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hydrophobically treated glass for w/o emulsion
Hello everyone, I’ve been reading this forum for years and can’t express how useful it has been for my career. I have a question regarding packaging for w/o emulsions. I recently read that w/o emulsions with high water content such as water-breaking (or water-drop) emulsions require a hydrophobically treated inner wall if using glass jars. It’s my understanding that typically, glass jars have a hydrophilic inner wall which is not ideal for these kinds of emulsions. However, I’m not clear on what is the reason for this requirement. Is instability expected to happen? and can this happen also in polypropylene? I do have seen a couple of my formulations gliding on the bottom of the beaker in a strange way and eventually pooling when transferred into glass jars, specifically in air pockets between the formulation and the glass wall. However, I’ve also seen this happening in polypropylene specimen cups.
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1 Reply
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Basically all w/o are not thermodynamically stable but “metastable.” Packaging into PP or HDPE should not affect this too much. The glass wall thing is a mystery to me. I have never seen that but I have seen inversion of w/o emulsions on Tygon transfer hoses, which are silicone based, but only when warm. Must be some tribology effect there we don’t often see? Try cooling the glass jar first to see what happens.
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