Chemically orthogonal trifunctional Janus beads by photochemical “sandwich” microcontact printing

Abstract

The combination of topographic and chemical orthogonality on polymer particles by site selective immobilization of functional thiols via thiol-ene chemistry provides a trifunctional particle surface with azide and acid functionalities on opposing poles and alkenes in the equatorial area. These Janus beads are accessible for site selective orthogonal chemical reactions as well as biomolecular recognition on the same particle.

Ordered arrays of pumpkin-shaped Janus particles with tailored surface morphologies via microcontact hot embossing

“…The forces exploited to transfer the ink onto the particles are mostly derived from intermolecular forces. Considering the instability of molecular interactions, Kaufmann et al presented a microcontact chemistry strategy to yield stable Janus microspheres with the covalent linkage between the ink and the sphere surface [18,20,28].…”

“…Those techniques provide us a novel perspective for the post-modification of particles in a simple way, while concerned researches are limited. For instance, there have been some reports [18,20,[23][24][25][26][27][28] on the asymmetric post-modification of particles via μCP, which mainly utilizes an elastomeric stamp (typically poly(dimethylsiloxane) (PDMS)) to transfer inks onto the contacted surface. Here, Cayre et al used μCP to generate Janus microparticles with dipolar surface charge distribution and further extended this technique to produce asymmetrically coated colloid particles by printing one colloidal monolayer on a latex particle monolayer of opposite charges [23,24].…”

Control of cross-linking and reactions in one-step dispersion polymerization toward particles with combined anisotropies

“…[7][8][9] A variety of techniques have been developed for fabrication of anisotropic particles, including phase separation, [10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27][28][29] microfluidics, 30 controlled surface nucleation, 31 and selective surface modification based on particle monolayer, 32,33 etc. The most recognized, promising technique so far for production of polymer anisotropic particles with precise control and high throughput is based on internal phase separation during seeded emulsion polymerization.…”

Preparation of Highly Monodisperse Monopatch Particles with Orthogonal Click-Type Functionalization and Biorecognition

“…Microcontact printing (μCP) on planar substrates is, on the other hand, a well‐established procedure to transfer reactive inks onto a broad variety of substrates. It was recently used to asymmetrically introduce functionalities into particles by printing low‐molecular weight inks onto particles . Despite its potentially broad applicability, one of the main bottlenecks in such molecular inks is the often unsatisfactory definition (broadening, nonuniformity) of the resulting patches, which is induced by the flow of inks during printing due to their high mobility.…”