Rice University researchers predict functional advantages of 3-D boron nitride
A three-dimensional porous nanostructure would have a balance of strength, toughness and ability to transfer heat that could benefit nanoelectronics, gas storage and composite materials that perform multiple functions, according to engineers at Rice University.
The researchers made this prediction by using computer simulations to create a series of 3-D prototypes with boron nitride, a chemical compound made of boron and nitrogen atoms. Their findings were published online July 14 in the Journal of Physical Chemistry C.
The 3-D prototypes fuse one-dimensional boron nitride nanotubes and two-dimensional sheets of boron nitride.
"We combined the tubes and sheets together to make them three-dimensional, thus offering more functionality," said Rouzbeh Shahsavari, assistant professor of civil and environmental engineering and of materials science and nanoengineering, who co-authored the paper with graduate student Navid Sakhavand.
In the 3-D nanostructure, the extremely thin sheets of boron nitride are stacked in parallel layers, with tube-shaped pillars of boron nitride between each layer to keep the sheets separated.
Shahsavari noted that in the one-dimensional and two-dimensional versions of boron nitride, there is always a bias in directional properties, either toward the tube axis or in-plane directions, which is not suitable for widespread 3-D use in technology and industrial applications.
For example, a one-dimensional boron nitride nanotube can be stretched about 20 percent of its length before it breaks, but the 3-D prototype of boron nitride can be stretched about 45 percent of its length without breaking.
When the typical one- or two-dimensional boron nitride materials are stretched in one direction, they tend to shrink in the other perpendicular directions. In the 3-D prototype, however, when the material stretches in the in-plane direction, it also stretches in perpendicular directions. "Here, the junction between the tubes and sheets has a unique curve-like structure that contributes to this interesting phenomenon, known as the auxetic effect," Shahsavari said.
The thermal transport properties of the 3-D prototype are also advantageous, he said. The one-dimensional boron nitride tubes and two-dimensional sheets can carry heat very fast but only in one or two directions. The 3-D prototype carries heat relatively fast in all 3-D directions. "This feature is ideal for applications that require materials or coating with the capability of extremely fast thermal diffusion to the environments. Examples include car engines or computer CPUs where a fast heat transfer to the environments is critical in proper functioning," Shahsavari said.
The 3-D boron nitride prototype has a very porous and lightweight structure. Each gram of this Swiss cheese-like structure has a surface area equivalent to three tennis courts. Such a high surface area lends itself to customized applications. Shahsavari and Sakhavand predicted that the 3-D prototype of boron nitride would allow efficient gas storage and separation, for example, in vehicles that run on hydrogen cells.
Unlike graphene-based nanostructures, boron nitride is an electrically insulating material. Thus, the 3-D boron nitride prototype has a potential to complement graphene-based nanoelectronics, including potential for the next generation of 3-D semiconductors and 3-D thermal transport devices that could be used in nanoscale calorimeters, microelectronic processes and macroscopic refrigerators.
The actual 3-D boron nitride prototype still has to be created in the lab, and numerous efforts are already underway. "Our computer simulations show what properties can be expected from these structures and what the key factors are that control their functionality," Shahsavari said.
The research was funded by Rice University. The supercomputers used for the research are supported by the National Institutes of Health, IBM, CISCO, Qlogic and Adaptive Computing and the Data Analysis and Visualization Cyber infrastructure funded by the National Science Foundation.
A high-resolution image is available for download at:
A copy of the Journal of Physical Chemistry C paper is available at:
Follow Rice News and Media Relations on Twitter @RiceUNews.
Located on a 300-acre forested campus in Houston, Rice University is consistently ranked among the nation's top 20 universities by U.S. News & World Report. Rice has highly respected schools of Architecture, Business, Continuing Studies, Engineering, Humanities, Music, Natural Sciences and Social Sciences and is home to the Baker Institute for Public Policy. With 3,920 undergraduates and 2,567 graduate students, Rice's undergraduate student-to-faculty ratio is just over 6-to-1. Its residential college system builds close-knit communities and lifelong friendships, just one reason why Rice has been ranked No. 1 for best quality of life multiple times by the Princeton Review and No. 2 for "best value" among private universities by Kiplinger's Personal Finance.
David Ruth | Eurek Alert!
New method opens crystal clear views of biomolecules
11.02.2016 | Deutsches Elektronen-Synchrotron DESY
Scientists from MIPT gain insights into 'forbidden' chemistry
11.02.2016 | Moscow Institute of Physics and Technology
Today, plants and microorganisms are heavily used for the production of medicinal products. The production of biopharmaceuticals in plants, also referred to as “Molecular Pharming”, represents a continuously growing field of plant biotechnology. Preferred host organisms include yeast and crop plants, such as maize and potato – plants with high demands. With the help of a special algal strain, the research team of Prof. Ralph Bock at the Max Planck Institute of Molecular Plant Physiology in Potsdam strives to develop a more efficient and resource-saving system for the production of medicines and vaccines. They tested its practicality by synthesizing a component of a potential AIDS vaccine.
The use of plants and microorganisms to produce pharmaceuticals is nothing new. In 1982, bacteria were genetically modified to produce human insulin, a drug...
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock which attains an accuracy which had only been predicted theoretically so far. Their optical ytterbium clock achieved a relative systematic measurement uncertainty of 3 E-18. The results have been published in the current issue of the scientific journal "Physical Review Letters".
Atomic clock experts from the Physikalisch-Technische Bundesanstalt (PTB) are the first research group in the world to have built an optical single-ion clock...
The University of Würzburg has two new space projects in the pipeline which are concerned with the observation of planets and autonomous fault correction aboard satellites. The German Federal Ministry of Economic Affairs and Energy funds the projects with around 1.6 million euros.
Detecting tornadoes that sweep across Mars. Discovering meteors that fall to Earth. Investigating strange lightning that flashes from Earth's atmosphere into...
Physicists from Saarland University and the ESPCI in Paris have shown how liquids on solid surfaces can be made to slide over the surface a bit like a bobsleigh on ice. The key is to apply a coating at the boundary between the liquid and the surface that induces the liquid to slip. This results in an increase in the average flow velocity of the liquid and its throughput. This was demonstrated by studying the behaviour of droplets on surfaces with different coatings as they evolved into the equilibrium state. The results could prove useful in optimizing industrial processes, such as the extrusion of plastics.
The study has been published in the respected academic journal PNAS (Proceedings of the National Academy of Sciences of the United States of America).
Exceeding critical temperature limits in the Southern Ocean may cause the collapse of ice sheets and a sharp rise in sea levels
A future warming of the Southern Ocean caused by rising greenhouse gas concentrations in the atmosphere may severely disrupt the stability of the West...
12.02.2016 | Event News
09.02.2016 | Event News
02.02.2016 | Event News
12.02.2016 | Materials Sciences
12.02.2016 | Materials Sciences
12.02.2016 | Materials Sciences