HA-CS复合物界面作用与力学性能模拟

Simulation study on interfacial interactions and mechanical properties of hydroxyapatite-chitosan composite materials

羟基磷灰石(hydroxyapatite,HA)-壳聚糖(chitosan,CS)复合材料在很大程度上可实现HA与CS两者优势互补,有望成为一种理想的骨替换材料.本研究采用分子动力学(molecular dynamics,MD)方法研究HA的3个晶面(001)、(100)和(110)分别与CS复合后混合体系的相互作用,分析HA这3个晶面分别与CS复合后的力学性能.结果表明,3个晶面所对应结合能大小顺序为HA(110)>HA(100)>HA(001).其中,HA(110)面与壳聚糖复合后的力学性能最佳,复合结构的剪切模量由29.2 GPa升至42.4GPa;x、y、z方向上杨氏模量分别由92.0、62.7和57.0 GPa升至95.6、102.2和97.5 GPa,3个方向上的杨氏模量差量最大值由46.7%降为7.0%,由此克服了因材料各向异性导致的材料缺陷.

Hydroxyapatite-chitosan（HA-CS） composite could complement the advantages of the two materials and become an ideal bone replacement material. In this paper,by using the molecular dynamics（MD） method,we study the interactions between CS and the three lattice planes of HA（（001）,（100） and（110））,respectively.The mechanical properties in the composites are also studied and analyzed. The results show that the highest binding energy appears between HA（110） and CS,whereas the lowest is between HA（001） and CS. On the other hand,the combination between HA（110） and CS has the best mechanical properties. The shear modulus of the composite material increases from 29. 2 GPa to 42. 4 GPa. Accordingly,the Young＇s modulus rises from 92. 0,62. 7 and 57. 0 GPa to 95. 6,102. 2 and 97. 5 GPa,corresponding to the three Young＇s modulus values in x,y and z directions,respectively. The maximum difference of Young＇s moduli among the three directions are reduced from 46. 7% to 7. 0%,indicating that the material defects resulting from anisotropy could be overcome.