Rice U: Nano-Shells could deliver more chemo with fewer side effects


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Researchers from Rice University and Northwestern University loaded light-activated nano-shells (gold and light blue) with the anticancer drug lapatinib (yellow) by encasing the drug in an envelope of albumin (blue). Light from a near-infrared laser (center) was used to remotely trigger the release of the drug (right) after the nano-shells were taken up by cancer cells. Credit: A. Goodman/Rice University

Researchers investigating ways to deliver high doses of cancer-killing drugs inside tumors have shown they can use a laser and light-activated gold nanoparticles to remotely trigger the release of approved cancer drugs inside cancer cells in laboratory cultures.

The study by researchers at Rice University and Northwestern University Feinberg School of Medicine appears in this week’s online Early Edition of the Proceedings of the National Academy of Sciences. It employed gold nanoshells to deliver toxic doses of two drugs — lapatinib and docetaxel — inside breast cancer cells. The researchers showed they could use a laser to remotely trigger the particles to release the drugs after they entered the cells.

Though the tests were conducted with cell cultures in a lab, the research was designed to demonstrate clinical applicability: The nanoparticles are nontoxic, the drugs are widely used and the low-power, infrared laser can noninvasively shine through tissue and reach tumors several inches below the skin.

“In future studies, we plan to use a Trojan-horse strategy to get the drug-laden nanoshells inside tumors,” said Naomi Halas, an engineer, chemist and physicist at Rice University who invented gold nanoshells and has spent more than 15 years researching their anticancer potential. “Macrophages, a type of white blood cell that’s been shown to penetrate tumors, will carry the drug-particle complexes into tumors, and once there we use a laser to release the drugs.”

Co-author Susan Clare, a research associate professor of surgery at the Northwestern University Feinberg School of Medicine, said the PNAS study was designed to demonstrate the feasibility of the Trojan-horse approach. In addition to demonstrating that drugs could be released inside cancer cells, the study also showed that in macrophages, the drugs did not detach prior to triggering.

“Getting chemotherapeutic drugs to penetrate tumors is very challenging,” said Clare, also a Northwestern Medicine breast cancer surgeon. “Drugs tend to get pushed out of tumors rather than drawn in. To get an effective dose at the tumor, patients often have to take so much of the drug that nausea and other side effects become severe. Our hope is that the combination of macrophages and triggered drug-release will boost the effective dose of drugs within tumors so that patients can take less rather than more.”

If the approach works, Clare said, it could result in fewer side effects and potentially be used to treat many kinds of cancer. For example, one of the drugs in the study, lapatinib, is part of a broad class of chemotherapies called tyrosine kinase inhibitors that target specific proteins linked to different types of cancer. Other Federal Drug Administration-approved drugs in the class include imatinib (leukemia), gefitinib (breast, lung), erlotinib (lung, pancreatic), sunitinib (stomach, kidney) and sorafenib (liver, thyroid and kidney).

“All the tyrosine kinase inhibitors are notoriously insoluble in water,” said Amanda Goodman, a Rice alumna and lead author of the PNAS study. “As a drug class, they have poor bioavailability, which means that a relatively small proportion of the drug in each pill is actually killing cancer cells. If our method works for lapatinib and breast cancer, it may also work for the other drugs in the class.”

Halas invented nanoshells at Rice in the 1990s. About 20 times smaller than a red blood cell, they are made of a sphere of glass covered by a thin layer of gold. Nanoshells can be tuned to capture energy from specific wavelengths of light, including near-infrared (near-IR), a nonvisible wavelength that passes through most tissues in the body. Nanospectra Biosciences, a licensee of this technology, has performed several clinical trials over the past decade using nanoshells as photothermal agents that destroy tumors with infrared light.

Clare and Halas’ collaboration on nanoshell-based drug delivery began more than 10 years ago. In earlier work, they showed that a near-IR continuous-wave laser — the same kind that produces heat in the photothermal applications of nanoshells — could be used to trigger the release of drugs from nanoshells.

In the latest study, Goodman contrasted the use of continuous-wave laser triggering and triggering with a low-power pulse laser. Using each type of laser, she demonstrated the remotely triggered release of drugs from two types of nanoshell-drug conjugates. One type used a DNA linker and the drug docetaxel, and the other employed a coating of the blood protein albumin to trap and hold lapatinib. In each case, Goodman found she could trigger the release of the drug after the nanoshells were taken up inside cancer cells. She also found no measureable premature release of drugs in macrophages in either case.

Halas and Clare said they hope to begin animal tests of the technology soon and have an established mouse model that could be used for the testing.

“I’m particularly excited about the potential for lapatinib,” Clare said. “The first time I heard about Naomi’s work, I wondered if it might be the answer to delivering drugs into the anoxic (depleted of oxygen) interior of tumors where some of the most aggressive cancer cells lurk. As clinicians, we’re always looking for ways to keep cancer from coming back months or years later, and I am hopeful this can do that.”

Story Source:

Materials provided by Rice UniversityNote: Content may be edited for style and length.

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Rice U: Long Nanotube fibers for use in Large-Scale Aerospace, Consumer Electronics and Textile Applications


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Rice University researchers advance characterization, purification of Nanotube wires and films

RICE UNIVERSITY

To make continuous, strong and conductive carbon nanotube fibers, it’s best to start with long nanotubes, according to scientists at Rice University.

The Rice lab of chemist and chemical engineer Matteo Pasquali, which demonstrated its pioneering method to spin carbon nanotube into fibers in 2013, has advanced the art of making nanotube-based materials with two new papers in the American Chemical Society’s ACS Applied Materials and Interfaces.

The first paper characterized 19 batches of nanotubes produced by as many manufacturers to determine which nanotube characteristics yield the most conductive and strongest fibers for use in large-scale aerospace, consumer electronics and textile applications.

