Smart wood - The ecosystem at work to preserve itself

PROJECT: SMART WOOD - THE ECOSYSTEM AT WORK TO PRESERVE ITSELF

Cup: J53D23014890001

Codice MUR: P2022ZHBZE

Importo finanziato: 239.948,00 Euro

Decreto Direttoriale MUR n. 1409 del14/09/2022 - Bando PRIN 2022 PNRR - Missione 4 “Istruzione e Ricerca” del Piano Nazionale di Ripresa e Resilienza - componente C2 – investimento 1.1, Progetti di Rilevante Interesse Nazionale - PRIN

Today, issues related to the energy saving, the use of sustainable materials, the need for production methods with low CO2 emissions are fundamental aspects to be taken in account for the development of modern society. In this regard, the use of glass as a basic material for the construction of buildings has several disadvantages: high heat loss due to poor thermal management capacity, production method involving high amounts of CO2 emissions, high fragility and low impact resistance. Transparent wood has recently been proposed as an alternative material to glass, which is obtained through delignification processes and subsequent infiltration with polymers having refractive indexes similar to those of wood. This new material has a number of advantages with respect to glass, including: higher toughness and impact resistance, lower fragility, optical transmittance similar to common glass, lower thermal conductivity. Moreover, the use of wood as substitute of glass is advantageous in terms of less CO2 emissions and environmental sustainability.

Starting from this state of the art, the objective of this project proposal is to design a wood polymer composite that also has electrochromic or optoelectronic properties, in order to obtain a stimuli responsive glass to be used in smart windows. In new glass-like materials the electrochromic properties will allow to change the color of the wood composite in response to electrical stimuli, while the optoelectronic properties will be exploited to obtain electric energy through solar radiation.

In the first phase of the project, various types of wood will be tested in order to find the best material in terms of availability, cost, ease of cutting into thin sheets, mechanical properties, ease of absorption of monomers and polymer solutions. The chosen wood will then undergo chemical modification processes, for the partial or total removal of the lignin (necessary to obtain a transparent wood) and the functionalization of the hydroxyl groups to facilitate the adhesion of the polymers with photoactive properties. Simultaneously, a series of π-conjugated compounds (monomers and oligomers), suitable for giving the wood tunable optical and electronic features, will be synthesized.

In the second part of the project, the smart transparent wood with optical and electronic properties will be synthesized. The general procedure that will be carried out to obtain this, will first include the introduction of photoactive molecules into the wood cavities (electrochromic groups), and the subsequent filling of the empty cavities with "classic" polymers for the improvement of optical (transparency) and mechanical properties. Finally, the optical (UV-visible spectrometry), morphological (SEM), mechanical (dynamometry), electrical (photoelectrochemistry and cyclic voltammetry), photophysical (ultrafast spectroscopy) properties will be studied in order to optimize the performance of the material.