School of Civil Engineering and Architecture, Wuhan Polytechnic University, Wuhan 430023, China.
Department of Civil & Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USA.
J Nanosci Nanotechnol. 2021 May 1;21(5):3123-3133. doi: 10.1166/jnn.2021.19282.
Foamed paste has attracted much attention because of its excellent thermal insulation performance and diverse applications in infrastructure projects. However, there are still some shortcomings hindering the further application of foamed paste, such as the low mechanical strength and the lack of effective methods to evaluate the properties of foaming bubbles. In this study, surface tension was used as the key parameter to characterize the properties of bubbles. A novel nanomaterial, graphene oxide was employed to enhance the mechanical strength of foamed paste, which was also effective in decreasing the surface tension of aqueous solution. A central composite design scheme was employed to evaluate the influence of three selected factors, surface tension, Sodium Phosphate/foaming reagents mass ratio, and graphene oxide/binder mass ratio, on the engineering properties of foamed paste. Additionally, mercury intrusion porosimetry and scanning electron microscope were employed to elucidate the structure of pores, X-ray diffraction and thermogravimetric analysis were employed to further analyze the hydration products at the microscopic scale. This study reveals that surface tension holds great potential in predicting the engineering properties or performances of foamed paste, and a new mechanism may be developed for explaining the influence of graphene oxide on the pore structure of cementitious materials by evaluating the surface tension of pore solution.
泡沫胶因其优异的保温性能和在基础设施项目中的广泛应用而备受关注。然而，泡沫胶仍存在一些缺点，限制了其进一步的应用，例如机械强度低和缺乏有效评估泡沫气泡性能的方法。在本研究中，表面张力被用作表征气泡性能的关键参数。一种新型纳米材料氧化石墨烯被用于增强泡沫胶的机械强度，同时也有效降低了水溶液的表面张力。采用中心复合设计方案评估了三个选定因素，即表面张力、磷酸钠/发泡剂质量比和氧化石墨烯/胶凝材料质量比，对泡沫胶工程性能的影响。此外，还采用压汞法和扫描电子显微镜研究了孔隙结构，采用 X 射线衍射和热重分析进一步从微观尺度分析了水化产物。本研究表明，表面张力在预测泡沫胶的工程性能或性能方面具有很大的潜力，通过评估孔隙溶液的表面张力，可能会开发出一种新的机制来解释氧化石墨烯对水泥基材料孔隙结构的影响。
