Michelle (UR) - This is why backup plans are developed...

After waiting patiently for over a month, I finally received the alginate powder. The first step was to mix the powder with distilled water, and determine the amounts needed for a nice gel-like consistency. I started with 1.0061g of alginate, and added 1mL of distilled water until the desired consistency was reached.

This was as close to 1 gram that I could get.

Adding 1mL of distilled water at a time.

 The best consistency turned out to be 3 mL of distilled water per 1g of  alginate. I pressed the gel flat on a dish, and placed it in a Fisher Scientific Isotemp Oven at 102°C for 5 minutes. This was done to stiffen the gel for testing. After drying, the gel measured 1.5µm. I covered a 30mL beaker with the alginate gel and attempted to pour 1mL of water through it. The water did not filter through the alginate, instead it pooled on the top. I decided to repeat the process using 5.0400g of powder and 15mL of distilled water, pressed to a thickness of 0.5mm and dried in the oven for 5 minutes. No water filtered through this thickness either, so I decided to try to dry it for an additional 5 minutes. Water still did not pass through. This gel was returned to the oven to dry for 21 hours and 50 minutes, while a 50mL beaker was lined with a mixture of 7.0139g alginate powder and 21mL distilled water and left to dry in the oven for 20 hours and 35 minutes. Both forms of alginate were shriveled to the point that they could not be tested as a filter. As no thickness was allowing water to pass through, I decided to move on to my backup plan, attempting to use alginate as truly disposable cups.

Alginate after 21 hours and 50 minutes in the Isotemp Oven.

Alginate after 20 hours and 35 minutes in the Isotemp Oven.

The final test was a mixture of 23.8460g of powder and 69mL distilled water, hand rolled into a ball and split in two. I used a rolling pin to roll each section to a thickness of 1µm. Each half was draped over an upside-down 30mL beaker, with one placed in the oven and the other allowed to air dry. Both were checked and inverted after 20 and 40 minutes. The gel in the oven peeled away from the beaker and broke after 40 minutes. The alginate left to air dry is being left alone for 7 days. Fingers crossed!

Emma asked: What is the financial feasibility for using alginate for these purposes? Is there anything that stands in the way of using it, if you are successful? What should we consider before this is a widespread filter or environmentally friendly disposable cups?

 Great question, Emma! Thanks! The powder from Carolina Biological was about $15 for 25g of powder. My tests were originally for a filter, and the total cost would have been comparable to other filters, which depend on the size needed. As for disposable cups, it will depend on whether or not my method works. I imagine future research could look into using the glaze that goes on pottery, to ensure no taste changes. Also, different amounts of powder would need to be tested, to see what consistency would work best for molding into the cups and utensils. I hope to have more information after the 7 day air drying process is finished.