Instituto de Tecnología Celulósica, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2654, Santa Fe, Argentina.
Instituto de Tecnología Celulósica, Facultad de Ingeniería Química, Universidad Nacional del Litoral, Santiago del Estero 2654, Santa Fe, Argentina.
Carbohydr Polym. 2015 Feb 13;116:131-9. doi: 10.1016/j.carbpol.2014.04.081. Epub 2014 Apr 28.
In this work, polyelectrolyte complexes (PECs) were formed by adding polyacrylic acid (PAA) or 4-O-methylglucuronoxylan (Xyl) on poly(allylamine hydrochloride) (PAH) solutions, at different ionic strength and neutral pH. Turbidity curves, charge densities of the cationic complexes determined by polyelectrolyte titration method, and z-potential values showed clear differences between both complexes. Stirring favourably reverses the effects of sedimentation of Xyl/PAH complexes, as demonstrated by colloidal stability tests. Adsorption studies on silica surfaces, performed by Quartz Crystal Microbalance with Dissipation (QCM-D) showed that PAA/PAH adsorbed complexes layers were rigid, while the corresponding Xyl/PAH layers were viscoelastic. Despite the different conformations, both complexes were adsorbed as spherical particles, as observed by Atomic Force Microscopy (AFM). Adsorption isotherms performed on fibre suspensions showed that the ionic strength of the liquid medium determines the amount of PEC retained. Finally, it was found that the papermaking properties were significantly increased due to the addition of these PECs.
在这项工作中，通过在聚（盐酸烯丙胺）（PAH）溶液中添加聚丙烯酸（PAA）或 4-O-甲基葡糖醛酸木聚糖（Xyl），在不同的离子强度和中性 pH 值下形成聚电解质复合物（PECs）。浊度曲线、聚电解质滴定法测定的阳离子复合物的电荷密度以及 zeta 电位值表明两种复合物之间存在明显差异。搅拌有利于通过胶体稳定性测试逆转 Xyl/PAH 复合物的沉降影响。通过石英晶体微天平耗散（QCM-D）在硅胶表面上进行的吸附研究表明，PAA/PAH 吸附的复合物层是刚性的，而相应的 Xyl/PAH 层是粘弹性的。尽管存在不同的构象，但通过原子力显微镜（AFM）观察到两种复合物都以球形颗粒的形式吸附。在纤维悬浮液上进行的吸附等温线表明，液体介质的离子强度决定了保留的 PEC 量。最后，发现由于添加了这些 PEC，造纸性能显著提高。
