Wang Zhixin, Rong Xian, Zhao Lei, Xing Xueyang, Ma Hui
School of Civil and Transportation Engineering, Hebei University of Technology, Tianjin 300401, China.
School of Civil Engineering, Binzhou University, Binzhou 256600, China.
ACS Omega. 2022 Mar 30;7(14):11988-11994. doi: 10.1021/acsomega.2c00170. eCollection 2022 Apr 12.
Geopolymer is a kind of material with a better ability of high-temperature and corrosion resistance. Poor adhesion could easily lead to problems such as coating cracks, peeling at an early stage, and inability to work with the substrate. The adhesion depends on many factors such as chemical composition of the raw materials, the formulation of the geopolymer, the type of substrate, surface roughness of the substrate, etc. The higher the Si/Al ratio, the greater the shear strength of the coating. This is because geopolymers synthesized with different Si/Al ratios have different phases in the geopolymer binder. Each study uses different multi-parameter combinations selected by itself, which is not uniform and has no universal applicability. As the parameter Ra is determined by the profile centerlines of the substrate surface, it is difficult to get an appropriate value of Ra to represent the roughness of the substrate surface. The parameter-relative area, determined by area scale fractal analysis, can effectively characterize the surface roughness, predict the texture component of bond strength, and establish a connection between which and the bonding performance of the geopolymer coating at a high level of confidence. The bonding strength reduces with the decrease in the value of the relative area. The magnitude of scale employed should be seriously determined when characterizing the surface roughness.
地质聚合物是一种具有较好耐高温和耐腐蚀能力的材料。附着力差容易导致涂层出现裂纹、早期剥落以及无法与基材协同工作等问题。附着力取决于许多因素，如原材料的化学成分、地质聚合物的配方、基材的类型、基材的表面粗糙度等。硅铝比越高，涂层的剪切强度越大。这是因为用不同硅铝比合成的地质聚合物在地质聚合物粘结剂中有不同的相。每项研究都自行选择不同的多参数组合，这不统一且没有普遍适用性。由于参数Ra是由基材表面的轮廓中心线确定的，很难得到一个合适的Ra值来表示基材表面的粗糙度。通过面积尺度分形分析确定的参数——相对面积，能够有效地表征表面粗糙度，预测粘结强度的纹理成分，并在高置信水平下建立其与地质聚合物涂层粘结性能之间的联系。粘结强度随着相对面积值的减小而降低。在表征表面粗糙度时，应认真确定所采用的尺度大小。
