nanoed

Not all carbon nanotubes are created equally

2011-05-24T18:52:00.000-07:00

The family of carbon nanotubes is large. There can be single walled carbon nanotubes (SWNTs), which are like a rolled up sheet of graphene - a monolayer of carbon bonded into a tubelike structure or they could be multiwalled carbon nanotubes, which have concentric layers of these graphene tubes. These carbon nanotubes can have large aspect ratios (length to width) or could be cut into ultra short carbon nanotubes. In fact, carbon nanotubes come in thousands of different molecular weights and isomers.

One of the most interesting characteristic of Carbon Nanotubes is how dependent the material properties are on small changes in structure. For example, small changes in the way that the carbon atoms align results in the difference between the SWNT being a metal or a semiconductor. This difference in the way the carbons align is called Chirality. Here is an easy way to demonstrate what chirality is. Take a transparency sheet with graphene's structure copied on it and connect two ends to form a cylinder. That is the model of one kind of carbon nanotube with the chiral index of (n, m) where n is the number of carbon atoms across the grid (at the center of each hexagonal structure on your transparency) and m would be zero since you havent moved down the matrix. If you want to make another kind of nanotube, you need to twist the graphene transparency and make a new tube that has a constant diameter. Scientists discovered an odd trend. When (n-m) is divisible by 3 (the product is an integer) then the SWNT is metallic, otherwise it is a semiconductor. Small changes in the arrangement of carbon atoms affects the electronic nature of these materials.

tectosquares

2010-11-28T07:37:00.000-08:00

I am writing this blog as I procrastinate writing the final exam for my BioNano class this fall. During the class, student picked current peer reviewed journal articles and presented them in a short Pecha Kucha format. This means presenting 20 PPT with 20 sec per slide. Topics ranged from applications of gold nanoparticles for lung cancer detection, the effects of feeding Buckyballs to mice, and antimicrobial properties of nanosilver. Students in the class were required to read the papers chosen by their classmates and write up a list of questions (collected for a grade). I thought the format worked out well. Very short presentations followed by fairly animated dialogue (for a 9:30 AM class).

Since the students chose the articles, some were very familiar to me but some were quite unexpected. One of the more interesting topics that I learned about was making tectosquares that are RNA sequences that self assemble into ladder-like nanostructures. In the paper listed below, they used nanogold particles to quantify the spacing. Very Elegant.
Controlled Spacing of Cationic Gold Nanoparticles by Nanocrown RNA
Alexey Y. Koyfman,§,† Gary Braun,§ Sergei Magonov,‡ Arkadiusz Chworos,§ Norbert O. Reich,§,† and Luc Jaeger*,§,† J. AM. CHEM. SOC. 2005, 127, 11886-11887

ice and water

2010-11-06T18:11:00.000-07:00

The phase transitions between frozen and liquid H2O are so critical to human survivial that we have developed words - Ice and water - To describe these important but not so different events.
Normally phase changes are described by simple subscripts but water is different because it is so vital. How is ice different from liquid water?
Look at these simulations
http://iclcs.illinois.edu/index.php/chemistry-simulations

Why is water so unique?

2010-10-10T07:24:00.000-07:00

A year or two ago, I was involved in a debate with some smart people about water. This wasnt a debate over water purity or the future scarceness of water, both of which are important and compelling topics, but something more fundamental. What is water? How are snowflakes formed? What do we call H2O structures? Does it fall under the category of "self assembly"?

One person on this committee didnt think that water fell into the category of nanotechnology, and it lacked the size dependent properties that we use to define nanotechnology. It was deemed too simple and not as compelling as some of the other topics we were thinking about (nanoelectronics, gold nanoshells, quantum dots). However, we don't really understand water and probing the interactions between water molecules is necessary before we can understand complicated structures and biological systems like transport through cell membranes.

However, if we think of the important characteristics of water like hydrogen bonding, solvation, and how it serves as the basis of life (along with some carbon and nitrogen), then we must realize that understanding the chemistry of water is essential to understanding the future of science. Research on water is not a trivial exploration and this study exemplifies some of the complexity of the substance we take for granted http://pubs.acs.org/doi/abs/10.1021%2Fjp1060792

proton size?

2010-07-13T06:12:00.000-07:00

I woke up this morning feeling maybe smaller, maybe less energized. In fact, a new study in Nature calculates that the proton is 4% smaller than previously thought or as this Scientific American headline reads "proton shrinks in size" http://www.scientificamerican.com/article.cfm?id=proton-shrinks-in-size. So perhaps my jeans really do fit better today because my protons are smaller than they were last week.

What do these studies imply? Does this mean that we don't understand the basic structure of the atom as well as we thought? Does a 4% difference matter? Perhaps there was a calculation error and this newest technology that was used in this experiment is just off somewhat. Since now the Rydberg constant would now be different, does this through a glitch into the whole concept of quantum theory? Should we care? While protons are measured in femtometers are a lot smaller than nanometers (1,000,000times), all matter is composed of protons, electrons and neutrons. So when someone says your protons are smaller than they thought, you should take note.

