ACS Applied Engineering Materials最新文献

Three green amino acid-based ionic liquids (AAILs) were synthesized, and their tribological properties, corrosion inhibition capabilities, and biodegradability as water-based additives were systematically evaluated. The addition of 1 wt % of AAILs significantly enhanced the lubrication performance and corrosion resistance of water, of which triisopropanolamine-lauroyl glutamic acid (TIPA-LG) exhibited the most outstanding tribological properties. Compared to water, the coefficient of friction (COF) and wear volume (WV) of TIPA-LG were reduced by 68.5 and 95.5%, respectively. TIPA-LG can form a physical and chemical adsorption film and a friction chemical reaction film at the friction interface. The synergistic effect of these two lubrication films effectively reduces the direct contact between metal surfaces, thereby enhancing the friction-reducing and antiwear properties of the lubricant. Furthermore, TIPA-LG demonstrated excellent environmental compatibility, achieving a biodegradation rate of 80.89% within 28 days. These environmentally friendly, high-performance, water-based lubricant additives show promise in metal working applications.

Developing high-performance thermal insulation is vital for addressing the ongoing global demand for reduced energy costs. Polyisocyanurate (PIR) foams are commonly used in residential and commercial buildings and in various industrial applications owing to their relatively high thermal insulation properties and fire resistivity. This study aims to further improve the thermal resistivity of PIR foams by (1) incorporating low thermal conductivity blowing agents; (2) tailoring the anisotropy of their cells; (3) tuning polymeric isocyanate quantities; and (4) incorporating a facer barrier, while using steps that easily integrate into current manufacturing processes for PIR foams. The resulting PIR foams exhibit a significant enhancement in thermal resistivity, achieving initial values as high as 8.3 h·ft²·°F/Btu/in., commonly abbreviated as R-8.3/in., which is a 20% improvement compared with that of commercially used PIR foams that achieve approximately R-7/in. The detailed analysis of thermal conductivity measurements, mechanical testing, and morphological characterization elucidates the structure–property relationships. The developed high-performance PIR foams provide a critical pillar for next-generation high-performance insulation, offering promising thermal insulation for buildings and many other applications that have a significant effect on global energy costs.

The design of bioactive, biocompatible scaffolds with enhanced osteogenic potential is critical for advancing bone tissue regeneration strategies. In this study, five innovative composite scaffolds were formulated using biphasic calcium phosphate (BCP), egg white (EW), nanosilica (Si), and fish-derived gelatin (G), and evaluated for their mechanical, physicochemical, and biological performance. The optimized BESG composite (BCP + EW + Si + G) exhibited a compressive strength of 4.51 ± 0.13 MPa, a porosity of 66.4 ± 1.29%, and an enhanced apatite-forming ability in simulated body fluid, confirming its structural integrity and bioactivity. FTIR and XRD analyses confirmed the successful integration of organic and inorganic components without compromising phase purity. SEM and TEM revealed an interconnected porous network suitable for cellular infiltration. Biological assessments using rat bone marrow progenitor stem cells demonstrated that BESG significantly improved cell viability (p< 0.001) and promoted osteogenic differentiation, as indicated by increased alkaline phosphatase activity (3.9 ± 0.22 IU/mg) and mineralization in ARS assays. Fluorescent staining confirmed the formation of dense extracellular matrix and high viability. In silico studies further validated the scaffold’s bioactivity; DFT calculations indicated a low HOMO–LUMO energy gap (0.11 eV), suggesting favorable electronic stability. Molecular docking and 100 ns MD simulations revealed strong binding affinities of BESG components with BMP-7 and ALP (binding energies: –10.9 and −9.3 kcal/mol, respectively), supported by stable RMSD and compact Rg values. ADMET analysis predicted excellent biocompatibility and low toxicity. This work introduces a sustainable BESG scaffold synthesized exclusively from biowaste-derived sources, integrating BCP, egg white, nanosilica, and gelatin. The in vitro and in silico synergy underscores its promise for sustainable and clinically translatable bone regeneration.

