All posts by Tom Geiss

I am a middle school teacher in El Paso Texas. I will be an intern this summer at the NEWT Lab at UTEP. I will be working on a project that is using nano-materials to remove arsenic form water.

I Got Nothing

Week 4 NEWT RET Tom Geiss

 

Title: I Got Nothing

This week’s title “I Got Nothing” has a double meaning. On one hand, I couldn’t think of a catchy title that refers to what I am doing in the lab. On the other hand, it refers to the fact that I gots no data from our experiment regarding the adsorption of arsenic by composite nanomaterials vs a zinc ZIF. I know I promised you guys some real Rick and Morty stuff this week. I was going to wow you guys with a story about how we were going to gather data from our experiment using a ICP-MS that would tell us how our nanomaterials had adsorbed arsenic from our NEWT fresh water media.

 

Inductively Coupled Plasma Mass Spectrometry or ICP-MS is an analytical technique used for elemental determinations. I could go into to detail about how “An ICP-MS combines a high- temperature ICP (Inductively Coupled Plasma) source with a mass spectrometer. The ICP source converts the atoms of the elements in the sample to ions. These ions are then separated and detected by the mass spectrometer.”1However for the sake of brevity and for understanding by my target audience, I would say that the ICP-MS is like the sorting hat at Hogwarts. Its freaking magic that muggles would struggle to comprehend.

The advantage of the ICP MS compared to other types of elemental analysis is that it can detect concentrations of matter at the really low end of the spectrum. A typical ICP-MS device can detect concentrations as low as 1 in 1015.

So, we were all set to take the samples from our adsorption experiment to the ICP-MS in the chemistry lab at UTEP. Unfortunately, this is a complicated device and can only be run by one person here at UTEP and that person is in Europe until August. To make matters worse, on the same day, I found out that there is no Taco Tuesday at the Pick and Shovel (our version of the Servery for you Rice NEWTS). I was inconsolable to say the least.

With a poster deadline looming Mariana Marcos my mentor pulled a rabbit out of her hat and shipped our samples to ASU where a really nice NEWT person named Ariel will run the tests on Monday and email the results to us just before my rough draft of the poster is due on the 13th.

 

Accurate vs Precise

I don’t know about you guys but the abstract due on Friday was way harder than I thought it would be. Here is what I leaned. When writing for a scientific publication you can’t just pull stuff out of your ass like we do during the school year for our principals who do not have a scientific background. My principal wouldn’t know a GMO from a solar eclipse and let’s keep it that way.

I finished my rough draft and sent it to Mariana Marcos, my mentor, for analysis. When reviewing it with her I realized that you really have to focus on stating precisely what you have learned from your research in the lab as well as what you have learned from your scholarly readings. Simply put, the hardest 250 words I have ever written.

Well, thanks for reading. See you next week

  1. Ruth E. Wolf, Ph.D., Research Chemist, USGS/CR/CICT, March 2005

NEWT Water is Weighing On Me

NEWT RET Week 3 Blog Tom Geiss

I began my week in the lab assisting Marina Marcos and Roy Arietta in preparing composite nanomaterials for an experiment to test the composite materials ability to adsorb Arsenic from a simulated fresh water sample with an Arsenic Concentration of 50 ppb. Just a reminder, the composite material is made of three different nanomaterials: graphene, iron oxide and Zinc ZIF. Last Friday, we prepared our NEWT fresh water sample using the NEWT recipe. We did everything except add the Arsenic to the NEWT fresh water solution.

Making the NEWT Fresh water can be a little challenging as some of the masses can be very small. Below is a photo of one of the salts we add to the solution as it sits on the scale. As you can see the mass (0.00072 g) is one tiny  spec of the salt.

The next step was to measure different masses of the composite nanomaterial. We measure out 10 different masses ranging from 0.000125 g to 3 grams. On two different masses we measure duplicate masses so that we can verify the validity of the test data.

After the all of the masses of the composite materials were measured we then buffered the samples with Sodium Bicarbonate. We let the different masses soak overnight. The next day we used a pH meter to record the pH and confirm they were within an acceptable range. After recording the pH we rinsed the samples in DI water. That’s when we realized we had a problem. While rinsing and decanting we saw we were losing small amounts of mass of each different sample as we were decanting. We tried to compensate by using a magnet (my idea) while decanting but we still lost material in the process. This meant that the masses we recorded at the beginning of the experiment would not be valid.

