Quantum of sonics: Bonded, not stirred
Nanoparticles are extremely useful but are difficult to contain because they are invisible and are easily carried in the air. They can also enter the body easily, creating a concern for the safety of industrial workers and the public. A new method to stick nanoparticles to one another into something you can handle safely with your fingers, without changing their useful properties, could have implications for a range of everyday applications.
"Using ultrasound is a very gentle low-energy process compared to traditional furnaces and welding, so even active drugs and enzymes can easily be built into carriers to make new hybrid materials," says Prof. Barralet, lead investigator of the study and Director of Research in the Department of Surgery at the Research Institute of the McGill University Health Centre (RI-MUHC).
Ultrasound induces short-lived bubbles (known as cavitation) that create, for a fraction of a microsecond, when they collapse, 'hotspots' of thousands of degrees. Because this bubble formation is a random and infrequent process, scientists have struggled with ways to harness this incredibly powerful phenomenon for assembling materials rather than for destroying them. The key to the McGill team's finding was developing a way to localize cavitation at the nanoparticles' surface. This led to the discovery that their phosphate coating interacts with unstable radicals created at these hotpots and makes the nanoparticles 'weld' together irreversibly.
Just as a mixologist (cocktail waiter) shakes drinks together to create your favourite martini, materials scientists can now simply mix preformed nanoparticles together and zap them in the ultrasonic bath to create new weird and wonderful hybrid and fully functional microparticle materials, such as conductive ceramic catalysts, magnetic polymers, and drug-loaded metals.
"Our discovery may help alleviate the loss of platinum from catalytic converters in car exhausts, for example. Half of the platinum mined annually worldwide is used to make catalytic converters and up to half of this platinum is lost into the atmosphere during the lifetime of the car. This results from a lack of a better method -- up to now -- for bonding nanoparticles in a robust and durable manner while still maintaining their activity."
The study's co-author and former McGill doctoral student, David Bassett, helped make the discovery when he spotted something unusual in the bottom of his ultrasonic bath.
"Instead of getting smaller, these things grew and kept on growing. We went up many blind alleys and it took me three years to unravel what was going on. It was painstaking but now it's really satisfying to finally have a grip on it."
Welcome to SUV System Ltd!
SUV System Ltd is ISO 90012008 Certified electronics distributor with 10 years of experiences.
We have built up long term business relationship with about many companies which are stockers and authorized agents. we have a steady and reliable supply to meet customer's demands to the greatest extent .Confidently, we are able to lower your cost and support your business with our years of professional service.
SUV System Ltd is Electronic Components Distributor Supplies,Find Quality Electronic Components Supplies Products IC(Integrated Circuits),Connectors,Capacitor,Resistors,Diodes,Transistors,LED at Suvsystem.com. Sourcing Other Energy, Environment, Excess Inventory Products from Manufacturers and Suppliers at Suvsystem.com
Electronic Components distributor:http://www.suvsystem.com
Connectors Distributor:http://www.suvsystem.com/l/Connectors-1.html
IC Distributor:http://www.suvsystem.com/l/IC(Integrated-Circuits)-1.html
LED Distributor:http://www.suvsystem.com/l/LED-1.html
Capacitor Distributor:http://www.suvsystem.com/l/Capacitor-1.html
Transistor Distributor:http://www.suvsystem.com/l/Transistors-1.html
Resistor Distributor:http://www.suvsystem.com/l/Resistors-1.html
Diode Distributor:http://www.suvsystem.com/l/Diodes-1.html
SUV System Ltd insists on the managing faith ofsincereness,speciality,foresight, win-win,so we build up stable-relationship customers located all over the world, including the States, Europe, Argentina, UAE, Malaysia, Australia,and India etc
we are focus on the following fields,and hope we can help you.
Industrial IC Infineon Technologies Transistors YAGEO Resistors Schottky Diodes Chip Inductors About US Fast Recovery Diodes TOSHIBA Transistors ALTERA IC ON Diodes SANYO IC NS IC Transistors LITTELFUSE Diodes Diodes Inc Ligitek LED Voltage Regulators Transistors Fleld Effect Transistors ON Transistors MOTOROLA IC Zener Diodes Current Sensors Resistors Switching Diodes Chip Fuses Other Parts Renesas parts IC Diodes chip Filter saws Low Ohmic Resistors Switches FAIRCHILD diodes Multi-units Transistors Freescale Semiconductor IR transistor LINEAR IC AVX Resistors Thin Film Resistors Chip Ferrite Beads High Precision Resistors Connectors
http://www.suvsystem.com/a/4373.aspx
