An improved method of fitting point-by-point is proposed to determine the absorption coefficient from infrared （IR） transmittance. With no necessity of empirical correction factors, the absorption coefficient can be...An improved method of fitting point-by-point is proposed to determine the absorption coefficient from infrared （IR） transmittance. With no necessity of empirical correction factors, the absorption coefficient can be accurately determined for the films with thin thicknesses. Based on this method, the structural properties of the hydrogenated amorphous silicon oxide materials （a-SiOx：H） are investigated. The oxygen-concentration-dependent variation of the Si-O-Si and the Si-H related modes in a-SiOx：H materials is discussed in detail.展开更多
Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation processes.Herein,we demon...Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation processes.Herein,we demonstrate a green and facile route to up-recycle waste fabrics(cotton-polyester blending or cotton fabrics)into a high-performance microwave absorber.In this design,an assistant coating was deposited onto the fiber surface of the waste fabric through the assembly of tannic acid-Fe^(2+)(TA-Fe^(2+)),which effectively catalyzed the polymer fiber into highly graphitized porous carbon fiber at high temper-atures.Meanwhile,the Fe nanoparticles from the reduction of Fe^(2+)ions were evenly embedded on the surface of porous carbon fibers.Consequently,the resultant porous carbon/Fe composites with hierarchi-cal microstructures displayed excellent microwave absorption performances.Typically,the microwave ab-sorber from waste polyester-cotton blended fabric could reach a minimum reflection loss(RL)of-50.5 dB at a thin coating thickness of 1.7 mm,and the minimum RL from waste cotton fabric absorber reached-47.1 dB at a thickness of 2.5 mm.This work provides a new idea to convert waste fabrics into high value-added microwave absorbing materials in a simple and environmentally friendly way,which will help reuse resources and protect the environment.展开更多
基金supported by the National Basic Research Program of China(Grant Nos.2011CBA00705,2011CBA00706,and 2011CBA00707)the National Natural Science Foundation of China(Grant No.60976051)the Program for New Century Excellent Talents in University of China(Grant No.NCET-08-0295)
文摘An improved method of fitting point-by-point is proposed to determine the absorption coefficient from infrared （IR） transmittance. With no necessity of empirical correction factors, the absorption coefficient can be accurately determined for the films with thin thicknesses. Based on this method, the structural properties of the hydrogenated amorphous silicon oxide materials （a-SiOx：H） are investigated. The oxygen-concentration-dependent variation of the Si-O-Si and the Si-H related modes in a-SiOx：H materials is discussed in detail.
基金supported by the National Natural Science Foun-dation of China(Nos.52122302,51991351,and 51790504)Funda-mental Research Funds for the Central Universities,Young Elite Sci-entists Sponsorship Program by CAST.Financial support by the 111 Project(No.B20001)is sincerely acknowledged.
文摘Nowadays,a large amount of waste fabrics has brought huge environmental and resource problems,while the traditional recycling routes are downcycling with low efficiency and complex separation processes.Herein,we demonstrate a green and facile route to up-recycle waste fabrics(cotton-polyester blending or cotton fabrics)into a high-performance microwave absorber.In this design,an assistant coating was deposited onto the fiber surface of the waste fabric through the assembly of tannic acid-Fe^(2+)(TA-Fe^(2+)),which effectively catalyzed the polymer fiber into highly graphitized porous carbon fiber at high temper-atures.Meanwhile,the Fe nanoparticles from the reduction of Fe^(2+)ions were evenly embedded on the surface of porous carbon fibers.Consequently,the resultant porous carbon/Fe composites with hierarchi-cal microstructures displayed excellent microwave absorption performances.Typically,the microwave ab-sorber from waste polyester-cotton blended fabric could reach a minimum reflection loss(RL)of-50.5 dB at a thin coating thickness of 1.7 mm,and the minimum RL from waste cotton fabric absorber reached-47.1 dB at a thickness of 2.5 mm.This work provides a new idea to convert waste fabrics into high value-added microwave absorbing materials in a simple and environmentally friendly way,which will help reuse resources and protect the environment.