The researchers determined the nanotubes’ aspect ratio — length versus width — is a critical factor, as is the overall purity of the batch. They found the tubes’ diameters, number of walls and crystalline quality are not as important to the product properties.

Pasquali said that while the aspect ratio of nanotubes was known to have an influence on fiber properties, this is the first systematic work to establish the relationship across a broad range of nanotube samples. Researchers found that longer nanotubes could be processed as well as shorter ones, and that mechanical strength and electrical conductivity increased in lockstep.Rice II nanotubes

The best fibers had an average tensile strength of 2.4 gigapascals (GPa) and electrical conductivity of 8.5 megasiemens per meter, about 15 percent of the conductivity of copper. Increasing nanotube length during synthesis will provide a path toward further property improvements, Pasquali said.

The second paper focused on purifying fibers produced by the floating catalyst method for use in films and aerogels. This process is fast, efficient and cost-effective on a medium scale and can yield the direct spinning of high-quality nanotube fibers; however, it leaves behind impurities, including metallic catalyst particles and bits of leftover carbon, allows less control of fiber structure and limits opportunities to scale up, Pasquali said.

“That’s where these two papers converge,” he said. “There are basically two ways to make nanotube fibers. In one, you make the nanotubes and then you spin them into fibers, which is what we’ve developed at Rice. In the other, developed at the University of Cambridge, you make nanotubes in a reactor and tune the reactor such that, at the end, you can pull the nanotubes out directly as fibers.

“It’s clear those direct-spun fibers include longer nanotubes, so there’s an interest in getting the tubes included in those fibers as a source of material for our spinning method,” Pasquali said. “This work is a first step toward that goal.”

Q Flow MODEL-OF-CARBON-NANOTUBE-PAIDThe reactor process developed a decade ago by materials scientist Alan Windle at the University of Cambridge produces the requisite long nanotubes and fibers in one step, but the fibers must be purified, Pasquali said. Researchers at Rice and the National University of Singapore (NUS) have developed a simple oxidative method to clean the fibers and make them usable for a broader range of applications.

The labs purified fiber samples in an oven, first burning out carbon impurities in air at 500 degrees Celsius (932 degrees Fahrenheit) and then immersing them in hydrochloric acid to dissolve iron catalyst impurities.

Impurities in the resulting fibers were reduced to 5 percent of the material, which made them soluble in acids. The researchers then used the nanotube solution to make conductive, transparent thin films.

“There is great potential for these disparate techniques to be combined to produce superior fibers and the technology scaled up for industrial use,” said co-author Hai Minh Duong, an NUS assistant professor of mechanical engineering. “The floating catalyst method can produce various types of nanotubes with good morphology control fairly quickly. The nanotube filaments can be collected directly from their aerogel formed in the reactor. These nanotube filaments can then be purified and twisted into fibers using the wetting technique developed by the Pasquali group.”

Pasquali noted the collaboration between Rice and Singapore represents convergence of another kind. “This may well be the first time someone from the Cambridge fiber spinning line (Duong was a postdoctoral researcher in Windle’s lab) and the Rice fiber spinning line have converged,” he said. “We’re working together to try out materials made in the Cambridge process and adapting them to the Rice process.”

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Alumnus Dmitri Tsentalovich, currently an academic visitor at Rice, is lead author of the characterization paper. Co-authors are graduate students Robert Headrick and Colin Young, research scientist Francesca Mirri and alumni Junli Hao and Natnael Behabtu, all of Rice.

Thang Tran of Rice and NUS and Headrick are co-lead authors of the catalyst paper. Co-authors are graduate student Amram Bengio and research specialist Vida Jamali, both of Rice, and research scientist Sandar Myo and graduate student Hamed Khoshnevis, both of NUS.

The Air Force Office of Scientific Research, the Welch Foundation and NASA supported both projects. The characterization project received additional support from the Department of Energy. The catalyst project received additional support from the Temasek Laboratory in Singapore.

Influence of Carbon Nanotube Characteristics on Macroscopic Fiber Properties: http://pubs.acs.org/doi/abs/10.1021/acsami.7b10968

Purification and Dissolution of Carbon Nanotube Fibers Spun from Floating Catalyst Method: http://pubs.acs.org/doi/abs/10.1021/acsami.7b09287

This news release can be found online at http://news.rice.edu/2017/10/15/long-nanotubes-make-strong-fibers/

1-blind CNTWhat Are Carbon Nanotubes and What are some of their Applications

Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure.

 

 

 

These cylindrical carbonmolecules have unusual properties, which are valuable for nanotechnologyelectronicsoptics and other fields of materials science and technology. Owing to the material’s exceptional strength and stiffness, nanotubes have been constructed with length-to-diameter ratio of up to 132,000,000:1,[1] significantly larger than for any other material.

In addition, owing to their extraordinary thermal conductivity, mechanical, and electrical properties, carbon nanotubes find applications as additives to various structural materials. For instance, nanotubes form a tiny portion of the material(s) in some (primarily carbon fiber) baseball bats, golf clubs, car parts or damascus steel.

 

Rice University (NEWT) / China team use phage-enhanced nanoparticles to kill bacteria that foul water treatment systems


Clusters of nanoparticles with phage viruses attached find and kill Escherichia coli bacteria in a lab test at Rice University. 

Abstract:
Magnetic nanoparticle clusters have the power to punch through biofilms to reach bacteria that can foul water treatment systems, according to scientists at Rice University and the University of Science and Technology of China.
Magnetized viruses attack harmful bacteria: Rice, China team uses phage-enhanced nanoparticles to kill bacteria that foul water treatment systems.

