水泥基吸波涂层的设计与研究

发布时间：2018-05-30 13:58

本文选题：水泥基吸波涂层 + MnO_2/活性炭复合吸波剂　；参考：《沈阳理工大学》2017年硕士论文

【摘要】：随着人类科技的不断进步,电磁污染已成为全球第四污染,威胁到人类生存。若能使数量众多的建筑物具备电磁波吸收能力,必然能有效解决电磁污染问题。本文采用氮吸附法、压汞法、SEM微观扫描研究了蒸馏水、稀盐酸、氢氧化钠溶液预处理对活性炭性能的影响,然后利用活性炭吸附性能制备了MnO_2/活性炭复合吸波剂,在此基础上,制备了水泥基吸波涂层,并研究了吸波涂层的拉伸粘结强度、耐水性、耐磨性以及吸波性能。采用沉淀法,利用活性炭的吸附性,以高锰酸钾、四水乙酸锰为原料,制备了MnO_2/活性炭复合吸波材料。研究了预处理方法对活性炭孔结构,微观形貌,高锰酸钾吸附量的影响。结果表明,用稀盐酸预处理活性炭的平均粒径明显减小。酸洗有利于打开活性炭微孔,提高其孔隙率,活性炭的BET比表面积增大15.7%;氢氧化钠溶液对活性炭有刻蚀作用,可以增大活性炭孔隙率和平均粒径。用稀盐酸酸洗之后再用氢氧化钠溶液碱洗的活性炭对高锰酸钾的吸附量最大,比未预处理的活性炭增加14.5%。采用在吸波涂层中掺加橡胶颗粒的方法缓解涂层开裂问题,研究了涂层拉伸粘结强度、耐磨性及耐水性能。研究结果表明,橡胶颗粒会降低涂层拉伸粘结强度,但在涂层拉伸粘结强度大于1.5MPa的前提下,能提高涂层的耐磨性。复合吸波剂能吸收部分水,不利于水泥水化。涂层14d拉伸粘结强度最大达到2.4MPa,耐磨性最大时,磨坑弦长最小为16.3mm,涂层耐水性优良,仅少数发生变形,脱落,开裂的现象。采用弓形法测量了水泥基吸波涂层的反射率,研究了水泥基吸波涂层的吸波性能。研究结果表明,制备的水泥基吸波涂层最小反射率为-15.38dB,反射率低于-10dB的频带带宽达8.8GHz,反射率低于-5dB的频带带宽达14GHz,占测试频段的90%,具有实际使用意义。吸波性能最优的吸波涂层各组分的质量比为水泥:锰锌铁氧体:MnO_2/活性炭复合吸波剂:橡胶:水=7.5:7.5:1:1:5.5。
[Abstract]:With the continuous progress of human science and technology, electromagnetic pollution has become the fourth pollution in the world, threatening human survival. If a large number of buildings can absorb electromagnetic wave, the problem of electromagnetic pollution will be solved effectively. In this paper, the effects of pretreatment of distilled water, dilute hydrochloric acid and sodium hydroxide solution on the properties of activated carbon were studied by means of nitrogen adsorption method and mercury entrainment method. Then, the composite wave absorbent of MnO_2/ activated carbon was prepared by using the adsorption property of activated carbon. The cement-based absorbing coating was prepared, and the tensile bond strength, water resistance, wear resistance and wave absorbing property of the coating were studied. The composite wave absorbing material of MnO_2/ activated carbon was prepared by precipitation method and using potassium permanganate and manganese acetate tetrahydrate as raw materials. The effects of pretreatment methods on pore structure, micromorphology and adsorption capacity of potassium permanganate were studied. The results showed that the average particle size of activated carbon pretreated with dilute hydrochloric acid was obviously reduced. Acid pickling can open the micropores of activated carbon and increase the porosity of activated carbon. The BET surface area of activated carbon increases by 15.7.The sodium hydroxide solution has etching effect on activated carbon, which can increase the porosity and average particle size of activated carbon. The adsorption of potassium permanganate on activated carbon washed with sodium hydroxide solution after acid washing with dilute hydrochloric acid was the largest, which increased 14.5g than that of unpretreated activated carbon. The crack of the coating was alleviated by adding rubber particles into the absorbing coating. The tensile bond strength, wear resistance and water resistance of the coating were studied. The results show that the rubber particles can reduce the tensile bond strength of the coating, but the wear resistance of the coating can be improved when the tensile bond strength of the coating is greater than that of 1.5MPa. The composite absorbent can absorb some water, which is not good for cement hydration. The maximum tensile bond strength of the coating for 14 days is 2.4 MPA, and the minimum chord length of the grinding pit is 16.3 mm when the wear resistance is the greatest. The coating has good water resistance, only a few of the phenomena of deformation, shedding and cracking occur. The reflectivity of cement based absorbing coating was measured by bow method, and the absorbing property of cement based absorbing coating was studied. The results show that the minimum reflectivity of the cement-based absorbing coating is -15.38 dB, the bandwidth of the band less than -10 dB is 8.8 GHz, and the band bandwidth of less than -5 dB is 14 GHz, accounting for 90 dB of the test band, which is of practical use. The mass ratio of each component of the best absorbing coating is cement: MnZn ferrite: MNO _ 2 / activated carbon composite absorbent: rubber: water 7.5: 7.5: 1: 1: 5.5.
【学位授予单位】：沈阳理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB34

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