Controlled evaporative self‐assembly of polymer nanoribbons using oscillating capillary bridges. Issue 23 (21st September 2018)

• Record Type: Journal Article
• Authors: Choudhary, Satyan; Crosby, Alfred J.
• Is Part Of: Journal of polymer science. Volume 56:Issue 23(2018)
• Page Start: 1545
• Page End: 1551
• Publication Date: 2018-09-21
• Subjects: flow coating -- evaporative self‐assembly -- mesoscale assemblies -- polymer nanoribbons; 547
• DOI: 10.1002/polb.24730
• Languages: English
• ISSNs: 0887-6266

Abstract

ABSTRACT: Evaporative self‐assembly (ESA), based on the "coffee‐ring" effect, is a versatile technique for assembling particle solutions into mesoscale patterns and structures on different substrates. ESA works with a wide variety of organic and inorganic materials, where the solution is a combination of volatile solvent and nonvolatile solute. Modified ESA methods, such as "stop‐and‐go flow coating, " use a programmed meniscus "stick–slip" motion to create mesoscale assemblies with controlled shape, size, and architecture. However, current methods are not scalable for increased production volumes or patterning large surface areas. We demonstrate a new ESA method, where an oscillating blade controls the meniscus depinning and drives the evaporative assembly of solutes at the pinned meniscus. Results show that oscillation frequency and substrate speed control time/distance intervals between successive meniscus depinning, and the assembly dimensions depend on solution concentration, oscillation frequency, substrate speed, and meniscus height. We report the mechanism of the meniscus depinning and the control over assembly cross‐sectional dimensions. This advance provides a scalable ESA method with faster processing times and maintained advantages. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys.2018, 56, 1545–1551 Abstract : As a template‐free, bottom‐up self‐assembly technique for creating polymer/nanoparticle‐based mesoscale structures and patterns on substrates, the oscillating capillary bridge method is user‐friendly and scalable, allowing precise control over pattern spacing and assembly dimensions. In this method, an oscillating meniscus drives the evaporative self‐assembly of solutes at a three‐phase contact line, and the combined motion of the blade and the substrate dictate a programmed periodic meniscus stick–slip motion.