Graphene Coating: introduction and market status - Page 23

Researchers at the Norwegian University of Science and Technology (NTNU), Aberystwyth University in the UK, University of Gothenburg and Dublin City University discovered the merits of using graphene as an alternative coating for catheters to improve the delivery of chemotherapy drugs. 

Since negative interactions may occur between the most commonly used chemotherapy drug, 5-Fluorouracil (5-Fu), and silver (one of the most widely used coating materials in medical applications), the drugs may not deliver the desired therapeutic effect in patients. Also, a by-product of the reaction between 5-Fu and silver is hydrogen fluoride (HF), a strong acid, that may further compromise the patient. The scientists found that placing graphene on the internal surfaces of intravenous catheters (commonly used to deliver chemotherapy drugs into a patient's body) can help prevent these interactions and improve the efficacy of treatments, and reduce the potential of the catheters breaking. 

A team of researchers at MIT developed a method of coating condensers used in power plants with graphene, to make them durable and transfer heat rapidly. Condensers are the equipment that collects steam and condense them back to water in electricity-producing plants. Improving their efficiency could greatly contribute to the overall power plant efficiency.

The scientists coated the condenser surfaces with a layer of graphene, and found that this can improve the rate of heat transfer by a factor of four. The improvement in condenser heat transfer could lead to an overall improvement in power plant efficiency of 2 to 3 percent, enough to make a significant change in global carbon emissions.

Researchers at the University of Illinois designed a single-step method of creating textures in graphene ("crumpling") to allow for larger surface areas, thus tapping into graphene's benefits for electronics. The scientists believe that "crumpled" graphene may also be used as high surface area electrodes for batteries and supercapacitors. As a coating layer, the 3D graphene could allow omniphobic/anti-bacterial surfaces for advanced coating applications.

The "crumpling" process is based on a known shape-memory polymer substrate (a material capable of returning to its original shape after being distorted, mostly by thermal means). The thermoplastic nature of the substrate also allows for the crumpled graphene morphology to be arbitrarily re-flattened at the same elevated temperature for the crumpling process. 

The UK-based Applied Graphene Materials brought in independent coatings experts to conduct performance testing on graphene- reinforced polyurethane coatings and reported positive preliminary findings. 

While the test program is still ongoing, the initial results demonstrate that low loading levels of AGM's graphene nanoplatelets substantially enhance the scratch resistance and ultimate tensile strength of a polyurethane clearcoat, with minimal impact on transparency or colour.

Researchers at Purdue University designed a new process for coating copper nanowires with graphene, that lowers resistance and heating. This process may suggest potential applications in computer chips and flexible displays, as copper nanowires are essential for efficient data transfer and heat conduction in such applications.

The researchers developed a technique for encapsulating the wires with graphene, which was shown to create hybrid wires that are capable of 15% faster data transmission while lowering peak temperature by 27% compared with uncoated copper nanowires. The graphene coating prevents the copper wires from oxidizing, preserving low resistance and reducing the amount of heating.

2-DTech is spearheading a project to improve anti-corrosive coatings through incorporation of graphene via a scalable and commercially-viable process. Copper has been in extensive use for this purpose, but its disadvantages are enough for 2-DTech to explore the production of high crystalline quality silicon-doped graphene as a replacement.

The introduction of silicon as a dopant aims to fortify the multi-layer graphene’s domain boundaries. This could result in an improvement in anti-corrosive silicon-graphene conductive films for application on to copper substrates via thermal chemical vapor deposition (TCVD). The combination would create an extremely thin coating while protecting against corrosion without disrupting the intra-domain crystalline structure.

Researchers at the University of Illinois at Urbana-Champaign developed a single-step process to achieve 3D texturing of graphene and graphite, using a commercially available thermally activated shape-memory polymer substrate. 

Since crumpled graphene was shown to have modulated electrical and optical properties, finding methods to produce folded/crumpled graphene surfaces can be helpful for various applications, like electronics and biomaterials, electrodes for battery and supercapacitor applications, coating layers, omniphobic/anti-bacterial surfaces for advanced coating applications and more.

Researchers at the University of Nebraska-Lincoln found that coats of graphene are able to protect delicate nanostructures from high temperatures. 

The scientists have shown that graphene makes nanostructures thermally stable, which means it expands their working range of temperatures. They established that graphene protects nanostructures based on cobalt and titanium, metals that feature significantly different physical and chemical properties. Their results suggest that graphene might be employed to also protect other metallic (and possibly nonmetallic) materials that might be used in nanotechnology.

A researcher from the South Dakota School of Mines and Technology has been awarded $500,000 by the National Science Foundation to develop graphene-based corrosion-resistant coatings.

The scientists started his research about two years ago while collaborating with graphene experts at Rensselaer Polytechnic Institute in New York. His work on corrosion-resistant coatings attempts to help metal resist rust, thus offering a solution for microbial corrosion on infrastructure, which costs the U.S. nearly $1 billion annually, accounting for 20 to 40 percent of the nation's total corrosion costs.

Researchers at the University of Manchester developed a new coating made from graphene-oxide that can be used to enable ultra-strong non-corrosive coating paints, hermetic food packaging and even a good substrate for flexible electronics.

The researchers developed the graphene-oxide coating by taking graphene-oxide and treating it with a "simple chemical treatment". The resulting film behaves like graphite in terms of chemical and thermal stability but becomes mechanically nearly as tough as graphene.