Diverse functionalization with high surface area and availability of hetero atoms of porous organic polymers (POPs) makes them a promising material for environmental remediation. A tri-s-triazine-based porous organic polymer was synthesized with a high specific surface area of 258.95 m² g^–1 and investigated for adsorptive desulfurization of model fuel (dibenzothiophene in n-hexane). The triazine-based POP showed a maximum adsorption capacity of 147.22 mg g^–1 for DBT at room temperature for isotherm studies of concentrations from 50 to 1500 mg L^–1 DBT with a 20 mL volume and 0.1 g of POP adsorbent without oxidation or external functionalization. The POP was thoroughly characterized using techniques such as FTIR, XRD, XPS, ¹³C NMR, TGA, BET-N₂ and FESEM-EDS analyses. The mechanistic features of the adsorptive desulfurization process were corroborated by isotherm, kinetic, and thermodynamic models that affirmed that the reaction is exothermic and spontaneous following pseudo-second-order kinetics fitting with the Langmuir isotherm. The material was reusable for up to five cycles of adsorption and desorption. Along with removal, the POP material exhibited an excellent fluorescent property that was turned off by the addition of the DBT compound. Therefore, the as-synthesized POP could be a promising adsorbent for desulfurization along with sensing application.

Protection against chemical warfare agents (CWA) needs to be improved, and the addition of self-decontaminating properties to passive protective clothes is a promising tool to avoid (cross-)contamination issues. The purpose of this work was to investigate the layer-by-layer (LbL) deposition of photocatalytically active TiO₂ nanoparticles over textiles for providing additional organophosphorus degradation properties. Here, it is shown how to control the homogeneous and efficient coverage of textile fibers by finding the optimal conditions of the LbL deposition parameters. Then, various commercial TiO₂ references (P25, P90, UV100, PC500, Anatase nanopowder, and Rutile nanopowder from Sigma) differing in their structural, surface, and morphological properties were examined. The resulting functionalized textiles were assessed and compared toward dimethyl methylphosphonate droplets (DMMP, used as an analogue for neurotoxic CWA) photocatalytic degradation under artificial UV irradiation. Preparation/structure/activity correlation of the resulting functionalized textiles highlighted the crucial impact of (i) the surface charges and particle size of TiO₂ in the precursor suspension during LbL deposition and (ii) the charge carrier generation and dynamics under UV-A activation (studied by time-resolved microwave conductivity measurements). Finally, we investigated the mechanisms of DMMP degradation over TiO₂-functionalized textiles through DMMP elimination kinetics monitoring and X-ray photoelectron spectroscopy and FTIR studies.

The persistent environmental challenges posed by synthetic plastics, particularly petroleum-derived petropolymers, such as polyethylene (PE), polypropylene (PP), and polystyrene (PS), have intensified the need for innovative recycling methods. Traditional recycling techniques often rely on harsh conditions, raising environmental and economic concerns. Biofilm-mediated biodegradation has emerged as a promising alternative, operating under mild conditions such as room temperature, neutral pH, and atmospheric pressure. However, the interactions between biofilm-forming microorganisms and synthetic plastics and the roles of secreted enzymes in these processes remain incompletely understood. This review explores the current understanding of biofilm-mediated biodegradation─biodeterioration, biofragmentation, bioassimilation, and mineralization─and the biochemical and physical interactions that control these processes. We highlight the latest findings on the enhancement of petropolymer degradation by biofilms, focusing on the roles of oxidative and attachment enzymes and the environmental factors influencing degradation efficiency. Understanding these complex interactions can inform the design of next-generation enzyme-responsive polymers that are not only easier to degrade but can also serve as smart materials for diverse applications, such as antifouling coatings on metals. This perspective bridges critical knowledge gaps and provides insights into harnessing biofilm-mediated processes for sustainable material innovation.

