Flame retardant epoxy is closely related to the safety of a human's life against the surrounding fire threat. Flame retardant properties can be obtained by supplementing with additives, such as phosphorus compounds and nanomaterials, or synthesizing flame retardant monomers. The principle of improving flame retardancy is based on the capture of oxygen radicals and the formation of a char layer, which blocks flammable gases. This paper focuses on a flame retardant epoxy resin using naturally occurring tannic acid (TA) as a hardener, which is both an oxygen-radical quencher and a charring agent. TA is reacted with the commercially available diglycidyl ether of bisphenol A (DGEBA). The reaction between the epoxy ring of the DGEBA and multiple functional groups in TA is empirically demonstrated using dynamic scanning calorimetry (DSC) and Brillouin spectra. The most effective flameretardant TA-DGEBA (TD) thermoset had an limiting oxygen index (LOI) value 46% higher than the control sample. This result suggests that TA-based epoxy resins could be promising flame-retardant polymers.

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Proton conduction is an essential process that regulates an integral part of several enzymatic catalyses and bioenergetics. Proton flows in biological entities are sensitively controlled by several mechanisms. To understand and manipulate proton conduction in biosystems, several studies have investigated bulk proton conduction in biomaterials such as polyaspartic acid, collagen, reflectin, serum albumin mats, and eumelanin. However, little is known about the bulk proton conductivity of short peptides and their sequence‐dependent behavior. Here, this paper focuses on a short tyrosine‐rich peptide that has redox‐active and cross‐linkable phenol groups. The spin‐coated peptide nanofilm is immersed in potassium permanganate solution to induce cross‐linking and oxidation, simultaneously leading to hybridization with manganese oxide (MnOx). The peptide/MnOx hybrid nanofilm can efficiently transport protons, and its proton conductivity is ≈18.6 mS cm−1 at room temperature. This value is much higher than that of biomaterials and comparable to those of other synthetic proton‐conducting materials. These results suggest that peptide‐based hybrid materials can be a promising new class of proton conductor.

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Anaerobic digestate of piggery wastewater (ADPW) contains high concentrations of ammonia and phosphorus with unbalanced molar ratio. Thus, ammonia remains at a high level even after phosphorus is completely removed through struvite formation. In this study, both ammonia and phosphorus were recovered by adding leachate of sewage sludge ash (SSA) into ADPW. It was demonstrated that 11,600 mg L of total phosphorus and 7266.7 mg L of [Formula: see text]-P were extracted from SSA by using sulfuric acid at the HSO/SSA mass ratio of 0.35. ADPW and the leachate of SSA were mixed at the volumetric ratio of 1:1.29, and then struvite was formed at the molar ratio of 1.2 (Mg):1.0 ([Formula: see text]-P):1.0 (NH-N). Removal efficiencies of ammonia and phosphorus were 91.95% and 99.65%, respectively. The obtained struvite was analyzed by various methods and was found to meet the Korean fertilizer standards, except for copper.

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