Category: Coatings

Protection against bacteria, viruses and fungi with graphene coatings

Posted on | by Energeia Graphenemex

Protection against bacteria, viruses and fungi

with graphene coatings

In less than 20 years the world has faced a series of abnormal phenomena caused by highly infectious pathogens. The easy and rapid transmission of infections forces us to seek increasingly efficient strategies to strengthen health services, in addition to representing a radical change in our lifestyle, where extreme hygiene techniques are in first place of importance to avoid the spread and massive contagion inside and outside hospitals.

Viral diseases of greater impact.

  • 2002-2003. Severe acute respiratory syndrome (SARS-Cov).
  • 2012. Middle East Respiratory Syndrome (MERS-Cov).
  • 2014- 2016. Ebola.
  • 2019- 2022. SARS-Cov-2.

>6.5 million deaths.

Dangerous bacteria for human health:

  • Staphylococcus aureus.
  • Streptococcus pneumoniae.
  • Pseudomonas aeruginosa.
  • Haemophilus influenzae.
  • Helicobacter pylori.

Common fungi in the domestic environment:

  • Aspergillus spp.
  • Cladosporium spp.
  • Alternaria spp.
  • Acremonium spp.
  • Epiccocum spp.
  • Penicillium spp.
  • Stachybotrys spp.

Graphene as an adjuvant in infection control

In 2018, Energeia- Graphenemex® launched the antimicrobial Graphenergy line, made up of two specialized vinyl- and vinyl-acrylic-based coatings with graphene oxide, whose antimicrobial potential is 400 times higher than common products, helping to keep surfaces free of fungi and bacteria for a long time.

In vitro studies and in a relevant environment carried out by the Laboratory of Pathology, Biochemistry and Microbiology of the Faculty of Stomatology of the U.A.S.L.P., showed that surfaces protected with antimicrobial Graphenergy remain free of microorganisms for more than 6 months, without the need for additional chemicals. Figure 1.

Fig. 1. Results at 2, 4 and 6 months on the protection of antimicrobial Graphenergy compared to a control group (No Graphene Oxide).
Important: A clean surface is in the range of 1-10 CFU/cm2.

In 2022, the strategic alliance between the companies Energeia-Graphenemex® and Oxical® is preparing to launch a new 100% natural coating, without toxic compounds (VOCs), highly waterproof, breathable and highly antimicrobial, made from high-quality and purity lime modified with Graphene nanoparticles, under the ecological Graphenecal brand.

Its extraordinary antimicrobial capacity is not only a great aid in keeping spaces free of microorganisms, but also protects surfaces against biodeterioration, particularly those with high historical value. Figure 2.

Fig. 2. Graphene-free lime paint has a microbial biofilm on more than 90% of its surface. The area covered with organic Graphenecal remained free of contamination for more than 100 days of incubation. The antimicrobial effect of organic Graphenecal is highly effective, with a reduction of microorganisms of 7 Log10.

Is graphene nanotechnology safe?

Yes, Graphenergy and Graphenecal antimicrobial coatings are as safe as any conventional paint or coating. The graphene and graphene oxide nanoparticles contained in its formulations do not shed or release toxic substances into the environment.

“Not all microorganisms are dangerous, but it is better to keep them away”

How do graphene materials work?


  1. Physical barrier- High impermeability. Graphene materials are usually presented in millions of blocks composed of 1 to 10 nanometric sheets similar to a pack of cards, with multiple sinuous paths between each sheet that act as an external barrier that suppresses the entry of essential nutrients for microbial growth.

  2. Graphene and its derivatives can act as electron donors or acceptors, altering the respiratory chain of the microorganism or extracting its electrons. This imbalance in the form of a nano-circuit is so fast that it does not give the microorganism time to recover and, therefore, inactivates it before adhering to the surface.

  3. Structural damage. The edges of the nanomaterial sheets act like small knives that damage or break the cell membrane of the microorganism, altering its functioning and preventing its viability.

Do graphene materials have antiviral activity?

