Key Laboratory of Bio-based Material Science and Technology of Ministry of Education, Northeast Forestry University , Harbin, 150040, People's Republic of China.
ACS Appl Mater Interfaces. 2017 Jul 12;9(27):23039-23047. doi: 10.1021/acsami.7b06803. Epub 2017 Jun 30.
Improving the flame retardancy of wood is an imperative yet highly challenging step in the application of wood in densely populated spaces. In this study, Mg-Al-layered double-hydroxide (LDH) coating was successfully fabricated on a wood substrate to confer flame-retardant and smoke-suppression properties. The chemical compositions and bonding states characterized by energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy confirmed the coating constituents of Mg-Al LDH. The coating evenly covered the sample wood surfaces and provided both mechanical enhancement and flame-retardancy effects. The limiting oxygen index of the Mg-Al LDH-coated wood increased to 39.1% from 18.9% in the untreated wood. CONE calorimetry testing revealed a 58% reduction in total smoke production and a 41% reduction in maximum smoke production ratio in the Mg-Al LDH-coated wood compared to the untreated wood; the peak heat release rate and total heat release were also reduced by 49% and 40%, respectively. The Mg-Al LDH coating is essentially hydrophilic, but simple surface modification by fluoroalkyl silane could make it superhydrophobic, with a water contact angle of 152° and a sliding angle of 8.6°. The results of this study altogether suggest that Mg-Al LDH coating is a feasible and highly effective approach to nanoconstructing wood materials with favorable flame-retardant and smoke-suppression properties.
提高木材的阻燃性是将木材应用于人口密集空间的必要且极具挑战性的步骤。在本研究中，成功地在木材基底上制备了 Mg-Al 层状双氢氧化物（LDH）涂层，以赋予其阻燃和抑烟性能。通过能量色散 X 射线光谱和 X 射线光电子能谱对化学成分和键合状态进行了表征，证实了涂层中含有 Mg-Al LDH。涂层均匀地覆盖了样品木材表面，提供了机械增强和阻燃效果。Mg-Al LDH 涂层木材的极限氧指数从未处理木材的 18.9%提高到 39.1%。锥形量热计测试表明，与未处理木材相比，Mg-Al LDH 涂层木材的总烟雾释放量减少了 58%，最大烟雾释放率减少了 41%；峰值热释放率和总热释放量也分别减少了 49%和 40%。Mg-Al LDH 涂层本质上是亲水的，但通过氟烷基硅烷进行简单的表面改性可以使其具有超疏水性，水接触角为 152°，滑动角为 8.6°。本研究的结果表明，Mg-Al LDH 涂层是一种可行且高效的方法，可以纳米构造具有良好阻燃和抑烟性能的木材材料。
