Tag Archives: nanometer

Berkeley Lab Researchers Create Nanoparticle Thin Films That Self-Assemble in One Minute

By Guest PostSeptember 10, 2014Scienceberkeley lab, block copolymers, create, fossiles exemplar, gold nanoparticles, joseph kao, kari thorkelsson, knochenfischen, lungenfischen, martin thunemann, microtechnology, mysterioese fossil, nanocomposite, nanometer, palaeospondylus, palaeospondylus gunni, pet cell tracking, peter bai, polymer scientist, researcher, robert feil, self assemble, supramolecule, taskin deniz, ting xu

The days of self-assembling nanoparticles taking hours to form a film over a microscopic-sized wafer are over. Researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) have devised a technique whereby self-assembling nanoparticle arrays can form a highly ordered thin film over macroscopic distances in one minute.

Ting Xu, a polymer scientist with Berkeley Lab’s Materials Sciences Division, led a study in which supramolecules based on block copolymers were combined with gold nanoparticles to create nanocomposites that under solvent annealing quickly self-assembled into hierarchically-structured thin films spanning an area of several square centimeters. The technique is compatible with current nanomanufacturing processes and has the potential to generate new families of optical coatings for applications in a wide number of areas including solar energy, nanoelectronics and computer memory storage. This technique could even open new avenues to the fabrication of metamaterials, artificial nanoconstructs that possess remarkable optical properties. (more…)

Nanocrystals Not Small Enough to Avoid Defects

By Guest PostDecember 15, 2012Scienceals, berkeley lab, bin chen, computer simulation, crystal, defect, dislocation, gas turbine, grains, high pressure, jet engine, jialin lei, jinyuan yan, katie lutker, mechanical properties, metal, nanocrystal, nanocrystalline nickel, nanometer, nickel, non metal, plastic deformation, protective coating, resistance, selva vennila raju, stress, ultraviolet light, waruntorn kanitpanyacharoen

Berkeley Lab Scientists at Advanced Light Source Show Dislocations Can Be Induced by Pressure in Ultrafine Nanocrystals

Nanocrystals as protective coatings for advanced gas turbine and jet engines are receiving a lot of attention for their many advantageous mechanical properties, including their resistance to stress. However, contrary to computer simulations, the tiny size of nanocrystals apparently does not safeguard them from defects.

In a study by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab)and collaborators from multiple institutions, nanocrystals of nickel subjected to high pressure continued to suffer dislocation-mediated plastic deformation even when the crystals were only three nanometers in size. These experimental findings, which were carried out at Berkeley Lab’s Advanced Light Source (ALS), a premier source of X-rays and ultraviolet light for scientific research, show that dislocations can form in the finest of nanocrystals when stress is applied. (more…)

Researchers Create ‘Nanoflowers’ for Energy Storage, Solar Cells

By Guest PostOctober 18, 2012Scienceacs nano, atomic structure, batteries, carnation, chun li, device, energy storage, flow, flower like, flower structure, gayatri pongur snigdha, germanium sulfide, ges, ges nanoflower, ges powder, ges vapor, graphite, liang huang, linyou cao, lithium ion, marigold, material, micrometer, nanometer, next generation, non-toxic, north Carolina, petal, semiconductor, solar cell, state university, structure, surface area, toxic, useable power, vaporize, yifei yu

Researchers from North Carolina State University have created flower-like structures out of germanium sulfide (GeS) – a semiconductor material – that have extremely thin petals with an enormous surface area. The GeS flower holds promise for next-generation energy storage devices and solar cells.

“Creating these GeS nanoflowers is exciting because it gives us a huge surface area in a small amount of space,” says Dr. Linyou Cao, an assistant professor of materials science and engineering at NC State and co-author of a paper on the research. “This could significantly increase the capacity of lithium-ion batteries, for instance, since the thinner structure with larger surface area can hold more lithium ions. By the same token, this GeS flower structure could lead to increased capacity for supercapacitors, which are also used for energy storage.” (more…)

Graphene Membranes May Lead To Enhanced Natural Gas Production, Less CO2 Pollution, Says CU Study

By Guest PostOctober 16, 2012Environment, Science2010, andre geim, argon, atomic crystal, atomic scale, carbon atom, carbon dioxide, chicken wire, colorado boulder, diameter, emission, energy-efficient, engineering faculty, England, exhaust pipe, gas molecule, graphene membrane, hexagonal, hydrogen, industrial scale, john pellegrino, konstantin novoselov, lattice, luda wang, manchester university, membrane, methane, molecular sieve, molecular size, nanometer, natural gas, nature nanotechnology, nitrogen, nobel prize, oxidative etching, pore, power plant, production, scott bunch, sieving, size selective, steven koenig, sulphur hexafluoride, ultraviolet light, university

Engineering faculty and students at the University of Colorado Boulder have produced the first experimental results showing that atomically thin graphene membranes with tiny pores can effectively and efficiently separate gas molecules through size-selective sieving.

The findings are a significant step toward the realization of more energy-efficient membranes for natural gas production and for reducing carbon dioxide emissions from power plant exhaust pipes.

