氮气吸附法研究偏高岭土基地聚合物孔结构特征

发布时间：2018-11-07 20:28

【摘要】：为揭示偏高岭土基地聚合物的微观孔结构特征并探索介孔地聚合物制备和微孔结构调控途径,采用氮气吸附法研究了偏高岭土基地聚合物的吸附/脱附等温曲线和微观孔结构特征(包括总孔体积、比表面积、孔形状和孔径分布等),并讨论了水玻璃模数和水用量对地聚合物孔结构的影响。结果表明:偏高岭土基地聚合物吸附/脱附等温曲线为IV型,迟滞回线为H1和H3混合型;总孔体积为0.141 8~0.313 6 cm~3/g,比表面积为28.87~53.25 m~2/g,孔径为2~92 nm,其中孔径为2~50 nm的介孔分别占总孔体积和比表面积的97.82%和98.87%;地聚合物中的孔以两端开放的圆柱形孔、平行板狭缝孔为主,同时存在少量一端封闭的圆柱形孔、平行板狭缝孔或墨水瓶孔。调整水玻璃模数和水用量均可在一定范围内调控偏高岭土基地聚合物孔结构。水玻璃模数由1.2增至1.8时,其总孔体积由0.225 3 cm~3/g降至0.141 8 cm~3/g,最可几孔径在13.91~19.56 nm范围;水用量由15.5增至18.5时,其总孔体积从0.221 9 cm~3/g逐渐增至0.313 6 cm~3/g,孔径分布先由水用量为15.5的单峰分布变为双峰分布;水用量增至18.5时,孔径分布显著宽化,最可几孔径消失。水用量比水玻璃模数对偏高岭土基地聚合物孔结构具有更强的调控效应。
[Abstract]:In order to reveal the micropore structure characteristics of metakaolin base polymers and explore the preparation of mesoporous geopolymers and the regulation of micropore structure, The adsorption / desorption isotherm curves and micropore structure (including total pore volume, specific surface area, pore shape and pore size distribution) of metakaolin base polymers were studied by nitrogen adsorption method. The effects of water glass modulus and water content on the pore structure of geopolymers were discussed. The results show that the adsorption / desorption isotherm curve of metakaolin base polymer is IV type, and the hysteresis loop is H _ 1 and H _ 3 mixed type. The specific surface area of the total pore volume is 0.141 ~ 0.313 6 cm~3/g, and the specific surface area is 28.87 ~ 53.25 mm / g, and the pore diameter is 2 ~ 92 nm,. The mesopore with a pore diameter of 2 ~ 50 nm accounts for 97.82% of the total pore volume and 98.87% of the specific surface area, respectively. The pores in the geopolymers are mainly cylindrical holes with open ends and narrow slit holes in parallel plates. At the same time there are a few closed cylindrical holes parallel plate slit holes or ink bottle holes at the same time. The pore structure of metakaolin base can be controlled by adjusting the modulus of sodium silicate and the amount of water. When the modulus of sodium silicate increased from 1. 2 to 1. 8, the total pore volume decreased from 0.225 3 cm~3/g to 0.141 8 cm~3/g,. The most suitable pore size was in the range of 13.91 nm and 19.56 nm. When the amount of water increased from 15.5 to 18.5, the total pore volume increased from 0.221 cm~3/g to 0.313 6 cm~3/g,. The pore size distribution changed from a single peak distribution to a bimodal distribution. When the amount of water increased to 18.5, the pore size distribution became wider and the most effective pore size disappeared. The water content has a stronger regulation effect on the pore structure of metakaolin base than the water glass modulus.
【作者单位】：南京工业大学材料科学与工程学院;
【分类号】：TQ177

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