Opportunity to share your ideas about nanotech with the Office of the President

2010-06-20T06:34:00.000-07:00

President's Council of Advisors on Science and Technology(PCAST) will be hosting a webcast on nano, bio and information technology. If you go to the OpenPCAST website, http://pcast.ideascale.com/ and submit your ideas. The webcast will be on Tuesday, June 22 from 10 am to 2:30 pm. See the PCAST site for more details. http://www.whitehouse.gov/blog/2010/06/15/polishing-technology-s-golden-triangle

Nanocomposites and everyday things

2010-06-10T19:44:00.000-07:00

I just put some Saran wrap on leftovers. Was it Saran or some cheaper knock off? Does it matter? Probably not, since my family will eat it tomorrow regardless (they are not picky). However, if you were packing a product to be shipped around the world, like an expensive pharmaceutical product or even an inexpensive snack, you would care. Time is money - esp. when it is sitting on a store shelf.

How does this relate to the esoteric term, nanocomposites? The cause of most food spoilage is are either microbial or chemical- specifically oxidation. Microbes are relatively large (micron sized), so plastic films easily act as a barrier. A molecule of oxygen, however, is very small (more than 1000 times smaller than a microbe) and can be transported through plastics (also known as polymers) easily. This transport or permeability depends on the solubility of oxygen (or how well it dissolves) in the polymer and its ability to diffuse or move through the polymer.

Different polymers have vastly different gas transport properties and cheap polyethylene (Glad wrap) is much more permeable to gases than polyvinylidene chloride (Saran wrap). However, if you look at the packaging after you finish those chips from the vending machine, you will see that they have an additional layer of aluminum foil that really prevents gas transport.

Recently it has been found that when polymers are sequentially prepared into nanometer thick layer cakes, the barrier properties of the materials improve. Because polymers are glass-like structures, they tend to change or relax over time. This relaxation basically allows the polymer molecules to get closer together and this more compact structure blocks the transport of gas through the material. So controlling the nanostructure of polymer films could increase the shelf life of products and potentially eliminate the need for the expensive aluminum layer in packaging.

More specifically, a composite in a combination of materials. A polymer with nanosized additives would be called a nanocomposite. Adding nanosized particles to polymers can increase its strength, decrease its weight and improve its barrier properties (or how well it blocks oxygen). The nanosized material could be relatively inert clay materials or potentially antioxidant or antimicrobial particles.

While many people think of packaging as either something for marketing or something that is waste issue, and indeed both are true, good packaging prevents food spoilage and protects the activity of pharmaceutical products. Every day we pack a lunch, save leftovers, open a container from the store. Whether we like it or not, packaging is a part of our everyday lives.

Nanotechnology lectures freely available from CHEM 570 Nanotechnology for Teachers

2010-05-04T12:42:00.000-07:00

Dr. John Hutchinson and I taught Nanotechnology for Teachers out of Rice University and The University of Colorado at Boulder in the Spring of 2009 using distance learning software. All of the course content, including cutting edge research presentations from Rice Faculty, Post-Docs and Graduate students are freely available at http://webcast.rice.edu/webcast.php?action=details&event=1724

Fun Nano labs

2010-03-14T08:02:00.001-07:00

Synthesizing ferrofluids and liquid crystals are laboratory activities that can be conducted in a 75 minute lab. At Rice University we have incorporated these labs in our freshmen chemistry course and have taught it to teachers in our Nanotechnology for Teachers course. An outline of the protocol is described by Dr. Mary McHale at http://cnx.org/content/m15768/latest/

Stellar Nanotubes

2010-03-08T17:51:00.001-08:00

In 2008, carbon nanostructures that looked like long carbon nanotubes were
identified in three meteorites. This was surprising because on earth, the temperatures and pressures associated with making carbon fullerene structures were/are very energy intensive and involve very toxic and/or expensive catalysts. However, scientists are now looking at ways to mimic interstellar reactions to create carbon fullerine structures. http://www.sciencedaily.com/releases/2010/02/100224214434.htm

Which is appropriate because the first carbon fullerene structures that were identified by Kroto, Curl and Smalley at Rice University, were bucky balls or soccerball shaped structures of carbon. The discovery of the buckyball came out of investigations of carbon structures in interstellar space.

what is in your kitty litter

2009-11-19T17:16:00.000-08:00

Diatomaceous earth is a common material that we buy in bulk and put into our pool filters and kitty litter. If you thought it was just dirt take a close look. We are mining fossils; an antique algae that looks like a nanomachine.

