Inyang Hilary I, Bae Sunyoung
Global Institute for Energy and Environmental Systems, University of North Carolina, CARC Bld, Room 238, Charlotte, NC 28223-0001, USA.
Chemosphere. 2005 Jan;58(1):19-31. doi: 10.1016/j.chemosphere.2004.08.090.
Physico-chemical interactions among polymer molecules in aqueous solution and clay mineralogical/textural characteristics influence the sorption of polymer molecules on clay barrier minerals. Amendment of potentially unstable barrier clays with aqueous polymers can improve barrier material resistance to environmental stresses during service. In this research, the ability of molecular coils of polyacrylamide (PAM) to overlap in solution and to enter interlayer space in Na-montmorillonite (specific surface=31.82+/-0.22 m2 g(-1)) and kaolinite (specific surface=18+/-2 m2 g(-1)) were analyzed theoretically and experimentally, using solution viscosity measurements, and X-ray diffractometry. Experimental data on two theoretical indices: relative size ratio (RSR); and molecular availability (Ma) that are formulated to scale polymer molecular sorption on clay interlayer, indicate that the sorption of PAM A (Mw=4000000) and PAM B (Mw=7000000) does not produce any significant change in the d-spacing of both clay minerals. Although the negative Ma values of -3.51 g l(-1) for PAM A and -3.88 g l(-1) for PAM B indicate high levels of entanglement of polymer molecular coils in solution, sorption data confirm that the entangled coils are still able to sorb onto Na-montmorillonite highly and kaolinite to a lesser extent.
聚合物分子在水溶液中的物理化学相互作用以及粘土的矿物学/质地特性会影响聚合物分子在粘土屏障矿物上的吸附。用水性聚合物对潜在不稳定的屏障粘土进行改良，可以提高屏障材料在使用过程中对环境应力的抗性。在本研究中，通过溶液粘度测量和X射线衍射法，对聚丙烯酰胺（PAM）分子线圈在溶液中重叠以及进入钠蒙脱石（比表面积 = 31.82±0.22 m² g⁻¹）和高岭石（比表面积 = 18±2 m² g⁻¹）层间空间的能力进行了理论和实验分析。关于两个理论指标的实验数据：相对尺寸比（RSR）；以及为衡量聚合物分子在粘土层间吸附而制定的分子可及性（Ma），表明PAM A（Mw = 4000000）和PAM B（Mw = 7000000）的吸附并未使两种粘土矿物的d间距产生任何显著变化。尽管PAM A的Ma值为 -3.51 g l⁻¹，PAM B的Ma值为 -3.88 g l⁻¹，表明聚合物分子线圈在溶液中高度缠结，但吸附数据证实，缠结的线圈仍能够大量吸附到钠蒙脱石上，而在高岭石上的吸附程度较小。