The antiviral effect of graphene materials seems not to be very different from that described against fungi and bacteria. The hypotheses are directed towards an interesting synergistic effect between impermeability, structural damage and electrostatic interactions due to the positive polarity of some viruses (SARS-Cov-2) and the negative polarity of graphene oxide, in addition to its great protein-anchoring capacity.

Energeia- Graphenemex®is the pioneer Mexican company in Latin America focused on the research and production of graphene materials for the development of applications at an industrial level. In addition to adding value to its products with the multifunctional properties of Graphene and its derivatives, the company also aims to create strategic alliances to support innovative developments with graphene nanotechnology.

References

  1. García-Contreras R, Guzmán Juárez H, López-Ramos D & Alvarez Gayosso C. Biological and physico-mechanical properties of poly (methyl methacrylate) enriched with graphene oxide as a potential biomaterial. J Oral Res 2021; 10(2):1-9. Doi:10.17126/joralres. 2021.019
  2. UM.D. Giulio, R. Zappacosta, S.D. Lodovico, E.D. Campli, G. Siani, A. Fontana, L. Cellini, Antimicrobial and antibiofilm eficacy of graphene oxide against chronic wound microorganisms. Antimicrob. Agents Chemother. 62(7), e00547-18 (2018). https://doi.org/10.1128/AAC.00547-18
  3. H.E. Karahan, C. Wiraja, C. Xu, J. Wei, Y. Wang, L. Wang, F. Liu, Y. Chen, Graphene materials in antimicrobial nanomedicine: current status and future perspectives. Adv. Healthc. Mater. 7(13), 1701406 (2018). https://doi.org/10.1002/ adhm.201701406
  4. Sydlik SA, Jhunjhunwala S, Webber MJ, Anderson DG, Langer R. In vivo compatibility of graphene oxide with differing oxidation states. ACS Nano. 2015. 9: 3866
  5. Yang K, Zhang S, Zhang G, Sun X, Lee ST, Liu Z. Graphene in mice: ultrahigh in vivo tumor uptake and efficient photothermal therapy. Nano Lett. 2010. 10: 3318.
  6. Bhattacharya K, Farcal LR, Fadeel B. Shifting identities of metal oxide nanoparticles: focus on inflammation. 2014. MRS Bull; 39: 970
  7. Huang PJ, Pautler R, Shanmugaraj J, Labbé G, Liu J. Inhibiting the VIM-2 metallo-β-lactamase by graphene oxide and carbon nanotubes. ACS Appl Mater Interfaces 2015; 7: 9898.
  8. Moghimi SM, Wibroe PP, Wu L, Farhangrazi ZS. Insidious pathogen-mimicking properties of nanoparticles in triggering the lectin pathway of the complement system. Eur J Nanomedicine. 2015; 7: 263.
  9. Bhattacharya K, Mukherjee SP., Gallud A., Burkert SC., Bistarelli S., Bellucci S., Bottini, M., Star A., Fadeel B. Biological interactions of carbon-based nanomaterials: From coronation to degradation. Nanomedicine: Nanotechnology, Biology, and Medicine. 2016. 12. 333

Graphene oxide: a promising alternative in nanotechnology

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Graphene oxide:

a promising alternative in nanotechnology

Since graphene was isolated for the first time in 2004 by the Manchester group, this nanomaterial has proven to be the most revolutionary for the development of new applications at an industrial level.

Graphene has extraordinary electrical, optical, thermal properties and high mechanical resistance. The properties of graphene are attributed to its structure in the form of two-dimensional (2D) sheets, made up of hexagonally bonded carbon atoms and a thickness of one carbon atom.

Currently there are different methods of graphene production, these can be classified into two methods, according to their origin, the “bottom-up” method and the “top down” method. The “bottom-Up” method consists in the creation of graphene structures through building blocks (atoms, molecules), for example, by Chemical Vapor Deposition (CVD); and the “top down” method involves the production of graphene from the oxidation of graphite. Graphite is made up of sheets of graphene that are stacked on top of each other. The following diagram represents the process for obtaining graphene from the oxidation of graphite.

