Navigation Links
Spiraling nanotrees offer new twist on growth of nanowires
Date:5/1/2008

>

His team created its nanotrees specifically by applying a slight variation of a synthesis technique called chemical vapor deposition to the material lead sulfide. But the chemists believe the new mechanism will be applicable to many other materials, as well.

We think these findings will motivate a lot of people to do this purposefully, to design dislocation and try to grow nanowires around it, Jin says. Or perhaps people who have grown a structure and were puzzled by it will read our paper and say, Hey, we see something similar in our system, so maybe now we have the solution.

What initially puzzled Jin and his students about their pine tree structures was the long length of the trunks compared with the branches, a difference that indicated the trunks were growing much faster. The result was surprising because when complex, branching nanostructures are grown with metal catalysts, the branches are usually all of similar length because of similar growth rates, leading to boxy shapes rather than the cone-shapes of the trees.

Another oddity was the twist to the trunks, which sent the branches spiraling.

The long and twisting trunks were telling us we had a new growth mode, says Jin. Suspecting dislocation, the team set about refining their technique for growing the pine trees they soon learned to produce entire forests with ease and then confirmed the presence of dislocations with a special type of transmission electron microscopy.

Upon closer examination, the twisting trunks and spiraling branches also turned out to embody a well-known general theory about the mechanical deformation of crystalline materials caused by screw dislocations. Although this so-called Eshelby twist was first calculated back in 1953 and is discussed in many textbooks, Jins experimental results likely offer the best support yet for the theory.

These are beautiful, truly intriguing structures, but behind them is also a really beautiful, i
'/>"/>

Contact: Song Jin
jin@chem.wisc.edu
608-262-1562
University of Wisconsin-Madison
Source:Eurekalert

Page: 1 2 3

Related biology technology :

1. Emisphere Technologies, Inc. Announces Pricing of Registered Direct Offering
2. Roche Extends Tender Offer for Ventana
3. ATS Medical Expands Open Pivot Heart Valve Offerings
4. New 200 mg Vial for Eloxatin(R) (Oxaliplatin Injection) Offers Greater Convenience and Efficiency of Preparation
5. Updated NIH Guidelines Offer Valuable Information on Asthma Diagnosis and Management
6. ARYx Therapeutics, Inc. Files Registration Statement for Initial Public Offering
7. Anacor Files Registration Statement for Initial Public Offering
8. NPS Pharmaceuticals Commences Tender Offer for 3.0% Convertible Notes Due 2008
9. Clinsys Clinical Research, Inc. Announces Key Hires, Rajagopalan Srinivasan, Ph.D, to Strengthen Global Biostatistics Service Offering and Christopher Gregory, Ph.D, to Scientific Affairs
10. Schering-Plough Announces Pricing of Senior Notes Offering
11. Exelixis Announces Closing of Public Offering of Common Stock
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:1/15/2014)... and SAN JOSE, California , January 15, ... developing antibody-drug conjugates for cancer, today announced the appointment of ... Dr Reynolds has over 20 years, development experience gained in ... Seattle Genetics. "I am delighted to welcome Tom ...
(Date:1/15/2014)... Toronto, Canada (PRWEB) January 15, 2014 ... perspectives on nonclinical and clinical safety assessment in biosimilars. ... a path for biosimilar drug development, however the complex ... regards to quality, safety and efficacy extremely challenging. Based ...
(Date:1/15/2014)... 2014 More than 5 million Americans ... in 3 seniors will die with Alzheimer’s or another ... figures have shocked many Americans into looking for ways ... these tragic age-related cognitive disorders. Jonathan Weisman, president of ...
(Date:1/15/2014)... 2014 The Microcompetition with Foreign DNA theory ... of these latent viruses is the Epstein Barr Virus (EBV), ... arthritis (RA) is a chronic inflammatory disease that destroys the ... that RA patients have high concentrations of EBV DNA in ...
Breaking Biology Technology:Oxford BioTherapeutics Appoints Thomas C Reynolds MD, PhD to its Board of Directors 2Oxford BioTherapeutics Appoints Thomas C Reynolds MD, PhD to its Board of Directors 3Xtalks Life Sciences Webinar Examines Safety Assessment of Biosimilars 2Biohack Pure Offers 5 Tips for Increasing Memory in 2014 2Study: Rheumatoid Arthritis (RA) Patients Have EBV; The CBCD Says this is Consistent with Microcompetition 2Study: Rheumatoid Arthritis (RA) Patients Have EBV; The CBCD Says this is Consistent with Microcompetition 3
... April 12, 2011 Drs. Rodney Landreneau and ... non small cell lung cancer study at the 2011 Society ... Landreneau is Director of the Lung Center at UPMC Shady ... at UPMC Passavant Medical Center and Director of the Division ...
... 12, 2011 Biotech Medical, Inc. is set to ... SpectraSan™ "Hungry Enzymes". The products will be available for ... a Pet Stain & Odor Eraser, Spa & Whirlpool ... All-Purpose Cleaner & Degreaser, Glass & Stainless Steel Cleaner ...
... Dr. Fresh®, Inc., maker of the popular FireFly® children,s ... to raise awareness and funds for Smile Train, the ... company will donate $1 for every new "Like" on ... Smile Train.  The organization provides life-changing surgery for poor ...
Cached Biology Technology:Precision Therapeutics' ChemoFx® Demonstrates Significant Role in Selection of Chemotherapy Doublets in Non Small Cell Lung Cancer 2Biotech Medical, Inc. Introduces a Full Line of Enzyme Cleaners 2FireFly® Toothbrush Facebook Campaign Raises Funds for Smile Train 2
(Date:4/17/2014)... have hit on a novel method to help ... and most effective treatment possible., Kidney stones represent ... developing world. If left untreated, apart from being ... and other complications. In many patients treated successfully, ... more effective pathological approach to diagnosis and treatment ...
(Date:4/17/2014)... meeting painted a stark warning on the possible effects ... greenhouse effect 32 times that of carbon dioxide. Now ... substances act as fully regenerable electron acceptors which helps ... wetlands instead of being released to the atmosphere. However, ... it may enter into a vicious cycle to release ...
(Date:4/17/2014)... University researchers have detected new early-warning signs of the ... could have far-reaching implications for the diagnosis and treatment ... 25 million Americans. , "We had not expected to ... early stages," said Ann Elsner, professor and associate dean ... of the study. "We set out to study the ...
Breaking Biology News(10 mins):Methane climate change risk suggested by proof of redox cycling of humic substances 2New technique detects microscopic diabetes-related eye damage 2New technique detects microscopic diabetes-related eye damage 3
... Gary Hoyle, PhD, professor, University of Louisville School of ... research to develop an effective medical treatment to counteract ... of terrorism. The National Institute of Environmental Health Sciences ... have awarded Hoyle $2.6 million over five-years to further ...
... in the southeastern United States, and for scientists trying to ... ) is not cooperating. So far botanists have ... plant to boiling water, dry heat up to 284 degrees ... coax them into germination. Nothing has worked. "Complete ...
... and conservation successes in the face of rapid environmental ... plants adapt to local climate. To improve scientists, ... 7, 2011 issue of Science helps define ... The National Science Foundation partly funded the study, ...
Cached Biology News:UofL researcher awarded $2.6 million NIH grant renewal 2Super-tough seed coat keeps Michaux's sumac on critically endangered list 2