the revolution in the construction industry

Although the exact date on which lime was discovered by man is not known, there are records dating back more than 14,000 years regarding its use. In the case of Mexico, it has been used since pre-Hispanic times both for construction and for nixtamalization, in ancient Greece it was used to color numerous frescoes (2800 B.C.- 1000 A.D.), the Chinese wall was built after stabilizing the soil with lime (500 AD) and among many other historical data, lime became popular in Europe during the Middle Ages for its disinfectant, breathable and fire-retardant properties, being used mainly as a coating on the exterior of houses and barracks. Subsequently, its implementation in the cities extended until the beginning of 1900 and it was not until the middle of that same century that it reached rural areas, a period in which synthetic paints gained ground over lime thanks to their ease of application, wide range of colors and low cost.

However, at the end of the 1970s and due to the awareness of the dangers of some synthetic paints with respect to health and the environmental pollution caused by certain components (heavy metals and volatile organic compounds [VOC]), lime paints once again had a boom as they are safer products and have a smaller footprint on the environment.

Among the benefits of lime-based paints or coatings are that they are 100% natural, ecological and VOC-free products, which absorb CO2 during their hardening process, which means that their use contributes to air purification. They are also breathable materials, that is, they allow the structures to “breathe” and do not concentrate moisture. In addition, they are thermoregulators, this means that they do not allow drastic changes in temperature in the buildings and, on the contrary, they help the buildings to stay cool.

However, and despite their great advantages, one of the main drawbacks of lime-based paints is their high permeability and, therefore, poor resistance to humidity, which is in turn related to limited adherence that requires constant repair work. maintenance. On the other hand, and although antimicrobial or biocidal properties are attributed to lime, it is not convenient to ensure that all the products that contain it offer this protection, since they are materials susceptible to being attacked by microbial species such as Aspergillus spp., Cladosporium spp, Fusarium spp., Trichoderma spp., Actinobacteria and Bacteroidetes among other species responsible for its biodeterioration as well as some infections.

With the aim of contributing to a sustainable present and future, in 2022 the strategic alliance between the companies Energeia-Graphenemex® and Oxical®, after almost 2 years of research, launched a new coating made from modified high-purity lime with Graphene nanoparticles, under the Graphenecal® brand.

Graphenecal nanoengineering reaches the market to create a new generation of lime-based coatings that exceed the characteristics of water-based paints made from chemical resins. The nanometric network that generates the graphene nanoparticles in combination with the high-purity lime and other natural products used in its formulation, compacts and organizes its entire structure at the molecular level, offering greater durability to the coating and improving its characteristics, thanks to the perfect balance that exists between greater impermeability (>50-80%) with adequate breathability avoiding the accumulation of moisture on surfaces, coupled with the excellent benefits offered by its great antimicrobial capacity (>99.9%) that prevents the adhesion and formation of microbial biofilms not only to protect against the biodeterioration of structures but also as a tool in infection control, among other advantages such as excellent adhesion, covering power, resistance against the effects of weather, greater thermoregulation, CO2 capture and lower carbon footprint in comparison with other products, no need for chemical additives, biocide products or contaminants, placing Mexico at the vangard in the development of environmentally friendly products.

Greater Impermeability

After 4 days of application, Graphenecal is 50% more waterproof than lime-based paints without graphene. As of day 30, this property rises to 85% without affecting the breathability of the product.
Representative image of the impermeability of Graphenecal on two different substrates.

Antimicrobial Capacity

On the graphene-free lime paint, a microbial biofilm was formed on more than 90% of its surface. The Graphenecal coated area remained free of contamination during the test.

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?

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.

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.

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.

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