Nanocars and such

2009-11-06T19:27:00.000-08:00

I was asked at dinner tonight about Dr Jim Tour's work on Nanocars by a nonscientist. What I said is that Jim Tour's research on nanocars really highlights how creative minds can envision chemical structures, synthesize them, and then see them in real time because of recent advances in nanotechnology. Dr. Tour takes organic chemistry and makes it interesting by using analogies between nanoscopic molecules and macroscopic things we can see in our everyday life. Nanocars are molecules that have flexible bonds between ring-like structures that can rotate like wheels on a car. Dr. Tour has tested these molecules on various surfaces and used imaging modalities like atomic force microscopy to prove that these molecules do in fact have wheel-like structures that rotate like car tires (he has also synthesized nanoworms or molecules that simply slide across surfaces). What needs to be clarified is that there is not a driver of Dr. Tour's nanocars. These are not nanobots that can be programmed to do a specific function nor can they replicate or be controlled by an outside forces. These nanocars are simply organic molecules that respond to forces like heat and friction to change their conformations (ie. rotate or move) just like any other molecule in the world. It is just that they are synthesized to look like cars and can move across surfaces like roads however they are driven by random thermal energetic forces. They are quite pretty and have an unique ability to engage people in science but just remember, they are molecules that react to physical forces, not magic, not science fiction.

Gold Nanoshells

2009-10-26T17:34:00.000-07:00

Why are gold nanoshells for cancer treatment so interesting?

Gold nanoshells are 90- 130 nm particles of silica coated with a thin layer of gold that have unusual optical feature and can potentially be used for cancer therapy and diagnosis. The thin gold coating on the glassy substrate results in a product that can be designed to absorb and scatter light at very specific frequencies. This "tunable" property means by changing the ratio of the silica core to the gold ,gold nanoshells can be manufactured to respond to near infrared light frequencies (>800nm) that are very desirable for therapy and disease detection because near infrared light can pass through human tissue relatively easily.

We have chromophores in our body, like hemoglobin, that like to absorb light in the visible region of the electromagnetic spectrum. So if we can design particles that absorb at the near infrared spectrum (slightly outside of the visible spectra) then these light waves can travel through our tissues without interference from our chemicals that are naturally present in our bodies.

How do nanoshells kill cancer cells?
Called photoablation therapy, this process works because when specific frequency of light is directed at nanoshells, they heat up and the tissue where the nanoshells are located is destroyed via heat. The nanoshells collect around tumors because the blood vessels that are formed to feed the fast growing cancer cells are very abnormal and have a leaky characteristic that let nanoparticles somewhat selectively stay in the the cancerous area.
Because of the surface phenomena that is inherent in metal nanoparticles, gold nanoshells respond to an incident light beam and heat up.

Why do nanoshells heat up?
There are electrons on the surfaces of metals that are free to move around. Because nanoparticles have a lot more surface area exposed than larger particles, the phenomena that occurs at the surface plays a much larger role in determining the physics of the system than if you had a large, bulk chunk of metal. In nanogold, the electrons on the surface of the metal particle can respond to incident light. They basically can vibrate or resonate in frequency with the color of the the light. This is analogous to a child being pushed on a swing. Just like there is an inherent frequency to the push on the swing that will keep the child in motion, light waves can induce a frequency response in the electron on the surface of a metal. This cloud of electrons, often called a plasmon, can swish back and forth across the nanoparticle in response to the incident light. Some of the light energy is transferred in heat and so the particles heat up at specific frequencies. This heat is what kills the cancer cells.

NIH challenge grant rabbit-hole

2009-05-12T18:01:00.000-07:00

I have not written a blog lately because the NIH released a Science Technology Engineering and Math (STEM) challenge grant 12-OD-102 that was equivalent to saying Drink Me. And then another (12-OD-101) that said Eat Me. The first was to develop a high impact professional development program for science teachers; the other was to show that there was a more effective way for students to learn science. Once someone really smart told me if there seems like there should be a better way, there probably is. Certainly we know a lot about how people learn, yet we aren't teaching that way. This is how I wound up writing two challenge grants, or at least working on them on my spare time.

Released on March 4, 2009,and due on April 27, 2009, the NIH RFA OD-09-003 had a compelling white rabbit to follow: Come up with a unique solution to an important health or education problem that could be tested in a two year period at a price tag of $500,000/year. The challenge areas ranged from bioethics to translational medicine, with this outreach and education solicitation in the middle of the pack.

For those of you who haven't had the opportunity to write an NIH grant lately (it had been a decade for me), this rabbit takes some curious turns (pools of tears, caterpillar advice, etc). Learning that the background section is not allowed, Time 12 font is illegal, and that using the NSF biosketch format could cause your grant to be rejected are just some of the treats at this tea party. Luckily, our university hired extra excellent staff to help us learn how to play croquet with the queen. So now our grant has been submitted and we occasionally get emails that it has passed through another threshold on its journey to be reviewed.

I am not complaining about the experience because we came up with two good ideas that I hope some agency will eventually fund. I am just trying to justify my absence from my blog. I also hope that the reviewers of our grant like the opening: Twas brillig

ACS annual meeting Nanoscience: Challenges for the Future

2009-03-24T08:17:00.000-07:00

As I pack up to leave Salt Lake City and the 237th American Chemical Society meeting, I wanted to reflect on some of the comments about the future of nanotechnology and nanoeducation.

