Periodic Reporting for period 1 - RELIANCE (Smart Response sELf-desInfected biobAsed NanoCoatEd surfaces for healthier environments.)
Reporting period: 2022-06-01 to 2023-11-30
RELIANCE project aims to design and develop smart response self-disinfectant antimicrobial (AM) nanocoatings based on a new range of smart antimicrobial nanoparticles (NPs). They will consist of mesoporous silica NPs with metallic copper in their structure, modified with biobased bioactive compounds: Antimicrobial peptides (AMP’s) based on protein containing waste streams, and essential oils (EOs) coming from non-edible plants. The antibacterial action of these additives will be adjusted to the specific application, according to the dosages and durability requirements. In this way, two alternatives to incorporate the bioactive compounds will be considered:
• The incorporation of the biobased EO into the porous substrate, to allow a controlled release (T or pH) of the bioactive compounds to the environment,
• The attachment of the AMP to the NPs surface, to allow a long-term action of the bioactive compound to the environment. RELIANCE project combines contact killing and leachable antibacterial actions ascribed to the additive with the non-sticking action due to the coatings’ formulation, thus providing an integral holistic solution to antimicrobial problems on different surfaces.
The nature of the coatings, their characteristics (hydrophobicity and surface roughness) and their application methods (direct deposition by cold-atmospheric plasma, high throughput spraying or selective digital printing) will be specifically designed to allow not only the microbial repelling action, but also the adhesion of the coatings to different substrates commonly found in our living environments, such as metals, plastics or textiles, and to maximize their durability (in terms of performance and antibacterial properties). Moreover, electrochemical sensors will be tested to evaluate the leaching of EOs, and therefore activity of the coatings.
• The incorporation of the biobased EO into the porous substrate, to allow a controlled release (T or pH) of the bioactive compounds to the environment,
• The attachment of the AMP to the NPs surface, to allow a long-term action of the bioactive compound to the environment. RELIANCE project combines contact killing and leachable antibacterial actions ascribed to the additive with the non-sticking action due to the coatings’ formulation, thus providing an integral holistic solution to antimicrobial problems on different surfaces.
The nature of the coatings, their characteristics (hydrophobicity and surface roughness) and their application methods (direct deposition by cold-atmospheric plasma, high throughput spraying or selective digital printing) will be specifically designed to allow not only the microbial repelling action, but also the adhesion of the coatings to different substrates commonly found in our living environments, such as metals, plastics or textiles, and to maximize their durability (in terms of performance and antibacterial properties). Moreover, electrochemical sensors will be tested to evaluate the leaching of EOs, and therefore activity of the coatings.
The project started with the review of the technical specifications, functionalities and market requirements to be fulfilled by prototypes. Based on these requirements, a pre-selection of the antimicrobial bioactives, reactants for the synthesis of the NPs and components of the coatings formulations has been carried out. An initial preliminary sustainability and economic analysis of preselect compounds has been done showing that initial selection of materials and production/application methods won’t limit the market introduction of the new developed materials as well as their environmental and societal acceptance.
WP2 started with the synthesis of the NPs. Until now, silica mesoporous nanoparticles with a size lower than 100 nm, a specific surface area higher than 700 m2/g and a pore diameter range between 1-6 nm have been successfully obtained at lab scale. The procedure has been shown to be scalable, with small optimization of the original recipes. Two methods to incorporate copper on SMIN particles are being explored: i) incorporation on preformed particles or ii) incorporation during the synthesis of the NPs. At the moment, the state of the cupper in the particles is being analyzed. First attempts to incorporate EO on the SMIN particles and of functionalizing the NPs have been performed (activity in progress). Moreover, several AMP have been extracted from keratine with proved antiviral and antibacterial activity.
WP3 started with the development two different type of sustainable coating formulation. On the one hand, a hybrid (inorganic-organic) easy-to-clean coating to be a hosting matrix for the WP4 tasks dedicated to development of AM coatings for home appliance applications (targeted substrates are stainless steel and glass) is being developed. Until now, a PDMS like structure has been developed and applied on glass substrates by dip coating exhibiting Haze <0.5%, good adhesion - Hardness (ISO 4586-2) 6N, WAC >105°and good oil repellency (HAC > 35°). First spray coated samples were prepared with good overall aspect (however slightly more diffusive Haze ~ 0.8%). On the other hand, a fluor-free and mostly water based organic coatings formulations are also being targeted for the development of AM coatings for textiles used in protective clothing. A series of different PU with bio-content from 25 to 70% and elongation at break between 100 and 400% were prepared. First results obtained show promising results with performance fully comparable to commercial coatings. Moreover, another PU formulation is being developed to be further adapted to be compatible with digital printing equipment, especially viscosity management.
The project activities continued in WP4 with the dispersion of synthesized NPs with ultrasonic reactor and homogeniser in solvents compatible with formulations prepared in WP3 are being carried out. Initial results shows that stabilizers are needed to prevent sedimentation. Modelling done in WP5 is supporting the research activities in the project by helping to design new formulations with enhanced antimicrobial activity, and establishing a correlation between favorable interactions and physiological responses to the pathogens, to be further exploited in RELIANCE. The research activities rely on an accurate measurement of antimicrobial activity of the developed AMPs, EOs, NPs and nanocoatings, that is done in WP7. Until now, the different testing procedures have been optimized and the efficiency of a wide range of AMPs and EOs have been evaluated. Regarding the nanotoxicity and ecotoxicity studies, this part of the work will be executed in following months as the initial versions of the NPs are starting to be upscaled. Environmental evaluation started in WP8 with specific LCA questionnaires developed to collect formulation and coating process Life Cycle Inventory (LCI) for the 3 reference use cases, inventory data compiled, LCI data evaluated according to ReCiPe methodology, and finally performing LCAs and preliminary results (environmental impacts) of the reference available commercial antimicrobial materials and coatings applied on the 3 selected industrial applications.
