Influence of the plasma sheath on plasma polymer deposition in advance of a mask and down pores.
Influence of the plasma sheath on plasma polymer deposition in advance of a mask and down pores.
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等离子体鞘对掩模前和孔下等离子体聚合物沉积的影响。
DOI：
10.1021/jp902137y
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
Zelzer M
中科院分区：
文献类型：
--
作者：
Zelzer M
形成等离子体聚合物沉积物的等离子体物质容易穿透小开口，因此非常适合涂覆多孔物体的内部。在这里，我们展示了方形通道的横截面的大小如何影响来自己烷等离子体的活性物质的渗透，以及它如何影响这些模型孔内部的表面化学梯度的形成。WCA映射和ToF-SIMS成像用于可视化模型孔内部的等离子体聚合物存款，并证明润湿性梯度分布的强依赖性仅存在于约1 mm的通道横截面。XPS数据使我们能够计算等离子体聚合己烷（ppHex）的沉积速率。在表面上的离散位置，并表明，ppHex的沉积速率降低了掩模的存在，直到16毫米的距离，在通道开口的前面。发现在孔开口前的第一个2 mm内，ppHex沉积速率对通道横截面的强烈依赖性。鞘层厚度的估计表明，这种效果可以归因于等离子体鞘层，扰动等离子体前面的孔。等离子体质谱法允许我们识别从等离子体穿过孔渗透的等离子体物质的性质，并且显示没有带负电荷的离子能够穿过小通道。中性和带正电的物质沿通道向下渗透几毫米，因此这两种物质都可能有助于样品上存款的形成。此外，在气相中观察到带正电荷的较高分子量己烷碎片的形成，证明了等离子体中中性-阳性反应的可能性。
Plasma species that form plasma polymer deposits readily penetrate through small openings and are therefore well suited to coat the interior of porous objects. Here, we show how the size of the cross section of square channels influences the penetration of active species from a hexane plasma and how it affects the formation of surface chemical gradients in the interior of these model pores. WCA mapping and ToF-SIMS imaging are used to visualize the plasma polymer deposit in the interior of the model pores and demonstrate that a strong dependence of the wettability gradient profile only exists up to a channel cross section of about 1 mm. XPS data allow us to calculate a deposition rate of plasma polymerized hexane (ppHex) at discrete positions on the surface and show that the deposition rate of ppHex is reduced by the presence of the mask up to a distance of 16 mm in advance of the channel opening. A strong dependence of the ppHex deposition rate on the cross-section of the channels is found within the first 2 mm in front of the pore opening. An estimation of the sheath thickness suggests that this effect can be attributed to the plasma sheath that perturbs the plasma in front of the pores. Plasma mass spectrometry allows us to identify the nature of the plasma species penetrating from the plasma through the pores and shows that no negatively charged ions are able to penetrate through the small channels. Neutral and positively charged species penetrate several millimeters down the channels and both species are therefore likely to contribute to the formation of the deposit on the sample. In addition, the formation of positively charged higher molecular mass hexane fragments is observed in the gas phase, demonstrating the likelihood of neutral-positive reactions in the plasma.