碳纳米管(CNTs)在生物学和医学领域显示出巨大的应用潜力,一旦他们的预期目的实现了,消除残留的碳纳米管对于避免负面影响至关重要。在这项研究中,我们证明了通过热对流有效收集和简单去除分散在悬浮液中的CNT。首先,锥形光纤尖端,锥角和端直径为10°和3μm,分别,是通过加热和拉伸方法制造的。Further,功率和波长为100mW和1.55μm的激光束,分别,被发射到锥形纤维尖端,将其置于CNT悬浮液中,导致在纤维尖端上形成微泡。微气泡和悬浮液表面的温度梯度引起悬浮液中的热对流,这导致碳纳米管在纤维尖端的积累。实验形成的CNT簇具有直径为87μm的圆形顶表面和高度为19μm的拱形横截面。此外,该CNT簇牢固地附着到纤维尖端。因此,CNT簇的去除可以通过简单地从悬浮液中去除纤维尖端来实现。此外,我们模拟了引起CNT聚集的热对流。获得的结果表明,纤维尖端附近的对流流向它,它将CNT推向纤维尖端,并使它们附着在纤维尖端上。Further,流速对称分布为高斯函数,这导致CNT簇的圆形顶表面和拱形横截面轮廓的形成。我们的方法可用于生物医学中纳米药物残留的收集和去除。
Carbon nanotubes (CNTs) have exhibited immense potential for applications in biology and medicine, and once their intended purpose is fulfilled, the elimination of residual CNTs is essential to avoid negative effects. In this study, we demonstrated the effective collection and simple removal of CNTs dispersed in a suspension via thermal
convection. First, a tapered fiber tip with a cone angle and end diameter of 10° and 3 μm, respectively, was fabricated via a heating and pulling method. Further, a laser beam with a power and wavelength of 100 mW and 1.55 μm, respectively, was launched into the tapered fiber tip, which was placed in a CNT suspension, resulting in the formation of a microbubble on the fiber tip. The temperature gradient on the microbubble and suspension surface induced thermal
convection in the suspension, which resulted in the accumulation of CNTs on the fiber tip. The experimentally formed CNT cluster possessed a circular top surface with a diameter of 87 μm and an arched cross-section with a height of 19 μm. Furthermore, this CNT cluster was firmly attached to the fiber tip. Therefore, the removal of CNT clusters can be realized by simply removing the fiber tip from the suspension. Moreover, we simulated the thermal
convection that caused CNT aggregation. The obtained results indicate that
convection near the fiber tip flows toward it, which pushes the CNTs toward the fiber tip and enables their attachment to it. Further, the flow velocity is symmetrically distributed as a Gaussian function, which results in the formation of a circular top surface and arched cross-sectional profile for the CNT cluster. Our method may be applied in biomedicine for the collection and removal of nano-drug residues.