Coordination-Driven Multistep Assembly of Metal–Polyphenol Films and Capsules

Abstract

We report the assembly of metal-polyphenol complex (MPC) films and capsules through the sequential deposition of iron­(III) ions (Fe(III)) and a natural polyphenol, tannic acid (TA), driven by metal–ligand coordination. Stable Fe(III)/TA films and capsules were formed, indicating lateral and longitudinal cross-linking of TA by Fe(III) in the film structure. Quartz crystal microbalance, ultraviolet–visible (UV-vis) spectrophotometry, and X-ray photoelectron spectroscopy were carried out to quantitatively analyze the film growth. A comparison of the MPC capsules prepared through multistep assembly with those obtained through one-step deposition, as reported previously [Ejima et al., Science 2013, 341, 154–156], reveals substantial differences in the nature of complexation and in their physicochemical properties, including permeability, stiffness, and degradability. This study highlights the importance of engineering MPC films with different properties through implementing different assembly methods.

Enhanced catalytic application of Au@polyphenol-metal nanocomposites synthesized by a facile and green method

“…4c), implying the presence of ferric species. 29 In addition, the peak appearing at 531.2 eV in the split O 1s spectrum (Fig. S3 †) can be attributed to Fe-O species arising from the coordination between TA and Fe 3+ .…”

Anisotropic polydopamine capsules with an ellipsoidal shape that can tolerate harsh conditions: efficient adsorbents for organic dyes and precursors for ellipsoidal hollow carbon particles

“…The PS core is not crosslinked and therefore the linear PS chains dissolved in THF can diffuse out of the PDA shell, as conrmed by many previous works. 6,23,24,40,49 TEM and SEM of the PDA coated particles and the ones aer removing PS are listed in Fig. 1.…”

“…S4 †). 4,6,7,9,12,24,37,38,40 Interestingly, although collapsing of the spherical PDA capsules isotopically occurs to all directions around the curved surface (Fig. S4 in ESI †), 9,38 the micrometersized ellipsoidal PDA capsules collapse along their side of the long axis into attered shells.…”

Tailoring stimuli-responsive delivery system driven by metal–ligand coordination bonding

“…Tannic acid (TA), a high-molecular weight polyphenol, contains five digalloyl ester groups covalently attached to a central glucose core. 24 The unique structure of TA can help in interacting with a variety of materials through multiple reaction pathways. [24][25][26][27] Like many other polyphenols, a salient feature of TA is its strong metal chelation ability and material surface-binding affinity, by which it acts as a polydentate ligand for metal ion coordination bonding.…”

“…24 The unique structure of TA can help in interacting with a variety of materials through multiple reaction pathways. [24][25][26][27] Like many other polyphenols, a salient feature of TA is its strong metal chelation ability and material surface-binding affinity, by which it acts as a polydentate ligand for metal ion coordination bonding. 28,29 Due to diverse structural and functional properties of TA, combined with its chelation ability, metal-TA coordination complexes could form three-dimensional films on a range of substrates.…”