Ceramic microparticles and capsules via microfluidic processing of a preceramic polymer.

Prior research has established microfluidic techniques for creating monodispersed particles in various materials. However, the application of these methods to preceramic polymers remains limited. It was already known that silsesquioxane polymers can be pyrolyzed into ceramic oxycarbide glasses, but their controlled fabrication into complex structures like capsules was not fully explored. This gap motivated the development of a new fabrication approach. No prior work had resolved how to efficiently generate double emulsions using microcapillary devices. Existing methods often require multiple steps or lack precise control over particle morphology. The need for scalable production of ceramic particles with tunable properties remains unmet. This paper introduces a new method for fabricating ceramic particles and capsules using microfluidics. The novelty lies in the integration of preceramic polymer processing with microfluidic emulsification.

The aim of this study is to develop a reliable method for fabricating ceramic particles and capsules from silsesquioxane preceramic polymer using microfluidic technology. The specific problem addressed is the lack of a single-step, high-throughput process for producing monodispersed ceramic particles with controlled morphology. The motivation stems from the need for scalable fabrication of ceramic materials with tunable properties. The study focuses on the use of a microcapillary device to generate double emulsions. The goal is to enable the production of particles with adjustable diameters, shell thicknesses, and pore sizes. The method's versatility allows for extension to other preceramic polymers. The authors propose that this technique can generate unique core-shell multimaterial particles. The study aims to demonstrate the feasibility of pyrolyzing the polymer into ceramic oxycarbide glass.

The study employs a microcapillary microfluidic device to generate monodispersed emulsion drops from silsesquioxane preceramic polymer. The device consists of two round capillaries aligned within a square capillary. Three fluids are used to create double emulsions: inner, middle, and outer. The inner fluid flows through the input capillary, while the middle fluid fills the space between the square and inner capillaries. The outer fluid flows in the opposite direction. The three fluids are forced through an exit capillary, forming double emulsions in a single step. The emulsions are produced at rates up to 2000 drops per second. The silsesquioxane polymer is cross-linked in solution and then dried and pyrolyzed in an inert atmosphere. The device allows for precise control over particle morphology by adjusting flow rates, device dimensions, and fluid composition.

The study successfully produced monodispersed ceramic particles and capsules with diameters ranging from 30 to 180 micrometers. Shell thicknesses varied from 10 to 50 micrometers, and pore diameters ranged from 1 to 10 micrometers. The particles were fabricated using a single-step microfluidic process at high throughput rates. The silsesquioxane polymer was cross-linked and pyrolyzed to form oxycarbide glass particles. The method allows for precise control over particle morphology by adjusting flow rates and device dimensions. The produced particles can be used in their polymeric state or converted to ceramic. The technique is extendable to other preceramic polymers. The results demonstrate the feasibility of generating unique core-shell multimaterial particles.

The authors propose that this method provides a scalable and efficient approach for fabricating ceramic particles and capsules from preceramic polymers. The study demonstrates the ability to produce particles with tunable diameters, shell thicknesses, and pore sizes. The microfluidic process enables high-throughput production at rates up to 2000 drops per second. The technique allows for the fabrication of particles in their polymeric state or as pyrolyzed ceramic oxycarbide glass. The authors suggest that the method can be extended to other preceramic polymers. The results indicate the potential for generating unique core-shell multimaterial particles. The study confirms the feasibility of using microfluidics for controlled ceramic particle fabrication. The authors propose that this approach can be applied to a wide range of materials and structures.