Researchers at Rice and the University of Science and Technology of China have developed a combination of antibacterial phages and magnetic nanoparticle clusters that infect and destroy bacteria that are usually protected by biofilms in water treatment systems. (Credit: Alvarez Group/Rice University)

The nanoclusters developed through Rice’s Nanotechnology-Enabled Water Treatment (NEWT) Engineering Research Center carry bacteriophages – viruses that infect and propagate in bacteria – and deliver them to targets that generally resist chemical disinfection.

Without the pull of a magnetic host, these “phages” disperse in solution, largely fail to penetrate biofilms and allow bacteria to grow in solution and even corrode metal, a costly problem for water distribution systems.

The Rice lab of environmental engineer Pedro Alvarez and colleagues in China developed and tested clusters that immobilize the phages. A weak magnetic field draws them into biofilms to their targets.

The research is detailed in the Royal Society of Chemistry’s Environmental Science: Nano.
“This novel approach, which arises from the convergence of nanotechnology and virology, has a great potential to treat difficult-to-eradicate biofilms in an effective manner that does not generate harmful disinfection byproducts,” Alvarez said.

Biofilms can be beneficial in some wastewater treatment or industrial fermentation reactors owing to their enhanced reaction rates and resistance to exogenous stresses, said Rice graduate student and co-lead author Pingfeng Yu. “However, biofilms can be very harmful in water distribution and storage systems since they can shelter pathogenic microorganisms that pose significant public health concerns and may also contribute to corrosion and associated economic losses,” he said.

The lab used phages that are polyvalent – able to attack more than one type of bacteria – to target lab-grown films that contained strains of Escherichia coli associated with infectious diseases and Pseudomonas aeruginosa, which is prone to antibiotic resistance.

The phages were combined with nanoclusters of carbon, sulfur and iron oxide that were further modified with amino groups. The amino coating prompted the phages to bond with the clusters head-first, which left their infectious tails exposed and able to infect bacteria.

The researchers used a relatively weak magnetic field to push the nanoclusters into the film and disrupt it. Images showed they effectively killed E. coli and P. aeruginosa over around 90 percent of the film in a test 96-well plate versus less than 40 percent in a plate with phages alone.

The researchers noted bacteria may still develop resistance to phages, but the ability to quickly disrupt biofilms would make that more difficult. Alvarez said the lab is working on phage “cocktails” that would combine multiple types of phages and/or antibiotics with the particles to inhibit resistance.

Graduate student Ling-Li Li of the University of Science and Technology of China, Hefei, is co-lead author of the paper. Co-authors are graduate student Sheng-Song Yu and Han-Qing Yu, a professor at the University of Science and Technology of China, and graduate student Xifan Wang and temporary research scientist Jacques Mathieu of Rice.


The National Science Foundation and its Rice-based NEWT Engineering Research Center supported the research.

Rice University: Designing Materials with ‘Stiffness and Flexibility’


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Materials scientists at Rice University are looking to nature — at the discs in human spines and the skin in ocean-diving fish, for example — for clues about designing materials with seemingly contradictory properties — flexibility and stiffness.

In research graduate student Peter Owuor, research scientist Chandra Sekhar Tiwary and colleagues from the laboratories of Rice Professor Pulickel Ajayan and Jun Lou found they could increase the stiffness, or “elastic modulus,” of a soft silicon-based polymer by infusing it with tiny pockets of liquid gallium.

Such composites could find use in high-energy absorption materials and shock absorbers and in biomimetic structures like artificial intervertebral discs, they said.

Owuor said conventional wisdom in composite design for the past 60 years has been that adding a harder substance increases modulus and adding a softer one decreases modulus. In most instances, that’s correct.

“People had not really looked at it from the other way around,” he said. “Is it possible to add something soft inside something else that is also soft and get something that has a higher modulus? If you look at the natural world, there are plenty of examples where you find exactly that. As materials scientists, we wanted to study this, not from a biological perspective but rather from a mechanical one.”

For example, the discs between the vertebrae in human spines, which act like both shock absorbers and ligaments, are made of a tough outer layer of cartilage and a soft, jelly-like interior. And the outer skin of deep-diving ocean fish and mammals contain myriad tiny oil-filled chambers — some no larger than a virus and others larger than entire cells — that allow the animals to withstand the intense pressures that exist thousands of feet below the ocean’s surface.Rice Flex Materials2 38906-53.jpg

Choosing the basic materials to model these living systems was relatively easy, but finding a way to bring them together to mimic nature proved difficult, said Tiwary, a postdoctoral research associate in Rice’s Department of Materials Science and NanoEngineering.

Polydimethylsiloxane, or PDMS, was chosen as the soft encapsulating layer for a number of reasons: It’s cheap, inert, nontoxic and widely used in everything from caulk and aquarium sealants to cosmetics and food additives. It also dries clear, which made it easy to see the bubbles of liquid the team wanted to encapsulate. For that, the researchers chose gallium, which like mercury is liquid at room temperature, but unlike mercury is nontoxic and relatively easy to work with.

Owuor said it took nearly four months to find a recipe for encapsulating bubbles of gallium inside PDMS. His test samples are about the diameter of a small coin and as much as a quarter-inch thick. By curing the PDMS slowly, Owuor developed a process by which he could add gallium droplets of various sizes. Some samples contained one large inner chamber, and others contained up to a dozen discrete droplets.

Each sample was subjected to dozens of tests. A dynamic mechanical analysis instrument was used to measure how much the material deformed under load, and various measures like stiffness, toughness and elasticity were measured under a variety of conditions. For example, with a relatively small amount of cooling, gallium can be turned into a solid. So the team was able to compare some measurements taken when the gallium spheres were liquid with measures taken when the spheres were solid.

Collaborators Roy Mahapatra and Shashishekarayya Hiremath of the Indian Institute of Science at Bangalore used finite element modeling and hydrodynamic simulations to help the team analyze how the materials behaved under mechanical stress. Based on this, the researchers determined that pockets of liquid gallium gave the composite higher energy absorption and dissipation characteristics than plain PDMS or PDMS with air-filled pockets.

