Vermeer AWP, Koopal LK
Laboratory of Physical Chemistry and Colloid Science, Wageningen Agricultural University, Wageningen, 6700 EK, The Netherlands
J Colloid Interface Sci. 1999 Apr 1;212(1):176-185. doi: 10.1006/jcis.1998.6050.
The proton adsorption to a mixture of purified Aldrich humic acid (PAHA) and hematite is investigated. Basic insight into the charge adjustment process is obtained by using a self-consistent-field lattice theory for polyelectrolyte adsorption. The calculations indicate that upon adsorption the component with the highest initial charge density tends to induce charges on the other component. The number of induced charges can show a maximum when the surface charge and the charge of the segments in direct contact with the surface roughly balance each other. Experimentally, the humic acid-hematite system is investigated by proton titrations. The alterations in charge density caused by adsorption of PAHA to hematite are investigated by comparing the proton adsorption on the individual samples with that on their mixtures. Upon adsorption a part of the functional groups of humic acid forms complexes with some of the surface sites of hematite. This interaction reduces the proton binding to the humic acid at relatively low pH and it promotes the proton adsorption on the oxide surface at relatively high pH. Copyright 1999 Academic Press.
研究了质子吸附到纯化的Aldrich腐殖酸（PAHA）和赤铁矿混合物上的情况。通过使用聚电解质吸附的自洽场晶格理论，对电荷调节过程有了基本的认识。计算表明，吸附时初始电荷密度最高的组分倾向于在另一种组分上诱导电荷。当表面电荷与直接与表面接触的链段电荷大致平衡时，诱导电荷的数量可能会出现最大值。在实验上，通过质子滴定研究了腐殖酸 - 赤铁矿体系。通过比较质子在单个样品及其混合物上的吸附情况，研究了PAHA吸附到赤铁矿上引起的电荷密度变化。吸附时，腐殖酸的一部分官能团与赤铁矿的一些表面位点形成络合物。这种相互作用在相对较低的pH值下减少了质子与腐殖酸的结合，并在相对较高的pH值下促进了质子在氧化物表面的吸附。版权所有1999年学术出版社。
