Park Soo-Jin, Seo Dong-Il, Nah Changwoon
Advanced Materials Division, Korea Research Institute of Chemical Technology, P.O. Box 107, Yusong, Taejon, 305-600, Korea.
J Colloid Interface Sci. 2002 Jul 1;251(1):225-9. doi: 10.1006/jcis.2002.8336.
In this work, red mud (RM) was chemically modified by 0.1, 1, and 5 M H(3)PO(4) solution to prepare epoxy/RM nanocomposites. The effect of chemical treatment on a RM surface was studied in terms of pH, acid-base values, N(2)/77 K gas adsorption, equilibrium spreading pressure (pi(e)), and surface free energy. The mechanical interfacial properties of epoxy/RM nanocomposites was measured in the context of critical stress intensity factor (K(IC)) and critical strain energy release rate (G(IC)) measurements. From the experimental results, the acidic surface treatment led to a modification of the RM surface properties, such as the surface acid values, porosity, specific surface area, pi(e), and London dispersive component (gamma(S)(L)) of surface free energy of the treated RM as an increase of the treatment concentration. In the fracture toughness (K(IC) and G(IC)) measurements, the mechanical interfacial properties of epoxy/treated RM nanocomposites were intimately correlated with the improvement of interfacial adhesion between the RM surface and a matrix and the increase of gamma(S)(L) of surface free energy of the RM due to the development of S(BET) or porosity of RM surfaces.
在本研究中，采用0.1 M、1 M和5 M的H₃PO₄溶液对赤泥（RM）进行化学改性，以制备环氧/RM纳米复合材料。从pH值、酸碱值、N₂/77 K气体吸附、平衡铺展压力（πe）和表面自由能等方面研究了化学处理对RM表面的影响。在临界应力强度因子（KIC）和临界应变能释放率（GIC）测量的背景下，测定了环氧/RM纳米复合材料的机械界面性能。实验结果表明，酸性表面处理导致RM表面性能发生改变，如表面酸值、孔隙率、比表面积、πe以及处理后RM表面自由能的伦敦色散分量（γS(L)）随处理浓度的增加而增加。在断裂韧性（KIC和GIC）测量中，环氧/处理后RM纳米复合材料的机械界面性能与RM表面和基体之间界面附着力的提高以及由于RM表面S(BET)或孔隙率的增加导致的RM表面自由能γS(L)的增加密切相关。
