Bioinspired Living Coating System in Service: Evaluation of the Wood Protected with Biofinish during One-Year Natural Weathering

Abstract

The service life performance of timber products exposed to natural weathering is a critical factor limiting the broad use of wood as an external building element. The goal of this study was to investigate the in-service characterization of an innovative biofinish coating system. It is a novel surface finishing solution based on the bioinspired concept of living fungal cells designed for effective wood protection. The performance of Scots pine (Pinus sylvestris L.) wood coated with biofinish was compared with uncoated references. Samples were exposed to natural weathering for 12 months under the climatic conditions of northern Italy. The visual appearance, colour, gloss, wettability, and 3D surface topography of the wood surface were examined. Results revealed that the total colour changes (∆E) of biofinish-coated wood were negligible. Untreated Scots pine wood revealed the changes in colour after just three months of exposure. The gloss changes of both surface types were small. The contact angle measured on biofinish-coated wood was higher compared to that of uncoated Scots pine. Surface roughness increased in uncoated wood due to the erosion effect caused by the weathering progress. Conversely, the surface roughness of biofinish-coated samples decreased along the exposure time. This phenomenon was explained by two self-healing mechanisms: migration of non-polymerized oil to the cracked surface, where it polymerizes and creates a closed layer, and local regrowth to cover damaged spots by living fungal cells present in the coating. The obtained results revealed the superior aesthetic performance of the biofinish surface treatment against natural weathering. By considering the fully bio-based nature of the investigated coating, it was concluded that this solution can be an attractive alternative for state-of-the-art wood protection technologies.

Effect of Number of Impregnations of Microberlinla sp with Microcapsule Emulsion on the Performance of Self-Repairing Coatings on Wood Surfaces

“…To a certain extent, the application of coatings to wood surfaces can isolate moisture in the air and protect the wood substrate from mildew [11] and decay [12]. However, due to natural shortcomings such as dimensional instability [13] and poor durability [14,15], micro-cracks often inevitably appear on the surface coatings during the use of wooden products [16,17], which negatively impacts the coating's appearance, firmness, and longevity, resulting in the service life of the coating being greatly shortened [18]. When the coating loses its efficacy, the unprotected wood becomes more vulnerable to damage, resulting in unnecessary economic losses.…”

Deterioração da superfície de cinco madeiras amazônicas expostas ao intemperismo natural

“…Estudos têm sido realizados para avaliação de madeiras amazônicas expostas ao intemperismo artificial (Barreto e Pastore, 2009;Costa et al, 2011;Mendes et al, 2016;Pastore et al, 2008;Silva et al, 2007). Apesar de demandar mais tempo, a realização de trabalhos com a exposição ao intemperismo natural, permite avaliar de forma mais fidedigna a deterioração superficial da madeira, pois não se trata de uma simulação e sim a real condição de exposição às intemperes (Cogulet et al, 2017;Poohphajai et al, 2021).…”

Special Issue “Wood Modification: Characterization, Modelling, and Applications”

“…The wide range of covered modification processes and the scope of applications proved that wood modification is not only the sole concern of a few wood scientists but it became a truly inter-disciplinary research area. Novel formulations, characterization methods, and serviceability are presented and deeply discussed in several publications contributing to the Special Issue [2][3][4][5][6][7]. A broad portfolio of characterization methods can be successfully implemented for the evaluation of complex mechanisms of deterioration process occurring during service life.…”

“…A broad portfolio of characterization methods can be successfully implemented for the evaluation of complex mechanisms of deterioration process occurring during service life. Artificial [2,3], natural [4,5], and combined [6] weathering methods are used for the assessment of the performance of different substrates and coatings. The performance of wood finished with a broad range of coatings systems is highly improved when compared to that of unmodified wood.…”

“…The performance of an innovative, bioinspired, and fully biobased coating system containing living fungal cells provides testimony for technological development. [5]. In this case, the desired occurrence of fungi as a part of the coating formulation provides self-healing properties.…”