Study On Preparation And Performance Of Conductive Carbon Black And Hydrophilic Carbon Black

Carbon black is an ancient carbon nanomaterial,which is widely used in some traditional fields,such as rubber tires,plastics,and black pigments.With the development of materials science,the varieties of carbon black have gradually become functional and diversified.For example,high-performance conductive carbon black has excellent conductivity,oxidation resistance,and thermal stability,and has a wide range of applications in the fields of batteries,capacitors,electromagnetic shielding,etc.However,the research and development of our country’s high-conductivity carbon black is still in its infancy,and its technical strength is weak.The domestically produced conductive carbon black cannot meet the growing demands of the military and civilian markets,and all high-end products rely heavily on imports.In addition,carbon black has high blackness value,stable chemical properties,and is cheap and easy to obtain.It is a good raw material for black pigments,coatings,inks and other fields.However,most of these application fields use water as the dispersion medium,and ordinary carbon black has extremely strong hydrophobicity.Therefore,it is of great significance to functionally modify ordinary carbon black to expand the application fields of carbon black.The thesis uses ordinary carbon black as the raw material and the preparation of functionalized carbon black as the main goal.The methods of "CO2 oxidationgraphitization" and phenolic amine biomimetic modification are used to prepare high-conductivity carbon black and hydrophilic carbon black respectively.The specific content is as follows:(1)Using CO2 to oxidize carbon black,explore the effect of CO2 oxidation on the structure and conductivity of carbon black.And a series of modified carbon blacks were prepared.The results show that as the reaction time increases,the specific surface area of carbon black gradually increases and the pore size distribution becomes wider,which is beneficial to improve the conductivity of carbon black.CO2 is destructive to the graphite-like crystallites of carbon black.As the reaction time increases,the defect density(ID/IG)of carbon black increases,and the arrangement thickness(Lc)of the crystallites decreases.Finally,the highest conductivity of carbon black is about 6 times that of the original.(2)The carbon black was modified by CO2 oxidation-graphitization coprocessing(TO and OTO),and its influence on the structure and conductivity of carbon black was explored.The results show that TO and OTO modified carbon blacks have higher specific surface area and wider pore size distribution.At the same time,the oxidation-graphitization coordinated treatment weakens the corrosive effect of CO2 on the carbon black crystallites,reduces the density of crystallite defects,increases the lateral size,and is more conducive to the movement of π-electrons.TO and OTO methods can greatly improve the conductivity of carbon black.The conductivity of carbon black is increased to about 10 times and 16 times,respectively,which is better than the single use of CO2 treatment.The modification effect of the OTO method is better than that of the TO method,and the carbon black modified by the OTO method forms a unique "spherical shell structure".This provides a new idea for further improving the conductivity of carbon black and achieving the conductivity of Ketjen Black ECP-600JD.Finally,the self-made conductive carbon black was applied as a conductive agent to the lithium battery,and the electrochemical performance of the battery was tested.The results show that compared with ECP-300JD,N134-TO as a conductive agent is beneficial to increase the specific discharge capacity of lithium batteries and reduce the charge transfer resistance of the battery.(3)The surface modification of carbon black was carried out by oxidative co-deposition of tannic acid and polyamine,to prepare highly hydrophilic carbon black.And the influence of TA concentration on the hydrophilic properties of modified carbon black was explored.XPS,FTIR and TGA and other ways have proved that TA/DETA polycondensate is successfully deposited on the surface of carbon black,providing abundant amino groups and hydroxyl groups on the surface of carbon black;and as the concentration of TA increases,the amount of TA/DETA deposition gradually increases.SEM,particle size analysis,standing sedimentation and contact angle test show that the optimal reaction concentration of TA is 3.0 g/L.Under this condition,the contact angle of the modified carbon black is reduced to 32 °,and it can exist stably in a uniform suspension and solution,showing good hydrophilicity.The tannic acid-diethylenetriamine biomimetic modification method has the characteristics of high efficiency,low cost,and environmental friendliness.The hydrophilic carbon black prepared by this method can be quickly and stably dispersed in water,which improves the hydrophilicity of carbon black,providing a new way of hydrophilic modification of carbon black.