“What we’ve shown is that putting liquid inside a solid is not always going to make it softer, and thanks to our collaborators we are able to explain why this is the case,” Tiwary said. “Next we hope to use this understanding to try to engineer materials to take advantage of these properties.”

Owuor and Tiwary said just using nanoengineering alone may not provide a maximum effect. Instead, nature employs hierarchical structures with features of varying sizes that repeat at larger scales, like those found in the oil-filled chambers in fish skin.

“If you look at (the fish’s) membrane and you section it, there is a layer where you have spheres with big diameters, and as you move, the diameters keep decreasing,” Owuor said. “The chambers are seen across the whole scale, from the nano- all the way out to the microscale.

Tiwary said, “There are important nanoscale features in nature, but it’s not all nano. We may find that engineering at the nanoscale alone isn’t enough. We want to see if we can start designing in a hierarchical way.”

Ajayan is chair of Rice’s Department of Materials Science and NanoEngineering, the Benjamin M. and Mary Greenwood Anderson Professor in Engineering and a professor of chemistry.

The research was supported by the Air Force Office of Scientific Research. Additional Rice co-authors include Lou, Alin Chipara and Robert Vajtai.

Rice U Researchers Create 3-D printed Graphene Foam (Ultra-Thin Graphene) + New Video for ‘Graphene Nano-Tubes’ ~ Supports New Li-Io Battery Technology


3D Graphene

Researchers from Rice University and China’s Tianjin University have used 3-D laser printing to fabricate centimeter-sized objects of atomically thin graphene.

The research could yield industrially useful quantities of bulk graphene and is described online in a new study in the American Chemical Society journal ACS Nano.

“This study is a first of its kind,” said Rice chemist James Tour, co-corresponding author of the paper. “We have shown how to make 3-D graphene foams from nongraphene starting materials, and the method lends itself to being scaled to graphene foams for additive manufacturing applications with pore-size control.”

Graphene, one of the most intensely studied nanomaterials of the decade, is a two-dimensional sheet of pure carbon that is both ultrastrong and conductive. Scientists hope to use graphene for everything from nanoelectronics and aircraft de-icers to batteries and bone implants. But most industrial applications would require bulk quantities of graphene in a three-dimensional form, and scientists have struggled to find simple ways of creating bulk 3-D graphene.

For example, researchers in Tour’s lab began using lasers, powdered sugar and nickel to make 3-D graphene foam in late 2016. Earlier this year they showed that they could reinforce the foam with carbon nanotubes, which produced a material they dubbed “rebar graphene” that could retain its shape while supporting 3,000 times its own weight. But making rebar graphene was no simple task. It required a pre-fabricated 3-D mold, a 1,000-degree Celsius chemical vapor deposition (CVD) process and nearly three hours of heating and cooling.

In the latest study, a team from Tour’s lab and the labs of Rice’s Jun Luo and Tianjin’s Naiqin Zhao adapted a common 3-D printing technique to make fingertip-size blocks of graphene foam. The process is conducted at room temperature. No molds are required and the starting materials are powdered sugar and nickel powder.

“This simple and efficient method does away with the need for both cold-press molds and high-temperature CVD treatment,” said co-lead author Junwei Sha, a former student in Tour’s lab who is now a postdoctoral researcher at Tianjin. “We should also be able to use this process to produce specific types of graphene foam like 3-D printed rebar graphene as well as both nitrogen- and sulfur-doped graphene foam by changing the precursor powders.”

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3-D graphene foam objects are produced by shining a laser on a mixture of powdered sugar and nickel powder. The laser is moved back and forth to melt sugar in a 2-D pattern, and nickel acts as a catalyst to spur the growth of graphene foam. The process is repeated with successive layers of powder to build up 3-D objects. (Image courtesy of Tour Group/Rice University)

Three-D laser printers work differently than the more familiar extrusion-based 3-D printers, which create objects by squeezing melted plastic through a needle as they trace out two-dimensional patterns. In 3-D laser sintering, a laser shines down onto a flat bed of powder. Wherever the laser touches powder, it melts or sinters the powder into a solid form. The laser is rastered, or moved back and forth, line by line to create a single two-dimensional slice of a larger object. Then a new layer of powder is laid over the top of that layer and the process is repeated to build up three-dimensional objects from successive two-dimensional layers.

The new Rice process used a commercially available CO2 laser. When this laser was shone onto the sugar and nickel powder, the sugar was melted and the nickel acted as a catalyst. Graphene formed as the mixture cooled after the laser had moved on to melt sugar in the next spot, and Sha and colleagues conducted an exhaustive study to find the optimal amount of time and laser power to maximize graphene production.

The foam created by the process is a low-density, 3-D form of graphene with large pores that account for more than 99 percent of its volume.

“The 3-D graphene foams prepared by our method show promise for applications that require rapid prototyping and manufacturing of 3-D carbon materials, including energy storage, damping and sound absorption,” said co-lead author Yilun Li, a graduate student at Rice.

Read More: Video

Graphene foam reinforced with carbon nanotubes can hold thousands of times its own weight and still bounce back to its full height, according to Rice University scientists. The material is thermally stable and highly conductive, making it suitable for batteries and other electrical applications. Read about it at http://news.rice.edu/2017/02/13/graph…

Rice U: New Lithium metal battery prototype boasts 3X the capacity of current lithium-ions ~ Dendrite Problem Solved?


graphene-nanotube-lithium-battery-4

Could a new material involving a carbon nanotube and graphene hybrid put an end to the dendrite problem in lithium batteries? (Credit: Tour Group/Rice University)

The high energy capacity of lithium-ion batteries has led to them powering everything from tiny mobile devices to huge trucks. But current lithium-ion battery technology is nearing its limits and the search is on for a better lithium battery. But one thing stands in the way: dendrites. If a new technology by Rice University scientists lives up to its potential, it could solve this problem and enable lithium-metal batteries that can hold three times the energy of lithium-ion ones.

