Rice University - Page 3

Rice University scientists led by Prof. James Tour have turned adhesive tape into a silicon oxide film (mixed with laser-induced graphene) which replaces troublesome anodes in lithium metal batteries.

At left, a copper current collector with a laser-induced silicon oxide coating created at Rice University. At right, a scanning electron microscope image of the coating created by lasing adhesive tape on the copper collector. Courtesy of the Tour Group

The researchers used an infrared laser cutter to convert the silicone-based adhesive of commercial tape into the porous silicon oxide coating, mixed with a small amount of laser-induced graphene from the tape’s polyimide backing. The protective silicon oxide layer forms directly on the current collector of the battery.

As researchers and companies all over the world set out to battle the Coronavirus pandemic, many are revisiting graphene as a material with potential for helping to win this fight. The reasons for such potential could be found in graphene's known antibacterial/antiviral properties, its beneficial traits for medical sensors and devices and more.

Graphene has been shown in the past as extremely useful for creating various sensors. Earlier this month, a team led by Boston College researchers used a sheet of graphene to track the electronic signals inherent in biological structures, in order to develop a platform to selectively identify deadly strains of bacteria. In October 2019, Rice University team under chemist James Tour transformed their laser-induced graphene (LIG) into self-sterilizing filters that grab pathogens out of the air and kill them with small pulses of electricity. Commercially sold graphene-based sensors exist, like the graphene oxide (GO) sensor developed by the ICN2 Nanobioelectronics and Biosensors group that was added in 2016 to the list products offered by Biolin Scientific, a prestigious instrumentation company devoted to the production of analytical devices. The Q-Sense GO sensor enables interaction studies of GO with various analytes (measured substances) of interest and may open the door to various applications with interest for diagnostics, safety/security and environmental monitoring.

Scientists at Rice University, the University of Tennessee, Knoxville (UT Knoxville) and Oak Ridge National Laboratory (ORNL) have demonstrated the use of a very small visible beam to burn graphene into microscopic patterns.

Scientists recorded the formation of laser-induced graphene made with a small laser mounted to a scanning electron microscope. Image credit: the Tour Group

The labs of Rice chemist James Tour, which discovered the original method to turn a common polymer into graphene in 2014, and Tennessee/ORNL materials scientist Philip Rack revealed they can now watch the conductive material form as it makes small traces of LIG in a scanning electron microscope (SEM).

Researchers from the University of Toronto have shown that graphene is highly resistant to fatigue and is able to withstand more than a billion cycles of high stress before it breaks.

The intrinsic strength of graphene has been measured at more than 100 gigapascals, among the highest values recorded for any material. But materials don't always fail because the load exceeds their maximum strength. Stresses that are small but repetitive can weaken materials by causing microscopic dislocations and fractures that slowly accumulate over time, a process known as fatigue.

A team of researchers at the Rice University lab of chemist James Tour has designed a ‘Green’ process that produces pristine graphene in bulk using waste food, plastic and other materials. According to the team, this process can help facilitate a reduction of the environmental impact of concrete and other building materials.

The new process can turn bulk quantities of just about any carbon source into graphene flakes. The process is quick and cheap; Tour said the flash graphene technique can convert a ton of coal, food waste or plastic into graphene for a fraction of the cost used by other bulk graphene-producing methods.

Rice University team under chemist James Tour has transformed their laser-induced graphene (LIG) into self-sterilizing filters that grab pathogens out of the air and kill them with small pulses of electricity. This may be of special interest to hospitals, where according to the Centers for Disease Control and Prevention, patients have a 1-in-31 chance of acquiring a potentially antibiotic-resistant infection during hospitalization.

The device reportedly captures bacteria, fungi, spores, prions, endotoxins and other biological contaminants carried by droplets, aerosols and particulate matter.

Dotz Nano has shared a new research that finds its graphene quantum dots (GQDs) technology effective in treating brain injuries, strokes, multiple sclerosis and heart attacks. According to the company, the study demonstrated that these dots, manufactured from coal, can assist in fighting oxidative stress to assist in treating patients suffering from the serious conditions.

Led by the Company's scientific advisor, Professor James Tour, the study was conducted by five universities and research facilities including Rice University, with the findings covered by multiple medical publications.

Rice University researchers have recently taken the idea of wearable devices that harvest energy from movement to a new level. Prof. James Tour's lab has adapted laser-induced graphene (LIG) into small, metal-free devices that generate electricity.

Putting the LIG composites in contact with other surfaces produces static electricity that can be used to power devices. This relies on the triboelectric effect, by which materials gather a charge through contact. When they are put together and then pulled apart, surface charges build up that can be channeled toward power generation.

Researchers from Rice University, the Texas A&M Health Science Center and the McGovern Medical School at The University of Texas Health Science Center at Houston (UTHealth) have found that graphene quantum dots drawn from common coal may be the basis for an effective antioxidant for people who suffer traumatic brain injuries, strokes or heart attacks.

Coal-derived graphene quantum dots as seen under an electron microscope

The QDs' ability to quench oxidative stress after such injuries was the subject of a study, which showed that the biocompatible dots, when modified with a common polymer, are effective mimics of the body’s own superoxide dismutase, one of many natural enzymes that keep oxidative stress in check.

Researchers from Nankai University in China and Rice University in the U.S. have developed a type of graphene-based foam that retains its texture when exposed to extremely cold temperatures.

Structure of the 3D graphene foam

The researchers note that almost all materials become more brittle and stiffer when exposed to very cold temperatures, often leading to loss of strength. In this new work, the researchers sought to find a material that would spring back after being crushed while exposed to extreme temperatures. To that end, they turned to graphene as a possible solution.