Schematic diagram of the process for obtaining GO, through the oxidation of graphite.

The graphite oxidation process begins with the addition of graphite in sulfuric acid (H2SO4), with constant mechanical stirring. Subsequently, potassium permanganate (KMnO4) is slowly added, producing a chemical reaction that allows the graphite (graphene sheets stacked on top of each other) to be chemically modified in its structure. When KMnO4 reacts with H2SO4, it forms manganese oxide VII (Mn2O7), which is a very selective oxidizing agent on double bond aromatic compounds, such as graphite. The oxidizing agent molecularly attacks the structure of each graphene sheet in the graphite, grafting oxygenated functional groups (with oxygen), such as epoxide groups (C-O-C) and hydroxyl groups (-OH), on each sheet, and carboxyl groups (-COOH, CO2H ) on the edges of each sheet, obtaining graphite oxide and graphene oxide (GO), see Figure 1.

Figure 1. Structure of graphene oxide

The incorporation of oxygenated functional groups allows a material such as graphite, which is highly hydrophobic (which repels water) and a good electrical conductor, to become graphite oxide and graphene oxide (GO), highly hydrophilic materials, that is, they mix and disperse easily with water (See Figure 2). GO is chemically similar to graphite oxide, but structurally differs in the arrangement and number of stacked sheets.

Figure 2. (a and b) Behavior of graphite and graphene oxide (GO) in water, c) GO sheet, Transmission Electron Microscopy (TEM).

The GO can be defined as a single exfoliated graphene sheet or stack of few sheets (3-4) that is functionalized with different oxygenated groups. Among its main characteristics is that it is hydrophilic, insulating and hygroscopic (absorbs moisture). On the other hand, graphene oxide sheets possess a large surface area and exhibit high mechanical strength and flexibility.

Applications

Graphene oxide has attracted great interest in various fields of science and technology, due to its remarkable mechanical, chemical, and thermal properties, among others. So numerous investigations began, to take advantage of the properties of graphene oxide.

In 2011, the first investigations of the use of GO as a precursor in the large-scale production of graphene emerged, for use as filler/reinforcement material/in polymeric matrices, such as high-density polyethylene (HDPE) and low-density polyethylene (HDPE). density (LDPE).

By 2014, GO was considered feasible for use as a flame retardant agent. Research is still ongoing to functionalize it with different polymeric materials.

In 2017, the first reports of the manufacture of GO-based membranes began, since it is impermeable to gases and liquids, showing its ability to filter small particles, organic molecules and even its use for seawater desalination.

In 2018, Energeia-Graphenemex started research on graphene oxide as a new additive for the production of anticorrosive and antimicrobial coatings. By 2019, studies of graphene oxide in coatings with antibacterial behavior increased, associated with the fact that GO is capable of penetrating the cell membrane of bacteria, producing oxidative stress and inhibiting their reproduction.

In particular, the functionalization of GO allows it to be applicable in biological systems, development of biosensors for the identification of specific molecules, drug delivery systems, among others.

Energeia – Graphenemex®, a leading Mexican company in Latin America in research and production of graphene materials for the development of industrial applications. It has extensive experience in the production of graphene oxide (GO) on a large scale, with different degrees of oxidation and high quality for use in different applications and industries. Currently, it uses graphene oxide in the production of concrete additives and anticorrosive and antimicrobial coatings that are marketed under the Graphenergy brand.

References

  1. M. Fang, K. Wang, H. Lu, Y. Yang y S. Nutt, «Covalent polymer functionalization of graphene nanosheets and mechanical properties of composites,» Journal of Materials Chemistry, vol. 19, pp. 7098-7105, 2009.
  2. B. Dittrich, K.-a. Wartig, R. Mülhaupt y B. Schartel, «Flame-Retardancy Properties of Intumescent Ammonium Poly(Phosphate) and Mineral Filler Magnesium Hydroxide in Combination with Graphene,» Polymers, vol. 6, pp. 2875-2895, 2014.
  3. Y.-j. Wan, L.-x. Gong, L.-c. Tang, L.-b. Wu y J.-x. Jiang, «Mechanical properties of epoxy composites filled with silane-functionalized graphene oxide,» COMPOSITES PART A, vol. 64, pp. 79-89, 2014.
  4. J. Wang, C. Xu, H. Hu, L. Wan, R. Chen, H. Zheng, F. Liu, M. Zhang, X. Shang y X. Wang, «Synthesis , mechanical , and barrier properties of LDPE / Graphene nanocomposites using vinyl triethoxysilane as a coupling agent,» J. Nanopart Res, vol. 13, pp. 869-878, 2011.

