"Meta-chemistry": Nanoscale chemical control using spatially localised solvent heating

点击翻译按钮获取中文摘要

The industrial mass production of machines and devices relies on the assembly of different components in a specific order in the most rapid and efficient way. However what is routine at everyday length scales is infinitely more difficult and time consuming when we consider linking components to create nano-devices. This is particularly the case when one wishes to create a specific molecule-nanostructure construct. The individual component molecules and complex nanostructure architectures can be mass produced using tools of synthetic chemistry and nanofabrication techniques (e.g. nano-imprint and injection moulding). However, established technologies for combining these individual elements in a specific way are slow (e.g. dip pen nanolithography takes tens of hours to functionalise cm2 samples) and hence low throughput (i.e. incompatible with mass production). Therfore, creating relative complex hybrid molecular-nanofabricated materials is comparable to handcrafting a Bentley rather than the assembly line mass production of Volkswagen Golfs. We propose an innovative approach for nanoscale spatial control of chemical functionalisation of (plasmonic) nanostructures which has both nanoscale resolution ca. 20 nm and is simple and rapid. The concept, which we call "Meta-chemistry", involves using a pulsed laser to locally heat the solvent in specific regions surrounding a nanostructure. These nanoscale thermal gradients can then be exploited to drive chemistry in a spatially selective manner. In the proposal we will develop a fundamental understanding of how heat is generated and transported in a liquid surrounding a nanostructure, thus providing the foundation for optimal spatial control. Also crucially, we will synthesise thermally responsive polymers which will be transformed in the locally heated solvent, creating nano-domains which can be subsequently chemically functionalised. Using the meta-chemistry concept cm2 of a nanostructured substrate can be both spatially and selectively chemically modified, in preparation for subsequent chemical functionalisation, in less than 60 seconds. The proposal is at the cusp of chemistry physics and engineering, it will discover novel fundamental science which in the longer term could be the foundation of a powerful flexible technology for the nanoscience toolbox.