Marina and Roy being much brighter than I, quickly came up with a solution. Not a new solution of composite but a new solution to the problem.  They concluded the answer was to create additional composite material buffered in sodium bicarbonate, then create 10 new samples of composite that had been buffered and cleaned. That way the masses stay consistent throughout the experiment.

So by late Thusday or Friday we can continue our experiment with adsorption of 50 ppb of arsenic.

While were measuring our masses and preparing our samples, discussion turned to the diversity training we had attended on Monday. Mariana asked what I thought about the training. What ensued was a thoughtful discussion of how diversity is addressed in academia, business, middle school, and high school. I shared that I thought that among my peers that I teach with diversity is accepted and valued. I also thought that people still had perceptions based upon stereotypes that might be expressed in nuanced ways. Mariana shared a story about being in a food court and an acquaintance expressed surprise at her choice of food thinking she might chose a food that was more culturally relevant to her. It surprised her that someone would assume that based upon her ethnicity she only eats a certain type of food.

I have been thinking a lot about the TED talk we watched last week about “The Danger of Single Story” by Chimamanda Ngozi Adichie.  I have thought about this in a few ways. One, I think about how  I make assumptions about what types of activities they can and can’t do in a lab setting. Or how I may have preconceptions about their reading or math ability that may not be true. Even when we engage in “data mining” based upon STAR practice tests, it doesn’t tell the whole story of that student’s ability or even their real reading level. Some of my students according to the data are 8th graders that read at the 2nd grade level. However, when reading aloud in class they clearly have a higher comprehension of what they read, than what their test scores reveal. Reason being, they tanked the test on purpose because they did not care about the outcome.

I have also been thinking about how close minded my students are of anyone who is slightly different than they are. My students are predominantly Hispanic males between the ages of 12 and 15. They are dismissive  of anyone who does not look like them, act like them, like the same music as them, does not talk like them, does not like the same food as them, etc. etc. I know some of this is part of adolescence, but the intolerance as such a young age is depressing.

How do you get that close minded at such a young age? My stepfather was a closet racist. He worked in a culturally diverse work place. When he came home he made derogatory comments about people of different ethnic and religious backgrounds that I am sure he did not share at work. Rather than parrot these ideas, I compared his observations with the children I went to school with. I grew up in Topeka Kansas. Home if the famous Brown vs Board of Education. That Supreme Court case was decided in 1954. By 1965 when I started school, we had a diverse student population. In my observations the children of color were no different than me. We all wore pretty much the same clothes, ate the same food, listened to the same varieties of music and played and learned together with the same peaks and valleys. So I quickly decided my step father was full of it and tuned him out when he went on his racist rants at home.

So I am really discouraged that 40 plus years after I attended middle school, in some ways we have gone backwards in time. During the Diversity seminar on Monday, a participant at another location stated that they thought that social and emotional learning was key to getting students to accept and respect diversity. I totally agree. We have started using circles at our campus to address social and emotional issues and build relationships between student and staff. Success has been limited, but I am optimistic.

On Wednesday we started synthesizing started nanomaterials for adsorption tests we will start We began on Friday. The first material we created was Zinc ZIF. We are going to test the adsorption rate of the Zinc ZIF so that we have a comparison to the adsorption rate of the composite material which has all 3 nanomaterials in it.

Once we have added Arsenic to our NEWT water we will put 500 mL of contaminated NWT water in 14 jars. One jar has no nanomaterial to serve as a control and the others have various amounts of nanomaterial.

Then for three days we put the jars in a shaker that slowly moves the jars in a circular motion. This allows the nanomaterials to be moved in solution with the contaminated NEWT water.

We ran into a problem with our NEWT water. I made a bone head move and did not make a correct calculation on one of the compounds you make NEWT water with. My error in calculation, ( I forgot to divide by 1,000) which made me add 1,000 times more Sodium Phosphate than was needed for experiment.

Marina told me this happens to everyone so don’t get too upset. So we tossed the contaminated water with arsenic down the drain and started again. Just kidding. There was no arsenic in it so we didn’t contaminate the El Paso water system.

