快速成形中PAN基碳纤维/HA力学性能模拟研究

在人工骨支架增材制造过程中，为了制造出具有不同力学性能的人造骨支架适合不同病患，提出利用分子动力学(Molecular dynamics，MD)模拟方法，研究所用基体复合材料(聚丙烯腈(Poly acrylonitrile，PAN)基碳纤维和羟基磷灰石(Hydroxyapatite, HA))表面之间的相互作用及力学性能。分别在原子模拟凝聚相优化分子势能力场(Condensed-phase optimized molecular potentials for atomistic simulation studies，COMPASS)和通用力场(Universal force field，UFF)下，对比计算HA和PAN基碳纤维/HA的力学性能，并比较其弹性模量和泊松比，证明羟基磷灰石是一种各向异性材料，并给出羟基磷灰石中添加PAN基碳纤维可以有效改善其力学性能。针对沿不同剪切方向上的PAN基碳纤维/羟基磷灰石进行动力学计算，表明在不同的力场下，羟基磷灰石均是在沿(110)剪切面上与聚丙烯腈纤维产生的结合能值较大。结合径向分布函数分析，揭示了PAN/HA复合材料主要是通过PAN中的N原子与HA表面发生强作用，从而提高PAN/HA基体力学性能。

Molecular Dynamics Simulation to Mechanical Properties of PAN/HA in Rapid Prototyping

During the artificial bone scaffold additive manufacturing process, in order to fabricating suitable artificial bone scaffold models with different mechanical properties for various patient, the molecular dynamics methodology can be proposed to study the mechanical properties of those bone scaffold composite material. Here, the mechanical properties and interface interaction values between the poly acrylonitrile (PAN) based carbon fibers and the hydroxyapatite crystal plane are calculated by using molecular dynamics (MD) simulation methods. The Young’s modulus and Poisson ratio are compared to prove that Hydroxyapatite is a kind of anisotropic materials. Add PAN-based carbon fiber to hydroxyapatite can effectively improve its mechanical properties. Along the (100), (110) and (111) three different crystallographic molecular dynamics simulations are employed to study the interaction of PAN/HA. The results show that the binding energy of PAN on HA (110) is the most high level under the condensed-phase optimized molecular potentials for atomistic simulation studies (COMPASS) or universal force field. Combined with the radial distribution function analysis, it reveals that the strong mechanical properties of PAN/HA composite materials is mainly derived from the strong interaction between the N atoms of PAN and Hydroxyapatite crystallographic plane.