摩尔比n(SiO2)/n(Al2O3)对发泡地质聚合物物理性能和微观结构的影响
Effect of n(SiO2)/n(Al2 O3) molar ratio on physical properties and microstructure of foamed geopolymer
-
摘要: 使用固硫灰(CFAS)、硅灰(SF)、水玻璃(WG)、NaOH和H2O2 制备发泡地质聚合物,用 硅灰来调节地质聚合物的摩尔比 n(SiO2)/n(Al2O3),测试新拌浆体的发泡倍数、发泡速率。 对 硬化后浆体进行强度和表观密度等性能的测试,结合Image-ProPlus软件分析孔径分布;通过X 射线衍射(XRD)、傅里叶红外光谱(FTIR)、扫描电镜(SEM)等手段分析发泡地质聚合物的 微观结构。 结果表明:在试验条件下,摩尔比 n(SiO2)/n(Al2O3)的提高加速了水化反应速 率,适宜的摩尔比使得发泡时间提前;红外光谱波数的迁移表明,碱激发后 Si—O 与 Al—O 键发生重排,合适的摩尔比对地质聚合物的重排反应是有利的,提高了聚合度;XRD图谱显示有 沸石等产物生成;当摩尔比 n(SiO2)/n(Al2O3)为2*79 时,试件28d 强度及表观密度分别为 1*06MPa和231g/L,此时试件微观结构具有良好的致密性。Abstract: Thefoaminggeopolymerwaspreparedbyexperimentsusingcirculatingfluidizedbedcom⁃ bustionflyash(CFAS),silicafume(SF),waterglass(WG),NaOHandH2O2,andsilicafumewas usedtoadjustthen(SiO2)/n(Al2O3)molarratioofthegeopolymers,thefreshpastewastestedforfoa⁃ mingexpansionfactorandfoamingrate*Thestrengthandapparentdensityofthepasteweretestedafter hardening*ThispaperanalyzedtheporesizedistributionbyImage-ProPlussoftware,andthemicro⁃ structuresofthefoamedgeopolymerswereanalyzedbyX-raydiffraction(XRD),Fouriertransformin⁃ fraredspectroscopy(FTIR) andscanningelectronmicroscope(SEM)*Theresultsshowthatthein⁃ creaseofthemolarratioofn(SiO2)/n(Al2O3)acceleratesthehydrationreactionrate,andtheappro⁃ priateratiomakesthefoamingtimeadvance*ThewavelengthshiftintheFTIRindicatesthattheSi—OandAl—Obondsrearrangeafteralkali-excited,andtheappropriateratioisfavorablefortherearrange⁃ mentreactionofthegeopolymerandincreasesthedegreeofpolymerization*Theproductsuchaszeolite wasformedfoundbyXRDpattens*Whenthen(SiO2)/n(Al2O3)molarratiois2*79,thestrengthand apparentdensityofthespecimenin28dare1*06MPaand231g/L,andthemicrostructureofthe specimenhasgoodcompactness*