Once the NEWT water was done and we had all of our different masses of nanomaterials weighed out. We put all 27 of our samples in the shaker at set the motion at 100 rpm (see photo below). We have 13 composite samples and 13 ZIF samples and 1 control. We will take them out of the shaker on Monday afternoon and then begin to prepare them for analysis to see how much Arsenic was removed from the solutions.

That’s all for now. Next week we get into some real Rick and Morty stuff. See you then!

Iron it Out

UTEP Newt

My first week of NEWT at UTEP was one of shock and awe.  I was shocked by how much I didn’t know about chemistry and I am in awe of the people in the group I have been assigned too. Their knowledge of inorganic chemistry and their patience with me is truly amazing.

I have been assigned to Dr. Dino Villagran at UTEP and I am working with his graduate student Mariana Marcos. I told Dr. Dino right away that I was a little concerned about my current level of understanding of chemistry. He graciously offered to let me sit in on his General Chemistry class that he is teaching at summer school. So almost every day this week my day has started at 8:00 AM with 150 other students in an auditorium. Boy have things changed since I took chemistry in college. When I took chemistry back when I was in college, there were only 40 elements on the periodic table of elements.

After chemistry class I head over to the lab. My mentor, Mariana Marcos is doing research on using nanomaterials to remove Arsenic from drinking water. The nano-materials that we will be working with and actually synthesizing are: graphene oxide (GO), magnetite (Fe3O4), and zeolitic imidazolate frameworks (ZIF).

Each of these three materials has shown selectivity in adsorption of arsenic in simulated drinking water. The objective of the project is to obtain and compare the adsorption capacity at 5 and 50 PPB (As) and determine the selectivity of each of the three composite nano-materials towards Arsenic.

Mariana gave me an article on removal of Arsenic from water titled: “Technologies for Arsenic Removal from Water: Current Status and Future Perspectives”, from the International Journal of Environmental Research and Public Health. The introduction of the article provided background of Arsenic as a pollutant in drinking water. Not only is Arsenic introduced to the environment via agriculture and various industrial uses, it is also introduced through natural sources such as the weathering of rocks which contain arsenic. I learned that Arsenic is a naturally occurring metalloid that that is very “mobile” in the environment based upon its parent mineral form, oxidation state, and mobilization mechanisms.

Based upon oxidation state, arsenic can exist in 4 forms. Of these 4 forms of arsenic the most prevalent forms found in water are arsenite (As (III)), and arsenate (As(V)), which are both inorganic.

Arsenic is known to be a highly toxic to all life forms and is classified as a group one carcinogenic substance by the World Health Organization.  The WHO has stated that arsenic concentrations in ground water should be limited to no higher than 10 µg/L. At levels above 50 µg/L in drinking water, people can develop a wide range of health problems including cancers. Collectively these disorders are referred to as arsenicosis. According to the article I read, the ground water contamination for arsenic is highest in Asian countries. In Bangladesh and India over 120 million people are exposed to contaminated ground water with above 50 µg/L. In Bangladesh, the arsenic level in some tube wells is as high as 4730 µg/L.

According to this article arsenic in its most common form arsenic can be difficult to remove because of its oxidation state. Typical water treatment methods for arsenic involve a two-step process for removal. First the oxidation of soluble arsenite to arsenate. After that, a removal technique must be used such as adsorption, coagulation, or ion exchange. According to the article, oxidation can be problematic as other contaminants in the water can interfere with the oxidation process.

So this is where nano-materials come in to save the day. Research has shown that iron oxide nano-materials have been five to ten times more effective in the removal of arsenic that conventional water treatment methodologies. Mainly because of their high surface-to-volume ratios. Plus, their magnetic properties make extraction from the water easier using magnets.

So this week I started in the lab helping Mariana Marcos synthesize some Fe304 nano-particles. You do this by a process called co-precipitation.  I don’t need to tell you guys that iron (Fe) exists in 2 oxidation states. So co-precipitation calls for using Fe3+ and Fe2+ ions in a 2 to 1 molar ratio. So a sample is prepared using 2 moles of FeCl3 and 1 mole of FeCl2. Then 100 ml of DI water is added. Then you heat the mixture to 85 degrees Celsius while stirring in a N2 environment. After the temperature is reached you introduce 12 ml of NH4OH. This reaction then yields the Fe304 nano-particles.