Graphene, the material of the future in coatings and paints industry

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Graphene, the material of the future

in coatings and paints industry

Graphene is currently the most revolutionary nanotechnological additive in the coatings and paints industry.

Coatings are regularly used for decorative purposes and for surface protection, especially for protection against corrosion, humidity, fouling, mechanical wear, among others. At a commercial level, there is a wide variety of coatings based on different types of resins and additives, their efficiency is generally associated with an increase in cost. However, the coatings still have low resistance to corrosion, abrasion and limited chemical and thermal resistance.

Therefore, the coatings industry, like many other industries, is constantly researching and developing new technologies for the formulation and application of new and better coatings.

Since 2004, when the graphene nanomaterial was first isolated, scientists in the coatings industry have been looking for ways to use graphene as an additive to improve the performance and technology of coatings in different application areas.

Graphene has unique properties, mainly attributed to its structure in the form of two-dimensional (2D) sheets, formed by carbon atoms linked in a hexagonal manner and a thickness of one carbon atom. This nanomaterial has extraordinary properties, which include high electrical and thermal conductivity, and high mechanical resistance. In addition, it possesses other distinctive properties, including gas impermeability, chemical resistance, antibacterial potential, and high surface area.

Graphene’s carbon-based composition and its compatibility make it a viable additive for organic polymeric coatings.

Among the advantages offered by the use of graphene is its ability to incorporate new or improved characteristics in the coatings. Different types of multifunctional coatings can be developed, such as:

  • Anticorrosive coatings

One of the main uses of graphene coatings is protection against corrosion. Graphene creates pathways that are very tortuous, preventing water and oxygen molecules and/or chemical agents from diffusing to the surface of metal-based materials, resulting in metal protection against oxidation and corrosion. corrosion.

  • Fire retardant coatings

Conventional additives based on halogens (bromine and chlorine), as well as phosphorous, melamine and inorganic compounds, are used to improve the fire resistance of coatings, however, these materials are toxic to humans and the environment. On the other hand, the high content of these flame retardants can cause the deterioration of other properties in the coatings.

Therefore, the application of graphene as a new additive in coatings can reduce or eliminate the use of conventional flame retardant additives, it can also provide the coating with better performance against extreme temperatures for a longer time and with better mechanical stability.

  • Coatings resistant to wear or abrasión

Graphene has proven to be a potential candidate for wear, abrasion and scratch resistant coatings. Graphene is the lightest material and two hundred times more resistant than steel, in addition, graphene has a high capacity to withstand large pressure differences and high mechanical resistance.

  • Antifouling coatings

Graphene is a good candidate for use as an anti-stick agent. Its application reduces the problem of fouling and the deposition of organic and inorganic materials in the hulls of ships, ships or marine vessels, oil platforms, among others. This type of application is mainly attributed to the hydrophobic (water repellent) and barrier properties of graphene.

  • Antimicrobial coatings

The use of graphene or graphene oxide sheets as an antimicrobial agent is innovative, since there are studies that have shown a strong antimicrobial activity against a wide variety of microorganisms, including Gram +, Gram – bacteria and fungi.

Associated with the fact that graphene materials are capable of penetrating the cell membrane of microorganisms, producing oxidative stress and inhibiting their reproduction.

