Precise Macroscopic Supramolecular Assembly by Combining Spontaneous Locomotion Driven by the Marangoni Effect and Molecular Recognition

Abstract

Macroscopic supramolecular assembly bridges fundamental research on molecular recognition and the potential applications as bulk supramolecular materials. However, challenges remain to realize stable precise assembly, which is significant for further functions. To handle this issue, the Marangoni effect is applied to achieve spontaneous locomotion of macroscopic building blocks to reach interactive distance, thus contributing to formation of ordered structures. By increasing the density of the building blocks, the driving force for assembly transforms from a hydrophobic-hydrophobic interaction to hydrophilic-hydrophilic interaction, which is favorable for introducing hydrophilic coatings with supramolecular interactive groups on matched surfaces, consequently realizing the fabrication of stable precise macroscopic supramolecular assemblies.

Elasticity‐Dependent Fast Underwater Adhesion Demonstrated by Macroscopic Supramolecular Assembly

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Macroscopic supramolecular assembly (MSA) is arecent development in supramolecular chemistry to associate visible building blocks through non-covalent interactions in amultivalent manner.Although various substrates (e.g.hydrogels,r igid materials) have been used, ag eneral design rule of building blocks in MSA systems and interpretation of the assembly mechanism are lacking and are required. [3] Currently,m ost reports on MSA attained the aforementioned multivalent effects by either using highly flowable hydrogel systems [2,[5][6][7][8] or applying af lexible spacing coating to rigid materials, [3,9] such as, polydimethylsiloxane (PDMS), polymethyl methacrylate; both strategies reveal the intrinsic material property of low elastic modulus providing ah igh degree of freedom of the interactive moieties,u nderlying the success of MSA. Moreover,this MSA rule applies well to the design of materials for fast underwater adhesion:S oft substrates (0.5 MPa) can achieve underwater adhesion within 10 sw ith one order of magnitude higher strength than that of rigid substrates (2.5 MPa).

Macroscopic supramolecular assembly (MSA), which represents aprocess of two macroscopic surfaces with numerous interactive groups associating through non-covalent interactions in amultivalent manner,has been developed as aunique methodology to fabricate bulk supramolecular materials by directly using building blocks larger than ten micrometer.

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“…One proven and effective strategy is to promote the multivalent effects of the interactive moieties by improving the deformability and motility of the surface. [3] Currently,m ost reports on MSA attained the aforementioned multivalent effects by either using highly flowable hydrogel systems [2,[5][6][7][8] or applying af lexible spacing coating to rigid materials, [3,9] such as, polydimethylsiloxane (PDMS), polymethyl methacrylate; both strategies reveal the intrinsic material property of low elastic modulus providing ah igh degree of freedom of the interactive moieties,u nderlying the success of MSA. However,issues regarding whether the elastic modulus determines MSA or acritical boundary exists between assembly and nonassembly events are yet to be understood, which can probably provide auniversal design rule of MSA systems and establish afundamental basis for further applications of MSA in tissue scaffold fabrication, [10] self-healing materials, [11][12][13] underwater adhesion.…”

Parallel and Precise Macroscopic Supramolecular Assembly through Prolonged Marangoni Motion

“…MSA is meaningful for the scalable manufacture of structured materials through self-assembly, [4][5][6] the fabrication of tissue scaffolds, [7,8] and the study and interpretation of adhesion phenomena. Until now,t he first issue has been addressed by introducing af lexible spacing coating to mediate the surface roughness, [12][13][14] while the second challenge is overcome with external agitation, such as rotation or shaking of the medium in which the macroscopic building blocks assemble,o rm agnetically assisted motion to cause directed diffusion and collision of the building blocks. Until now,t he first issue has been addressed by introducing af lexible spacing coating to mediate the surface roughness, [12][13][14] while the second challenge is overcome with external agitation, such as rotation or shaking of the medium in which the macroscopic building blocks assemble,o rm agnetically assisted motion to cause directed diffusion and collision of the building blocks.…”

“…[1][2][3][4] As ar esult, the quality of the desired precise alignment of building blocks is poor compared with that of the alignment achieved by molecular self-assemblies because the macroscopic assembly geometries are largely determined by complex dynamics during the agitation or shaking process, [6] leading to facially offset, nonequilibrium assemblies,w hich are undesired. [13,20] Therefore,t he Marangoni effect presents an ideal driving force to propel large objects and meanwhile its random character produces motional paths that resemble the random walk characteristics of molecular thermal motion. [13,20] Therefore,t he Marangoni effect presents an ideal driving force to propel large objects and meanwhile its random character produces motional paths that resemble the random walk characteristics of molecular thermal motion.…”

“…[13,20] Therefore,t he Marangoni effect presents an ideal driving force to propel large objects and meanwhile its random character produces motional paths that resemble the random walk characteristics of molecular thermal motion. [13] However,t he surfactant, applied to evoke the Marangoni effect, quickly saturates the interface. [13] However,t he surfactant, applied to evoke the Marangoni effect, quickly saturates the interface.…”