Directed Assembly of Soft Colloids through Rapid Solvent Exchange

Abstract

We studied the directed assembly of soft nanoparticles through rapid micromixing of polymers in solution with a nonsolvent. Both experiments and computer simulations were performed to elucidate the underlying physics and to investigate the role of various process parameters. In particular, we discovered that no external stabilizing agents or charged end groups are required to keep the colloids separated from each other when water is used as the nonsolvent. Furthermore, the size of the nanoparticles can be reliably tuned through the mixing rate and the ratio between polymer solution and nonsolvent. Our results demonstrate that this mechanism is highly promising for the mass fabrication of uniformly sized colloidal particles, using a wide variety of polymeric feed materials.

Simulating copolymeric nanoparticle assembly in the co-solvent method: How mixing rates control final particle sizes and morphologies

“…The mixing eventually triggers the precipitation of the constituents and the aggregation to particles. One way to tune the sizes of the particles is to vary the rate of solvent mixing [12,13,17,18]. In experiments, solvent mixing is often implemented by continuous flow mixing devices, called passive micromixers [12,13,17,18].…”

“…One way to tune the sizes of the particles is to vary the rate of solvent mixing [12,13,17,18]. In experiments, solvent mixing is often implemented by continuous flow mixing devices, called passive micromixers [12,13,17,18]. Mixing rates in passive micromixers increase with increasing flow rates v [19][20][21], and in turn, particle sizes are found to decrease with increasing v. Thiermann et al [12,13] have recently carried out an extensive study on the relation between flow rates and particle size in such a micromixer setup.…”

Constrained-volume assembly of organometal confined in polymer to fabricate multi-heteroatom doped carbon for oxygen reduction reaction

“…Synthesis, structure, and composition of materials Constrained-volume self-assembly is a continuous process exploiting an impinging jet mixer to bring about the precipitation of polymers under turbulent conditions [27][28][29]. The process is different from the slow time scale of solvent exchange and thermodynamic equilibrium of polymer assembly in conventional solution self-assembly.…”

Photodeformable Microspheres from Methacrylate‐Based Azo Homopolymers

“…The crude product was dissolved in THF and then precipitated with petroleum ether again. The final product was collected and then dried in a vacuum oven at 45 3 ). IR (KBr): ν = 1728 (s; ν(CO)), 1600, 1514, 1445 (m; ν(benz ring)), 1350 (m; ν(ArNRR′)), 1200, 1138 (s; ν(CO)).…”

“…In the final stage, the stability of the hydrophobic colloids in a pure aqueous environment against flocculation has been attributed to the hydroxide ions adsorbed at the hydrophobic surface to contribute the negative stabilizing surface charges. [43][44][45] Although both PEMCN-b and PEMCN-n can form uniform colloidal spheres in the self-assembling processes, the molecular weight and its distribution also play an important role in the processes. PEMCN-b shows the obviously lower CWCs compared with those of PEMCN-n for the cases with the different C 0 studied here.…”