Toughening Nanoparticle Films via Polymer Infiltration and Confinement
Toughening Nanoparticle Films via Polymer Infiltration and Confinement
复制标题
通过聚合物渗透和限制增韧纳米颗粒薄膜
DOI：
10.1021/acsami.8b15027
复制
发表时间：
2018
影响因子：
9.5
通讯作者：
Turner, Kevin T.
中科院分区：
文献类型：
--
作者：
Jiang, Yijie;Hor, Jyo Lyn;Lee, Daeyeon;Turner, Kevin T.
无序纳米颗粒膜作为涂层和膜具有重要的技术应用。不幸的是，迄今为止，它们的使用受到差的机械性能，特别是低断裂韧性的限制，这通常导致脆性失效和开裂。我们证明，通过聚苯乙烯渗透到薄膜中，TiO 2纳米颗粒薄膜的断裂韧性可以提高近一个数量级。不同聚合物体积分数的薄膜的断裂性能，其特征在于通过纳米压痕柱分裂试验。即使在聚合物体积分数较低的情况下也观察到显着的增韧，这使得纳米颗粒填料能够增韧，同时保持孔隙率。此外，较高分子量的聚合物在低聚合物体积分数下导致更大的增韧。在聚合物渗透的纳米颗粒膜中观察到的韧性增强可以归因于多种因素，包括颗粒间接触的面积和强度的增加、失效期间裂纹的偏转和钝化以及约束诱导的纳米颗粒的聚合物桥接。我们的研究结果表明，聚合物渗透是一种非常有效的途径，用于增强纳米颗粒填料，同时保持多孔性。
Disordered nanoparticle films have significant technological applications as coatings and membranes. Unfortunately, their use to date has been limited by poor mechanical properties, notably low fracture toughness, which often results in brittle failure and cracking. We demonstrate that the fracture toughness of TiO2nanoparticle films can be increased by nearly an order of magnitude through infiltration of polystyrene into the film. The fracture properties of films with various polymer volume fractions were characterized via nanoindentation pillar-splitting tests. Significant toughening is observed even at low volume fractions of polymer, which allows the nanoparticle packing to be toughened while retaining porosity. Moreover, higher-molecular-weight polymers lead to greater toughening at low polymer volume fractions. The toughness enhancement observed in polymer-infiltrated nanoparticle films may be attributed to multiple factors, including an increase in the area and strength of interparticle contacts, deflection and blunting of cracks during failure, and confinement-induced polymer bridging of nanoparticles. Our findings demonstrate that polymer infiltration is a highly effective route for reinforcing nanoparticle packings while retaining porosity.