Brushite mineralised Scots pine (Pinus sylvestris L.) sapwood - revealing mineral crystallization within a wood matrix by in situ XRD

Edita Garskaite; Giedrius Balciunas; Marian Drienovsky; Denis Sokol; Dick Sandberg; Alexandre C Bastos; Andrei N Salak

doi:10.1039/d3ra00305a

Brushite mineralised Scots pine (Pinus sylvestris L.) sapwood - revealing mineral crystallization within a wood matrix by in situ XRD

RSC Adv. 2023 Feb 16;13(9):5813-5825. doi: 10.1039/d3ra00305a. eCollection 2023 Feb 14.

Authors

Edita Garskaite¹, Giedrius Balciunas², Marian Drienovsky³, Denis Sokol⁴, Dick Sandberg¹, Alexandre C Bastos⁵, Andrei N Salak⁵

Affiliations

¹ Wood Science and Engineering, Department of Engineering Sciences and Mathematics, Luleå University of Technology Forskargatan 1 SE-931 87 Skellefteå Sweden Edita.garskaite@ltu.se.
² Laboratory of Thermal Insulating Materials and Acoustics, Institute of Building Materials, Vilnius Gediminas Technical University Linkmenu g. 28 Vilnius LT-08217 Lithuania.
³ Institute of Materials Science, Faculty of Materials Science and Technology in Trnava, Slovak University of Technology in Bratislava Ulica Jana Bottu 2781/25 91724 Trnava Slovakia.
⁴ Institute of Chemistry, Faculty of Chemistry and Geosciences, Vilnius University Naugarduko 24 Vilnius LT-03225 Lithuania.
⁵ Department of Materials and Ceramics Engineering and CICECO - Aveiro Institute of Materials, University of Aveiro 3810-193 Aveiro Portugal.

Abstract

Dicalcium phosphate dihydrate (CaHPO₄·2H₂O, DCPD, brushite) crystals were synthesised within Scots pine sapwood via a wet-chemistry route from aqueous solutions of Ca(CH₃COO)₂ and NH₄H₂PO₄ salts. SEM/EDS analysis was used to assess the saturation of the wood cell lumina and cell wall as well as morphological features and elemental composition of the co-precipitated mineral. Brushite mineral crystallization and crystallite growth within the wood matrix was studied by in situ XRD. The chemical composition of the mineral before and after the dissolution was evaluated using FTIR spectroscopy. The overall impact of brushite on the thermal behaviour of wood was studied by TGA/DSC and TGA/DTA/MS analysis under oxidative and pyrolytic conditions. Bending and compression strength perpendicular and parallel to the fibre directions as well as bending strengths in longitudinal and transverse directions of the mineralised wood were also evaluated. Results indicate the viability of the wet-chemistry processing route for wood reinforcement with crystalline calcium phosphate (CaP)-based minerals, and imply a potential in producing hybrid bio-based materials that could be attractive in the construction sector as an environmentally friendly building material.