期刊
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
卷 133, 期 1, 页码 313-319出版社
SPRINGER
DOI: 10.1007/s10973-017-6930-z
关键词
Enthalpy of formation of carbon nanotube; Carboxylated carbon nanotubes; Bulk enthalpy of formation; Surface enthalpy of formation
Carbon nanotubes (CNTs) with different content of carboxylated groups on their surface (depending on the duration of their treatment with nitric acid) were synthesized. All samples were analyzed by thermal analyses, X-ray photoelectron spectroscopy, Raman and energy-dispersive X-ray spectroscopy, transmission electron microscopy and S-BET. The adiabatic bomb calorimetry technique was used for the determination of enthalpy of formation. With the increase in time of treatment from 3 to 9 h, the content of oxygen increased from 7.49 to 8.22 at%. After 15-h treatment in nitric acid, CNTs contained 7.86 at%. The enthalpies of formation of all samples were negative and had nonlinear character. The changes of surface and bulk physicochemical characteristics of oxidized CNTs were analyzed. It was shown that despite decrease in surface enthalpy of formation a dagger(f) H (0)(298(surf.)) with the increase in oxygen content, the bulk enthalpy of formation a dagger(f) H (0)(298(bulk)) was very sensitive to defectiveness and structure of carbon layers. It resulted in the difficult correlation between oxygen content, morphology, defectiveness and a dagger(f) H (0)(298).
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据