狼尾草粉末/纳米CuO复合材料的制备与电磁屏蔽的应用

【目的】为高值清洁利用狼尾草资源。【方法】以狼尾草粉末为基材、纳米氧化铜为增强因子,通过高纯酒精分散与三维高效无偏析混合方法获得狼尾草粉末与纳米氧化铜的均匀混合物,采用温压成形工艺对均匀混合物实施双向成形制备狼尾草粉末/纳米CuO复合材料。以单因素试验结果为基础,采用BBD响应面法进行多元回归分析,建立CuO含量、成形温度、成形压力与复合材料静曲强度、吸水率的数学模型,研究不同工艺参数对静曲强度和吸水率的影响及变化规律,得到了最优制备工艺参数,评估其电磁屏蔽效能。【结果】狼尾草/纳米CuO复合材料的最优温压成形工艺参数与最佳成分配比为:成形温度185℃,成形压力70 MPa,保温保压时间30 min,CuO含量44 wt%。据此制备的狼尾草/纳米CuO复合材料的静曲强度为77.64 MPa,吸水率为2.3%,电磁屏蔽效能为60 dB。【结论】狼尾草/纳米CuO复合材料的吸水率不足高密度水泥纤维板吸水率(≤25%)的10%,仅为超薄高密度人造板吸水率(≤60%)的3.8%,优于人造板相关技术标准;其电磁屏蔽效能已达到工业应用标准(30~60 dB),可望达到军用标准(60~120 dB)。

Development of pennisetum-powder/nano-CuO composite and its electromagnetic shielding application

【Objective】To use the pennisetum resourcefor high value cleaning.【Method】Using pennisetum powder as the substrate and nano-CuO as the enhancement factor,the homogeneous mixture was obtained by high purity alcohol dispersion and 3D efficient non-segregation mixing method.Pennisetum powder/nano CuO composite was prepared by biaxially forming homogeneous mixture with warm compaction process.Based on the single factor test results,BBD response surface method was used for multiple regression analysis to establish the mathematical model of CuO content,forming temperature,forming pressure,static flexural strength and water absorption of the composite material.The impact of different process parameters on the static strength and water absorption and its variation law were studied.The optimal preparation parameters were obtained and the shielding efficiency was evaluated.【Result】The optimal forming parameters and composition ratio of pennisetum/nano-CuO composite are:forming temperature 185℃,forming pressure 70 MPa,holding time 30min,and CuO content 44wt%.The static bending strength,water absorption rate and electromagnetic shielding efficiency of the composite were 77.64 MPa,2.3%and 60 dB.【Conclusion】The water absorption of pennisetum/nano-CuO composite is less than 10%of that of high-density cement fiberboard(<25%),only 3.8%of that of ultra-thin high-density wood-based panel(<60%),which is superior to the relevant technical standards of wood-based panel.Its electromagnetic shielding effectiveness has reached the industrial application standard(30-60 dB)and is expected to reach the military standard(60-120 dB).