Uchimiya Minori, Pignatello Joseph J, White Jason C, Hu Szu-Tung, Ferreira Paulo J
USDA-ARS Southern Regional Research Center, 1100 Robert E. Lee Boulevard, New Orleans, Louisiana, 70124, USA.
Department of Environmental Sciences, The Connecticut Agricultural Experiment Station, New Haven, Connecticut, 06504, USA.
Sci Rep. 2017 Sep 18;7(1):11787. doi: 10.1038/s41598-017-12117-9.
Pyrogenic carbon is widespread in soil due to wildfires, soot deposition, and intentional amendment of pyrolyzed waste biomass (biochar). Interactions between engineered carbon nanoparticles and natural pyrogenic carbon (char) are unknown. This study first employed transmission electron microscopy (TEM) and X-ray diffraction (XRD) to interpret the superstructure composing aqueous fullerene C nanoparticles prepared by prolonged stirring of commercial fullerite in water (nC-stir). The nC-stir was a superstructure composed of face-centered cubic (fcc) close-packing of near-spherical C superatoms. The nC-stir superstructure (≈100 nm) reproducibly disintegrated pecan shell biochar pellets (2 mm) made at 700 °C into a stable and homogeneous aqueous colloidal (<100 nm) suspension. The amorphous carbon structure of biochar was preserved after the disintegration, which only occurred above the weight ratio of 30,000 biochar to nC-stir. Favorable hydrophobic surface interactions between nC-stir and 700 °C biochar likely disrupted van der Waals forces holding together the amorphous carbon units of biochar and C packing in the nC superstructure.
由于野火、烟尘沉积以及对热解废弃生物质（生物炭）的有意改良，热解碳在土壤中广泛存在。工程碳纳米颗粒与天然热解碳（炭）之间的相互作用尚不清楚。本研究首先采用透射电子显微镜（TEM）和X射线衍射（XRD）来解释通过在水中长时间搅拌商业富勒烯石制备的水性富勒烯C纳米颗粒（nC-搅拌）所构成的超结构。nC-搅拌是一种由近球形C超原子的面心立方（fcc）紧密堆积组成的超结构。nC-搅拌超结构（≈100纳米）可重复性地将在700°C下制备的山核桃壳生物炭颗粒（2毫米）分解成稳定且均匀的水性胶体（<100纳米）悬浮液。生物炭的无定形碳结构在分解后得以保留，这种分解仅在生物炭与nC-搅拌的重量比高于30000时发生。nC-搅拌与700°C生物炭之间有利的疏水表面相互作用可能破坏了将生物炭的无定形碳单元与nC超结构中的C堆积结合在一起的范德华力。
