Forming textured hydrophobic surface coatings via mixed wax emulsion impregnation and drying of poplar wood
Forming textured hydrophobic surface coatings via mixed wax emulsion impregnation and drying of poplar wood
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通过混合蜡乳液浸渍和干燥杨木形成纹理疏水表面涂层
DOI：
10.1007/s00226-020-01156-7
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发表时间：
2020-01-29
影响因子：
3.4
通讯作者：
Wang, Wang
中科院分区：
文献类型：
--
作者：
Chen, Cong;Chen, Jinyu;Wang, Wang
快速生长的种植园木材的亲水性是其户外应用的主要限制。本文报道了一种改善白杨疏水性的新方法。通过使用石蜡/巴西棕榈油（5：5和7：3）-混合蜡乳液体系。将白杨样品浸渍在固含量为4%的单一或混合蜡O/W乳液中，然后在高于石蜡熔点但低于巴西棕榈蜡熔点的70 °C下干燥处理。场发射扫描电镜（SEM）图像显示，经混合蜡乳液处理的木材细胞内腔表面和样品外表面均形成了纹理化表面，样品外表面为镶嵌有巴西棕榈蜡微柱的连续石蜡膜，接触角分析和吸水率测试表明，纹理化表面赋予混合蜡乳液处理木材良好的疏水性，使初始接触角大于140°，不仅改善表面性能，而且改善长期（120或192小时浸泡）拒水性。此外，在处理过的木材中的自由水和结合水的分数进行了定量测量，使用低场核磁共振。结果表明，混合蜡乳液处理显著降低了自由水含量，延缓了束缚水吸附。总之，这种混合蜡乳液处理可以作为一种高效的木材疏水化方法，用于扩大木材在户外的应用。
Hydrophilicity of fast-growing plantation wood is the major restriction for its outdoor applications. Herein, a novel method is reported for improving the hydrophobicity of Cathay poplar (Populus cathayanaRehd.) by using a paraffin/carnauba (5:5 and 7:3)-mixed wax emulsion system. The poplar samples were impregnated in the single or mixed waxO/Wemulsions of 4% solid content with subsequent drying treatment at 70 °C, which was higher than the paraffin wax melting point but lower than that of carnauba wax. The images obtained by field emission scanning electron microscopy confirmed that the mixed wax emulsion treatment developed textured surfaces in the inner lumen surface of wood cells and on the external surfaces of the samples comprising a continuous paraffin wax film with carnauba wax micropillars embedded in it. Contact angle analysis and water absorption tests show that the textured surface imparted the mixed wax emulsion-treated wood good hydrophobicity, rendering the initial contact angle greater than 140° and improving not only the surface property but also the long-term (120 or 192 h immersion) water repellency. In addition, free and bound water fractions in the treated wood were measured quantitatively using low-field nuclear magnetic resonance. The results show that the mixed wax emulsion treatment significantly decreased the free water content and delayed the bound water adsorption. In conclusion, this mixed wax emulsion treatment can be potentially utilized as a highly efficient wood hydrophobization method for expanding wood applications outdoors.