From the education sessions, it seems clear that K-12 teachers are taking bits and pieces of activities that have been developed through NNI funding. It has to "fit" into their curriculum and that means that it is only adapted if the teachers find it easy to use and it supports and augments the content they are required to teach. For example, 3 week modules on a topic on nanotechnology are unlikely to be used as designed and assessed. The school systems are not flexible enough to allow teachers to implement new curriculum and the testing schedules make it almost impossible for teachers to devote large chunks of time to new content.

The general consensus that I witnessed about undergraduate majors in nanotechnology was that they are too general and students would be better served by majoring on a core science or engineering and then doing nanoscience research in postgraduate studies. There was concern that the true interdisplinary strength of nanoscience research will be watered down if we don't have students with strong foundations in basic sciences. They need to approach nano-projects from different viewpoints. Nanotechnology minors might have more support. Especially if it encourages students to explore a series of courses where they get hands on exposure to some of the tools that are used in nanoscience research but may not be available to undergraduates.

Whitesides commented that nanotechnology as a field is maturing. We have passed beyond the hype and unreasonable expectations of the late 90's and have passed through the following disappointment stage of this decade and are now ready for steady growth - as long as we understand structure-property functions and create materials that have real applications.

science fair blues

2009-03-15T16:59:00.000-07:00

On Friday, I judged 14 chemistry projects at the Houston district science fair. This is a big deal. This was the 50th anniversary of Science and Engineering Fair of Houston. It is a big deal for a student to make it to the judging at the Houston convention center. Advancement to this division means that their project that was one of 30,000 projects entered in the preliminary school/district fair competitions that was chosen to be in this elite group of 1,300 projects from 140 schools. I remember when my daughter's science fair project progressed from from her class science fair, from her school, from her school's region to this large venue - a two day extravaganza.

However, as a judge for over a decade, I can honestly say that the science fair projects, at this level, have never been as dismal as it was on Friday. This was agreed upon by all of the judges in my group. Is it our No Child Left Behind Policy? Is it because the number of students in the Houston Independent School District (HISD) is decreasing while the population of Houston is growing? Are these new students choosing to attend schools outside of HISD? Because of our high stakes testing, I believe that teachers have less class time to devote to science fair projects.

What teachers need to understand is that science fair projects, the posters, and discussions about them, are real. This is really how scientists work. We have poster sessions at meetings where we show our data and defend our findings, seek advice and make connections. Science fair really matters.

health care

2009-03-07T18:15:00.000-08:00

This is outside my normal post, but I think that Health Care is important enough and personal enough to break through ideological constraints. Especially if I think I have something to contribute to the dialogue. Having been pregnant in Austin Texas and delivering a baby there (I drove myself to the hospital) and 2years later, having a baby in Stavanger Norway, I think that it is important that people understand what our idea of "free market" health care has wrought, at least in comparison to one of the most socialized systems in Europe. Our free market approach has created a market for competition in the the most exclusive realms of our health care system. It makes no sense from either an economic or sociological point of view. There are hospitals compteteing to the the most exclusive, up-to-date maternity wards for those few patients who have the luxury of a full American insurance plan.

Meanwhile, the rest of the country is suffering in ignorance and neglect. Strikingly,there are very few prenatal care options for women with out the type of insurance driven health care plan that I had. The average cost of a vaginal delivery in the US is $7,737 (http://www.associatedcontent.com/article/623715/estimating_the_cost_of_pregnancy_.html?cat=52) That does not include prenatal care. This make complete economical insanity because the costs for prenatal care are so much less than the costs for post natal issues (resulting from poor prenatal care).

Having a baby in the US is expensive. I was lucky because although I was in graduate school at the University of Texas at Austin, at a time where they decided to deny all graduate students health care benefits (something to do with having equal benefits with the other UT schools), my husband worked for a larger international company with excellent health care offerings. I was very fortunate because my pregnancy was not normal and involved a lot of extra testing due to issues with my blood, my chemical and x-ray exposures (I was a CHE grad student), and the baby's weight)

Luckily, my first child was completely normal - born on her due date with perfect APGAR scores. And under the American health care system and my husband's international corporations' generous health care insurance, I was in a sleek hospital in a private room with a jacuzzi tub (cant imagine a women in labor using that) but was sent home w/in 24 hours of delivery. Not a lot of care.

In Norway, all of my prenatal care was free. A surprise to me was the lack of paper work> Are you pregnant? was the question, and a simple "yes" entitled you to the best prenatel care in the world (in my opinion). No paperwork, no forms.

