论文标题
掉落冷冻：通过测量尖端角度检测污染物
Drop freezing: fine detection of contaminants by measuring the tip angle
论文作者
论文摘要
在这封信中，我们表明冻结水的形状可能对杂质的存在敏感。我们测量冻结在冷板上的水的尖端角度。我们的图像分析方法可牢固地捕获尖端角度的细微变化，该方法显示了与盐（NaCl），聚合物（PEG）和表面活性剂（TTAB）的纯净水的偏差，其浓度为$ 10^{ - 6} $，$ 10^{ - 6} $，$ 10^{ - 4} $和$ 10^{-6} $ 10^{-6} $ m。该方法可以改编成便携式水纯度测试仪，但该作品还突出了水冷冻的复杂性，因为它受到痕量杂质的影响。
In this Letter, we show that the shape of a freezing drop of water can be sensitive to the presence of impurities. We measure the tip angle of water drops frozen on a cold plate. The fine changes in tip angle are robustly captured by our image analysis method, which shows a deviation from that of pure water in solutions with salt (NaCl), polymer (PEG) and surfactant (TTAB) starting at concentrations of $10^{-6}$, $10^{-4}$ and $10^{-6}$ M respectively. The method could be adapted into a portable water purity tester, but the work also highlights the complexity of water freezing as it is influenced by trace concentrations of impurities.
