Liquid Marbles in Nature: Craft of Aphids for Survival
Liquid Marbles in Nature: Craft of Aphids for Survival
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DOI：
10.1021/acs.langmuir.9b00771
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发表时间：
2019-05-07
期刊：
影响因子：
3.9
通讯作者：
Fujii, Syuji
中科院分区：
文献类型：
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作者：
Kasahara, Moe;Akimoto, Shin-ichi;Fujii, Syuji
已知一些生活在寄主植物叶瘿中的蚜虫会制造由蜜露和蜡颗粒组成的液体弹珠，分别作为内部液体和稳定剂。在这项研究中，对由瘿蚜虫 Eriosoma moriokense 制造的液体大理石的尺寸和尺寸分布、形状、纳米形态、液体/固体重量比和化学成分进行了广泛的表征。立体显微镜研究证实，液体弹珠具有接近球形的形态，数均直径为368+/-152μm，比蜜露的毛细管长度小1个数量级。场发射扫描电子显微镜研究表明，微米大小的纤维状和饺子状的蜡颗粒覆盖了蜜露滴，使液体弹珠具有疏水性和不润湿性。此外，高度放大的扫描电子显微镜图像证实蜡颗粒是由亚微米尺寸的子纤维组合形成的。接触角测量表明蜡本质上是疏水性的，并且 Cassie-Baxter 模型中的蜡颗粒稳定了液体弹珠。确定蜜露和蜡颗粒的重量比为96/4，并且蜜露由19wt％的非挥发性组分和81wt％的水组成。 H-1核磁共振、傅里叶变换红外光谱和质谱研究证实，蜡主要由甘油三酯组成，蜜露主要由糖类（葡萄糖和果糖）和核糖醇组成。原子力显微镜研究证实，蜜露本质上是粘性的。
Some aphids that live in the leaf galls of the host plant are known to fabricate liquid marbles consisting of honeydew and wax particles as an inner liquid and a stabilizer, respectively. In this study, the liquid marbles fabricated by the galling aphids, Eriosoma moriokense, were extensively characterized with respect to size and size distribution, shape, nanomorphology, liquid/solid weight ratio, and chemical compositions. The stereo microscopy studies confirmed that the liquid marbles have a near-spherical morphology and that the number-average diameter was 368 +/- 152 mu m, which is 1 order of magnitude smaller than the capillary length of the honeydew. The field emission scanning electron microscopy studies indicated that micrometer-sized wax particles with fiber- and dumpling-like shapes coated the honeydew droplets, which rendered the liquid marbles hydrophobic and nonwetting. Furthermore, the highly magnified scanning electron microscopy images confirmed that the wax particles were formed with assemblage of submicrometer-sized daughter fibers. The contact angle measurements indicated that the wax was intrinsically hydrophobic and that the liquid marbles were stabilized by the wax particles in the Cassie-Baxter model. The weight ratio of the honeydew and the wax particles was determined to be 96/4, and the honeydew consisted of 19 wt % nonvolatile components and 81 wt % water. The H-1 nuclear magnetic resonance, Fourier transform infrared spectroscopy, and mass spectroscopy studies confirmed that the wax mainly consisted of triglycerides and that the honeydew mainly consisted of saccharides (glucose and fructose) and ribitol. The atomic force microscopy studies confirmed that honeydew is sticky in nature.