Hydrophilic surface modification of carbon black through a mussel-inspired reaction of tannic acid and diethlyenetriamine

Facile Preparation of Silica/Tannic Acid/Zein Microcapsules Templated from Non-Aqueous Pickering Emulsions and their Application in Cargo Protection

Microcapsules have attracted significant attention in academia and industry due to their unique properties for protecting and controlling the release of active substances. However, based on water-insoluble biopolymers, developing a straightforward approach to prepare microcapsules with improved biocompatibility and functional shells remains a great challenge. In this study, zein, a water-insoluble protein, is employed to prepare robust microcapsules facilely using oil-in-aqueous ethanol Pickering emulsions as templates. First, the emulsion template is stabilized by hydrophobic silica nanoparticles with in situ surface modification of tannic acid. The zein is then precipitated at the interface in a controlled manner using antisolvent approach to obtain silica/tannic acid/zein (STZ) microcapsules. It is found that the concentration of zein and the presence of tannic acid played a significant role in the formation of STZ microcapsules with well-defined morphology and a robust shell. The uniform deposition of zein on the surface of template droplets is facilitated by the interactions between tannic acid and zein via hydrogen bond and electrostatic force. Finally, the resulting STZ microcapsules showed super resistance to ultraviolet (UV) radiation and high temperature for the unstable, lipophilic, and active substance of β-carotene.

Colloidal Phenol-Amine Coating on Implants for Improved Anti-Inflammation and Osteogenesis

Phenol-amine coatings have attracted significant attention in recent years owing to their adjustable composition and multifaceted biological functionalities. The current preparation of phenol-amine coatings, however, involves a chemical reaction within the solution or interface, resulting in lengthy preparation times and necessitating specific reaction conditions, such as alkaline environments and oxygen presence. The facile, rapid, and eco-friendly preparation of phenol-amine coatings under mild conditions continues to pose a challenge. In this study, we use a macromolecular phenol-amine, Tanfloc, to form a stable colloid under neutral conditions, which was then rapidly adsorbed on the titanium surface by electrostatic action and then spread and fused to form a continuous coating within several minutes. This nonchemical preparation process was rapid, mild, and free of chemical additives. The in vitro and in vivo results showed that the Tanfloc colloid fusion coating inhibited destructive inflammation, promoted osteogenesis, and enhanced osteointegration. These remarkable advantages of the colloidal phenol-amine fusion coating highlight the suitability of its future application in clinical practice.

Bifunctional Modification Enhances Lithium Extraction from Brine Using a Titanium-Based Ion Sieve Membrane Electrode

Salt lake brine has become a promising lithium resource, but it remains challenging to separate Li⁺ ions from the coexisting ions. We designed a membrane electrode having conductive and hydrophilic bifunctionality based on the H₂TiO₃ ion sieve (HTO). Reduced graphene oxide (RGO) was combined with the ion sieve to improve electrical conductivity, and tannic acid (TA) was polymerized on the surface of ion sieve to enhance hydrophilicity. These bifunctional modification at the microscopic level improved the electrochemical performance of the electrode and facilitated ion migration and adsorption. Poly(vinyl alcohol) (PVA) was used as a binder to further intensify the macroscopic hydrophilicity of the HTO/RGO-TA electrode. Lithium adsorption capacity of the modified electrode in 2 h reached 25.2 mg g^-1, more than double that of HTO (12.0 mg g^-1). The modified electrode showed excellent selectivity for Na⁺/Li⁺ and Mg²⁺/Li⁺ separation and good cycling stability. The adsorption mechanism follows ion exchange, which involves H⁺/Li⁺ exchange and Li-O bond formation in the [H] layer and [HTi₂] layer of HTO.