this

[Bill_Toge]

generally speaking, polymers which thicken water will also thicken glycerine, propylene glycol and 1,2-propanediol, but they’ll hydrate much more slowly than they do in water, and may require heat

[Bill_Toge]

from my experience, it’s usually used to mean “less likely to irritate the skin or significantly strip the lipid layer, at recommended usage levels”

[Bill_Toge]

it’s a shame how the Guardian has declined in the last 20 years: it used to be a respectable paper, now its total lack of quality control makes it the world’s most pretentious tabloid

[Bill_Toge]

for what it’s worth, honey is about 80% sugar, about 20% water and miscellaneous trace compounds

[Bill_Toge]

in my experience 70% IPA is best, as it’s effective, easy to handle, evaporates readily, and doesn’t leave oxidising/reducing/odoriferous residues

[Bill_Toge]

a rotary lobe pump is best for non-Newtonian fluids

also, the engineering firm Bran & Luebbe supply mixing systems specifically designed for diluting SLES, you might want to look into one of them

link here

[Bill_Toge]

@Agate sugar is hygroscopic, and bug food; it’s better to be safe than sorry

@kelseaventures if there’s no water in it, how can it have a pH?