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借助石英晶体微量天平和耗散监测(quarts crystal microbalance and dissipation monitoring,QCM-D)技术,用模拟表面研究了单独及同时使用聚合氯化铝(PAC)和两性聚丙烯酰胺(PAM)在纸浆中的吸附行为。由于代表吸附质量值的QCM-D频率(Δf)数据和能量耗散值(ΔD)的变化,与在QCM-D仪器表面吸附的物质粘弹性质,以及PAM和相关化合物在模拟表面的吸附行为有对应关系,因此通过QCM-D数据的Δf和ΔD值评估了被吸附的PAM分子的粘弹性质和构象变化。得到的结果表明,模拟表面吸附的PAM分子构象变化既取决于模拟表面的物质,也取决于所添加的PAM。在pH=7～8附近,吸附的PAM量达到了最大值,这与PAM的等弹性点一致。Δf和ΔD值揭示,PAM分子在这一pH范围具有扩展的构象。虽然取得详细和精确的QCM-D数据关系比较困难,但是该研究的模拟实验提供了大量PAM分子在造纸过程中纸浆纤维上吸附行为的信息。
The effects of single and simultaneous polyaluminum chloride (PAC) and amphoteric polyacrylamide (PAM) on pulp were investigated using simulated surfaces using quarts crystal microbalance and dissipation monitoring (QCM-D) The adsorption behavior. Due to the change of the QCM-D frequency (Δf) data and the energy dissipation value (ΔD), which represents the adsorption mass value, the viscoelastic properties of the material adsorbed on the QCM-D instrument surface and the adsorption behavior of PAM and related compounds on the simulated surface Therefore, the viscoelastic properties and conformational changes of the adsorbed PAM molecules were evaluated by Δf and ΔD values of the QCM-D data. The results obtained show that the conformational change of the PAM molecule adsorbed on the simulated surface depends on both the material of the simulated surface and the added PAM. Near pH = 7 ~ 8, the amount of adsorbed PAM reaches the maximum, which is consistent with the equal elastic point of PAM. The Δf and ΔD values reveal that the PAM molecule has an extended conformation in this pH range. Although it is difficult to obtain detailed and accurate QCM-D data, the simulation experiments in this study provided information on the adsorption behavior of a large number of PAM molecules on pulp fibers during papermaking.