Fluorides are well-known as wood preservatives. One of the limitations of fluoride-based wood preservatives is their high leachability. Alternative to current fluoride salts such as NaF used in wood protection are low water-soluble fluorides. However, impregnation of low water-soluble fluorides into wood poses a challenge. To address this challenge, low water-soluble fluorides like calcium fluoride (CaF₂) and magnesium fluoride (MgF₂) were synthesized as nanoparticles via the fluorolytic sol−gel synthesis and then impregnated into wood specimens. In this study, the toxicity of nano metal fluorides was assessed by termite mortality, mass loss and visual analysis of treated specimens after eight weeks of exposure to termites, Coptotermes formosanus. Nano metal fluorides with sol concentrations of 0.5 M and higher were found to be effective against termites resulting in 100% termite mortality and significantly inhibited termite feeding. Among the formulations tested, the least damage was found for specimens treated with combinations of CaF₂ and MgF₂ with an average mass loss less than 1% and visual rating of “1”. These results demonstrate the efficacy of low water-soluble nano metal fluorides to protect wood from termite attack.

中文翻译：

---

纳米金属氟化物处理松木的白蚁抗性

氟化物是众所周知的木材防腐剂。氟化物基木材防腐剂的局限性之一是其高浸出性。低水溶性氟化物是目前用于木材保护的氟化物盐（如NaF）的替代品。然而，将低水溶性氟化物浸渍到木材中提出了挑战。为了应对这一挑战，低水溶性氟化物（如氟化钙（CaF ₂）和氟化镁（MgF ₂））通过氟化溶胶-凝胶法合成为纳米颗粒，然后浸渍到木材样品中。在这项研究中，纳米白氟化物的毒性通过白蚁死亡率，质量损失和在暴露于白蚁，白蚁（Coptotermes formosanus）八周后对处理过的标本进行目测分析来评估。发现溶胶浓度为0.5 M或更高的纳米金属氟化物可有效抵抗白蚁，导致白蚁死亡100％，并显着抑制白蚁摄食。在测试的配方中，使用CaF ₂和MgF ₂组合处理的样品的损坏最小，平均质量损失小于1％，视觉等级为“ 1”。这些结果证明了低水溶性纳米金属氟化物保护木材免受白蚁侵袭的功效。