“We decided against using titanium dioxide (TiO2) photocatalyst in our study despite the fact that TiO2 is considered good chemical stability, relatively low price, and no toxicity. Instead we opted for silver doped titanium dioxide (Ag/TiO2) photocatalyst which is more efficient in visible-light region” said Dr. Chamorn Chawengkijwanich, a research team member from NANOTEC. “The idea to use powdered photocatalyst thin film on plastic is because there is very limited study on this development”. 

The research study shows Ag/TiO2 exhibited the best performance for gaseous BTEX degradation under visible light. The maximum degradation efficiency was xylene (89%), ethylbenzene (86%), toluene (83%), and benzene (79%). 

The researchers reported their work in a paper published by Materials Science Forum. 

Collaborators on this research included King Mongkut’s University of Technology Thonburi, Center for Energy Technology and Environment (Ministry of Education), and National Nanotechnology Center (NANOTEC).

Dr. Chamorn

“Structural studies of nano materials with synchrotron light: scattering, absorption and photoemission”

May 24 (13.30 – 15.30 น. ห้อง 406) 

Speakers from SLRI

1. ดร.ศุภกร รักใหม่ 

2. ดร.ชนาภา คงมาก

3.ดร.ชนรรค์ เอื้อรักสกุล 

For registration: contact Panita (Ning) at panita@nanotec.or.th or call 6604 

Please come and claim your Door prizes!!!

http://nanotechweb.org/cws/article/tech/49391

http://nanotechweb.org/cws/article/tech/49418

 NANOTEC recognizing the importance of building in-house capability in sensor technologies will conduct a half day public forum on Nano Sensors during Intermach 2012 (ASEAN’s leading industrial machinery and subcontracting Exhibition) on May 18 at BITEC Bang Na (Room# MR 215). NANOTEC speakers will include Dr. Sirasak Teparkum, Deputy Executive Director, NANOTEC who will give an overview of nano senor research at NANOTEC; Dr. Jedsada Manyam (Nano Molecular Sensor Lab, NANOTEC) will talk on “Electronic Eye”, and Dr. Sirapat Pratontep (Nano Molecular Sensor Lab, NANOTEC) will talk on “NanoNose”.

 Free registration is open to the public at 08:30 – 09:00 AM on May 18. Presentation language will be in Thai.

http://www.benchmarkemail.com/c/l?u=D66321&e=17858B&c=11648&t=0&l=509EF52&email=oJqIf2KjWXmHq8wmEETBqdepgErh9aFv

http://www.benchmarkemail.com/c/l?u=D66320&e=17858B&c=11648&t=0&l=509EF52&email=oJqIf2KjWXmHq8wmEETBqdepgErh9aFv

Paresh Ray, who led the research, explained that the test fulfills an urgent need for a faster way to detect Salmonella, especially the multiple-drug resistant (MDR) strains that cause the most serious disease in both food and drinking water. In the U.S., Salmonella-contaminated food causes at least 1.6 million cases of food poisoning annually. Elsewhere in the developing world, drinking water contaminated with MDR Salmonella causes terrible outbreaks of typhoid fever, which strikes at least 17 million people annually. 

“The test for lettuce requires just a tiny sample of lettuce leaf,” Ray explained. “It doesn’t take a trained laboratory technician to perform the test or read the results. If the colourr changes from pink to bluish, that signals the presence of Salmonella. The test is suitable for use in farm fields and in remote areas of the developing world. We believe it may have enormous potential for rapid, on-site pathogen detection to avoid the distribution of contaminated foods.” 

To find the bacteria faster, Ray and colleagues at Jackson State Univ. in Mississippi enlisted gold nanoparticles, vanishingly small bits of gold so tiny that more than 25,000 would fit across the width of a human hair. The researchers attached antibodies, molecules similar to the ones that help the immune system find and fight infections with Salmonella, to the nanoparticles. Viewed under a powerful microscope, the gold nanoparticles look somewhat like individual pieces of popcorn. When these antibodies encounter Salmonella bacteria, they attach to the outer surface of the bacteria, carrying along their cargo of gold popcorn-shaped nanoparticles. The nanoparticle-antibody package is much smaller than an individual Salmonella bacterium, and several attach to each bacterium. The test, with its pink-to-blue color change, detects those gold nanoparticle-antibody-Salmonella structures, which Ray calls “aggregates.” 

