Sterlitech Blog

Today the Environmental Protection Agency awarded $32 million to 4 universities around the country to study the health impacts of air pollution. These centers will answering questions like, "does air pollution effect a child's learning ability?" "Are obese people more susceptible to health effects of air pollution?" "How does your commute effect your health?"

We work with a number of environmental labs to provide filtration materials, and one of the most common requests we get from them is for our 0.45 micron, 25mm silver membranes to comply with NIOSH methods for testing airborne contaminants such as silica and bromine.

Here is a breakdown of what the four new centers are focusing on:

• University of Washington - Effects of roadway pollution on on cardiovascular health.
• Michigan State University - The relationships between obesity and air pollution.
• Emory University / Georgia Institute of Technology - Characterize health risks of air pollution mixtures, research how social factors (living location, commute, etc.) impact health.
• Harvard University - Investigate health effects of short-term and long-term exposure to pollutants on specific health functions, including cognitive function, birth weight, and mortality.

See also:
"EPA Awards $32 Million to Understand Health Impacts of Air Pollution"

EPA Clean Air Research Centers Home

Two weeks ago I had the opportunity to mix business with pleasure during an ACS sponsored event at a local chocolate maker. Based out of Seattle, WA, Theo Chocolates, appropriately named after the chocolate bean bearing tree Theobroma cacao, is the only bean-to-bar, organic, fair trade chocolate factory in the USA. After a delicious round of tastings and an insightful tour of the production line, COO Andy McShea gave an interesting lecture on all things chocolate. Did you know that the antioxidant poly-phenols found in dark chocolate are known to lower blood pressure, reduce oral bacteria, and improve cognition? Still need convincing it’s ok to take one more piece?

At this point, you're probably wondering, but what does chocolate have to do with filtration? And you're right, not nearly as much as you’d find in the beverage industry. But Theo, in an effort to maintain its organic product status, uses only essential oils as opposed to extracts to create the sensational, true to flavor tastes its customers have come to enjoy. That’s where filtration comes in to play. Diatomite filtration has been used for decades in the food and beverage industry to produce essential oils for foods. In recent months, we’ve received several inquiries about the use of cross flow filtration for essential oil extraction as well. Science never smelled so sweet (or tasted this good)!

Visit Sterlitech at the ACS Spring 2011 Exposition in Anaheim, March 27th-31: Booth #313

Theo Chocolates are available at Whole Foods nationwide. For more information, visit www.theochocolate.com

According to a recent survey from Laboratory Equipment magazine on the usage of meters and monitors in lab experiments, most researchers do in fact trust their instrumentation; only 1% indicated that they were dissatisfied with their existing equipment. Another sign of trust: 71% of respondents plan to purchase direct replacements for their existing products when they buy new equipment.

You can take a look at these charts on what sort of meters and monitors are beings used and what they are being used for.

Last week the US Environmental Protection Agency announced that they are awarding $5.5 million to research possible health risks in nanotechnology. The information developed can guide the EPA and other agencies in policy decisions regarding the safety of materials and products made using nanotechnology.

The United Kingdom’s Natural Environment Research Council ($6,000,000) and the Consumer Product Safety Commission ($500,000) are also contributing to this research project. The grants will be divided between three different of researchers in the US and three in the UK.

In related news, the National Institute for Occupational Safety and Health (NIOSH) recently closed public comment on their draft document concerning possible health effects of exposure carbon nanotubes and nanofibers. The NIOSH document recommends:

Employers minimize work-related exposures until scientific studies can fully clarify the physical and chemical properties of carbon nanotubes and carbon nanofibers that define their potential for adverse occupational health effects through inhalation.

At present, NIOSH advises:

A recommended exposure limit (REL) of 7 micrograms of carbon nanotubes or carbon nanofibers per cubic meter of air as an eight-hour, time-weighted average, respirable mass concentration. 

While NIOSH does propose this specific exposure limit, it concedes, “the REL may not be completely health protective but its use should help lower the risk of developing [work-related] lung disease.”

Nanotechnology is the study of small matter called nanomaterials, which are between 1 to 100 nanometers in size. Applications that benefit from nanotechnology include drug delivery, energy storage, and pollution prevention. For more information on nanotechnology research, visit http://www.epa.gov/nanoscience/.

Click here to view the NIOSH document: Occupational Exposure to Carbon Nanotubes and Nanofibers

Scientists at Northern Illinois University recently published a new approach for fabricating hydrogen gas sensors by depositing palladium onto commercially available filtration membranes.  This creates networks of ultrasmall palladium nanowires without the traditional obstacles of nanofabrication (tedious production, potential contamination).  Palladium, besides poisoning Iron Man, is highly selective to Hydrogen gas and therefore commonly used in room-temperature solid-state Hydrogen sensors.

