Yoon Tae Hyun, Johnson Stephen B, Brown Gordon E
Surface & Aqueous Geochemistry Group, Department of Geological & Environmental Sciences, Stanford University, Stanford, California 94305-2115, USA.
Langmuir. 2004 Jul 6;20(14):5655-8. doi: 10.1021/la0499214.
The adsorption of Suwannee River fulvic acid (SRFA) on boehmite, gamma-AlO(OH), has been examined by both macroscopic adsorption and in situ ATR-FTIR spectroscopic techniques. At a SRFA concentration approaching surface saturation (F = 5.3 micromol m(-2)), adsorption is at a maximum at low pH and decreases as pH is increased. The ATR-FTIR spectral features of adsorbed SRFA are very similar to those measured approximately 1-2 pH units higher in solution, indicating that (i) the SRFA appears to be predominantly adsorbed at the boehmite/water interface in an outer-sphere complexation mode and (ii) the positively charged boehmite/water interface stabilizes SRFA molecules against protonation at low pH.
通过宏观吸附和原位衰减全反射傅里叶变换红外光谱（ATR-FTIR）技术，研究了苏万尼河富里酸（SRFA）在勃姆石（γ-AlO(OH)）上的吸附情况。在SRFA浓度接近表面饱和（F = 5.3 μmol m⁻²）时，吸附在低pH值下达到最大值，并随着pH值的升高而降低。吸附的SRFA的ATR-FTIR光谱特征与在溶液中高约1 - 2个pH单位时测得的光谱特征非常相似，这表明：（i）SRFA似乎主要以外层络合模式吸附在勃姆石/水界面；（ii）带正电荷的勃姆石/水界面使SRFA分子在低pH值下不易质子化。