After the solution is cooled down to room temperature it is washed twice with DI water and then sonicated.

The picture below shows how the nano-particles as it looked while it was cooling to RT.

As the solution was cooling we placed a magnet at the bottom of the flask to migrate the Fe304 nanoparticles to the bottom. This photo shows them before sonicating.

The next picture shows the nano-particles after they have been washed twice and sonicated.

The black residue at the bottom are the Fe04 nanoparticles which were then dried in a vacuum over-night.

On this particular batch, Mariana reduced the volume of reactants to see if the resultant nano-particles would be less aggregated. She is looking to see if this change will result in greater surface volume. We will take samples of two different preparations and then look at images of them in a scanning electron microscope (SEM)  to see if there is an advantage to using smaller volumes of reactant.

 I can’t say enough how helpful my mentors Mariana and Dr. Dino are. They have both taken a keen interest in the lesson I am preparing and I am looking forward to collaborating with them on this project.

 

The Iron Throne of Nanoparticles

The Iron Throne for Nanoparticles

 

As I started this week’s blog, I decided a needed a better hook for the title. Last week I went with “Iron it Out” because I was working in the lab assisting in creating Iron Oxide nanoparticles. Iron oxide, iron nanoparticles, Iron it Out. Get it? Nobody said anything about my title. I got no likes on the blog, my Facebook page, my twitter, my Instagram account, not even on my Myspace page. Then I realized, I have no social media presence. No wonder! So I figured maybe I needed a better hook. So what better cultural reference than the Iron Throne from Game of Thrones. So now that I have come up with a correlation/metaphor between the nanoparticles my group is working with and the characters of Game of Thrones.

Obviously the Iron Throne would be seized by the most powerful nanoparticle in the process of removing arsenic from water. So how will the battle for the nanoparticle be won? Will there be a “Red Wedding” where one nanoparticle is deceived by others at a moment of joy only to be slaughtered? Which nanoparticle will be like Cersei Lannister? Who will be the mother of dragons? Which particle will be the John Snow nanoparticle? Will the John Snow nanoparticle become romantically involved with the Daenerys Targaryen nanoparticle  in a relationship that is denounced by all the nanoparticles except for the Jaime and Cersei nanoparticles who say “What’s the big deal?” Let’s find out.

In comparing the three nanoparticles my mentor is working with, I needed to understand how these particles are evaluated in their ability to remove arsenic from drinking water. Is one better than the others. Unfortunately, this research has yet to be done at the lab here. It was however identified by my mentor as “future work” to be done on her poster presentation of her research. So maybe that will be something I can assist with.

This spring, at UTEP Mariana Marcos and Roy Arrieta did an experiment where they tested the adsorption rates of the composite materials in adsorbing arsenic from simulated drinking water. They varied the amount of composite material with 10 different trial masses. The simulated drinking water had a concentration of 5 ppb of arsenic.

The experiment yielded adsorption data of arsenic adsorption by a composite material made of Iron Oxide, Graphene, and Zeolitic imidazolate framework (ZIF). They did not have individual arsenic adsorption data of Graphene, iron oxide or ZIF to compare. Thus my Game of Thrones analogy is not relevant regarding the ability of these three nanomaterials to absorb arsenic. Their research does indicate that the composite that used the Zinc ZIF had a higher adsorption rate that the two other composites which used a cobalt ZIF and a zinc/cobalt ZIF respectively.

The image below is a TEM image of the three nanomaterials together.  In the lower right half of the image you can see an almost transparent screen in the background. This is the graphene oxide. The darkest parts of the image are areas where all three materials are coalesced together.

 

Follow up from Last Week

Last week I assisted Mariana in synthesizing Iron Oxide particles by reducing the mass of the reactants from their usual recipe to create iron oxide. The purpose was to get less aggregation so that the nanoparticles could be easily characterized.  It is easier to measure the size of the nanoparticles if they are less aggregated. The image below shows the particles we created last week as seen through a TEM with a 50 nanometer scale.

AMT Camera System
6/20/2018
3

Mariana is working with Dr. Ping at Rice by creating these iron oxide nanomaterials for him to use in his research in creating phages that will be conjugated with superparamagnetic nanoparticles. According to Mariana, he needs various sizes of nanoparticles of iron oxide ranging from 5 to 100 nanometers.