Estudio de los cambios de la composición química de un ionómero vítreo mediante la técnica de PIXE

ABSTRACT In the present work, the effect of commonly consumed beverages such as coffee, mate, tea and mineral water on the surface chemical composition of a commercial glass ionomer is studied. Ionomer samples were prepared according to the manufacturer; they were placed within infusions and stationed on culture stove at 36 ° C in the range of 21 hours to 33 days. The evolution of the chemical composition at different storage times was studied by Proton Induced X-Ray Emission (PIXE) technique. In all media except mineral water, to long times, the loss of Al, Si and Na was determined, suggesting the partial dissolution of Na aluminumsilicate. The concentration profile of Al and Si were different in every way, but the ratio Al: Si remained close to unity in all cases. The F was released associated with Na in mineral water, while in the rest of the beverages its concentration profile infers the formation of fluorinated compounds of Ca and La. Simultaneously, the adsorption of Mn, Mg and Fe to the glass ionomer surface was observed, not previously reported in the literature.

摘要 本研究探讨了日常饮用的咖啡、马黛茶（mate）、茶与矿泉水等饮品对商用玻璃离子体（glass ionomer）表面化学组成的影响。实验依照厂商说明书制备玻璃离子体样品，将其浸没于各饮品浸液中，置于36℃恒温培养箱内，浸泡时长覆盖21小时至33天。采用质子诱导X射线发射（Proton Induced X-Ray Emission, PIXE）技术，对不同浸泡时段下样品表面化学组成的演化过程进行了表征分析。结果表明，除矿泉水外的所有浸泡介质中，随着浸泡时间延长，可检测到铝（Al）、硅（Si）与钠（Na）的流失，提示铝硅酸钠发生了部分溶解。铝与硅的浓度分布特征存在显著差异，但所有实验组的铝硅比均接近1。在矿泉水中，氟（F）与钠同步释放；而在其余饮品中，氟的浓度分布特征暗示体系中生成了钙（Ca）与镧（La）的氟化物。同时本研究还观察到锰（Mn）、镁（Mg）与铁（Fe）在玻璃离子体表面的吸附现象，该现象此前未见文献报道。