User:Allison K. Alix/Notebook/CHEM-581/2013/02/13
|Washing/Drying of Nanogels||Main project page|
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Nanogels are currently in mineral oil that they were originally prepared in. Acetone will be used to separate the nanogels from the oil from which tey will then be able to be filtered out of and dried.
1) Add mineral oil/PVOH emulsion to separatory funnel. Add ~500mL of acetone and shake thoroughly, being careful to release any pressure that has built up.
2) Vacuum filter acetone and dry hydrogels. Store at 4°C
When acetone and mineral oil were placed in the separatory funnel, it was immediately noticed that mineral oil was insoluble in acetone. The original procedure which these methods were adapted from used silicone oil in place of mineral oil, which is slightly soluble in acetone. To accommodate for this, ~400mL H2O was then added to the mixture which the nanogels were then re-suspended in. They were rather concentrated and ended up adsorbing to one another so that there were several large aggregates. These aggregates were further broken apart using sonication. Although not completely detached from one another, the mixture was then vacuum filtrated. Upon removal from the vacuum filtration, it was evident that there was still water present in the nanogels. To completely remove this water and promote solid formation, they were lyopholized for 1 day. Before lyophilization, we were able to look at our sample under a microscope (See Data).
1)Final mass of PVOH (MW: 146,000)=0.4526g
2)Final mass of PVOH (MW: 130,000)=0.8244g
3)Final mass of PVOH (MW: 89,000-98,000)=0.7608g