Dendrites are microscopic lithium fibers that form on the anodes during the charging process, spreading like a rash till they reach the other electrode and causing the battery to short circuit. As companies such as Samsung know only too well, this can cause the battery to catch fire or even explode.

“Lithium-ion batteries have changed the world, no doubt,” says chemist Dr. James Tour, who led the study. “But they’re about as good as they’re going to get. Your cellphone’s battery won’t last any longer until new technology comes along.”

Rice logo_rice3So until scientists can figure out a way to solve the problem of dendrites, we’ll have to put our hopes for a higher capacity, faster-charging battery that can quell range anxiety on hold. This explains why there’s been no shortage of attempts to solve this problem, from using Kevlar to slow down dendrite growth to creating a new electrolyte that could lead to the development of an anode-free cell. So how does this new technology from Rice University compare?

For a start, it’s able to stop dendrite growth in its tracks. Key to it is a unique anode made from a material that was first created at the university five years ago. By using a covalent bond structure, it combines a two-dimensional graphene sheet and carbon nanotubes to form a seamless three-dimensional structure. As Tour explained back when the material was first unveiled:

“By growing graphene on metal (in this case copper) and then growing nanotubes from the graphene, the electrical contact between the nanotubes and the metal electrode is ohmic. That means electrons see no difference, because it’s all one seamless material.”

Close-up of the lithium metal coating the graphene-nanotube anode (Credit: Tour Group/Rice University)

 

Envisioned for use in energy storage and electronics applications such as supercapacitors, it wasn’t until 2014, when co-lead author Abdul-Rahman Raji was experimenting with lithium metal and the graphene-nanotube hybrid, that the researchers discovered its potential as a dendrite inhibitor.

“I reasoned that lithium metal must have plated on the electrode while analyzing results of experiments carried out to store lithium ions in the anode material combined with a lithium cobalt oxide cathode in a full cell,” says Raji. “We were excited because the voltage profile of the full cell was very flat. At that moment, we knew we had found something special.”

Closer analysis revealed no dendrites had grown when the lithium metal was deposited into a standalone hybrid anode – but would it work in a proper battery?

To test the anode, the researchers built full battery prototypes with sulfur-based cathodes that retained 80 percent capacity after more than 500 charge-discharge cycles (i.e. the rough equivalent of what a cellphone goes through in a two-year period). No signs of dendrites were observed on the anodes.

How it works

The low density and high surface area of the nanotube forest allow the lithium metal to coat the carbon hybrid material evenly when the battery is charged. And since there is plenty of space for the particles to slip in and out during the charge and discharge cycle, they end up being evenly distributed and this stops the growth of dendrites altogether.

According to the study, the anode material is capable of a lithium storage capacity of 3,351 milliamp hours per gram, which is close to pure lithium’s theoretical maximum of 3,860 milliamp hours per gram, and 10 times that of lithium-ion batteries. And since the nanotube carpet has a low density, this means it’s able to coat all the way down to substrate and maximize use of the available volume.

“Many people doing battery research only make the anode, because to do the whole package is much harder,” says Tour. “We had to develop a commensurate cathode technology based upon sulfur to accommodate these ultrahigh-capacity lithium anodes in first-generation systems. We’re producing these full batteries, cathode plus anode, on a pilot scale, and they’re being tested.”

The study was published in ACS Nano.

Source: Rice University

 

Energy from the sun, stored in a liquid – and released on demand OR … Solar to Hydrogen Fuel … And the Winner Is?


Liquid Solar Sweeden large_RkeCoGI3VB0jjnprwamEX8rEU6kapTZ8SQd-0sN5fzs

“The solar energy business has been trying to overcome … challenge for years. The cost of installing solar panels has fallen dramatically but storing the energy produced for later use has been problematic.”

Solar Crash I solar-and-wind-energy“In a single hour, the amount of power from the sun that strikes the Earth is more than the entire world consumes in an year.” To put that in numbers, from the US Department of Energy 

 

 

Each hour 430 quintillion Joules of energy from the sun hits the Earth. That’s 430 with 18 zeroes after it! In comparison, the total amount of energy that all humans use in a year is 410 quintillion JoulesFor context, the average American home used 39 billion Joules of electricity in 2013.

HOME SOLAR-master675Read About: What are the Most Efficient Solar Panels on the Market?

 

Clearly, we have in our sun “a source of unlimited renewable energy”. But how can we best harness this resource? How can we convert and  “store” this energy resource on for sun-less days or at night time … when we also have energy needs?

Now therein lies the challenge!

Would you buy a smartphone that only worked when the sun was shining? Probably not. What it if was only half the cost of your current model: surely an upgrade would be tempting? No, thought not.

The solar energy business has been trying to overcome a similar challenge for years. The cost of installing solar panels has fallen dramatically but storing the energy produced for later use has been problematic.

 

Now scientists in Sweden have found a new way to store solar energy in chemical liquids. Although still in an early phase, with niche applications, the discovery has the potential to make solar power more practical and widespread.

Until now, solar energy storage has relied on batteries, which have improved in recent years. However, they are still bulky and expensive, and they degrade over time.

Image: Energy and Environmental Science

Trap and release solar power on demand

A research team from Chalmers University of Technology in Gothenburg made a prototype hybrid device with two parts. It’s made from silica and quartz with tiny fluid channels cut into both sections.

 

The top part is filled with a liquid that stores solar energy in the chemical bonds of a molecule. This method of storing solar energy remains stable for several months. The energy can be released as heat whenever it is required.

