title: Adsorption of humic acid onto carbonaceous surfaces: atomic force microscopy study.
abstract: The adsorption of humic acid (HA) onto highly ordered pyrolytic graphite (HOPG) surfaces at different concentrations has been studied by atomic force microscopy. When HA concentration was increased from 10 to 1,000 mg/L, HA can sequentially form spherical particles, layered structures, and connected blocks on HOPG surfaces. The findings of the layer structures and small amount of fine chains have been verified and discussed. When HA was acidified by addition of acetic acid, it changed into small rigid particles. These results indicated that HA can be considered as supramolecular associations of self-assembling heterogeneous and relatively small molecules, and a small amount of polymers. The present results are important for understanding HA molecular structures and their adsorption characteristic on carbonaceous surfaces.
authors: Key Laboratory of Forest Plant Ecology of Ministry of Education, Northeast Forestry University, Harbin 150040, China.
authors: Zhiguo
authors: Z
authors: Liu
authors: Yuangang
authors: Y
authors: Zu
authors: Ronghua
authors: R
authors: Meng
authors: Zhimin
authors: Z
authors: Xing
authors: Shengnan
authors: S
authors: Tan
authors: Lin
authors: L
authors: Zhao
authors: Tongze
authors: T
authors: Sun
authors: Zhen
authors: Z
authors: Zhou
mesh_terms: D019342:Acetic Acid / Q000737:chemistry; D000327:Adsorption; D002244:Carbon / Q000737:chemistry* / Q000378:metabolism; D006812:Humic Substances / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D018625:Microscopy, Atomic Force / Q000379:methods*; D010316:Particle Size; D011108:Polymers; D012987:Soil / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D006812:Humic Substances; D011108:Polymers; D012987:Soil; C009139:pyrolytic carbon; D002244:Carbon; D019342:Acetic Acid