Surfaces with Patterned Wettability: Design and Applications.

[摘要] Surfaces with patterned wettability have well-defined domains containing both wettable and non-wettable regions. One of the key features of the surfaces with patterned wettability is their ability to localize wetting of liquids preferentially within the patterned wettable regions. This ability of the patterned surfaces has been widely explored as a simple route to pattern both liquids, as well as, solids for various applications such as microfluidics, electronic and optical devices, surfaces with enhanced heat transfer properties, etc. However, most of the patterned surfaces exhibit wettability contrast only with high surface tension liquids such as water, thereby limiting the applications of the patterned surfaces to only aqueous systems. Herein, we utilize the design principles of superomniphobicity (repellency towards all liquids) to develop the first-ever patterned superomniphobic-superomniphilic surfaces that exhibit extremely wettability contrast with both high and low surface tension liquids. Utilizing these patterned surfaces, we demonstrate site-selective self-assembly of various liquids including: oils, alcohols, polymer solutions and solid dispersions. We also demonstrate site-selective condensation and boiling with low surface tension liquids, which is crucial when designing surfaces with significantly enhanced, phase-change, heat-transfer properties. We have further utilized surfaces with patterned wettability as templates for fabricating monodisperse, multi-phasic micro- and nano-particles. The developed technique termed WETS (Wettability Engendered Templated Self-assembly) provides us with an unprecedented ability to manufacture multi-phasic particles, on a large-scale, with precise control over the size (down to 25 nm), shape, chemistry and surface charge of the particles. We further demonstrate the utility of the WETS technique in developing amphiphilic building blocks for self-assembly and multi-functional cargo carriers. Finally, we have also studied stimuli-responsive shape reconfigurations of the multi-phasic WETS particles. Overall, this dissertation puts forward design principles for developing surfaces with patterned wettability that are universal to almost all liquids, thus enabling novel applications for the patterned surfaces, such as the WETS technique reported here.

[发布机构] University of Michigan

[效力级别] Multiphasic particles

[关键词] Patterned wettability;Multiphasic particles;Materials Science and Engineering;Engineering;Science;Macromolecular Science and Engineering