The quantification of supramolecular host–guest interactions is important for finely modulating supramolecular systems. Previously, most host–guest interactions quantified using force spectroscopic techniques have been reported in force units. However, accurately evaluating the adhesion energies of host–guest pairs remains challenging. Herein, using a surface forces apparatus, we directly quantify the interaction energies between cyclodextrin (CD)-modified surfaces and ditopic adamantane (DAd) molecules in water as a function of the DAd concentration and the CD cavity size. The adhesion energy of the β-CD–DAd complex drastically increased with increasing DAd concentration and reached saturation. Moreover, the molecular adhesion energy of a single host–guest inclusion complex was evaluated to be ~9.51 kBT. This approach has potential for quantifying fundamental information toward furthering the understanding of supramolecular chemistry and its applications, such as molecular actuators, underwater adhesives, and biosensors, which require precise tuning of specific host–guest interactions.

The load-bearing proteins in mussel holdfasts rely on condensed tris-catecholato-Fe 3+ coordination complexes for their toughness and shockabsorbing properties, and this feature has been successfully translated into synthetic materials with short-term high-performance properties. However, oxidation of catecholic DOPA (3,4-dihydroxyphenylalanine) remains a critical impediment to achieving materials with longer-lasting performance. Here, following the natural mussel pathway for protein processing, we explore how DOPA oxidation impacts coacervation of mussel foot protein-1 (mfp-1) and its capacity for phase-specific metal uptake in vitro. Without metal, DOPA oxidation changed the rheological properties (i.e., viscosity, loss, and storage moduli) of mfp-1 coacervate droplets. However, oxidation-dependent changes were recovered with dithiothreitol (DTT), completely restoring the behavior of mfp-1 coacervates prior to oxidation. With metal, mfp-1 coacervates exhibited gel-like behavior with high viscosity and cohesive forces by forming recognizable bis-and tris-catecholato-Fe complexes, linked to increased energy dissipation and toughness of byssus. These results indicate that Fe 3+ -mediated conversion of liquid−liquid phase-separated polymers into metal-coordinated networks is thorough and rapid, and DTT effectively maintains redox integrity. Our study provides much-needed improvements for processing catechol-functionalized polymers into high-performance materials.

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Ion interactions with interfaces and transport in confined spaces, where electric double layers overlap, are essential in many areas, ranging from crevice corrosion to understanding and creating nano-fluidic devices at...

ABSTRACT:As the IFC (Industry Foundation Classes) was introduced to exchange data between different BIM (Building Information Modeling) applications, construction professionals speculated how effectively it would solve the interoperability issues between these applications. Although previous investigations have demonstrated some limitations of the IFC in terms of exchanging the geometry of the components in the BIM data, no full understanding of these differences in the IFC code level has been provided yet. This paper presents the preliminary outcome of our investigation on the differences between the IFC codes of the same components created using different BIM applications such as Revit Architecture and ArchiCAD. This preliminary investigation gave us a clear idea as to how we are supposed to use the IFC to sustain the BIM data for the building's lifecycle.