交联壳聚糖树脂对Ni(II)的吸附行为研究

研究了甲醛、环氧氯丙烷交联壳聚糖树脂(AECTS)对Ni(II)的吸附行为和吸附Ni(II)对树脂结构及性能的影响. 用FTIR, WAXD, TGA和DSC对吸附产物进行了结构表征, 并深入分析了AECTS与Ni(II)之间的作用机理. 结果表明: AECTS主要以配位形式吸附Ni(II); AECTS吸附Ni(II)后, 结晶度下降、总体上热稳定性变差; Ni(II)对AECTS的主链分解具有明显的催化功能, 而空气气氛中对AECTS在500 ℃附近的分解表现出火焰缓蚀作用. AECTS对Ni(II)的吸附行为符合Langmuir模型, 属于单分子层吸附, 所有吸附位对Ni(II)的作用近似相同; 与壳聚糖(CTS)比较, 造成AECTS对Ni(II)吸附量增大的主要原因是AECTS结晶度下降和孔隙率增加, 二者导致在交联处理前Ni(II)难于接近的吸附位点“活性”相对增大, 使其更容易与Ni(II)相结合; 不同介质对AECTS吸附Ni(II)的影响大小顺序为HCl＞CdCl₂＞MgCl₂＞NaCl, 前两者使吸附量减小, MgCl₂使吸附量稍有增加, NaCl对吸附量基本没有影响.     

Design and synthesis of self-healing polymers

Self-healing polymers represent a class of materials with built-in capability of rehabilitating damages. The topic has attracted increasingly more attention in the past few years. The on-going research activities clearly indicate that self-healing polymeric materials turn out to be a typical multi-disciplinary area concerning polymer chemistry, organic synthesis, polymer physics, theoretical and experimental mechanics, processing, composites manufacturing, interfacial engineering, etc. The present article briefly reviews the achievements of the groups worldwide, and particularly the work carried out in our own laboratory towards strength recovery for structural applications. To ensure sufficient coverage, thermoplastics and thermosetting polymers, extrinsic and intrinsic self-healing, autonomic and non-autonomic healing approaches are included. Innovative routes that correlate materials chemistry to full capacity restoration are discussed for further development from bioinspired toward biomimetic repair.