Abstract

In this study, a pH-sensitive indicator solution for the colorimetric naked-eye detection of dissolved carbon dioxide at room temperature was developed with the aim of environmental monitoring. The indicator solution was produced by the polyvinyl alcohol-coated green synthesized iron oxide nanoparticles and the natural anthocyanin extracted from red cabbage. The pH change upon carbon dioxide dissociation occurred in the indicator solution. The reaction was investigated using the stopped-flow method by monitoring the pH measurements at different dissolved CO₂ concentrations. The indicator solution changed color from blue to pink within a few seconds with pH change on the acidic side and returned to its initial state spontaneously without any treatment at the end of the CO₂ gas. The indicator solution showed sensitivity to dissolved CO₂ concentrations in the range of 600 − 3200 ppm in a fast reaction time and complete reversibility.

摘要

在这项研究中，为了环境监测，开发了一种用于在室温下比色肉眼检测溶解的二氧化碳的 pH 敏感指示剂溶液。指示剂溶液由聚乙烯醇包覆的绿色合成氧化铁纳米粒子和从红甘蓝中提取的天然花青素制成。二氧化碳解离时的pH变化发生在指示溶液中。使用停流法通过监测不同溶解CO ₂浓度下的pH测量值来研究反应。指示剂溶液在几秒钟内从蓝色变为粉红色，酸性一侧的 pH 值发生变化，并在 CO _{2结束时自发返回其初始状态，无需任何处理}气体。指示剂溶液在快速反应时间和完全可逆性的情况下对 600 - 3200 ppm 范围内的溶解 CO ₂浓度表现出敏感性。