Preparations and optical properties of. ordered arrays of submicron gel particles: Interconnected state and trapped state
Preparations and optical properties of. ordered arrays of submicron gel particles: Interconnected state and trapped state
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DOI：
10.1021/la060224g
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发表时间：
2006-04-25
期刊：
影响因子：
3.9
通讯作者：
Takeoka, Y
中科院分区：
文献类型：
--
作者：
Kumoda, M;Watanabe, M;Takeoka, Y
以二氧化硅胶体晶体为模板，通过极其简单的方法制备了两种温敏性蛋白石结构的水凝胶体系：“互连”和“捕获”凝胶颗粒阵列。虽然这两个系统都遵循布拉格定律和斯涅尔定律，但它们的光学性质的温度依赖性是完全不同的。“互连”阵列表现出可逆的变化，反射光谱的峰值，主要由水凝胶的溶胀比，作为水温的函数。由于膨胀率在峰值上占主导地位，因此我们可以通过互连型凝胶膜的颜色来观察水温。“捕获”阵列揭示了反射光谱的峰强度随温度变化的可逆变化，而没有观察到峰位置的变化。我们可以从以下几个方面来解释这一现象。随着温度的升高导致NIPA凝胶颗粒的水含量降低，凝胶颗粒在聚苯乙烯PPM的腔壁上变得更粘。这可能会引起凝胶颗粒有序阵列的干扰，并在PPM的反蛋白石结构中形成多层粗糙表面。这种情况可能导致来自凝胶颗粒的光的较强漫反射，导致在较高温度下峰强度的降低。
Two types of thermosensitive opal-structured hydrogel systems, "interconnected" and "trapped" gel particle arrays, were newly developed by extremely simple methods using silica colloidal crystal as a template. Although both systems diffract visible light following Bragg's law combined with Snell's law, the temperature dependences of their optical properties were quite different. The "interconnected" array exhibited a reversible change in the peak values of the reflection spectra, mainly determined by the swelling ratio of the hydrogel, as a function of the water temperature. Since the swelling ratio is dominant over the peak value, we can observe water temperature through the color of the interconnected type of gel membrane. The "trapped" array revealed a reversible change in the peak intensity of the reflection spectra with the change in temperature, whereas no change in the peak position was observed. We can interpret this phenomenon in the following ways. As the rise in temperature causes a decrease in the water content of the NIPA gel particles, the gel particles becomes stickier on the cavity wall of polystyrene PPM. This may induce a disturbance in the ordered array of the gel particles and form many layers of rough surfaces in the inverse opal structure of the PPM. This situation may lead to the stronger diffused reflection of light from the gel particles, resulting in the decrease in peak intensity at higher temperatures.