纳米粉体对传统电磁波吸收复合材料性能促进作用研究

【作者】 薛鹏；

【导师】 张兴华；

【作者基本信息】 广东工业大学 ， 材料学， 2004， 硕士

【摘要】 研究了各种纳米和普通吸收剂制备的聚合物基复合材料的电磁波吸收性能。主要工作包括以下三个方面：第一，用波导法研究了纳米氧化硅(nanometer SiOx)、乙炔碳黑(CB)及它们的混合物、碳纳米管(CNTs)的电磁特性；第二，将纳米氧化硅、碳纳米管、纳米氧化锌(nanometer ZnO)、氧化锌晶须(ZnOw)及乙炔碳黑等吸收剂单独或混合制成复合材料，用自由空间法测定这些材料的电磁波吸收性能；第三，设计、制备了不同厚度和不同结构的复合材料以提高对电磁波的吸收性能。主要研究结果如下： 1．通过对材料的电磁参数的研究，结果表明纳米氧化硅、乙炔碳黑及碳纳米管均为介电损耗型材料，少量的纳米氧化硅能够降低乙炔碳黑介电常数的实部，大幅度提高乙炔碳黑介电常数的虚部和介电损耗。 2．通过对复合粉体的吸波性能的研究，结果表明复合粉体的吸波性能优于单一吸波剂的吸波性能。5份纳米氧化硅能使含25份乙炔碳黑的复合材料的最小反射率从-10.54dB降低到-28.71dB，小于-10dB的吸收频宽从0.66 GHz提高到2.78 GHz。 3．通过对不同厚度材料的吸波性能研究，结果表明随材料厚度的减小，材料对电磁波的吸收峰向高频移动。 4．通过对不同结构材料的吸波性能研究，结果表明，材料结构设计合理的情况下，多层材料的吸波性能优于单层材料的吸波性能。ZnOw／CB／NBR(100／25／25)多层复合材料的最小反射率从-14.34dB降到-46.37dB，小于-10dB的吸收频宽从1.32GHz提高到1.91GHz。 在本实验的工作中发现与其它纳米材料不同的现象，纳米氧化硅的介电常数出现峰值，碳纳米管有两个介电损耗峰，建议以后的工作对其原因进行分析。更多还原

【Abstract】 Electro-magnetic wave absorption properties of polymer matrix composites made by blending polymer with nanometer powders and ordinary absorbers were investigated in the paper. Main work includes three parts. Firstly,the electro-magnetic parameters of nanometer SiOx, CB,their mixture and CNTs were researched by means of waveguide. Secondly, electro-magnetic wave absorption properties of composites made by mixing nanometer SiOx, CB, nanometer zonic, ZnOw, CNTs and their mixture with polymer were measured in the method of freespace. Thirdly, different depth and different structure composites were designed in order to improve electro-magnetic absorption properties of materials. Main results include:1. Investigation of electro-magnetic parameters shows that nanometer SiOx,CB and CNTs are dielectric loss materials, ’ of CB decreases and " and tg8 of CB are largely improved when a little quantity of nanometer SiOx is added to CB.2. Research shows that absorption properties of composite powders are better than those of single absorber.The minimum reflectivity of 25 phr CB can decrease from -10. 54dB to -28. 71dB and the absorption frequency width <-10 dB of 25 phr CB can be increased from 0. 66 GHz to 2. 78 GHz when CB is mixed with 5 phr nanometer SiOx.3. Results of absorption properties of different depth composites prove that the absorption peak is shifted to high frequency as the depth of materials decreases.4. Investigation of absorption properties of different structure composites shows that , on the condition of the reasonable structure design, absorption properties of multi-layer materials are better than those of single-layer materials. The minimum reflectivity of multi-layer ZnOw/CB/NBR ( 100/25/25) composites compared with single-layer ZnOw/CB/NBR (100/25/25) composites decreases from -14. 34dB to -46. 37dB, and the absorption frequency width <-10dB increases from 1. 32 GHz to 1.91GHz.The complex permittivity peak of nanometer SiOx and two dielectric losses of CNTs are discovered in our experiment which are different from properties of other nanometer materials. We should do the further research to reveal the truth.更多还原