Bio-inspired Coatings with Advanced Properties from Natural Resources

Project Aims:
The objective is the development of bio-based & bio-inspired functional coatings with advanced properties (e.g., adhesion, gas barrier, superhydrophobicity or oil repellency) for applications ranging from packaging or microencapsulation of active substances to self-cleaning surfaces. Widely available biomass materials, e.g., (nano)cellulose, (nano)lignin, (nano)chitin, in combination with other natural ingredients such as gums, proteins, peptides, inorganic (nano)particles, fatty acids, or waxes will be utilised and following Nature's hierarchical designs, I will modify & combine these individual building blocks into supramolecular assemblies that achieve the desired properties for the target applications. The molecular & supramolecular designs will be assisted by multiscale computational modeling, ranging from density functional theory (DFT) calculations to full-atomistic & coarse-grained molecular dynamics simulations. The data generated with these computational methods can be used to train machine learning models that will accelerate materials discovery and property predictions. Within the concept of circular economy, the new formulations will be based on natural ingredients, or compounds that could be obtained from the agrifood industry (an area in which AINIA has extensive expertise), & I will aim at materials that can be intrinsically designed for degradation, i.e., circularity by design. To achieve adequate properties for the target applications, while complying with natural principles of circularity and performance, we will initially consider lignocellulosic derivatives (e.g., microfibers of cellulose, nanolignin) as the core components of the coatings. These lignocellulosic derivatives can be used as received or after undergoing additional functionalization, following computational designs, or rational intuition. Furthermore, other additives will be included into the formulation to impart additional properties (e.g., flexibility, resistance). Examples of these additives are gums, proteins, peptides, inorganic particles, fatty acids, or waxes.

Two parallel research lines are proposed:
1. Biobased coatings for packaging applications, microencapsulation of active substances & functional food-grade paints - to develop coatings useful for packaging applications (substrate: paper), properties such as oxygen barrier, water and/or oil repellency, or sealing properties are required. Moreover, active packaging is also of interest, & antimicrobial substances must be incorporated into the final coating. This later coating could also be adapted to be applied over other surfaces (e.g., metal) as a functional paint. Thus, adequate modification of lignocellulosic materials & coating formulations will open new doors for its use in the microencapsulation of ingredients, actives, or fragrances, amongst others. To this end, the natural polymers should be modified to respond to an external stimulus (e.g., temperature, humidity, pH). This stimulus will then act as a trigger for the release of the microencapsulated substance.
2. Bio-adhesives for packaging application - industry seeks for oxygen-barrier bio-adhesives that could be employed, for example, in lamination applications (e.g., paper-based materials). This line of research will deal with the chemical modification of lignocellulosic derivatives and its formulation to develop a bio-adhesive adequate for food packaging applications. Biological systems like mussel threads, rich in catechol functional groups, or metal coordinated biopolymers can provide inspiration to guide the design process. Furthermore, using computational modeling we can explore the effect of polymer length, polymer chains entanglement, or degree of crosslinking in the adhesive properties, evaluating how chemical features control the adhesive or cohesive failure of the material under working conditions.

Desired outcomes:
Sustainability & societal impacts & enhanced functionality.