Capillary Microfluidic-Assisted Surface Structuring

Abstract

A facile and universal oxygen-tolerant, capillary microfluidic-derived, controlled radical polymerization for surface structuring (gradient and patterned polymer brushes) is reported. A syringe pump and a filter paper sheet are used as capillary microfluidic to supply the reaction solution (monomer, solvent, and ligand) to a sandwichshaped setup by placing a flat copper plate onto an ATRP initiator-modified substrate and resulting in gradient polymer brush formation with controlled thickness, steepness, and grafting area, polymers are showing the high chain-end fidelity. Two different polymer brushes (binary polymer brushes) can be simultaneously grown from both ends of the initiator modified substrate by using this method, which can be used to study the interfacial properties of different polymer brushes.

Boosting or moderating surface-initiated Cu(0)-mediated controlled radical polymerization with external additives

“…As mentioned before, low [CuBr 2 ] yielded more Cu I species as activators which would lead to termination, ultimately providing polymer brushes with low grafting density. 26,30 The above results also demonstrate that normal SI-CuCRP (in pure PMDETA and without external copper salts) is a well-controlled polymerization method.…”

“…[20][21][22][23][24][25][26][27][28][29] In addition, SI-CuCRP is well compatible with other structuring technologies such as lithography and microfluidics. 19,30 Due to these advantages, SI-CuCRP has been used in a variety of applications. [31][32][33] However, the polymerization process and mechanism of SI-CuCRP have not been completely understood yet.…”

“…An initiator-modified substrate was obtained via a self-assembly monolayer according to previous reports. 30,35 In normal SI-CuCRP, a copper plate and an initiator-modified substrate of the same size face each other with two 0.5 mm-thick spacers. The system is then immersed into a reaction solution (water, PMDETA as the ligand, and oligo(ethylene glycol)methacrylate (OEGMA) as the monomer, with/without external additives) without deoxygenation.…”

Surface Grafting “Band‐Aid” for “Everyone”: Filter Paper‐Assisted Surface‐Initiated Polymerization in the Presence of Air

“…To overcome these limitations and gain better control over the polymerization process, various external stimulimediated ATRP approaches have been developed recently for surface grafting, including activator regenerated by electron transfer radical polymerization (ARGET ATRP), [9] electrochemical-(eATRP), [10] and light stimulus (light ATRP), [11] as well as Cu 0 -mediated processes, [12] which enable the synthesis of polymer brushes with a remarkable degree of control under less rigorous standards. However, the choice of an appropriate method depends highly on the intrinsic nature of the monomers (e.g., structure, chain propagation rate, solubility), which can also be challenging.…”

Fabrication of Three-Dimensional Polymer-Brush Gradients within Elastomeric Supports by Cu0-Mediated Surface-Initiated ATRP

“…13,14,18 compositions could be synthesized with the aid of microfluidics. 21 Motivated by the versatility and the widespread applicability of Mt 0 SI-ATRP for the chemical and morphological structuring of polymer brush coatings on two-dimensional (2D) substrates, in this work, we concentrated on applying this technique for functionalizing three-dimensional (3D) supports in a spatially controlled fashion.…”