Nicoara Adrian Ionut, Badanoiu Alina Ioana
Department of Science and Engineering of Oxide Materials and Nanomaterials, Faculty of Applied Chemistry and Materials Science, University Politehnica of Bucharest, 1-7 Gheorghe Polizu Street, 011061 Bucharest, Romania.
Academy of Romanian Scientists, 54 Independentei, 050094 Bucharest, Romania.
Materials (Basel). 2021 Dec 25;15(1):147. doi: 10.3390/ma15010147.
The main objective of this study is the synthesis and characterization of low cost alkali-activated inorganic polymers based on waste glass (G-AAIPs) using a mixture of NaOH and Ca(OH) as alkali activators, in order to improve their hydrolytic stability. This paper also presents detailed information about the influence of composition determined by X Ray Diffraction (XRD), microstructure determined by Scanning Electronic Microscopy (SEM) and processing parameters on the main properties of G-AAIP pastes. The main factors analyzed were the glass fineness and the composition of the alkaline activators. The influence on intumescent behavior was also studied by heat treating of specimens at 600 °C and 800 °C. The use of Ca(OH) in the composition of the alkaline activator determines the increase of the hydrolytic stability (evaluated by underwater evolution index) of the G-AAIP materials compared to those obtained by NaOH activation. In this case, along with sodium silicate hydrates, calcium silicates hydrates (C-S-H), with good stability in a humid environment, were also formed in the hardened pastes. The highest intumescence and an improvement of hydrolytic stability (evaluated by underwater evolution index and mass loss) was achieved for the waste glass powder activated with a solution containing 70% NaOH and 30% Ca(OH). The increase of the waste glass fineness and initial curing temperature of G-AAIPs have a positive effect on the intumescence of resulted materials but have a reduced influence on their mechanical properties and hydrolytic stability.
本研究的主要目的是使用氢氧化钠和氢氧化钙的混合物作为碱激发剂，合成并表征基于废玻璃的低成本碱激发无机聚合物（G-AAIPs），以提高其水解稳定性。本文还详细介绍了通过X射线衍射（XRD）测定的组成、通过扫描电子显微镜（SEM）测定的微观结构以及加工参数对G-AAIP浆料主要性能的影响。分析的主要因素是玻璃细度和碱性激发剂的组成。还通过在600℃和800℃对试样进行热处理，研究了对膨胀行为的影响。与通过氢氧化钠活化获得的材料相比，在碱性激发剂组成中使用氢氧化钙可提高G-AAIP材料的水解稳定性（通过水下析出指数评估）。在这种情况下，除了硅酸钠水合物外，在硬化浆料中还形成了在潮湿环境中具有良好稳定性的硅酸钙水合物（C-S-H）。用含有70%氢氧化钠和30%氢氧化钙的溶液活化的废玻璃粉实现了最高的膨胀率和水解稳定性的提高（通过水下析出指数和质量损失评估）。G-AAIPs的废玻璃细度和初始养护温度的增加对所得材料的膨胀有积极影响，但对其机械性能和水解稳定性的影响较小。