My second child was a week late and I was in labor for 2 days. But we still thought it would be easy. IT wasn't. After an emergency C-section, I was in the hospital for 7 days (I could have stayed for 10 but wanted to get home for xmas). During those 7 days, I saw women being taught how to breast feed, how to care for their children, why it was important to vaccinate their children, what the vaccination schedule was, and all kinds of information that the US system hopes is picked up by homes, churches or other groups. Postpartum care was excellen with nurses coming to homes or local well baby checkup centers to ensure that ALL children were vaccinated.

This is important: After seven days of very high tech, personal care, I was told that I could go home. My question was what paperwork to I have to fill out? The answer was none. Just dress your baby and go home. The USA is so overwhelmed with bureaucracy when it comes to health care, we don't know has simple it can be.
Most new moms in Norway are in the hospital for 7 days in a ward room. In someways I was lucky. I had a private room. This had nothing to do with my ability to afford it but rather the complications involving my sons' birth.

My prenatal and postnatal care was better in Norway than in the US under any metric (cost, time, quality - any). So when people say the US has the best health care in the world, I have to wonder about what world they have been living in.

Medical procedures should be based on need not what you can afford. If you have a sick child, you will want the best possible health care. It is like paying for firemen when your house is burning down. Shouldn't we have a health care system that is better than that?

How to learn to teach nanotechnology in 3 days

2009-03-01T07:21:00.000-08:00

There are quite a few 1-3 day teacher workshops on nanotechnology offered around the world. Do they work? Can a middle school or high school teacher learn about these new advances in research AND learn how to effectively integrate it into their classrooms in such a short time? Most teachers who take nanotechnology workshops come away excited about the new applications that they have learned about - quantum dots are beautiful, gold nanoshells have tremendous potential, buckyballs are fun,and who wouldn't be excited about the idea of cheap and easy methods to clean up oil spills or purify contaminated water. However, how much of this content really gets back to the students?

Nanoscience topics are based on quantum mechanics and are challenging to everyone, especially for teachers that may have had excellent scientific training but have been out of college and the research environment for years/decades or for teachers that may have not have strong science backgrounds when they entered teaching. In 3 days, can we teach teachers about how gold nanoshells work via plasmon resonance, how scanning tunneling microscopes (STM) work via electron tunneling, how different chiral structures in nanotubes lead to different properties (metal or semiconductors), or how how the fluorescence of quantum dots is determined by it size because quantum confinement? In 3 days can teachers learn enough about any nanoscience topic to feel confident enough to teach it to their classes? In 3 days, can teachers take this newly acquired knowledge and tailor it to meet the needs of their students, align the requirements of the testing bodies, and are within the limited budgets of their science labs?

There are lots of articles, infomercials, products that claim to help people learn things fast: to read, to paint, to play piano, to manage effectively, to lose weight, to get abs of steel, learn latin. However, the real secret, and it is no secret, is time and practice. How long does it take to learn to be a surgeon, or a concert pianist, or an effective teacher, or great computer programmer?

Peter Norvig, the Director of Research at Google, has the "the best job in the world at the best company in the world" and some interesting essays on line, including Teach Yourself Programming in Ten Years http://norvig.com/21-days.html. In this article, he discusses how long it takes to really master a subject. He reiterates that people learn by doing, that people learn things over time, that we are always in such a rush to learn or teach something that we don't really accomplish our goals.

I run a teacher internship program and a full semester course CHEM 570 Nanotechnology for Teachers. I don't want to train teachers to be come nanoscience researchers. It takes a minimum of 10 years+ to become a research scientist (4 years undergrad, 4-6 years in graduate school, and then postdoctoral research). It probably takes even longer become an effective high school teacher (and a lot of patience, management skills and emotional maturity). However, if we are going to spend taxpayer money on nanoscience training, I do want to make it effective. I want teachers to learn about new developments in physical science, bring these applications back to their classrooms and translate these findings into lessons where kids have real learning experiences that will help them learn scientific content, motivate them to study/do homework/pay attention in class(this is one of the real issues with American students), perhaps think about careers in science and engineering, and to become adults who are scientifically literate.

It is my belief that we need to rethink these short courses and workshops for teachers in nanotechnology. We need to slow down and engage teachers over an extended period. We need a long term commitment to teaching advanced scientific content and helping teachers use it in their classrooms. Isolated workshops may be engaging and beneficial but it is too separated from the teacher's curriculum. Just in time teaching, ie. teaching the content to the teachers, when they are teaching the subjects in their classes and making it relevant to their teaching goals, will make these programs more effective.

by any other name

2009-02-22T10:18:00.000-08:00

What is nanoscience? Is it different from nanotechnology? Is it chemistry? Many chemists do think that nanoscience is another word for molecular chemistry. However, there are many who would argue that definition (including the physicists, mechanical engineers, chemical engineers, bioengineers working in nanotechnology). Is molecular physics also nanoscience?

Here is the interesting issue about nanoscience and nanotechnology. Kids tend to think it is cool. Or at least they don't associate it with words like chemistry and physics - words that they tend to have very negative feelings about. Scientists and chemists in particular are often the bad guys in movies (e.g. Batman).