Finally, an extensive activity in dissemination and communication has been done. More information about the project can be found at: http://reliance-he.eu(opens in new window) and social media.
WP2 started with the synthesis of the NPs. Until now, silica mesoporous nanoparticles with a size lower than 100 nm, a specific surface area higher than 700 m2/g and a pore diameter range between 1-6 nm have been successfully obtained at lab scale. The procedure has been shown to be scalable, with small optimization of the original recipes. Two methods to incorporate copper on SMIN particles are being explored: i) incorporation on preformed particles or ii) incorporation during the synthesis of the NPs. At the moment, the state of the cupper in the particles is being analyzed. First attempts to incorporate EO on the SMIN particles and of functionalizing the NPs have been performed (activity in progress). Moreover, several AMP have been extracted from keratine with proved antiviral and antibacterial activity.
WP3 started with the development two different type of sustainable coating formulation. On the one hand, a hybrid (inorganic-organic) easy-to-clean coating to be a hosting matrix for the WP4 tasks dedicated to development of AM coatings for home appliance applications (targeted substrates are stainless steel and glass) is being developed. Until now, a PDMS like structure has been developed and applied on glass substrates by dip coating exhibiting Haze <0.5%, good adhesion - Hardness (ISO 4586-2) 6N, WAC >105°and good oil repellency (HAC > 35°). First spray coated samples were prepared with good overall aspect (however slightly more diffusive Haze ~ 0.8%). On the other hand, a fluor-free and mostly water based organic coatings formulations are also being targeted for the development of AM coatings for textiles used in protective clothing. A series of different PU with bio-content from 25 to 70% and elongation at break between 100 and 400% were prepared. First results obtained show promising results with performance fully comparable to commercial coatings. Moreover, another PU formulation is being developed to be further adapted to be compatible with digital printing equipment, especially viscosity management.
The project activities continued in WP4 with the dispersion of synthesized NPs with ultrasonic reactor and homogeniser in solvents compatible with formulations prepared in WP3 are being carried out. Initial results shows that stabilizers are needed to prevent sedimentation. Modelling done in WP5 is supporting the research activities in the project by helping to design new formulations with enhanced antimicrobial activity, and establishing a correlation between favorable interactions and physiological responses to the pathogens, to be further exploited in RELIANCE. The research activities rely on an accurate measurement of antimicrobial activity of the developed AMPs, EOs, NPs and nanocoatings, that is done in WP7. Until now, the different testing procedures have been optimized and the efficiency of a wide range of AMPs and EOs have been evaluated. Regarding the nanotoxicity and ecotoxicity studies, this part of the work will be executed in following months as the initial versions of the NPs are starting to be upscaled. Environmental evaluation started in WP8 with specific LCA questionnaires developed to collect formulation and coating process Life Cycle Inventory (LCI) for the 3 reference use cases, inventory data compiled, LCI data evaluated according to ReCiPe methodology, and finally performing LCAs and preliminary results (environmental impacts) of the reference available commercial antimicrobial materials and coatings applied on the 3 selected industrial applications.
Finally, an extensive activity in dissemination and communication has been done. More information about the project can be found at: http://reliance-he.eu(opens in new window) and social media.
RELIANCE will have a clear scientific, economic/technological and societal impact:
• Scientific: A breakthrough innovation in material science and modelling, increasing the scientific multidomain knowledge, allowing for new design procedures to obtain AM nanocoatings with specific response and doses in accordance with the area of application.
• Economic: Boost sustainable research, development and innovation in the EU on nanotechnologies including NPs and nanocoatings. The developed high efficiency nanocoatings will have large economic potential in a wide range of sectors. An estimated market of 270 M€ is foreseen for 2025 only by 1% replacement with AM bioactives and AM coating new formulations an estimated market of.
• Societal: A more resilient society ensuring the well-being of its citizens. Lower exposure to harmful chemicals and improved health of EU citizens.
• Environmental: Reduced emissions of heavy metals and persistent chemicals in waste waters resulting in lesser toxicity and bioaccumulation.
• Scientific: A breakthrough innovation in material science and modelling, increasing the scientific multidomain knowledge, allowing for new design procedures to obtain AM nanocoatings with specific response and doses in accordance with the area of application.
• Economic: Boost sustainable research, development and innovation in the EU on nanotechnologies including NPs and nanocoatings. The developed high efficiency nanocoatings will have large economic potential in a wide range of sectors. An estimated market of 270 M€ is foreseen for 2025 only by 1% replacement with AM bioactives and AM coating new formulations an estimated market of.
• Societal: A more resilient society ensuring the well-being of its citizens. Lower exposure to harmful chemicals and improved health of EU citizens.
• Environmental: Reduced emissions of heavy metals and persistent chemicals in waste waters resulting in lesser toxicity and bioaccumulation.