Combinatorial Synthesis of Insoluble Oxide Library from Ultrafine/Nano Particle Suspension Using a Drop-on-Demand InkJet Delivery System

摘要

Although the combinatorial approach has been widely adapted in the search for novel functional materials,the parallel synthesis and high-throughput characterization are still the major obstacles hampering the application to a diversity of materials.Among various parallel synthesis strategies,thin-film deposition combined with physical masks (or photolithography) and solution-based synthetic methods are the most commonly used techniques.In solution-based parallel synthesis,droplets of precursor solutions are laid into predefined microreactors (usually microwells drilled into a ceramic substrate) from microdispensers (usually piezoelectric-driven ejectors).Then,the precursors are mixed and reacted to form a materials library.Through this method,materials libraries including phosphors,catalyst,etc.,have been fabricated from solution precursors.InkJet delivery shows many advantages over other microdispense apparatus,such as nanoliter dispensing capability with high accuracy.However,a significant limitation of the above-mentioned technique is the applicability:only soluble compounds had been used as the precursors.On the other hand,a lot of suspensions have been used with the inkjet technique in ceramic freeforming,fabrication of electronic devices,and functionally graded material.From this point of view,suspensions can be used with inkjet technique in solution-based parallel synthesis if a universal preparation method of insoluble suspensions can be developed.Evans et al.realized this and published the point of view from philosophy analysis,but to our best knowledge,no materials library was really made from suspensions.In this paper,we report a method to prepare ultrafineanoparticle suspensions of insoluble rare earth oxides in pure water and the synthesis of a materials library from such suspensions using a homemade drop-on-demand inkjet delivery system.