What difference does the name make? Do kids seek out nano-related activities over more traditionally named activities? Is this just rebranding of the same old science or is it something new? Can we make nanoscience something different? The physical sciences with real and currently developing applications that can positively impact human and environmental health? Could it be a course that is taught using inquiry based pedagogy w/o a lot of the baggage that other science courses have to carry around (rules and rote memorization)?

Can a new curriculum in nanotechnology improve science education?

2009-01-23T10:26:00.000-08:00

I was at a nanotechnology meeting and this question was thrown around. Since American kids, in general, don't like high school chemistry and don't even take physics, could we offer them an alternative science course that was developed by scientists. Would this be better than current science classes and who might take a course in nanotechnology?

Most of the scientists and educators at this NSF sponsored meeting agreed that our high school chemistry curriculum is in a sad state. There is no time for labs and the labs that we have are high stress cookbook affairs. There is little insight into the process of scientific discovery. There are many teachers who don't have the proper background in chemistry (i.e. not chemistry or chemical engineering). We don't have national standards for these well defined courses. and the list goes on.

So what if we developed a really good science class that integrated chemistry and physics and was driven by discovery learning, well trained teachers, and exciting applications and called it nanotechnology? What if we started with what is relevant to kids (their bodies, their gadgets, their environment) rather than significant figures, balancing equations, dropping bowling balls from airplanes? Could this work?

With the high emphasis on 5 point, advanced placement courses in high school, who would take this new class? Maybe it wouldnt attract that population of students, but perhaps it would engage a whole new demographic of students who think that science is just something that old white men do in isolated labs in boring places.

Maybe it could work - the next question is how would could it be implemented.

2008-12-15T06:49:00.000-08:00

In light of Sunday’s Houston Chronicle article about Houston Independent School District (HISD) magnet programs that suggested that support for magnet programs waning both locally and nationally, I would like to stress how important it is that support our magnet programs because they represent the some of the best schools in our city and provide school choice without funding private schools and igniting divisive church/state issues. HISD Superintendent Dr. Saavedra‘s statement that “only 27% of magnet students transfer to schools with higher academic ratings than their neighborhood schools” is either wrong or perhaps reflects that so few HISD schools have high academic ratings. In 2008, no zoned high schools received TEA exemplary status, however, there were 5 magnet high schools that received this highest academic rating. All 5 of these exemplary high schools were magnet schools with their own campuses. Every student at these 5 schools, Carnegie Vanguard, DeBakey High School for the Health Professions, East Early College, Eastwood Academy, and the High School for the Performing and Visual Arts (HSPVA) transferred from a zoned school with a lower academic rating since no locally zoned high schools in HISD are exemplary.

Any student in Houston can apply to these 5 outstanding high schools since they are not restricted by the geographical boundaries that have lead to such high disparities in our American educational system. Admission criteria vary amongst the schools and they are not all about test scores (for example there is no academic requirement for HSPVA). These schools represent the economic, racial, and ethnic diversity that make Houston such a dynamic city. These schools belong to every person in our school district and, as such, should be supported by all HISD board members. A serious effort should be made to inform families, especially those with limited resources, that their children can attend these schools.
HISD needs to invest in programs that work. Rather than encouraging students to attend their local schools, why not replicate or expand these successful programs? Large locally zoned schools that do not require any commitment from the students and their parents, other than showing up on the first day of school is a school model has resulted in high dropout rates and a huge achievement gap between wealthy and poor students. In a time when Houston’s population is growing faster than any other city in the nation, HISD’s enrollment is shrinking. Perhaps the magnet schools can serve as a mechanism to attract and retain students in our school district.

I have been very impressed with the quality of education that my children have received through the HISD magnet programs. My daughter is a senior at HSPVA and my son is a sophomore at Carnegie Vanguard. I want all Houston students to have the same educational experience my children have had and attend schools where the teachers are master in their subjects, where the curriculum is stimulating and engaging, and where the students and their parents all feel honored be part of educational excellence. It is time for a renewed investment in the 30 year old magnet program. Otherwise, HISD’s enrollment and quality will continue to decline as the most motivated students, most educated families and the most gifted teachers will continue to leave the district. This continued erosion in of one of the largest school districts in our country will result in greater inequities in our society.

Identifying what matters

2008-12-12T08:34:00.000-08:00

I attended a Houston Independent School District (HISD) board meeting last night to hear if they had decided to build a new facility for my son's school. However, all of this debate over buildings just drives home the fact that facilities do not enhance learning. The chart shown on the right illustrates the importance of different variables in determining student achievement. This graph is from Dr. John Hattie's analysis of the New Zealand school system (see http://www.knowledgewave.org.nz/forum_2003/speeches/Hattie%20J.pdf) shows that a student’s own ability (for example as measured by an IQ test) is the factor that correlates strongest to high student achievement – not a very surprising result. However, the next important factor is the teacher, not school, principal, home, or peers. Teachers make the critical difference in student learning, therefore we need to ensure that all children are taught by effective teachers. We need to invest in high quality teacher professional development and create a system where teaching is a well paid, highly honored profession.

