Kaolin-based geopolymers with various NaOH concentrations
Kaolin-based geopolymers with various NaOH concentrations
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DOI：
10.1007/s12613-013-0729-0
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发表时间：
2013-03-01
影响因子：
4.8
通讯作者：
Liew, Y. M.
中科院分区：
文献类型：
--
作者：
Heah, C. Y.;Kamarudin, H.;Liew, Y. M.
高岭土地质聚合物是通过用活化剂溶液（NaOH和硅酸钠溶液的混合物）碱活化高岭土来生产的。以6-14 mol/L的浓度制备NaOH溶液，并以Na 2SiO 3/NaOH质量比为0.24与硅酸钠溶液混合，以制备活化剂溶液。所用高岭土与活化剂溶液的质量比为0.80。本文旨在分析NaOH浓度对高岭土地质聚合物在80 ℃下1、2和3 d抗压强度的影响。高岭土地聚合物在水中稳定，强度测试结果表明，当NaOH浓度为12 mol/L时，高岭土结合剂具有足够的抗压强度。随着NaOH浓度的增加，SiO2/Na 2 O减小。X射线衍射（XRD）和傅里叶变换红外光谱（FTIR）分析表明，Na 2 O含量的增加促进了高岭土的溶解。然而，该含量过量不利于高岭土地质聚合物的强度发展。此外，在12 mol/L的样品中，有更多的地聚物凝胶形成。FTIR分析表明，样品的XRD图谱显示出较高的非晶含量和更多的地聚合物键合存在。
Kaolin geopolymers were produced by the alkali-activation of kaolin with an activator solution (a mixture of NaOH and sodium silicate solutions). The NaOH solution was prepared at a concentration of 6-14 mol/L and was mixed with the sodium silicate solution at a Na2SiO3/NaOH mass ratio of 0.24 to prepare an activator solution. The kaolin-to-activator solution mass ratio used was 0.80. This paper aimed to analyze the effect of NaOH concentration on the compressive strength of kaolin geopolymers at 80 degrees C for 1, 2, and 3 d. Kaolin geopolymers were stable in water, and strength results showed that the kaolin binder had adequate compressive strength with 12 mol/L of NaOH concentration. When the NaOH concentration increased, the SiO2/Na2O decreased. The increased Na2O content enhanced the dissolution of kaolin as shown in X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analyses. However, excess in this content was not beneficial for the strength development of kaolin geopolymers. In addition, there was the formation of more geopolymeric gel in 12 mol/L samples. The XRD pattern of the samples showed a higher amorphous content and a more geopolymer bonding existed as proved by FTIR analysis.