Guo Lin, Du Mu, Li Jiaqian, Li Wei, Yang Mingyang, Xin Gongming
Shenzhen Research Institute of Shandong University, Shenzhen 518000, China.
School of Energy and Power Engineering, Shandong University, Jinan 250100, China.
Gels. 2025 Jun 19;11(6):471. doi: 10.3390/gels11060471.
Despite their outstanding thermal insulation and ultralight structure, silica aerogels suffer from inherent mechanical fragility, making the investigation of their mechanical behavior crucial for expanding their practical utility in advanced applications. To enhance their mechanical performance, this study introduces a dual-phase reinforcement strategy by anisotropically incorporating carbon nanotubes (CNTs) and graphene oxide (GO) sheets into the aerogel matrix. Using molecular dynamic simulations, we systematically investigate the tensile behavior and pore structure evolution of these hetero-structured composites. The results reveal a non-monotonic dependence of tensile strength on loading ratio, distinguishing three strain-dependent reinforcement regimes. High loading content (11.1%) significantly improves strength under low strain (0-26%), whereas low loading levels (1.8%) are more effective at preserving structural integrity under large strain (44-50%). Moderate loading (5.1%) yields balanced performance in intermediate regimes. While increasing carbon content reduces initial pore size by partially filling the framework, tensile deformation leads to interfacial debonding and the formation of larger pores due to CNT-GO hybrid structure interactions. This work elucidates a dual reinforcement mechanism-physical pore confinement and interfacial coupling-highlighting the critical role of nanostructure geometry in tuning strain-specific mechanical responses. The findings provide mechanistic insights into anisotropic nanocomposite behavior and offer guidance for designing robust porous materials for structural and functional applications.
尽管二氧化硅气凝胶具有出色的隔热性能和超轻结构，但它们存在固有的机械脆性，因此研究其力学行为对于扩大其在先进应用中的实际用途至关重要。为了提高其力学性能，本研究引入了一种双相增强策略，即通过将碳纳米管（CNT）和氧化石墨烯（GO）片各向异性地掺入气凝胶基质中。利用分子动力学模拟，我们系统地研究了这些异质结构复合材料的拉伸行为和孔隙结构演变。结果揭示了拉伸强度对加载比的非单调依赖性，区分了三种应变相关的增强机制。高加载量（11.1%）在低应变（0-26%）下显著提高强度，而低加载量（1.8%）在大应变（44-50%）下更有效地保持结构完整性。中等加载量（5.1%）在中间区域产生平衡的性能。虽然增加碳含量会通过部分填充骨架来减小初始孔径，但拉伸变形会由于CNT-GO混合结构相互作用导致界面脱粘并形成更大的孔隙。这项工作阐明了一种双增强机制——物理孔隙限制和界面耦合——突出了纳米结构几何形状在调节特定应变力学响应中的关键作用。这些发现为各向异性纳米复合材料的行为提供了机理见解，并为设计用于结构和功能应用的坚固多孔材料提供了指导。