The highest paid jobs in HISD are not in the classroom, but rather in administration. The HISD superintendent’s salary as of July 2008, was $442,556. An article in the Houston Chronicle just announced that the new head of HISD’s human resources (named Department of Human Talent) will receive a salary of $145,000 (she was a teacher for 4 years). The highest pay grade in HISD is for a 12 month teacher with a PhD and 27+ years of experience is $86,000 It is not clear how many, if any, of the 12,000 teachers in HISD have a 12 month appointment and that level of experience.
http://www.houstonisd.org/HumanResources/Home/Pay%20&%20Benefits/Teacher%20Salary%20Schedule%2008-09.pdf

Out of field teaching in High Poverty Schools

2008-12-04T14:07:00.000-08:00

The disparity among the quality of our schools is heartbreaking. Some of this is a result of complex socioeconomic issues. However, teachers cannot teach what they do not know, and therefore, poorer American students are receiving instruction from teachers who are less effective teachers.

The Education Trust just released a report that analyzed prevalence of out of field teaching in US middle and high school classes based on the most recent US department of Education School and Staffing survey data (2003-2004). Out of field teachers were defined as teacher’s lacking certification or an academic major in the subject they are teaching. Not surprisingly, out of field teaching was much more common in high poverty schools , i.e. schools where 75% of students receiving reduced or free lunch. Twenty-seven percent of the core courses in these high poverty schools are taught by out of field teachers while that rate is fourteen percent in low poverty schools (15% or fewer students receiving free lunch). Mathematics is particularly problematic with 41% of math courses in high poverty schools being taught by teachers without state certification or an academic major in math or a math related subject like engineering, physics or math education.

American schools are not broken, just fractured. While there are many factors that lead to the relatively low ranking of American students in most international comparisons (e.g. in mathematics the US ranked 24th of 29 countries that participated in the 2006 Programme for International Student Assessment), it is clear that American students from our wealthiest schools are quite competitive as indicated by their high achievements at the university level. We need to provide economic incentives for the best teachers to take on the challenges of our inner city schools and we need to provide teachers who may lack content knowledge with the opportunity to gain content knowledge in the subjects that they are teaching. Recruitment bonuses for teachers at underresourced schools and high quality teacher professional development courses can help mend this fractured system.

How do we teach chemistry so that it is real and relevant?

2008-12-03T07:14:00.000-08:00

A few weeks ago I went to an innercity high school to observe a teacher that had been a participant in our professional development classes. This teacher is outstanding and was doing her best to engage 16 year old, economically disadvantaged students in her lecture on the structure of the atom. She used inquiry based methods, including “what do you know, what do you want to know, and what have you learned” prompts before, during, and at the end of class. She also used fun, exploratory techniques like modeling the Rutherford Gold Foil Experiment using a bowling ball as a model of the nucleus and having students throw tennis balls (see image). The students were enthusiastic and seemed to be learning about atomic structure – that atom is mostly empty space, that most of the mass is in the nucleus, protons are positive, etc.
She then lead the students through an introduction to electron orbital theory, which was less exciting but still very well taught.

At the end of what was an inspiring chemistry class, the teacher asked if there were any questions. One girl raised her hand and asked “Are there atoms inside me?”

How can a student who has taken a semester of 11th grade chemistry, a 10th grade in biology course, and 9th grade integrated physics and chemistry course, not understand that everything, including our bodies, is composed of atoms? How can we have this huge disconnect between what kids memorize for tests and what they really comprehend about science and our world?

Our Self Assembled Universe

2008-11-25T12:48:00.000-08:00

Often, after a presentation about the exiting developments in nanotechnology, a common question I am asked is "How are things made at the nanoscale?"

This is an insightful question because the person asking it has understood that at the nanoscale, where are working with molecules that are 80,000 times smaller than the diameter of a human hair, the idea of moving and attaching one molecule to another would be a tedious if not impossible task.

Other, more specific questions are:
"Are there nanomachines that build these nanomaterials?"
"How do we position the 60 carbons in a buckyball to get that soccer ball shape?"
"How long does this process take?"

The rather simple answer to these questions is that under certain conditions many molecules just self assemble - they make themselves. This process of self assembly is very fast and is analogous to molecules sticking together. Rather than forming covalent bonds, self assembly exploits weaker bonds (like hydrogen bonding) but because there are many many bonds, these self assembled structures can be very strong. Examples of naturally occurring self assembled structures include the collagen that makes up our bones and hair, DNA that codes our genes, and proteins - the stuff that makes us alive.

