Test-Paper-Like Photonic Crystal Viscometer
Test-Paper-Like Photonic Crystal Viscometer
复制标题
试纸式光子晶体粘度计
DOI：
10.1002/smll.201603351
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发表时间：
2017
期刊：
影响因子：
13.3
通讯作者：
Ge Jianping
中科院分区：
文献类型：
--
作者：
Zhang Yuqi;Fu Qianqian;Ge Jianping
张玉琪、前前夫、葛建平*呈正相关。此外，通过“圆盘”或“圆盘”在粘性液体中旋转工作的合理粘度计在工业应用中也得到了广泛应用。同样，它测量以已知速度旋转圆盘或钻头所需的扭矩，然后根据它们的正相关性确定流体的粘度。在实际测量中，通常需要一套不同毛细管径的U形管或不同型号的圆盘来测量未知粘度，并且在测量另一种液体之前必须对仪器进行清洗，这就给现场粘度监测带来了不便和低效。在这项工作中，我们将首次提出一种试纸式光子晶体粘度计。与Ubbelohde粘度计类似，PC粘度计还具有由乳白色二氧化硅光子晶体膜内微米级裂纹和纳米级粒间空洞组成的毛细系统，因此一旦获得渗透时间，就可以建立粘度与渗透时间的正相关关系，从而确定粘度。随着粘性液体对PC膜的渗透，其反射信号和结构颜色会发生相应的变化，以显示渗透时间，这意味着该传感器可以灵活地用于光谱仪测量或肉眼观察。试纸式PC粘度计考虑到其便携、一次性的特点和对小样本的要求，可以在不同的场合使用，快速测定多种液体的粘度。通过对聚碳酸酯薄膜微观结构的改性，可以制作出精确的试纸，更准确、高效地指示特定范围内的粘度；胶体聚碳酸酯是根据特定液体的粘度(η)与其渗透时间(T)的内在关系实现对聚碳酸酯的完全浸透。当粘性液体滴到二氧化硅PC的薄膜上时，它会立即填充胶体微晶之间微米级的裂缝，然后渗透到微晶中，直到颗粒空隙中的空气完全被粘性液体取代(图1)。同时，由于整个光子结构的折射率增加，PC的结构颜色逐渐发生变化。由于流体的粘度代表了它对剪应力或拉应力逐渐变形的抵抗力，不同粘度的液体完成渗透所需的时间是不同的。一般情况下，粘性较大的液体的渗透时间比非粘性液体的要长。当PC的结构颜色不再变化时，可以通过肉眼观察大致确定渗透时间。另一方面，可以获得更精确的入渗时间
Yuqi Zhang, Qianqian Fu, and Jianping Ge* their positive linear correlation. Furthermore, a rational viscometer working through the rotation of “disk” or “bob” in viscous liquid is also widely used in industrial applications. Similarly, it measures the torque required to rotate a disk or bob at a known speed and then determine the viscosity of fluid according to their positive correlation. Generally, a set of U-tubes with different capillary diameters or disks with different types designed for specific measurement range are required to determine an unknown viscosity in practical circumstance, and the instruments must be cleaned before measuring another liquids, which is inconvenient and inefficient to monitor the viscosity on site. In this work, we shall propose a test-paper-like photonic crystal viscometer for the first time. Similar to the Ubbelohde viscometer, the PC viscometer also has a capillary system composed of the micron-scale cracks and the nanoscale interparticle voids within the opaline SiO2 photonic crystal film, so that the positive correlation between viscosity and the infiltration time can be established to determine the viscosity once the infiltration time is acquired. Along with the infiltration of viscous liquid into PC film, its reflection signal and structural color will change accordingly to show the infiltration time, which means that the sensor can be flexibly used by spectrometer measurement or naked-eye observation. The test-paper-like PC viscometer can be used in different occasions to quickly determine the viscosity of many liquids, considering its portable and disposable characteristics and the requirement of little samples. Through modification in microstructures of PC film, precise test paper can be fabricated to indicate the viscosity in a specific range more accurately and efficiently.The sensing of viscosity by colloidal PC is realized based on the inherent relationship between viscosity (η) of a specific liquid and its infiltration time (t) for entirely soaking the PC. When the viscous liquid is dropped onto the thin film of SiO2 PC, it fills the micron-scale cracks between colloidal microcrystals immediately and then infiltrates into the microcrystals until the air in the particle voids is fully replaced by the viscous liquid (Figure 1). Meanwhile, the structural color of PC gradually changes due to the increased refractive index of the whole photonic structure. Since the viscosity of a fluid represents its resistance to gradual deformation by shear stress or tensile stress, it will take different time for liquids with different viscosities to accomplish the infiltration. Generally, the infiltration time for a more viscous liquid is longer than that of a nonviscous liquid. The infiltration time can be roughly determined by naked-eye observation when the structural color of PC does not change anymore. On the other hand, more precise infiltration time can be obtained