▎ 摘　　要

NOVELTY - A zinc-ferrite-silica-graphene absorber comprises zinc-ferrite-silica-graphene ternary complex and paraffin. The zinc-ferrite-silica-graphene ternary complex consists of composite of magnetic loss-type zinc ferrite, conductive and dielectric loss-type graphene and silica, and has excellent wave transmission characteristics. USE - Zinc-ferrite-silica-graphene absorber is used for electromagnetic wave shielding material, absorbing material and stealth material. ADVANTAGE - The zinc-ferrite-silica-graphene absorber having high yield, minimum reflection loss of -43.9 dB or less at 2-18 GHz and absorption bandwidth of less than 10 dB at more than 6 GHz is prepared by simple and environmentally-friendly method under mild reaction condition. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation of zinc-ferrite-silica-graphene absorber, which involves preparing zinc-ferrite-silica complex by weighing and dissolving 1.352-5.406 g iron chloride hexahydrate and 0.341-1.362 g zinc chloride in 40-80 ml ethylene glycol solution, adding 0.4-1.6 g trisodium citrate and 3.6-14.4 g anhydrous sodium acetate, ultrasonically stirring mixture for 0.5-1.5 hours, transferring yellow clear solution to stainless steel reactor, reacting mixture at 150-240 degrees C for 8-16 hours, naturally cooled mixture to room temperature, filtering mixture, washing solid phase with deionized water and ethanol for three times, dispersing solid phase in 50-100 mL ethanol-water mixed solvent, adding 1-3 mL concentrated aqueous ammonia, evenly stirring mixture to obtain mixture (a), dispersing 0.2-1.2 mL tetraethyl orthosilicate solution in 20-100 mL anhydrous ethanol, to obtain solution (b), dripping solution (b) to mixture (a) using constant-pressure dropping funnel, stirring solution at room temperature for 8-12 hours, separating solid phase product by magnet, washing mixture with deionized water and ethanol for three times and vacuum drying to constant weight, preparing zinc-ferrite-silica-graphene ternary complex by weighing 0.3-1.5 g expandable graphite and 3-9 g potassium manganate in 500 mL three-necked flask, evenly stirring, adding 60-180 mL concentrated sulfuric acid and 8-20 mL concentrated phosphoric acid to mixture, heating mixture in water bath at 50-80 degrees C, stirring mixture for 8-12 hours, cooling mixture to room temperature, pouring mixture to beaker with ice water, dripping hydrogen peroxide to mixed solution to form golden yellow solution, centrifugally separating golden yellow solution, discarding supernatant, washing solid phase with deionized water to form filtrate without sulfate, dispersing filtrate in 200-600 mL deionized water, ultrasonically processing mixture at room temperature for 8-12 hours to form suspension (s1), dissolving 0.2-1 g zinc-ferrite-silica-graphene ternary complex in 30-120 mL anhydrous ethanol, ultrasonically dispersing mixture, adding 0.3-1.2 mL 3-methyltrimethoxysilane, reacting mixture at 80-120 degrees C for 24 hours to obtain liquid (b), dripping suspension (s1) to liquid (b), stirring mixture for 8-12 hours, separating solid phase from magnet, washing mixture with deionized water and ethanol for twice times, drying solid phase in vacuum at 50-80 degrees C to constant weight, calcining mixture at 600 degrees C for 3 hours in nitrogen atmosphere, and preparing zinc-ferrite-silica-graphene absorber by mixing zinc-ferrite-silica-graphene ternary complex and paraffin in mass ratio of 1:5-5:1 and milling mixture for 8-12 hours.