| Traditional processes of manufacturing carbon black have serious problems like environmental pollution and waste of resources,thus,the plasma technique applied in this field seems to be a green and high-efficient process.However,carbon deposition and severe erosion of electrodes during the usual arc discharge plasma make this process quite confined.Besides,the structure of carbon black prepared by this method cannot be controlled as well as the poor quality and low yield.Hence,it is necessary to develop a continuous plasma process for the preparation of structure-controlled carbon black with high quality and yield.The arc discharge plasma usually suffers from the drawbacks of batch operation,small plasma volume and jumbly structure of carbon black.In order to solve these problems,a specific arc discharge process has been developed via the induction of easily-realized discharge in a fluidized bed to obtain a continuous process with the structure of carbon black in control.The effects of different discharging processes and flow conditions on the quality and yield of carbon black along with the stability of arc have been investigated.Finally,the formation mechanism of carbon black has been put forward.Based on the formation mechanism,a new plasma process of preparing graphene has been designed.The main results and conclusions are as follows:(1)AC arc discharge with arc longer than 5 cm could be realized via the induction of dielectric barrier discharge.A stable plasma environment with large volume and small temperature gradient could be obtained consequently.With the continuous generation of carbon black,the arc discharge would be weakened and the yield decreased to 44.8%drastically.After the realization of fluidization via the agglomeration of carbon black,the product had more developed structure and perfect crystallinity with yield higher than 80%.(2)DC arc discharge with arc as long as 4 cm could be initiated via the induction of AC gliding arc discharge.The yield of carbon black could be improved by 1-4 times by the combination of the advantages of non-thermal and thermal plasma together via the simultaneous discharge of AC arc and DC arc.Highest yield could be obtained as 2.7 g/h.Three kinds of carbon black including reinforcing black,conductive black and wear-resistant black could be prepared under different operating gas velocity and discharge modes,in which the electrical resistivity of conductive black was 2.2 ?·cm.Corresponding formation mechanisms have been illustrated.(3)A simple strategy of adding hydrogen into the plasma area during the discharge process could lead to the formation of surface-clean graphene,which mainly consisted of 1-6 layers with electrical conductivity of 3860 S/m and yield higher than 1.6 g/h.This plasma method shows milder operation conditions,lower costs and simpler process compared to other methods.High quality graphene powder could be obtained by a one-step process.(4)The compatibility and impact strength of polymer composite could be remarkably enhanced after the functionalization of ABS and EPDM by MAH,respectively.The tensile strength could be significantly improved with the addition of amount of raw ABS into the ABS-g-MAH/EPDM-g-MAH composites.Thus,excellent performance could be achieved after the addition of carbon black.With the addition of conductive black prepared by plasma process into the composites,electrical resistivity of composites could be decreased to 7.9?02 ?·cm at the addition amount of 10 wt%.The innovation in this study mainly includes the application of fluidization into the plasma preparation of carbon black,the combination of advantages of non-thermal and thermal plasma together and the development of fast,efficient,clean,low-cost continuous plasma process to prepare graphene in one-step operation,which exhibit practical significance on the development and classification of carbon black from plasma process,and the clean preparation of graphene powder in large-scale. |
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