High performance metakaolinite based cementitious materials were prepared with metakaolinite as main component, and the different modules of Na and Na-K silicate solutions as diagenetic agent. The results show that th...High performance metakaolinite based cementitious materials were prepared with metakaolinite as main component, and the different modules of Na and Na-K silicate solutions as diagenetic agent. The results show that the mechanical properties are affected by different silicate solutions, compressive strengths of pastes hydrated for 3 d and 28 d with Na-K silicate solution （The modulus is 1） are about 43.68 and 78.52 MPa respectively. By analyzing the mechanical properties of Metakaolinite based cementitious materials, the diagenetic effect of lower module is better than higher module, and Na-K silicate solution is better than Na silicate solution. The structure of the Na and Na-K silicate solutions is studied with IR and 29Si NMR, the reason of the lower module and Na-K silicate solution improving the mechanical properties is that the low module silicate solution has lower polymeric degree of silicon dioxide, and the higher polymeric degree of silicon oxide tetrahedron（Q^4） in Na-K silicate solution is less than Na silicate solution.展开更多
Composites of montmorillonite clay and sawdust were prepared with the desired result being having new materials which burn longer than unmodified sawdust. The three forms of clay used for preparation of composites wer...Composites of montmorillonite clay and sawdust were prepared with the desired result being having new materials which burn longer than unmodified sawdust. The three forms of clay used for preparation of composites were unmodified montmorillonite, mono-ionic montmorillonite and organically modified montmorillonite. Montmorillonite clay was converted to mono-ionic clay by ion exchange with sodium using a sodium chloride solution. The mono-ionic clay was organically modified with an organic surfactant, methyl triphenyl phosphonium bromide. Nanocomposites were then prepared by combining the modified and raw forms of the clay with sawdust. The solution blending method was used to make the nanocomposites. The samples were analysed using thermogravimetric analysis and cone calorimetry. The studies showed that the nanocomposite which was made from sawdust and 1% organically modified clay had the most improved results in terms of burning time and thermal stability, as well as giving a calorific value closest to unmodified sawdust and the least amount of residue.展开更多
基金Supported by the National 863 Plan Project of China(2003AA332020)National Natural Science Foundation of China(50474002)Key Project of Ministry of Education of China(104231)
文摘High performance metakaolinite based cementitious materials were prepared with metakaolinite as main component, and the different modules of Na and Na-K silicate solutions as diagenetic agent. The results show that the mechanical properties are affected by different silicate solutions, compressive strengths of pastes hydrated for 3 d and 28 d with Na-K silicate solution （The modulus is 1） are about 43.68 and 78.52 MPa respectively. By analyzing the mechanical properties of Metakaolinite based cementitious materials, the diagenetic effect of lower module is better than higher module, and Na-K silicate solution is better than Na silicate solution. The structure of the Na and Na-K silicate solutions is studied with IR and 29Si NMR, the reason of the lower module and Na-K silicate solution improving the mechanical properties is that the low module silicate solution has lower polymeric degree of silicon dioxide, and the higher polymeric degree of silicon oxide tetrahedron（Q^4） in Na-K silicate solution is less than Na silicate solution.
文摘Composites of montmorillonite clay and sawdust were prepared with the desired result being having new materials which burn longer than unmodified sawdust. The three forms of clay used for preparation of composites were unmodified montmorillonite, mono-ionic montmorillonite and organically modified montmorillonite. Montmorillonite clay was converted to mono-ionic clay by ion exchange with sodium using a sodium chloride solution. The mono-ionic clay was organically modified with an organic surfactant, methyl triphenyl phosphonium bromide. Nanocomposites were then prepared by combining the modified and raw forms of the clay with sawdust. The solution blending method was used to make the nanocomposites. The samples were analysed using thermogravimetric analysis and cone calorimetry. The studies showed that the nanocomposite which was made from sawdust and 1% organically modified clay had the most improved results in terms of burning time and thermal stability, as well as giving a calorific value closest to unmodified sawdust and the least amount of residue.