The lower section of the device uses sunlight to heat water which can be used immediately. This combination of storage and water heating means that over 80% of incoming sunlight is converted into usable energy.

Suddenly, solar power looks a lot more practical. Compared to traditional battery storage, the new system is more compact and should prove relatively inexpensive, according to the researchers. The technology is in the early stages of development and may not be ready for domestic and business use for some time.

 

From the lab to off-grid power stations or satellites?

The researchers wrote in the journal Energy & Environmental Science: “This energy can be transported, and delivered in very precise amounts with high reliability(…) As is the case with any new technology, initial applications will be in niches where [molecular storage] offers unique technical properties and where cost-per-joule is of lesser importance.”

A view of solar panels, set up on what will be the biggest integrated solar panel roof of the world, in a farm in Weinbourg, Eastern France February 12, 2009. Bright winter sun dissolves a blanket of snow on barn roofs to reveal a bold new sideline for farmer Jean-Luc Westphal: besides producing eggs and grains, he is to generate solar power for thousands of homes. Picture taken February 12.         To match feature FRANCE-FARMER/SOLAR              REUTERS/Vincent Kessler  (FRANCE) - RTXC0A6     Image: REUTERS: Kessler

The team now plans to test the real-world performance of the technology and estimate how much it will cost. Initially, the device could be used in off-grid power stations, extreme environments, and satellite thermal control systems.

 

Editor’s Note: As Solomon wrote in  Ecclesiastes 1:9:What has been will be again, what has been done will be done again; there is nothing new under the sun.”

Storing Solar Energy chemically and converting ‘waste heat’ has and is the subject of many research and implementation Projects around the globe. Will this method prove to be “the one?” This writer (IMHO) sees limited application, but not a broadly accepted and integrated solution.

Solar Energy to Hydrogen Fuel

So where does that leave us? We have been following the efforts of a number of Researchers/ Universities who are exploring and developing “Sunlight to Hydrogen Fuel” technologies to harness the enormous and almost inexhaustible energy source power-house … our sun! What do you think? Please leave us your Comments and we will share the results with our readers!

Read More

We have written and posted extensively about ‘Solar to Hydrogen Renewable Energy’ – here are some of our previous Posts:

Sunlight to hydrogen fuel 10-scientistsusScientists using sunlight, water to produce renewable hydrogen power

 

 

Rice logo_rice3Solar-Powered Hydrogen Fuel Cells

Researchers at Rice University are on to a relatively simple, low-cost way to pry hydrogen loose from water, using the sun as an energy source. The new system involves channeling high-energy “hot” electrons into a useful purpose before they get a chance to cool down. If the research progresses, that’s great news for the hydrogen […]

HyperSolar 16002743_1389245094451149_1664722947660779785_nHyperSolar reaches new milestone in commercial hydrogen fuel production

HyperSolar has achieved a major milestone with its hybrid technology HyperSolar, a company that specializes in combining hydrogen fuel cells with solar energy, has reached a significant milestone in terms of hydrogen production. The company harnesses the power of the sun in order to generate the electrical power needed to produce hydrogen fuel. This is […]

riceresearch-solar-water-split-090415 (1)Rice University Research Team Demonstrates Solar Water-Splitting Technology: Renewable Solar Energy + Clean – Low Cost Hydrogen Fuel

Rice University researchers have demonstrated an efficient new way to capture the energy from sunlight and convert it into clean, renewable energy by splitting water molecules. The technology, which is described online in the American Chemical Society journal Nano Letters, relies on a configuration of light-activated gold nanoparticles that harvest sunlight and transfer solar energy […]

NREL I downloadNREL Establishes World Record for Solar Hydrogen Production

NREL researchers Myles Steiner (left), John Turner, Todd Deutsch and James Young stand in front of an atmospheric pressure MDCVD reactor used to grow crystalline semiconductor structures. They are co-authors of the paper “Direct Solar-to-Hydrogen Conversion via Inverted Metamorphic Multijunction Semiconductor Architectures” published in Nature Energy. Photo by Dennis Schroeder.   Scientists at the U.S. […]

NREL CSM Solar Hydro img_0095NREL & Colorado School of Mines Researchers Capture Excess Photon Energy to Produce Solar Fuels

Photo shows a lead sulfide quantum dot solar cell. A lead sulfide quantum dot solar cell developed by researchers at NREL. Photo by Dennis Schroeder.

Scientists at the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) have developed a proof-of-principle photo-electro-chemical cell capable of capturing excess photon energy normally lost to generating heat. Using quantum […]

Batteries that Really Keep Going and Going and Going …


U of Waterloo: Forget the graphite-based lithium batteries currently powering your devices. Next-generation batteries could last for decades. Really.

With a potential lifespan of 10 to 20 years, Professor Zhongwei Chen’s next-generation rechargeable batteries are set to put the Energizer Bunny to shame.

This battery could last 10 years, or even more than 20 years.Energizer_Bunny

Dr. Chen and his team are developing next-generation batteries and fuel cells. They are working on two types of batteries that are destined to be longer lasting and more efficient. One of these batteries is a rechargeable zinc battery that uses renewable energy, such as solar and wind. It could also be cost effective, which means that everyone could use it in the future.

Dr. Chen and his team are using novel materials to upgrade the traditional battery. He says that the key is to use silicon-based materials instead of graphite materials, which are currently being used in the commercial battery. Why? Silicon’s energy density is 10 times higher.

The result is a potential 150% energy density increase compared to its graphite-based lithium battery counterpart, which is currently being used to power electric cars and our cell phones. With the popularity of electric cars on the rise, companies such as Tesla and Panasonic are already looking to move beyond the limitations of the lithium battery.

