聚合电解质在纸浆纤维表面多层沉积的研究

根据层层沉积技术原理,研究了在带负电荷的纸浆纤维表面构筑多层沉积膜过程中Zeta电位的变化和影响纤维吸附聚合电解质的因素。结果表明:依靠阴离子和阳离子之间的静电引力作用,实现了纸浆纤维表面聚合电解质的多层沉积,当聚合电解质吸附量达到一定数值后,纤维表面的电性发生反转。在聚合电解质的多层沉积过程中,纸浆Zeta电位的变化,可以作为沉积过程的监测指标。沉积体系的离子强度和纸浆打浆度是影响聚合电解质吸附量的重要因素。

Layer-by-Layer Deposition of Polyelectrolytes on the Surface of Pulp Fibers

The layer-by-layer deposition technique is one of the molecule self-assembly systems which has been developed as a fabrication tool in the past decade.The technique can be employed to modify pulp fiber in order to improve the properties of paper or other products.The change of zeta potential of pulp slurry during the polyelectrolytes multilayer built up and the factors affecting the adsorption efficiency of polyelectrolytes on pulp were studied.Cationic polyvinylamine(PVAm) and anionic polyacrylic acid(PAA) were alternately absorbed on negative fiber surface driven by electrostatic attraction and polyelectrolytes multilayer film on fiber was constructed.The fiber surface charge reversed due to the adsorption of polyelectrolytes during multilayer deposition.The change of zeta potential of pulp slurry could be used as indication in the process of layerby-layer deposition.The ion intensity and pulp freeness in the deposition system were important factors that affected the amount of polyelectrolytes adsorbed on pulp fiber surface.