Week 8

Hey everyone!

Like last week, this week was also focused on trying to fix the problem of collecting the hydrogen gas produced.

I checked the current caulk that I had on my device and found that there were some leaks because the material seemed to be dissolving away or was not fully leakproof.

I then researched about which caulk would be most suitable for my particular situation. I needed something that would both adhere well to plastic and not dissolve or crack under pressure or near water.

After searching online and going to the store, I talked to an associate about what I would need this caulk to do and showed them that the previous one had not worked. The associate then recommended me to try GE’s white silicone it caulk. I had researched online that 100% silicone was good for sealing and the product claimed to be permanently waterproof so I decided to try it out.

 

Before applying the new caulk I would have to remove all the old caulk and any dirt in the area in order for the new one to work effectively. I used a knife to scrape away at the old sealant and did so until it was sufficiently clean. I then carefully applied the new caulk (which was white rather than clear) to the device. This time I angled the electrodes to be closer together so that there was less resistance from the water between them when the experiment was run.

The label said that the caulk would be waterproof in 30 minutes but I decided to wait the full 24 hours before running the experiment so that the caulk could fully cure.

After the caulk was ready, I ran the experiment again, using my 9 Volt batteries in the same set up as before. Because I wasn’t sure if my makeshift balloon was tight enough (and thereby causing a leak), I found a real balloon and used a rubber band to tightly tie it to the collection tube instead of using string as before.

I left the experiment to run for a while, but again I did not see a change in the balloons shape. I’m still not sure what is wrong with the device but I decided I would talk to my professor about it the following week. 

Week 7

Hey Guys!

This week was spent focusing on trying to collect the Hydrogen gas that was produced by my device.

I went to the lab and talked to my professor about the issue and he suggested I try to increase the current output by putting more batteries in series. He also suggested I try to increase the water level so that there is less air in the container and so that it is more easily pressurized. He gave me some 1.5 Volt batteries, an old charger he didn’t need anymore and left me to work.

First thing I did was found some scissors and cut up the old charger into wires. I cut back the insulation so that the metal would be exposed to the batteries and made a set of mini wires I could use to connect the batteries. I didn’t have anything to hold the wires in place (I wouldn’t be able to hold all of them manually while I ran the experiment) so I found some parafilm and used it to tie the wires down onto the batteries, and then tie all of the batteries together. Together they made a much larger battery.

                      

Before I tested the new battery I increased the water level to 1000 mL and added a 1/4tsp of salt to keep the concentration of salt the same as before.

After preparing the solution, I tried the larger battery that I had created on my device. It contained four 1.5 volt batteries connected together in parallel. After wiring the battery to my device, I observed that there were no bubbles forming.

I then changed the set up of the battery and connected 2 batteries in parallel and connected it in series to another 2 batteries in parallel. The setup gave me 3 Volts instead of 1.5 as before. When testing it, I found that this time bubbles did form and gas was produced. The reaction however was still less severe than that of my 9 Volt battery.

I then sought some help from my graduate lab partners and they used a device called a potential state to check for the minimum voltage needed to start the reaction. To use the device, a range of different voltages are tested and the resulting current is measured.

 After experimenting we concluded from the graph above that the minimum voltage needed to start the reaction was 3 Volts because there was a drop in the rate of current increase at this location. At this point is where water begins to split. The reduction reaction uses the electrons to create the hydrogen gas causing a drop in the rate of current increase even with increasing voltage.  The graph also explained why the 1.5 volt batteries all in series did not work (we had not reached the minimum voltage required). 

I then tried using four 9 Volt batteries instead of 1.5 Volts to see if I could collect anything with the same setup (2 in parallel connected in series to another 2 in parallel) and left the device for an hour. After time was up there was still no change in the shape of the balloon and so I decided that I would have to change the brand of caulk I was using and check for any other leakages elsewhere.

Week 6

Hi everyone!

This week I finally got to put my device into action! Before I started I had to gather more materials. I went to visit my professor so that he could collect the salt needed to start testing. He gave me a small amount in a bag and told me that I wouldn’t need too much to get the reaction started. I also bought alligator clips with wire attached so that I would be able to connect my electrode to the battery/ solar cell.

Before experimenting, I had to choose a starting point for all of my variables. My container has a capacity that is slightly greater than 1 liter and my professor had suggested trying to fill the container about 3/4ths of the way with solution. I measured approximately 750ml of purified water with a beaker and put it inside my container. I started with my smallest measure, a 1/4^th tsp, to see if I could get a decent reaction and decided I could add more later on if needed. After stirring, I tested a 1.5 volt battery on the solution and checked for the formation of any bubbles at the cathode to indicate a presence of Hydrogen.

At 1.5 Volts, I didn’t see any reaction so I increased the voltage to 3 volts by adding another 1.5 Volt battery in a series circuit. This produced bubbles, but they formed very slowly, so I tried increasing the salt concentration in the water, adding another 1/4^th teaspoon, and the formation of bubbles increased. I added one more quarter teaspoon (with slightly increased bubble formation again) and then decided I needed a much bigger battery if I was going to produce enough Hydrogen to collect. I then went with one of the graduate students in my lab, Wen Si Huang, to go find one, and we purchased a 9 Volt battery from a nearby store to test.

The 9 Volt battery was visibly extremely effective at increasing bubble formation as shown in the video below:

Because it was rather difficult trying to ascertain whether or not there was any hydrogen flow coming from the collection tube, I cut a glove up and tied it with string to see if the makeshift balloon would inflate.

After waiting a while, unfortunately, even though there was hydrogen production, the balloon still did not inflate.

There are a couple of reasons I could think of for this result. Either there is not enough gas being produced to inflate the balloon, in which case I would have to try powering the device differently or there remains a leak in the devices sealing. I will have to try to resolve the issue next week.