Tannic Acid-A Universal Immobilization and Fixation Agent for Nanocarbon Materials: A Novel Strategy for Aqueous Fabrication of Functional Nanocarbon Coating onto Silicon-Based Substances

Abstract

We report a feasible and universal approach to fabricate nanocarbon material (NCM) coatings onto a wide range of silicon-based substances. Benefitting from the phenolic hydroxyl and star-shaped branched molecular structure, tannic acid (TA) could act as a functional agent for immobilization and fixation of NCMs in the aqueous phase. More specifically, steered molecular dynamics simulations verified that some unionized chains of TA could tightly attach to the NCM's surface in the neutral aqueous environment by π−π stacking interactions, and other free arms with ionized phenolic hydroxyl could act as surface charges of the TA/NCM coacervates, resulting in enhanced colloidal stability of this dispersion. Subsequently, these free arms could also interact with the aminated silicon-based substances, enabling TA to act as a "bridge" between the NCM and the silicon-based substances to form the nanocarbon coating. The obtained polydimethylsiloxane with TA/NCM coating represents favorable electrical and thermal conductivity along with excellent electromechanical performance under the cyclic compression-release test. This strategy is a great improvement for the fabrication of NCM layers and devices, which is not necessary to make the hydrophilic modification of NCM and beneficial to enhance the interaction between the carbon layer and substrate, avoiding the coating separation from the substances.

Sustainable Cathodes for Lithium‐Ion Energy Storage Devices Based on Tannic Acid—Toward Ecofriendly Energy Storage

“…The amount of leaked tannic acid does not correlate with the iron content in the samples, leading to the conclusion that iron does not act as a crosslinking agent for tannic acid in our samples. Therefore, we conclude that certain chemical or physical binding between carbon and tannic acid is established in a ball mill, probably a combination of π–π and electrostatic interactions, [ 27 ] forming a rather stable composite. It is important to mention that ultrasonication, a rather harsh method, results in the dissolution of more molecules than it would be the case during battery cycling.…”

Metal–Phenolic Networks as a Universal Aqueous Dispersing and Immobilizing Agent for Nanocarbon Materials: A Facile Strategy for Synthesis of Electronic and Energy Materials in the Aqueous Phase

“…As we know, the mechanism of TA as a dispersion agent could be attributed to its branched polymer structure and its monomer, pyrogallol, which could attach to nanocarbon materials through π−π stacking interaction. 16 The TA-Fe III complex could be regarded as a dimer or trimer of tannic acid, which has a larger accessible surface area than the pristine TA molecule. On the other hand, the TA-Fe III triscomplex exhibited a better appearance in a dispersion of nanocarbon materials than the TA-Fe III bis-complex, as shown in Figures 2A and 2E.…”

“…For example, the mean particle size of TA/MWCNT dispersion at a ratio (mTA/m­(MWCNT)) of 0.5 was 562 nm, and (TA-Fe III ) bis-complex/MWCNT dispersion at a ratio (mTA/m­(MWCNT)) of 0.5 was 351 nm. As we know, the mechanism of TA as a dispersion agent could be attributed to its branched polymer structure and its monomer, pyrogallol, which could attach to nanocarbon materials through π–π stacking interaction . The TA-Fe III complex could be regarded as a dimer or trimer of tannic acid, which has a larger accessible surface area than the pristine TA molecule.…”

“…The branched structure of the metal–TA network could function as tentacles of the octopus, interacting with different substrates via various interactions in the meantime, thus acting as a cross-linking agent for other objectives. It should be noted that the interaction between the metal–TA network and target objective could rely on the TA molecular state, which is tuned by the pH, ionic strength, or temperature . Therefore, it could be speculated that some regions of the metal–TA network could interact with nanocarbon materials by π–π interaction, and the remaining parts of the metal–TA network could act as the hydrophilic part of nanocarbon material, imparting the complex coacervate of the metal–TA network and nanocarbon material the ability to disperse in water.…”

Molecular interactions of tannic acid and matrix metalloproteinases 2 and 9

“…TA ( Fig. 1 a) is a star-shaped polymer with five digallic acid arms [31] . One TA molecule contains five pyrogallol groups in exterior positions and five catechol groups in interior positions [6] .…”