IESL-FORTH, Heraklion, Crete, Greece.
Nano Lett. 2013 Aug 14;13(8):3831-5. doi: 10.1021/nl401853k. Epub 2013 Jul 3.
We report for the first time on the redox multiphoton polymerization of an organic-inorganic composite material, in which one of the components, a vanadium metallo-organic complex, initiates the polymerization. The composite employs multiphoton absorption to self-generate radicals by photoinduced reduction of the metal species from vanadium (V) to vanadium (IV). We exploit this material for the fabrication of fully 3D structures by multiphoton polymerization with 200 nm resolution, employing a femtosecond laser operating at 800 nm, in the absence of a photoinitiator. Nonlinear absorption measurements indicate that the use of an 800 nm laser initiates the photopolymerization due to three-photon absorption of the vanadium alkoxide. The laser power required to induce this three-photon polymerization is comparable to what is required for inducing two-photon polymerization in materials using standard two-photon absorbers, most likely due to the high content of vanadium in the final composite (up to 50% mole).
我们首次报道了一种有机-无机复合材料的氧化还原多光子聚合反应，其中一个组件是钒金属有机配合物，它可以引发聚合反应。该复合材料通过多光子吸收，通过金属物种（从 V 到 IV）的光诱导还原来自产生自由基。我们利用这种材料，在没有光引发剂的情况下，通过在 800nm 飞秒激光下的多光子聚合反应，以 200nm 的分辨率来制造全 3D 结构。非线性吸收测量表明，使用 800nm 激光引发光聚合是由于烷氧基钒的三光子吸收。引发这种三光子聚合所需的激光功率与使用标准双光子吸收体的材料中引发双光子聚合所需的功率相当，这很可能是由于最终复合材料中钒的含量较高（高达 50%摩尔）。
