Study On Preparation And Properties Of Tungsten Disulfide-based Composites Absorbing Materials

WS₂ is a typical graphene-like layered material.In the field of electromagnetic wave absorption,WS₂ has the characteristics of large specific surface area,high dielectric loss and small size effect,surface effect,and boundary effect of nano-materials,which is conducive to electromagnetic wave entering the absorber and further attenuating electromagnetic wave.It is a kind of absorbing material with exploratory value.However,WS₂ has a single loss mechanism and limited absorption capacity for electromagnetic waves.It is difficult to meet the requirements of absorbing materials with"thin,light,wide and strong"at the same time.Composite treatment is an effective means to improve its absorbing performance.Therefore,the electromagnetic wave absorption properties of WS₂ microwave absorber prepared by hydrothermal method are studied in this paper.In order to further improve the absorbing properties of WS₂ nanomaterials,WS₂@SWCNTs and WS₂@Co composites were prepared by combining WS₂ with low-density single-walled carbon nanotubes?SWCNTs?and magnetic materials?Co nanosheets?,respectively.The effects of the content of each component and the amount of absorber on the absorbing properties of the composites were studied,and the optimum composition and the loads of absorber were determined.It provides research basis for the application of WS₂ in the field of microwave absorption.The main results are as follows:?1?The amount of WS₂ absorber has a significant effect on the absorbing properties of WS₂/paraffin composites.With the increase of the loads of WS₂ absorber,the permittivity of the material increases gradually,and the attenuation characteristics of electromagnetic wave also increase gradually.The electromagnetic permittivity are too large,but the impedance matching performance decreases.Therefore,under the combined action of various factors,the absorbing performance is the best when the amount of WS₂ absorber is 50 wt%.When the loads of WS₂ absorber is 50wt%,the minimum reflection loss of WS₂/paraffin is 2.7 mm at 7.8 GHz.When the matching thickness is 4 mm,the maximum absorption bandwidth is 4 GHz?13.9-17.9 GHz?.?2?For WS₂@SWCNTs composites,the results show that the addition of SWCNTs and the loads of microwave absorbent has a significant effect on the microwave absorbing properties of WS₂/SWCNTs paraffin composites.The optimum molar ratio of WS₂ to SWCNTs is 1:1,and the optimum addition of absorbent is 50wt%.At the same time,the minimum reflection loss of WS₂@SWCNTs composites reaches-65.9 dB when the matching thickness is 2.2 mm at 8.4 GHz,and the maximum absorption bandwidth less than-10 dB reaches 3.6 GHz?13.0-16.6 GHz?when the matching thickness is 1.3 mm.Compared with WS₂ nanomaterials,WS₂@SWCNTs composites have stronger electromagnetic wave absorption ability and thinner matching thickness when they are used as microwave absorbers.?3?For WS₂@Co composites,the results show that the relative content of Co source and the loads of WS₂@Co absorbent have significant effects on the absorbing properties of WS₂/Co paraffin composites.The optimum molar ratio of WS₂ to Co source of WS₂@Co composite is 1:10,and the optimum amount of absorbent is 60 wt%.At the same time,when the optimum relative content of Co source and the optimum amount of absorbent are satisfied,the absorbing property of WS₂@Co composite is the best,the minimum reflection loss is-46.5 dB when the matching thickness is 1.7 mm at 10.2 GHz,and the maximum effective bandwidth less than-10 dB is 5.4 GHz?11.3-16.7 GHz?when the matching thickness is 1.4 mm.Compared with WS₂ and WS₂@SWCNTs composite,the effective absorbing bandwidth is remarkable raised.