摘要
竹炭(Bamboo charcoal,BC)有一定的导电性能,具有被应用于电气材料领域的潜力。为提高竹炭的导电性能,本研究以绝缘竹炭为原料进行二次炭化,研究了二次炭化温度对竹炭理化性能及结构的影响。采用元素分析仪、量热仪、比表面积及孔隙度分析仪、红外光谱仪、拉曼光谱仪、X射线衍射仪、扫描电子显微镜和透射电子显微镜对竹炭的基本理化性能及微观结构进行测试。结果表明,700~1500℃内,随着炭化温度的升高,竹炭的比表面积先增大后减小,碳含量从82.45%增加至96.87%,固定碳含量从81.22%增加至96.3%,热值从31.385 MJ/kg增加至34.904 MJ/kg,电导率从10-8S/cm增加至92.94 S/cm;二次炭化降低了竹炭的极性,并且在纤维帽和细胞壁上形成许多大孔结构,竹炭的这种特征使其可作为复合材料的增强相;二次炭化后,竹炭形成弧形石墨边缘,石墨化程度随着温度的升高逐渐增大,BC1500的(002)峰对应的微晶尺寸为0.334 nm,接近石墨条纹间距0.34 nm。二次炭化显著增强了竹炭的导电性能,这是碳含量提高、细胞壁和纤维帽进一步收缩以及弧形石墨边缘形成的综合结果。二次炭化为高品质炭的制备提供了一种简单高效的方法。
Bamboo charcoal has certain electrical conductivity and the potential to be applied in the field of electrical materials.In order to improve the electrical conductivity of bamboo charcoal,this paper used insulating bamboo charcoal as the raw material for recarbonization.The physical and chemical properties and structure of bamboo charcoal after different temperatures recarbonization were studied.Elemental analyzer,calorimeter,specific surface area and porosity analyzer,infrared spectrometer,Raman spectrometer,X-ray diffractometer,scanning electron microscope and transmission electron microscope were used to measure the basic physical and chemical properties and microstructure of bamboo charcoal.The results showed that as the recarbonization temperature increased,the specific surface area of bamboo charcoal increased first and then decreased within the range of 700—1500℃.The C content increased from 82.45%to 96.87%,the fixed carbon content increased from 81.22%to 96.3%,and the calorific value from 31.385 MJ/kg to 34.904 MJ/kg,the conductivity increased from 10-8 S/cm to 92.94 S/cm.The recarbonization reduced the polarity of bamboo charcoal and resulted in the formation of many macroporous structures on the fiber cap and cell wall.This feature of bamboo charcoal can be advantage for bamboo charcoal to be used as a reinforcing phase for composite materials.After the recarbonization,the bamboo charcoal formed curved graphite edges,and the degree of graphitization gradually increased with the increase of temperature.The crystallite size corresponding to the(002)peak of BC1500 was 0.334 nm,which was close to the graphite stripe spacing of 0.34 nm.The recarbonization significantly enhanced the conductivity of bamboo charcoal,which was the result of increased carbon content,further shrinkage of cell walls and fiber caps,and formation of curved graphite edges.Recarbonization provides a simple and efficient method for the preparation of high-quality charcoal.
作者
江文正
章卫钢
子绚
刘贤淼
张文标
李文珠
JIANG Wenzheng;ZHANG Weigang;ZI Xuan;LIU Xianmiao;ZHANG Wenbiao;LI Wenzhu(College of Engineering,Zhejiang A&F University,Hangzhou 311300,China;International Center for Bamboo and Rattan,Beijing 100102,China)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2021年第8期23-27,共5页
Materials Reports
基金
国家十三五重点研发计划任务(2018YFF0214501)
浙江省重点研发计划项目(2018C02008)。
关键词
竹炭
电导率
石墨化
二次炭化
bamboo charcoal
electrical conductivity
graphitization
recarbonization
