Division of Chemistry and Materials Science, Graduate School of Engineering, Nagasaki University , Nagasaki 852-8521, Japan.
Faculty of Chemistry, Synthesis and Modification of Carbon Materials Research Group, Nicolaus Copernicus University in Toruń , Gagarin Street 7, 87-100 Toruń, Poland.
Langmuir. 2017 Oct 24;33(42):11180-11188. doi: 10.1021/acs.langmuir.7b02046. Epub 2017 Aug 29.
The detonation nanodiamonds form the aggregate having interparticle voids, giving a marked hygroscopic property. As the relationship between pore structure and water adsorption of aggregated nanodiamonds is not well understood yet, adsorption isotherms of N at 77 K and of water vapor at 298 K of the well-characterized aggregated nanodiamonds were measured. HR-TEM and X-ray diffraction showed that the nanodiamonds were highly crystalline and their average crystallite size was 4.5 nm. The presence of the graphitic layers on the nanodiamond particle surface was confirmed by the EELS examination. The pore size distribution analysis showed that nanodiamonds had a few ultramicropores with predominant mesopores of 4.5 nm in average size. The water vapor adsorption isotherm of IUPAC Type V indicates the hydrophobicity of the nanodiamond aggregates, with the presence of hydrophilic sites. Then the hygroscopic nature of nanodiamonds should be associated with the surface functionalities of the graphitic shell and the ultramicropores on the mesopore walls.
爆轰纳米金刚石形成具有粒子间空隙的聚集体，赋予显著的吸湿性。由于颗粒间纳米金刚石聚集体的孔结构与水吸附之间的关系尚未得到很好的理解，因此测量了在 77 K 下的 N 和在 298 K 下水蒸气的吸附等温线。高分辨率透射电子显微镜和 X 射线衍射表明，纳米金刚石具有高结晶性，其平均晶粒尺寸为 4.5nm。通过 EELS 检查证实了纳米金刚石颗粒表面存在石墨层。孔径分布分析表明，纳米金刚石具有少量的超微孔，平均尺寸为 4.5nm 的中孔为主。IUPAC 类型 V 的水蒸气吸附等温线表明纳米金刚石聚集体具有疏水性，同时存在亲水位。因此，纳米金刚石的吸湿性应与石墨壳的表面官能团和中孔壁上的超微孔有关。
