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The study evaluated copper, boron, and silicon release from wood samples treated with sol-gel formulations based on tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) functionalized with copper (II) chloride and boric acid, respectively. The adopted leaching procedure was Japanese protocol JIS K 1571 (2004). Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES) and Electron Spray Ionization Mass Spectrometry (ESI-MS) were employed for analyzing the leached solutions. The obtained results highlighted the important role of the amine function that was derived from the APTES precursor, in anchoring both copper and boron through coordinative and ionic interactions, respectively. In fact, copper formulations with TEOS alone (without APTES) showed higher copper leaching. In contrast, the silicon leaching was decreased due to better siloxane reticulation performed by TEOS alone. In addition, ageing (two months) of the samples treated with APTES containing formulation TEOS/APTES/Cu 10:1:0.2 resulted in a reduction of copper leaching (from 27% in the fresh samples to 7% in the aged ones), which was attributable to increased efficiency of inorganic sol-gel polymerization. The TEOS/APTES/B 1:1:0.2 formulation gave a leaching value of 20%, which was lower in comparison with the values reported in previous literature. [ABSTRACT FROM AUTHOR]

A novel treatment based on polyamidoamines (PAAs) for the preservation of wood against fungi and insects with a broad protection functionality, low effective concentration, and low environmental impact has been developed. PAAs were synthesized by nucleophile addition of ethanolamine (EtA) and/or 3-aminopropyltriethoxysilane (APTES) to N,N'-methylenebisacrylamide (MBA). The molar ratios in the tested formulation were: I) MBA:EtA = 1:1; II) MBA:APTES = 1:1; III) MBA:EtA:APTES = 1:0.5:0.5. These formulations, characterized by ESI-MS, NMR, FT-IR, were tested against: (a) the wood decay fungi (Coniophora puteana, Coriolus versicolor, and Poria placenta); (b) the subterranean termite Reticulitermes lucifugus, and the drywood termite Kalotermes flavicollis; (c) the woodborer Stegobium paniceum. Tests in combination with leaching showed that formulation II and III can be utilized as fungal wood preservatives for use classes 2-3 (EN 335:2013). In addition, all PAAs formulations were equally effective in preserving wood against the subterranean termite, and formulation II was most effective against drywood termite. On the other hand, the formulation I showed good efficacy against S. paniceum. [ABSTRACT FROM AUTHOR]

Abstract: A wood preservative based on tetraethyl orthosilicate (TEOS), 3-aminopropyltriethoxysilane (APTES), and boric acid (BA) in volume ratio TEOS/APTES 1:1 and in molar ratio APTES/BA 50:1 was applied to wood by the sol–gel process. Standard EN 113 and mini wood block tests were carried out to determine the effectiveness against fungal decay. The same formulation applied by immersion was tested against larvae of the wood-borer insect Hylotrupes bajulus. This formulation showed good efficacy against Coniophora puteana, Poria placenta, and Trametes versicolor, even after a leaching procedure. It was also effective against the coleopter H. Bajulus. Different molar ratios of APTES/BA—2.5:1, 5:1, and 10:1—were tested with a leaching procedure in accordance with EN 84 to determine the best fixation of boric acid into the wood. The ratio APTES/BA 5:1 was found to be the most effective for fixing boron into wood. [Copyright &y& Elsevier]

Previous preliminary studies showed good efficacy of treatments based on a mixture of siloxane materials, functionalized with amino groups and coupled with copper, against the brown rot fungus Coniophora puteana (Palanti et al. 2011). In the present work, a one-step impregnation was performed on two sets of samples differing in size, in order to verify and compare the homogeneity of treatments. Leaching and resistance against brown rot and white rot fungi were also tested according to European standards EN 84 and EN 113, respectively. Furthermore, an accelerated test of efficacy against fungal decay was also used for determining the treatment efficacy. The obtained results made it possible to validate the findings of the preliminary study concerning resistance of the treated wood against C. puteana, while extending them to the white rot fungus Trametes versicolor. In contrast, no protection was conferred by the treatment against the copper-tolerant fungus Poria placenta. [ABSTRACT FROM AUTHOR]

Wood modification with siloxanes bearing amino groups with copper-linking function was carried out by a sol-gel process. Tetraethoxysilane (TEOS) and 3-aminopropyltriethoxysilane (APTES) were the main components. Two different procedures were followed: a two-step process (impregnation with the TEOS/APTES mixture followed by dipping into a copper sulphate solution) and a one-step process (impregnation with a homogeneous sol mixture of TEOS, APTES and copper (II) chloride). The obtained materials were characterized by infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy dispersive X-ray microanalysis. The determination of copper content before and after leaching was performed by atomic absorption spectroscopy. The efficacy against the brown rot fungus Coniophora puteana was tested by an accelerated procedure. SEM analyses showed that silicon penetrated into wood, while copper is effectively drawn into wood only in the one-step treatment. Copper fixation to the silica gel proved to be adequately strong. Both sol-gel treatments gave good protection against Coniophora puteana. [ABSTRACT FROM AUTHOR]