Self assembly happens at a very fast pace, at the speed of an electron, and millions of molecules can attach in very specific fashions using simple rules. Yet the result can be very intricate structures (like snowflakes) and new materials like buckyballs. To make buckyballs, we just have to blast carbon monoxide or another carbon source into a furnace that is at the right temperature and pressure for the carbons to take on its soccer ball shape because carbon is obeying some simple thermodynamic rules to minimize its energy. As nanotechnologists, our job is to understand what these rules are and try to create the environmental conditions that will promote nature's ability to build itself. We live in a self assembled universe.

"My mother measures stuff when she makes a cake. How do you measure the atoms and molecules when you make a nanoproduct? Do you follow a recipe?"

2008-11-23T13:03:00.000-08:00

This was a question poised to me by Science Weekly for an issue on Nanotechnology. I was thinking about it yesterday as I watched a CBS film crew record a synthesis procedure for Nanorust in our university cafeteria. Nanorust is a technology that may be used to clean water because the nanometer-sized iron oxide particles bind to toxins like arsenic and then can be removed with a low powered magnetic. The procedure to make nanorust was modified from a traditional laboratory protocol to a kitchen cooktop method by substituting household products like olive oil and measuring cups for the chemicals and tools were normally order specifically for the laboratory. The goal of this Nanorust project is to freely provide the recipe to individuals or companies in developing nations so that they can use this nanotechnology to solve one of the most important global challenges: clean water. And yes, it is a recipe. The difference between kitchen chemistry and laboratory chemistry is often just the language we use (a chemist might say “now we add the water soluble fatty acids” while a cook might just say “I need some soap”) and the tools that we use (a chemist might use a transmission electron microscope to look at their products while a cook might just use their eyes, nose and yes, tongues).
Here is the Nanorust protocol
Olive oil and rust for magnetite nanocrystals
Cafer T. Yavuz
A. Soap making Process

1. In a crystallization dish or a similar container, weigh 100 g. of the liquid oil (if not liquid gently melt it and keep as melted).
2. In a 50 mL vial (or a cup) weigh 15 g. of crystal drain opener (or caustic soda, or sodium hydroxide, or potash).
3. Add 30 mL of tap water and shake (or stir) until all solid is dissolved (CAUTION: solution gets hot!). While still warm pour it into the liquid oil.
4. Stir with a spoon (or a magnetic stirbar) for about 15 minutes (or until tracing occurs – tracing is the visible tracks of stirring).
5. Let it sit open to air in a hood (or ventilated area) to dry and cure for couple days (or a week).

B. Oleic acid from soap with commercial vinegar

1. Weigh the dried soap (i.e. 60 g.)
2. Check the vinegar’s acidity (i.e. 9%)
3. Use 1 mL of acid for every gram of soap (i.e. 60 mL of acid, 650 mL of commercial vinegar with 9% acidity)
4. combine them in an erlen (or a big glass/steel jar)
5. Heat and stir them until all the chunks are dissolved (it may boil – takes about 15-30 minutes)
6. Turn off the heating and cool the solution down. You should see the two layers separating from each other.
7. Separate the top yellowish layer by a separatory funnel (or a spoon, syringe, anything that works) into a clean glass/steel jar.
8. Heat and boil the yellowish cloudy solution until it clears
9. Cool down and store as Fatty Acid Mixture (FAM)

C. Magnetite nanocrystals from rust and fatty acids

1. Collect the rust by shaving off of the rusted tools.
2. Grind the rust into fine powder.
3. Mix 1 grams of rust with 20 grams of fatty acid mixture in a glass or steel container (erlen or pan) and provide stirring.
4. Cover the top of the container with a loose cap for proper ventilation (reaction smokes and steams). This method produces 50-90 nm nanocrystals but if you want to make them smaller (~15-20 nm) you have to use a steam/pressure cooker instead.
5. Start heating and timing. It should be cooked at around 2 hours (or less) until complete/dark black solution with little or no smoking.

D. Transferring oily magnetite nanocrystals into water

1. Grind 10 grams soap (made above) into a 100 mL of water
2. Boil the mixture to dissolve while vigorously stirring (takes about 20-30 minutes)
3. Filter off the undissolved soap
4. Take a spoonful (3-5 grams) of black waxy mixture into 40 mL of the soap-water solution
5. Stir and boil the mixture for 30 minutes (add more water if significant loss of water observed)
6. Filter the solution to get rid of unreacted magnetite
7. Magnetically separate the nanocrystals (time varies: smaller crystals need overnight or couple days, larger ones need couple hours)
8. Once on the magnet gently swirl some water on the crystals to clean them
9. Redissolve in water (or ethanol, etc.)

What is this nanoed blog about?

2008-11-16T12:19:00.000-08:00

On this blog, I hope to post answers to questions that I am frequently asked about nanoscience and engineering and share some the research findings on nanotechnology. I will also discuss science education in general - some of the problems and potential solutions as well as interesting articles and science activities that I come across.

For example,Sir Harry Kroto, who won the Nobel Prize in 1996 with Dr. Rick Smalley and Dr. Robert Curl, has a great video where he discusses the discovery at http://tinyurl.com/6q2jxm