Controlled release of biocides in solid wood. II. Efficacy against Trametes versicolor and Gloeophyllum trabeum wood decay fungi

Abstract

Biocide-containing nanoparticles were suspended in water to prepare wood treating suspensions able to deliver up to 0.8 kg biocide/m 3 of wood. The nanoparticle preparation method was versatile, and three fungicides (tebuconazole, chlorothalonil, and KATHON 930) and one insecticide (chlorpyrifos) were incorporated into the nanoparticles with little customization of the preparative method. Greater customization was required when the polymer matrix was changed, but the method was generally robust; nanoparticles could be prepared from several different polymers, copolymers, and polymer blends. The median nanoparticle size increased as the matrix hydrophobicity increased. Nanoparticles were quantitatively delivered into birch and southern yellow pine (SYP) at low suspension loadings, but the delivery efficiency decreased with increased suspension loading and with increased matrix hydrophobicity. The delivery efficiency was also less for birch than for SYP. Undelivered nanoparticles were found to have undergone aggregation. Greater aggregation occurred in the more hydrophobic formulations than in the hydrophilic formulations. High biological efficacy was found for all the biocides tested. Nanoparticle-treated birch was exposed to Trametes versicolor for 55 days and some protection was afforded, even at biocide loading levels of only 0.1 kg/m 3 . At the highest loadings (ϳ0.6 kg/m 3 ) the weight loss after exposure to T. versicolor was generally ϳ10% for most formulations. The SYP was treated with KATHON 930 in polyvinylpyridine. At levels of 0.1 kg of biocide/m 3 of wood less than 5% of the SYP mass was lost after 50 days of exposure to Gloeophyllum trabeum.

Amphiphilic Core/Shell Nanoparticles to Reduce Biocide Leaching From Treated Wood, 1 – Leaching and Biological Efficacy

“…[2][3][4] Since TEM micrographs indicate a nanoparticle diameter below 100 nm, the low delivery U. Salma et al efficiency is attributed to particle aggregates blocking some of the pit pores. If this blockage occurs earlier in the treatment, the nanoparticle delivery is significantly reduced.…”

“…In prior work on controlled release of wood preservatives [1][2][3][4][5] we found that wood was effectively protected by means of controlled-release nanoparticles. Those nanoparticles were made by a precipitation-displacement route, and were delivered with high efficiency into wood.…”

“…micelles [6][7][8][9][10] and clathrates, [11] films [12][13][14][15] and solid micro-and nanoparticles [1][2][3][4][5][16][17][18][19][20][21] were developed for use in the biomedical area, where neither extensive work-up nor materials costs are a barrier to their intended use.…”

“…[1][2][3][4] High solids systems that use low-cost materials and require minimal work-up can reduce water use and energy use and might make controlled release technology more affordable for wood treatment. Using a core/shell type of nanoparticle might allow better fine-tuning of the release rate to increase ultimate longevity of treated wood.…”

Effect of Silver Nanoparticles Synthesized with NPsAg-Ethylene Glycol (C2H6O2) on Brown Decay and White Decay Fungi of Nine Tropical Woods

“…7 8 Wood has also been researched to improve its properties. Silver nanoparticles have been applied to improve the protection of the wood, [9][10][11][12] its behavior against fire, improved physical properties, densification of wood, properties of particleboard and dried-wood. 5 13 14 Various methods for silver nanoparticle synthetizing are available (Tan and Cheong 2013) of those, 15 reduction methods are among the most important.…”