壳聚糖改性地聚合物的力学及吸附性能

采用壳聚糖增韧改性矿渣基地聚合物，研究了壳聚糖掺量对矿渣基地聚合物强度与弯曲韧性、吸附重金属离子性能的影响规律，采用FTIR、NMR、SEM及EDS等测试手段揭示了壳聚糖对矿渣基地聚合物的改性机制。结果表明，与空白样相比，壳聚糖掺量（与矿粉质量比）为2%的矿渣基地聚合物28天弯曲韧性系数提高497.22%，对Pb2+、Cr3+的吸附效率分别提高68.89%、81.45%。壳聚糖在分子层面（C—O—Si键的形成及SiO₄]聚合度的降低）及亚微观层面（三维互穿网络结构的形成）对矿渣基地聚合物进行增韧改性。壳聚糖自身较高的吸附性及低Ca/Si比C—S—H凝胶数量的增加，是矿渣基地聚合物吸附性能显著提升的关键。 

Mechanical and adsorption properties of geopolymer modified by chitosan

The chitosan is used to improve the toughness and the adsorption of heavy metal ions of slag based geopolymer. The effects of chitosan content on the strength, flexural toughness and the adsorption of heavy metal ions of slag based geopolymer were focused, and FTIR, NMR, SEM and EDS was employed to explore the modification mechanisms of chitosan on slag based geopolymer. The results show that the 28 days flexural toughness coefficient of the slag based geopolymer with addition of 2% chitosan increases by 497.22% and its adsorption efficiency of Pb2+ and Cr3+ increases by 68.89%, 81.45%, respectively, compared with the blank sample. The chitosan can modify microstructures of the slag based geopolymer both in the molecular level, which is the formation of the C-O-Si bond and the reduction of polymerization degree ofSiO₄], and in submicroscopic level, which is the formation of three-dimensional interpenetrating network structure of chitosan and slag based geopolymer. The high adsorption of chitosan and the increase of the C-S-H gel with low Ca/Si ratio are the main reason for markedly enhancement of the adsorption capacity of the slag based geopolymer.