The approach also has potential for killing MDR Salmonella, Ray says. “When you shine the right wavelength of light into contaminated water, for instance, the gold nanoparticles absorb that light and heat up,” he explained. “Those hot particles burn through the outer membrane of the Salmonella bacteria, killing the bacteria.”  Ray and colleagues first developed the popcorn-shaped particles to find and fight cancer. The shape was chosen because it boosts the signal for detection using something called Raman spectroscopy, which looks at the light given off after atoms or molecules absorb energy. Ray explained that this detection method is useful in other applications of the particles. “In science, we call that the lightning rod effect,” says Ray, describing how the splayed “tips” of the popcorn shape enhance the signal and make it easier to see. The group has also used the nanoparticles to detect other microbes, like E. coli. 

Despite gold’s stature as a precious and very costly metal, only tiny amounts are needed, Ray noted. About $90 worth of gold is enough to make gallons of the solution containing the nanoparticles. And only a few drops of the solution are needed seek out Salmonella bacteria. 

Ray says the technology can be commercialized, and a patent is pending. With concerns about the potential health and environmental effects of many kinds of nanoparticles, Ray’s team is investigating the effects of gold nanoparticles remaining in purified water, for instance. So far, they have found no short-term toxicity and will be checking on any potential long-term toxicity.

To acknowledge the importance of Knowledge Management (KM), NANOTEC recently invited Prof. Vicharn Panich, M.D. Chairman of Knowledge Management Institute (KMI) to give a talk on “KM and Research Community” at the monthly NANO Talk session.

“When we talk about KM we are talking about the interaction between Tacit Knowledge and Explicit Knowledge” said Prof. Vicharn. “Tacit Knowledge deals with subjective and experimental experiences which can not be express in words. While Explicit Knowledge deals with objective and rational this can be expressed in words”.

Prof. Vicharn went on to say that in order for research institution to incorporate KM in their research approach, there must exist the mood and tone for the need to incorporate healthy change that will foster positive attitude, bottom up and top down, everyone exercise leadership and creativity, and accept the concept of unity within diversity.

NANO Talk is a monthly public forum organized by NANOTEC for researchers and visiting professors to exchange knowledge and be updated on technology trends. Visiting professors to Thailand are encouraged to participate. Please contact NANOTEC if you are interested in receiving updates or would like to recommend a speaker. The NANO Talk session in May will look at the applications of synchrotron technology.

“Among all the nanowires, silver (Ag) nanowires have been used continually in an area of active research due to the high electrical and thermal conductivities of bulk silver” said Kanpitcha. “Therefore, silver nanowires are an important material in many fields, including electronics and catalysis. In this research, the synthetic procedure was developed by using Cu(II), Ni(II), K(I) and Na(I) to control growth of the silver nanowires in the presence of poly(vinylpyrrolidone)(PVP)”.

 “As for me, I am fascinated with the use of gas chromatography (GC) to investigate the decrease of an odor model, isoamyl acetate vapor (banana-like flavor), by the adsorption ability of Ag/TiO2/BC, comparing to those of BC and TiO2/BC is a followup research” said Sudarat. “Prior to this, we combined antibacterial, photocatalyst and adsorption properties to silver and titania-modified bamboo charcoal (Ag/TiO2/BC), which was successfully fabricated. Further studies using dark condition and with or without the as-prepared samples are currently underway”.

NANOTEC encourages upcoming researchers and assistant researchers to submit and participate in scientific poster presentations in order to gain exposures, networks, and opportunity to exchange knowledge with peers.

Sudarat and Kanpitcha show their certificates