Dr. Chen explains how he plans to solve the problems associated with the traditional battery as we move forward to meet the increased energy demands of the future.

MORE: Watch Our Current Battery Technology Project Video

A new company has been formed to exploit and commercialize the Next Generation Super-Capacitors and Batteries. The opportunity is based on Technology & Exclusive IP Licensing Rights from Rice University, discovered/ curated by Dr. James M. Tour, named “One of the Fifty (50) most influential scientists in the World today”

The Silicon Nanowires & Lithium Cobalt Oxide technology has been further advanced to provide a New Generation Battery that is:

 Energy Dense
 High Specific Power
 Affordable Cost
 Low Manufacturing Cost
 Rapid Charge/ Re-Charge
 Flexible Form Factor
 Long Warranty Life
 Non-Toxic
 Highly Scalable

Key Markets & Commercial Applications

 Motor Cycle/ EV Batteries
 Marine Batteries
 Drone Batteries and
 Power Banks
 Estimated $112B Market for Rechargeable Batteries by 2025

MIT: Light-emitting particles (quantum dots) open new window for biological imaging


QD Bio Image V images

‘Quantum dots’ that emit infrared light enable highly detailed images of internal body structures

For certain frequencies of short-wave infrared light, most biological tissues are nearly as transparent as glass. Now, researchers have made tiny particles that can be injected into the body, where they emit those penetrating frequencies. The advance may provide a new way of making detailed images of internal body structures such as fine networks of blood vessels.

The new findings, based on the use of light-emitting particles called quantum dots, is described in a paper in the journal Nature Biomedical Engineering, by MIT research scientist Oliver Bruns, recent graduate Thomas Bischof PhD ’15, professor of chemistry Moungi Bawendi, and 21 others.

Near-infrared imaging for research on biological tissues, with wavelengths between 700 and 900 nanometers (billionths of a meter), is widely used, but wavelengths of around 1,000 to 2,000 nanometers have the potential to provide even better results, because body tissues are more transparent to that light. “We knew that this imaging mode would be better” than existing methods, Bruns explains, “but we were lacking high-quality emitters” — that is, light-emitting materials that could produce these precise wavelengths.

QD bio Image II imagesLight-emitting particles have been a specialty of Bawendi, the Lester Wolf Professor of Chemistry, whose lab has over the years developed new ways of making quantum dots. These nanocrystals, made of semiconductor materials, emit light whose frequency can be precisely tuned by controlling the exact size and composition of the particles.

The key was to develop versions of these quantum dots whose emissions matched the desired short-wave infrared frequencies and were bright enough to then be easily detected through the surrounding skin and muscle tissues. The team succeeded in making particles that are “orders of magnitude better than previous materials, and that allow unprecedented detail in biological imaging,” Bruns says. The synthesis of these new particles was initially described in a paper by graduate student Daniel Franke and others from the Bawendi group in Nature Communications last year.

The quantum dots the team produced are so bright that their emissions can be captured with very short exposure times, he says. This makes it possible to produce not just single images but video that captures details of motion, such as the flow of blood, making it possible to distinguish between veins and arteries.

QD Bio Image IV GAAlso Read About

Graphene Quantum Dots Expand Role In Cancer Treatment And Bio-Imaging

 

 

The new light-emitting particles are also the first that are bright enough to allow imaging of internal organs in mice that are awake and moving, as opposed to previous methods that required them to be anesthetized, Bruns says. Initial applications would be for preclinical research in animals, as the compounds contain some materials that are unlikely to be approved for use in humans. The researchers are also working on developing versions that would be safer for humans.QD Bio Image III 4260773298_1497232bef

 

The method also relies on the use of a newly developed camera that is highly sensitive to this particular range of short-wave infrared light. The camera is a commercially developed product, Bruns says, but his team was the first customer for the camera’s specialized detector, made of indium-gallium-arsenide. Though this camera was developed for research purposes, these frequencies of infrared light are also used as a way of seeing through fog or smoke.

Not only can the new method determine the direction of blood flow, Bruns says, it is detailed enough to track individual blood cells within that flow. “We can track the flow in each and every capillary, at super high speed,” he says. “We can get a quantitative measure of flow, and we can do such flow measurements at very high resolution, over large areas.”

Such imaging could potentially be used, for example, to study how the blood flow pattern in a tumor changes as the tumor develops, which might lead to new ways of monitoring disease progression or responsiveness to a drug treatment. “This could give a good indication of how treatments are working that was not possible before,” he says.

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The team included members from MIT’s departments of Chemistry, Chemical Engineering, Biological Engineering, and Mechanical Engineering, as well as from Harvard Medical School, the Harvard T.H. Chan School of Public Health, Raytheon Vision Systems, and University Medical Center in Hamburg, Germany. The work was supported by the National Institutes of Health, the National Cancer Institute, the National Foundation for Cancer Research, the Warshaw Institute for Pancreatic Cancer Research, the Massachusetts General Hospital Executive Committee on Research, the Army Research Office through the Institute for Soldier Nanotechnologies at MIT, the U.S. Department of Defense, and the National Science Foundation.

Additional background

ARCHIVE: A new contrast agent for MRI http://news.mit.edu/2017/iron-oxide-nanoparticles-contrast-agent-mri-0214

ARCHIVE: A new eye on the middle ear http://news.mit.edu/2016/shortwave-infrared-instrument-ear-infection-0822

ARCHIVE: Chemists design a quantum-dot spectrometer http://news.mit.edu/2015/quantum-dot-spectrometer-smartphone-0701

ARCHIVE: Running the color gamut http://news.mit.edu/2014/startup-quantum-dot-tv-displays-1119

ARCHIVE: Fine-tuning emissions from quantum dots http://news.mit.edu/2013/fine-tuning-emissions-from-quantum-dots-0602

Rice University’s Nanophotonics team creates low-voltage, multicolor, electrochromic glass


nanophotonicAdding and removing an electron from neutral perylene (center column) produces an anion (left) and cation (right), respectively, with different electronic structures (middle row). Upon excitation with visible light, the anion and cation …more
Rice University’s latest nanophotonics research could expand the color palette for companies in the fast-growing market for glass windows that change color at the flick of an electric switch.

