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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.

Nuove poliammidoammine (PAA) funzionalizzate sono state sviluppate per la protezione sostenibile di legno e carta. Esse sono polimeri ecocompatibili, biocompatibili, dotati di un ampio spettro di azione protettiva e attivi a bassa concentrazione. Le PAA sono veicolabili omogeneamente con mezzi acquosi all'interno dei manufatti lignocellulosici dove esercitano soprattutto le azioni deacidificante e biostatica contro batteri, funghi, muffe e insetti. Nel caso di antichi manoscritti possono fissare l'inchiostro ferro-gallico formando complessi insolubili di ferro.

The alpha-hydroxyacid 2-hydroxy-4-methylthiobutanoic acid (the so-called methionine hydroxy-analogue, MHA), largely used in animal nutrition as a source of methionine, forms stable metal chelates with divalent metals of formula [{CH(3)SCH(2) CH(2)CH(OH)COO}(2)M].nH(2)O. Protonation and iron(III) and copper(II) complex formation constants have been determined by potentiometry at 25 degrees C. Distribution diagrams show that no free Fe(3+) cations are present in solution at pH2.5. ESI-MS (Electron-Spray Ionization Mass Spectrometry) investigations carried out both on iron and zinc complexes in solution have evidenced various species with different MHA/metal ratios. In vivo trials were carried out with rats. After receiving a zinc-deficient diet for 3 weeks, animals were fed the same diet added with zinc sulfate or zinc/MHA chelate; the zinc content of faeces was higher (+45%; P0.05) in sulfate fed rats, whereas zinc retention was higher (+61%; P0.05) in the Zn/MHA diet. Experiments in vitro with human intestinal Caco-2 cells indicated that the MHA/Fe chelate was taken up by the cells without any apparent toxic effect. The iron uptake was higher than that of iron nitrilotriacetate (Fe(3+)NTA), an effective chelate for delivering iron to milk diets. In conclusion, these data indicate that the use of MHA chelates could be a valuable tool to increase bioavailability of trace minerals and reduce the environmental impact of animal manure.

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.

Wood modification by sol-gel treatments shows many positive features, like antimicrobial properties. Wood was also successfully modified with alkoxysilanes enhancing its resistance against soil micro-organisms. Silver, copper, zinc compounds, boric acid or organic biocides such as alkylammonium compounds may be added to the sol-gel to enhance its biocidal properties. Nevertheless, if some of these active ingredients and compounds are not fixed into wood by chemical reactions, they can be easily leached out by water. To overcome this limitation, a system based on silica sol-gel material starting from alkoxysilanes has been functionalized with organic groups having copper linking function. Sol-gel was also coupled with boric acid. As preliminary tests against the brown rot agent Coniophora puteana (Schumacher ex Fries) gave good results, the sol-gel formulations were also tested for their efficacy against subterranean termites. A no-choice test was set up, in two different time scales. Results show that though the sol-gel treatments act in very different ways, all of them are efficacy against subterranean termites. The total mortality occurred in the longer test suggested that active ingredients may be added in lower quantity. Consiglio Nazionale delle Ricerche, Instituto per la Valorizzazione del Legno e delle Specie Arboree LNEC Università degli Studi di Parma, Dipartimento di Chimica Generale ed Inorganica, Chimica Analitica, Chimica Fisica, P.co Area delle Scienze 7 2 12 DE/NEM 2009 24 a 28 de Maio

At present the main products against wood decay are copper salts with other "co-formulating" substances such as boron, azoles and organic compounds. The role of these compounds is to increase the protective effect and the fixation of the copper derivatives to the wood, aiming at reducing their dispersion in the environment. Some copper-based preservatives described in literature consist of copper complexes with amines, among them ethanolamine is largely used owing to its copper fixative properties. The present research arises from the demand to realize a wood preservative with a broad spectrum of action, a low environmental impact and a good fixation into the wood. Our proposal in order to satisfy this goal is a preservative with copper chelates, in particular aminoacid derivatives and copper amine complexes grafted to functionalized silica gel. On the basis of the preliminary screening test it is possible to affirm that copper chelates alone and associated to boric acid, show a good efficacy against fungal decay to wood. The development of the research is going through the following steps: 1. Agar plate screening tests of systems based on copper aminoacid chelates alone and in mixture with boric acid 2. Vacuum-pressure impregnation of copper aminoacid chelates into the wood 3. Production of systems based on silica sol-gel materials (starting from alkoxysilanes) functionalized with organic groups having copper linking function 4. Accelerated efficacy test against fungal decay 5. Studies on the diffusion into wood of copper chelate compounds The accelerated tests against fungal decay gave promising and encouraging results.