Globally, research and development of graphene-based coatings continues. Currently there are several companies and institutions that have made improved formulations with graphene for coatings, among which the following stand out:

  • Applied Graphene Materials, based in the United Kingdom, in collaboration with the American company Sherwin-Williams, are developing graphene-based anticorrosive paints. Its objective is to incorporate graphene in different formulations, especially in maritime paint for use in ship hulls to protect them from corrosion.
  • The Sixth Element Materials, a Chinese company that focuses on the research, development and sale of graphene materials, has launched a graphene-zinc-based anticorrosive primer for offshore wind power towers.
  • Graphenstone, a Spanish company, has developed ecological paint that combines graphene and lime technology. Obtaining paints with greater resistance, flexibility, quality and a longer life span compared to conventional lime-based paints.

Energeia – Graphenemex®, a leading Mexican company in Latin America in the research and production of graphene materials for the development of industrial applications, through its Graphenergy line, has launched a wide range of nanotechnological coatings with graphene. These coatings offer high anticorrosive and antimicrobial protection. In addition, it provides high resistance to wear, resistance to UV rays, impermeability and extraordinary adherence, in order to improve the useful life of any surface or installation and reduce maintenance costs.

Graphene coatings, in addition to having anticorrosive protection, can provide greater chemical resistance, UV resistance, higher thermal performance in a wide range of temperatures, as well as more flexible and crack-resistant coatings.

References

  1. DuMée, L.F., et al., Carbon, 87, 395–408 (2015); doi:10.1016/j.carbon.2015.02.042.
  2. Wang, E.N., et al., Nano Lett., 15 (5), 2902–2909 (2015).
  3. J. Chen, H. Peng y X. Wang, Nanoscale, vol.6, pp. 1879-1889, 2014
  4. Md J. Nine, Martin A. Cole, Diana N.H. Tran, and Dusan Losic, J. Mat. Chem. A, 2015.
  5. Sachin Sharma Ashok Kumar, Shahid Bashir, K. Ramesh, S. Ramesh, Progress in Organic Coatings, 154, (2021)

Nanotechnology and tube labelling: an effective solution for material identification

Posted on | by Energeia Graphenemex

Nanotechnology and tube labelling:

an effective solution for material identification

Mexico City – Energeia Graphenemex® is a pioneering nanotechnology company in Latin America, dedicated to the research and production of graphene materials, as well as the development of applications at an industrial level.

Within the company’s research and development protocols, it seeks to solve problems faced by companies or industries on a daily basis, for which research agreements or alliances are made to seek to develop a solution in which graphene is become the agent of change.

Why we developed Graphenergy Ink?

In 2019 there was an approach with one of the largest companies in the world in the manufacture of steel tubes that was facing a serious problem in its process of marking the tubes, which were marketed.

During the tube manufacturing process, marking is necessary for rapid identification and traceability, optimizing all the processes and procedures that each of the steel tubes must go through. However, there was a problem: the ink used in the marking process erased very easily and did not withstand application temperatures above 70°C, in addition to having low resistance to abrasion.

In the course of manufacturing steel tubes, it is normal for these tubes to be subjected to different processes; rotation on conveyors, rollers, shot blasting and transport with cranes, where there is high friction and abrasion between tubes, so the ink ended up being torn off, erasing the marking on the metal surface, and thus losing all control and traceability of the tubes.< /p>

To offer a comprehensive solution to the marking problem, Energeia Graphenemex®, through its Graphenergy Anticorrosive line, developed a new white marking ink with graphene oxide.

Among the most important characteristics of this developed graphene oxide marking ink are:

  • Extraordinary thermal resistance (resists more than 200 °C)
  • Resistance to UV rays
  • Anticorrosive property
  • High adhesion to metallic substrates
  • Abrasion resistance
  • Ultra-fast drying (3 seconds)
  • Excellent covering power

Thermal resistance to extreme temperatures

Thanks to the development of the marking ink, the problem of the lack of adherence of the marking ink was solved, as well as the issue of abrasion that occurs when moving the tubes during transport, thus maintaining the traceability of the tubes .

Due to its characteristics, the production process was additionally benefited by:

  • Ultra-fast drying: it allowed the production line not to stop, which could improve production times
  • Anti-corrosion protection: a version of the transparent ink was formulated that is applied on the tubes after marking, preventing them from rusting.