In a new paper in the American Chemical Society journal ACS Nano, researchers from the laboratory of Rice plasmonics pioneer Naomi Halas report using a readily available, inexpensive hydrocarbon molecule called perylene to create that can turn two different colors at low voltages.

“When we put charges on the molecules or remove charges from them, they go from clear to a vivid color,” said Halas, director of the Laboratory for Nanophotonics (LANP), lead scientist on the new study and the director of Rice’s Smalley-Curl Institute. “We sandwiched these molecules between glass, and we’re able to make something that looks like a window, but the window changes to different types of color depending on how we apply a very low voltage.”

Adam Lauchner, an applied physics graduate student at Rice and co-lead author of the study, said LANP’s color-changing glass has polarity-dependent colors, which means that a positive voltage produces one color and a negative voltage produces a different color.

“That’s pretty novel,” Lauchner said. “Most color-changing glass has just one color, and the multicolor varieties we’re aware of require significant voltage.”

 Credit: Rice University

Glass that changes color with an applied voltage is known as “electrochromic,” and there’s a growing demand for the light- and heat-blocking properties of such glass. The projected annual market for electrochromic glass in 2020 has been estimated at more $2.5 billion.

Lauchner said the glass project took almost two years to complete, and he credited co-lead author Grant Stec, a Rice undergraduate researcher, with designing the perylene-containing nonwater-based conductive gel that’s sandwiched between glass layers.

“Perylene is part of a family of molecules known as polycyclic aromatic hydrocarbons,” Stec said. “They’re a fairly common byproduct of the petrochemical industry, and for the most part they are low-value byproducts, which means they’re inexpensive.”

There are dozens of (PAHs), but each contains rings of carbon atoms that are decorated with hydrogen atoms. In many PAHs, carbon rings have six sides, just like the rings in graphene, the much-celebrated subject of the 2010 Nobel Prize in physics.

Nanophotonics team creates low-voltage, multicolor, electrochromic glass
Grant Stec and Adam Lauchner of Rice University’s Laboratory for Nanophotonics have used an inexpensive hydrocarbon molecule called perylene to create a low-voltage, multicolor, electrochromic glass. Credit: Jeff Fitlow/Rice University

“This is a really cool application of what started as fundamental science in plasmonics,” Lauchner said.

A plasmon is wave of energy, a rhythmic sloshing in the sea of electrons that constantly flow across the surface of conductive nanoparticles. Depending upon the frequency of a plasmon’s sloshing, it can interact with and harvest the energy from passing light. In dozens of studies over the past two decades, Halas, Rice physicist Peter Nordlander and colleagues have explored both the basic physics of plasmons and potential applications as diverse as cancer treatment, solar-energy collection, electronic displays and optical computing.

The quintessential plasmonic nanoparticle is metallic, often made of gold or silver, and precisely shaped. For example, gold nanoshells, which Halas invented at Rice in the 1990s, consist of a nonconducting core that’s covered by a thin shell of gold.

“Our group studies many kinds of metallic nanoparticles, but graphene is also conductive, and we’ve explored its plasmonic properties for several years,” Halas said.

Nanophotonics team creates low-voltage, multicolor, electrochromic glass
Rice University researchers demonstrated a new type of glass that turns from clear to black when a low voltage is applied. The glass uses a combination of molecules that block almost all visible light when they each gain a single electron. Credit: Jeff Fitlow/Rice University

She noted that large sheets of atomically thin graphene have been found to support plasmons, but they emit infrared light that’s invisible to the human eye.

“Studies have shown that if you make graphene smaller and smaller, as you go down to nanoribbons, nanodots and these little things called nanoislands, you can actually get graphene’s plasmon closer and closer to the edge of the visible regime,” Lauchner said.

In 2013, then-Rice physicist Alejandro Manjavacas, a postdoctoral researcher in Nordlander’s lab, showed that the smallest versions of graphene—PAHs with just a few carbon rings—should produce visible plasmons. Moreover, Manjavacas calculated the exact colors that would be emitted by different types of PAHs.

“One of the most interesting things was that unlike plasmons in metals, the plasmons in these PAH molecules were very sensitive to charge, which suggested that a very small electrical charge would produce dramatic colors,” Halas said.

Nanophotonics team creates low-voltage, multicolor, electrochromic glass
Student researchers Grant Stec (left) and Adam Lauchner (right) with Rice plasmonics pioneer Naomi Halas, director of Rice University’s Laboratory for Nanophotonics. Credit: Jeff Fitlow/Rice University

Lauchner said the project really took off after Stec joined the research team in 2015 and created a perylene formulation that could be sandwiched between sheets of conductive glass.

In their experiments, the researchers found that applying just 4 volts was enough to turn the clear window greenish-yellow and applying negative 3.5 volts turned it blue. It took several minutes for the windows to fully change color, but Halas said the transition time could easily be improved with additional engineering.

Stec said the team’s other window, which turns from clear to black, was produced later in the project.

“Dr. Halas learned that one of the major hurdles in the electrochromic device industry was making a window that could be clear in one state and completely black in another,” Stec said. “We set out to do that and found a combination of PAHs that captured no visible light at zero volts and almost all visible light at low voltage.”

Explore further: Nanoscale drawbridges open path to color displays

More information: Grant J. Stec et al. Multicolor Electrochromic Devices Based on Molecular Plasmonics, ACS Nano (2017). DOI: 10.1021/acsnano.7b00364