Mechanical engineering professors Scott Bunch and John Pellegrino co-authored a paper in Nature Nanotechnology with graduate students Steven Koenig and Luda Wang detailing the experiments. The paper was published Oct. 7 in the journal’s online edition. (more…)

Questions for Rashid Zia: Brown to Lead Multi-University Quantum Metamaterials Research

By Guest PostOctober 4, 2012Scienceair force, arto nurmikko, Diamond, electric dipole, encrypted communication, harry atwater, interaction, jelena vuckovic, kevin stacey, light, light wave, mark brongersma, matter, multidisciplinary, muri, nader engheta, nanometer, nicholas fang, office, optical memory, optical microprocessor, optical wavelength, quantum emitter, quantum metamaterials, quantum metaphotonics, quantum optics, quantum scale, rashid zia, research initiative, scalable technology, semiconductor, seth bank, shanhui fan, spatial variation, telecommunication, university, xiang zhang

Through a new Multidisciplinary University Research Initiative (MURI) awarded by the Air Force Office of Scientific Research, Brown will lead an effort to study new optical materials and their interactions with light at the quantum scale. The initiative, which includes six other top universities, will receive $4.5 million over three years, with a possible two-year extension.

Harnessing the power of light at the quantum scale could clear the way for superfast optical microprocessors, high-capacity optical memory, securely encrypted communication, and untold other technologies. But before any of these potential applications sees the light of day, substantial obstacles must be overcome — not the least of which is the fact that the wavelength of light is larger than quantum-scale objects, limiting the range of possible light-matter interactions. (more…)

Nano-Sandwich Technique Slims Down Solar Cells, Improves Efficiency

By Guest PostJune 29, 2012Scienceamorphous silicon, Berkeley, cadmium telluride, chemical fuel, efficiency, electricity, linyou cao, nano-sandwich, nanometer, nanostructures, nm, organic materials, paul alivisatos, solar cells, solar energy, substrate, technique, Technology, university of california, vivian ferry

Researchers from North Carolina State University have found a way to create much slimmer thin-film solar cells without sacrificing the cells’ ability to absorb solar energy. Making the cells thinner should significantly decrease manufacturing costs for the technology.

“We were able to create solar cells using a ‘nanoscale sandwich’ design with an ultra-thin ‘active’ layer,” says Dr. Linyou Cao, an assistant professor of materials science and engineering at NC State and co-author of a paper describing the research. “For example, we created a solar cell with an active layer of amorphous silicon that is only 70 nanometers (nm) thick. This is a significant improvement, because typical thin-film solar cells currently on the market that also use amorphous silicon have active layers between 300 and 500 nm thick.” The “active” layer in thin-film solar cells is the layer of material that actually absorbs solar energy for conversion into electricity or chemical fuel. (more…)

Golden Potential for Gold Thin Films

By Guest PostApril 29, 2012Science1d chain, 2d nanoparticle, 2d sheet, berkeley lab, block, catalysis, co polymer, DNA, gold nanoparticle, joseph kao, microdomain, microtechnology, nanometer, nanoparticle, peter bai, peter ercius, plasmonic metamaterial, plasmonic technology, polymer scientist, polymer supramolecule, scalable nanomanufacturing, semiconductor nanocrystal, solvent evaporation, supramolecular nanocomposites, thin film, three dimensional array, ting xu, uc, university of california, vivian chuang, zhang jiang

Berkeley Lab Researchers Direct the Self-Assembly of Gold Nanoparticles into Device-Ready Thin films

Scientists with the Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley have directed the first self-assembly of nanoparticles into device-ready materials. Through a relatively easy and inexpensive technique based on blending nanoparticles with block co-polymer supramolecules, the researchers produced multiple-layers of thin films from highly ordered one-, two- and three-dimensional arrays of gold nanoparticles. Thin films such as these have potential applications for a wide range of fields, including computer memory storage, energy harvesting, energy storage, remote-sensing, catalysis, light management and the emerging new field of plasmonics.

“We’ve demonstrated a simple yet versatile supramolecular approach to control the 3-D spatial organization of nanoparticles with single particle precision over macroscopic distances in thin films,” says polymer scientist Ting Xu, who led this research. “While the thin gold films we made were wafer-sized, the technique can easily produce much larger films, and it can be used on nanoparticles of many other materials besides gold.” (more…)

The Weird World of “Remote Heating”

By Guest PostApril 10, 2012Scienceatom, bounce, carbon nanotube, electric current, electron, john cumings, joule heating, kamal baloch, metal wire, nanoelectronic, nanometer, nanoscale, nature nanotechnology, object, phenomenon, university of maryland

*UMD Researchers Discover Nanoscale Phenomena with Potential for Computer Speed Advances*

College Park, Md.– A team of University of Maryland scientists have discovered that when electric current is run through carbon nanotubes, objects nearby heat up while the nanotubes themselves stay cool, like a toaster that burns bread without getting hot. Understanding this completely unexpected new phenomenon could lead to new ways of building computer processors that can run at higher speeds without overheating.

“This is a new phenomenon we’re observing, exclusively at the nanoscale, and it is completely contrary to our intuition and knowledge of Joule heating at larger scales-for example, in things like your toaster,” says first author Kamal Baloch, who conducted the research while a graduate student at the University of Maryland. “The nanotube’s electrons are bouncing off of something, but not its atoms. Somehow, the atoms of the neighboring materials-the silicon nitride substrate-are vibrating and getting hot instead.” (more…)