@article{oai:kanazawa-u.repo.nii.ac.jp:00029353,
 author = {大橋, 竜太郎 and 長尾, 誠也 and 山本, 政儀 and 水野, 元博 and Tamamura, Shuji and Ohashi, Ryutaro and Nagao, Seiya and Yamamoto, Masayoshi and Mizuno, Motohiro},
 issue = {5},
 journal = {Colloids and Surfaces A: Physicochemical and Engineering Aspects},
 month = {Oct},
 note = {Molecular-size-distribution (MSD)-dependent aggregation of Fluka and International Humic Substance Society humic acids (HAs) in the presence of Na(I), Ca(II), Ag(I), and Eu(III) were studied using high-performance size-exclusion chromatography. Larger molecular size fractions (>8000. Da) rich in aliphatic carbons were observed to aggregate in the presence of Na(I) and Ca(II), whereas both large and small molecular size fractions concurrently aggregated in the presence of Ag(I) and Eu(III). In view of the non-specific binding of Na(I) and Ca(II) with HAs, the electric-field screening effect is probably the main cause of HA aggregation by Na(I) and Ca(II), preserving the intrinsic hydrophobicity of the HAs. Reduced surface charges and the hydrophobic heterogeneities of different MSD fractions of HAs by direct binding of Ag(I) and Eu(III) are postulated to induce insignificant dependence of aggregation on the different MSD fractions. © 2013 Elsevier B.V.},
 pages = {9--15},
 title = {Molecular-size-distribution-dependent aggregation of humic substances by Na(I), Ag(I), Ca(II), and Eu(III)},
 volume = {434},
 year = {2013}
}