The new method involves a network of ultrasmall palladium nanowires (<10nm) being placed on 60 micron thick membranes with a nominal filtration pore diameter of 20nm. The end result is that this new type of fabrication method outperformed traditional hydrogen sensors, such as continuous reference film, by providing higher sensitivity and shorter response times. Better hydrogen sensing can lead to greater efficiency in areas such as steel manufacturing and clean energy research.

The Department of Energy and Savannah River National Laboratory recently published a study regarding their efforts to improve performance on cross-flow filtration for high level waste treatment. Even though the waste being treated in this case is actually radioactive material from nuclear power plants, the process they describe, along with the issues they raise and recommendations for improvement, can be applied to the more common uses for cross-flow filtration.

The stated goal of this DOE research was to improve filter fluxes in their existing cross-flow equipment, a common request of many customers. The study examines the problem of increasing cross-flow filtration efficiency from a number of different approaches: Backpulsing, cake development, scouring, and cleaning were all taken into consideration.

At the end of the study SRNL was able to draw some conclusions to take into consideration when evaluating your own setup.

• Higher solids concentration presents a greater challenge to filtration.
• The presence of a filter cake can improve the solids separation by an order of magnitude as determined by turbidity.
• Scouring a filter without cleaning will lead to improved filter performance.
• Filtrate flux decline is reversible when the concentration of the filtering slurry drops and the filter is scoured.

You can read the full report here to see a detailed description of their setup and complete results.

This week the New York Times gave a very nice shout out to one of our customers, Ion Torrent, and their CEO, Dr. Jonathan Rothberg. Ion Torrent is increasing the prevalence of genetic sequencing by developing smaller and more affordable machines. The article compares what they are doing with genetic equipment to what Steve Jobs did with the personal computer – so clearly Ion Torrent has some big, ambitious plans.

They’ve been using our bench scale products for a little while now, and it’s nice to know they are going to good use. My favorite part, “If somebody is to get the Nobel Prize for next-generation sequencing, it should be Jonathan.”

Just make sure to wave to us from Stockholm!

Read the complete article here.

Have you ever wondered where you would be without Thomas Graham? If you are a chemist or membrane scientist, you probably should. Scientists of many disciplines are indebted to Thomas Graham for his groundbreaking studies on gas flow through microporous membranes. His work, which included creating Graham’s Laws of Diffusion to describe the relative permeation rate of two gases, was instrumental in the creation of colloidal chemistry and the advancement of membrane science.

In terms of real world applications, Graham’s efforts are a precursor to inventions ranging from the artificial kidney to the atomic bomb. His feats are even more impressive when you consider that in order to perform his experiments he had to first generate the necessary gases himself, and also that his selection of membrane materials was limited to whatever objects he could find, such as rubber balloons, animal bladders, and thin metal sheets.

Thomas Graham was born in Edinburgh, Scotland in 1805 and enrolled in the University of Glasgow at the tender age of 14! He went on to become Professor of Chemistry at Anderson’s College (now part of Strathclyde University) and then at University College London. In 1854, Graham was named Master of the Mint, a position once held by Sir Isaac Newton. Even though this was considered to be more of an honorary title at the time, Graham invested himself so heavily in its duties that he actually suspended his research for several years. The position was permanently retired following his death in 1869.

Thomas Graham’s influence has grown considerably since his passing. In addition to Graham’s Laws for diffusion and effusion of gases, he introduced the terms gel, sol, colloids, crystalloids, and dialyzer into the scientific lexicon. Other important contributions include his determining the formulas of the PxOy polyatomic ions, and in the 1850’s he hypothesized that a membrane machine could be created that would separate the blood toxins that built up in kidney failure, paving the way for modern kidney dialysis. His tenacity was rewarded with several honors in his lifetime, including the Copley Medal of the Royal Society, the Royal Medal of the Royal Society (twice), and the Prix Jecker of the Paris Academy of Sciences.

Sources:
“Thomas Graham,” D. Lane and J. Solon, Woodrow Wilson Leadership Program in Chemistry, The Woodrow Wilson National Fellowship Foundation, CN 5281, Princeton, NJ 08543; http://www.woodrow.org/teachers/ci/1992/Graham.html.

“Membrane Pioneers: Thomas Graham,” S. Alexander Stern and Richard W. Baker. Membrane Quarterly. Volume 25, Number 1, January 2010, pgs. 17-19.

This is another short week for Sterlitech as we get ready to celebrate the New Year. We will be closed Thursday and Friday, and we look forward to working with you all again in 2011!

Just a reminder, but the Sterlitech office will be closed for the holiday tomorrow and Friday and we will reopen on Monday, December 27th. Have a happy and safe holiday weekend!