Speaker： Dr. Sajid Bashir
 

Time： 2015.5.21  16:00
 

Place:：实验楼116
 

Abstract： Synthesis of two new designs of nanocomposites: (1) core-shell bimetallic nanoparticles, and (2) new metal organic framework (MOF) was undertaken and evaluated as potential disinfectants. The electrical properties of the synthesised nanocomposites was further investigated, such as band gap changes upon metal insertion (e.g. Fe into TiO2), using synchronous soft x-ray absorption (XAS), emission (XES) and resonance (RIXS) spectroscopies at beam line (BL) 7.1 at the Lawrence Berkeley National Laboratory, Advanced Light Source, CA.
The band-gap energy increased for the iron insertion into titania system as a function of percent mole iron, indicating that slight distortion of the rutile form of titania, including small distortions of the grain boundary. The iron-inserted titania was tested as a disinfectant through measurement of minimal bacterial concentrations (MBC) using Escherichia coli and Staphylococcus aureus as Gram-negative and positive model microbes respectively. Other bimetallic systems such as silver-titania were similarly evaluated and were demonstrated as potent disinfectants versus model microbes. The concentration was approximately 3 ppm and effectiveness was de4monstrated within ten minutes of application. The Co-MOF design was tested with Mycobacterium, a microbe known to be resistant to chemical disinfectants and was also shown to be highly effective within 30 minutes at concentrations of less than 25 ppm. Collectively, these projects will enable us to design and fabricate new and more effective disinfectants against a range of microbes including.