CS/APAM层层自组装增强再生纤维

Layer-by-layer self-assembly of CS/APAM on the surface of recycled fibers

采用层层自组装技术,在废旧瓦楞纸再生纤维表面沉积了阳离子壳聚糖(CS)/阴离子聚丙烯酰胺(APAM)复合膜。借助扫描电镜观察了复合膜形貌特征以表征自组装复合膜的形成,通过动电特性试验研究了复合膜形成的动力学特征,使用红外光谱分析了复合膜形成机理。同时还考察了层层自组装的实验因素对再生纤维力学性能的影响。结果表明,再生纤维表面吸附有聚电解质,随着沉积层数的增加,纤维电性发生变化,Zeta电位正负交织呈现。再生纤维力学性能试验显示,在适宜的条件下,当自组装外层为APAM时,再生纤维力学性能有很好的增强效果,经过4层自组装后,再生纤维抄成纸页的抗张指数提高了55.34%,而耐破强度增大了4倍。

Chitosan（CS）and anion polyacrylamide（APAM）have been used to build up polyelectrolyte multilayers on recycled fibers based on the technology of layer-by-layer self-assembly.Scanning electron microscopy （SEM）was introduced to observe the morphology of the CS/APAM multilayers,zeta potential analyzer was adopted to monitor the dynamic features of pulp slurry during the polyelectrolyte multilayers build up,and FT-IR technique was used to investigate the formation mechanism.It was shown that chitosan（CS）and anion polyacrylamide（APAM）were alternately absorbed on negative fiber surface driven by electrostatic attraction.The fiber surface charge reversed due to the absorption of chitosan（CS）and anion polyacrylamide（APAM）.The change of zeta potential of recycled fiber slurry can be believed as the indication of the process of layer-by-layer self-assembly.Strength measurements of the sheets including burst index and folding strength showed significant improvements ranging from 55to 400%,which depend on the type of polyelectrolyte in the outer layer.