Department of Chemical and Biomolecular Engineering, North Carolina State University, Raleigh, North Carolina 27695, United States.
ACS Appl Mater Interfaces. 2013 Jun 12;5(11):5253-9. doi: 10.1021/am401095r. Epub 2013 May 31.
Low-temperature vapor-phase tungsten atomic layer deposition (ALD) using WF6 and dilute silane (SiH4, 2% in Ar) can yield highly conductive coatings on nylon-6 microfiber mats, producing flexible and supple nonwovens with conductivity of ∼1000 S/cm. We find that an alumina nucleation layer, reactant exposure, and deposition temperature all influence the rate of W mass uptake on 3D fibers, and film growth rate is calibrated using high surface area anodic aluminum oxide. Transmission electron microscopy (TEM) reveals highly conformal tungsten coatings on nylon fibers with complex "winged" cross-section. Using reactant gas "hold" sequences during the ALD process, we conclude that reactant species can transport readily to reactive sites throughout the fiber mat, consistent with conformal uniform coverage observed by TEM. The conductivity of 1000 S/cm for the W-coated nylon is much larger than found in other conductive nonwovens. We also find that the nylon mats maintain 90% of their conductivity after being flexed around cylinders with radii as small as 0.3 cm. Metal ALD coatings on nonwovens make possible the solvent-free functionalization of textiles for electronic applications.
使用 WF6 和稀释的硅烷（SiH4，在 Ar 中 2%）的低温气相钨原子层沉积（ALD）可以在尼龙-6 微纤维垫上产生高导电性涂层，从而生产出具有约 1000 S/cm 电导率的柔韧、柔软的无纺布。我们发现氧化铝成核层、反应物暴露和沉积温度都会影响 3D 纤维上 W 质量吸收速率，并且使用高表面积的阳极氧化铝来校准薄膜生长速率。透射电子显微镜（TEM）揭示了尼龙纤维上高度保形的钨涂层，具有复杂的“翼形”横截面。通过在 ALD 过程中使用反应物气体“保持”序列，我们得出结论，反应物可以很容易地输送到纤维垫的各个反应位点，这与 TEM 观察到的保形均匀覆盖一致。涂有 W 的尼龙的电导率为 1000 S/cm，远大于其他导电无纺布。我们还发现，尼龙垫在被弯曲到半径小至 0.3 厘米的圆柱体周围时，其电导率保持在 90%。无纺金属 ALD 涂层使电子应用中纺织品的无溶剂功能化成为可能。
