Lovikka Ville A, Airola Konsta, McGuinness Emily, Zhang Chao, Vehkamäki Marko, Kemell Marianna, Losego Mark, Ritala Mikko, Leskelä Markku
Department of Chemistry, University of Helsinki A.I. Virtasen Aukio 1, P.O. Box 55 FI-00014 Helsinki Finland
School of Materials Science and Engineering, Georgia Institute of Technology Atlanta Georgia 30332 USA.
Nanoscale Adv. 2022 Aug 23;4(19):4102-4113. doi: 10.1039/d2na00291d. eCollection 2022 Sep 27.
Selective deposition of hybrid and inorganic materials inside nanostructures could enable major nanotechnological advances. However, inserting ready-made composites inside nanocavities may be difficult, and therefore, stepwise approaches are needed. In this paper, a poly(ethyl acrylate) template is grown selectively inside cavities condensation-controlled toposelective vapor deposition, and the polymer is then hybridized by alumina, titania, or zinc oxide. The hybridization is carried out by infiltrating the polymer with a vapor-phase metalorganic precursor and water vapor either a short-pulse (atomic layer deposition, ALD) or a long-pulse (vapor phase infiltration, VPI) sequence. When the polymer-MO hybrid material is calcined at 450 °C in air, an inorganic phase is left as the residue. Various suspected confinement effects are discussed. The infiltration of inorganic materials is reduced in deeper layers of the cavity-grown polymer and is dependent on the cavity geometry. The structure of the inorganic deposition after calcination varies from scattered particles and their aggregates to cavity-capping films or cavity-filling low-density porous deposition, and the inorganic deposition is often anisotropically cracked. A large part of the infiltration is achieved already during the short-pulse experiments with a commercial ALD reactor. Furthermore, the infiltrated polymer is more resistant to dissolution in acetone whereas the inorganic component can still be heavily affected by phosphoric acid.
在纳米结构内部选择性沉积杂化材料和无机材料能够推动纳米技术取得重大进展。然而，将现成的复合材料插入纳米腔可能存在困难，因此需要采用逐步的方法。在本文中，通过冷凝控制的拓扑选择性气相沉积在腔体内选择性生长聚（丙烯酸乙酯）模板，然后使该聚合物与氧化铝、二氧化钛或氧化锌杂化。杂化过程是通过用气相金属有机前驱体和水蒸气以短脉冲（原子层沉积，ALD）或长脉冲（气相渗透，VPI）序列渗透聚合物来实现的。当聚合物 - 金属有机杂化材料在空气中于450℃煅烧时，会留下无机相作为残余物。文中讨论了各种可能的限域效应。在腔体内生长的聚合物较深的层中，无机材料的渗透会减少，并且这取决于腔体的几何形状。煅烧后无机沉积物的结构从分散的颗粒及其聚集体到覆盖腔体的薄膜或填充腔体的低密度多孔沉积物各不相同，并且无机沉积物常常会出现各向异性开裂。使用商用ALD反应器进行短脉冲实验时，很大一部分渗透过程就已完成。此外，渗透后的聚合物在丙酮中的溶解性降低，而无机成分仍会受到磷酸的严重影响。
