Self-sorting in macroscopic supramolecular self-assembly via additive effects of capillary and magnetic forces

Abstract

Supramolecular self-assembly of μm-to-mm sized components is essential to construct complex supramolecular systems. However, the selective assembly to form designated structures at this length scale is challenging because the short-ranged molecular recognition could hardly direct the assembly of macroscopic components. Here we demonstrate a self-sorting mechanism to automatically identify the surface chemistry of μm-to-mm components (A: polycations; B: polyanions) based on the A-B attraction and the A-A repulsion, which is realized by the additivity and the competence between long-ranged magnetic/capillary forces, respectively. Mechanistic studies of the correlation between the magnetic/capillary forces and the interactive distance have revealed the energy landscape of each assembly pattern to support the self-sorting results. By applying this mechanism, the assembly yield of ABA trimers has been increased from 30%~40% under conventional conditions to 100% with self-sorting. Moreover, we have demonstrated rapid and spontaneous self-assembly of advanced chain-like structures with alternate surface chemistry.

Pathway Complexity in Supramolecular Copolymerization and Blocky Star Copolymers by a Hetero-Seeding Effect

“…Upon adding the aged O-NMI “seed” solution (fibrillar assembly) to the spherical assembly of S-NMI as a “monomer reservoir” in an equimolar ratio in decane, we did not observe any helical 1D growth for S-NMI (Figure S16a), unlike self-seeded polymerization of O-NMI or its statistical copolymerization with S-NMI . Rather, immediate precipitation was observed, indicating phase separation due to self-sorting between the two individual self-assembled components, which was also evident from the AFM studies (Figure S16b). This suggests that there is no dynamic mixing between S-NMI and O-NMI at room temperature when they coexist in their respective thermodynamically stable self-assembled forms.…”

“…The appearance of the negative Cotton effect for S-NMI indicates that O-NMI could transfer its helical bias to S-NMI by hetero-interaction in the 2 day aged co-assembly. This clearly points out different microstructural organizations in the helical assembly of the O-NMI + S-NMI (1:1) copolymer as compared to the O-NMI homopolymer and eliminates any possibility of the self-sorted assembly of the two monomers. Moreover, we monitored the variable-temperature CD spectra of the mixture (Figure b) and compared the CD melting curves at the absorbance of O-NMI (λ max = 363 nm) and S-NMI (λ max = 402 nm), which showed exactly identical melting temperatures ( T m = 50 °C) for the two monomers (Figure c).…”

“…This essentially means that the two monomers should exhibit very slow dynamics of mixing (ideally no mixing) and should have less preference for hetero-stacking as compared to homo-stacking, which will otherwise end up in the formation of statistical copolymers. (4) In order to achieve that, an optimal mismatch penalty between the two monomers is desirable to avoid the other extreme possibility of narcissistic self-sorting . (5) In addition to all of these, even for the same monomer, the formation of a desired self-assembly product may be highly sensitive to even seemingly trivial parameters such as sonication power and time, cooling rate, equilibration time, the presence of trace amounts of protic solvents, and others. , Thus, it is not trivial to realize all these features simultaneously to achieve successful hetero-seeded supramolecular block copolymerization and requires a delicate monomer design, making this field extremely challenging.…”

Proton Affinity in the Chemistry of Beta-Octamolybdate: HPLC-ICP-AES, NMR and Structural Studies

“…Most self-assembly cascade reactions are pH driven when fast protonation-deprotonation processes provoke rapid species transformation/organization into various associates up to nanoscopic size. The study of self-assembly processes is one of the top subjects in modern chemical science [ 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 ]. Such a specific organization of the matter in different solutions is a research focus for a large number of research groups.…”

Organic‒inorganic semi-interpenetrating networks with orthogonal light- and magnetic-responsiveness for smart photonic gels

“…Stimuli-responsive materials are smart materials that are responsive to external stimuli such as light 1 – 4 , electric 5 and magnetic fields 6 , 7 , temperature 8 , 9 , humidity 10 , 11 , or pH 12 – 15 . Stimuli-responsive materials are widely studied because they exhibit potential applications in robotics 16 , biomedicine 17 , 18 , self-healing 19 – 21 , photonics 22 , etc.…”