Development of epoxy resins with multiple properties, such as high tensile strength, transparency, hydrophobicity, and flame retardancy, presents a significant challenge. In this study, three phosphorus–fluorine additives (F1, F4, and F6) were synthesized via a single-step Kabachnik–Fields reaction. The additive F1 confers hydrophobicity and flame retardancy upon bisphenol A type epoxy resin (DGEBA) through fluorine and phosphorus–fluorine synergy while preserving its transparency. Besides, increased tensile strength of F1_10%/EP is attributed to the formation of more π–π stacking and hydrogen bonds. When 10 wt % of F1 (with a theoretical phosphorus content of 0.64 wt %) is incorporated into the DGEBA system, the yielding product of F1_10%/EP, which achieves a V-0 rating in the UL-94 test and exhibits a high limiting oxygen index of 35%, attributing to the presence of both phosphorus and fluorine. During combustion, the peak heat release value and carbon monoxide production of F1_10%/EP are reduced by 54.1 and 18.5%, respectively, and the amounts of carbon residue and graphitic carbon are significantly increased compared to neat epoxy resin. The mechanism reveals that trifluoromethyl radical (·CF₃) and phosphorus free radicals (PO· and PO₂·) generated during F1 combustion contribute to gas-phase interactions, while the resulting phosphoric acid and polyphosphate facilitate carbonization of the epoxy resin. The EP composites can still maintain its flame-retardant and hydrophobic properties at 85 °C. Those findings of this study offer valuable insights for the development of multifunctional epoxy resin additives, which can enhance tensile strength, durable hydrophobicity, and flame retardancy.

Composite material products made of two or more materials are widely used worldwide. However, recycling these materials is not widespread as separating the individual components is challenging. Therefore, a technology to effectively separate materials is essential to enhance recycling rates and establish a sustainable recycling industry. In this study, we aimed to separate common polymer materials from the multimaterial products using an eco-friendly hydrothermal technique that utilizes only water, leveraging the melting point depression of polymers in water. For instance, airbags as multimaterial products are commonly installed as safety devices in automobiles. Most airbags are typically composed of a polyamide 66 (PA66) base fabric coated with silicone to improve airtightness. As it is challenging to separate PA66 and silicone, most airbags are currently being discarded. This study revealed that PA66 could be separated by treating the airbags at temperatures exceeding 200 °C. Additionally, the separated PA66 retained its melting point, indicating that it could be separated without decomposing into monomers─unlike common chemical recycling methods. These findings suggest possibilities for mechanical recycling, using the difference in melting points to separate the individual components in their polymeric state from various combinations of composites.

Currently, it is imperative to develop highly efficient adsorbents using straightforward and gentle techniques for gold recycling from e-waste in order to achieve resource reutilization. Herein, a cross-linked silsesquioxane-based network (PCS-SNO), containing abundant N, O, and S atoms, was designed and synthesized through a simple one-pot sequence synthesis strategy, i.e., first using the “amine-ene” reaction of triaminoethylamine (TAA) with excessive dipentaerythritol penta-/hexa-acrylate (DP/HA) and then using the “thiol–ene” reaction of octamercaptopropylsilsesquioxane (SQ-SH₈) with the remaining acrylate group of DP/HA. The hybrid network is fully characterized using FTIR, ¹³C, and ²⁹Si NMR spectra, XRD, TGA, and BET. PCS-SNO shows a high adsorption capacity of 2152 mg g^–1 and a good selectivity for gold entrapment. The adsorption process conforms to the Langmuir model (R² = 0.965), and the pseudo-second-order model fits with adsorption kinetics (R² = 0.977). Notably, PCS-SNO exhibited a pronounced efficacy in the removal of gold ions at low concentrations (from 12 mg L^–1 to 0.1 mg L^–1), indicating its superior suitability for efficient capture of gold from e-waste. The remarkable adsorption effect can be ascribed to the intricate coordination, redox, and electrostatic interactions of gold ions with PCS-SNO. Moreover, PCS-SNO shows a good selectivity toward gold ions from the e-waste leaching solution. The result indicates that the simple one-pot sequence synthesis strategy is feasible for the preparation of highly efficient hybrid adsorbents containing multiheteroatoms; moreover, the PCS-SNO demonstrates the outstanding entrapment of gold, both at low concentrations and in practical CPU treatment, and is expected to be applied in industrial production.

The photocatalytic application of pure TiO₂ is limited because of its wide band gap, which restricts its activity only in the UV (ultraviolet) region of the solar spectrum. The high recombination of electron and hole charge carriers is another drawback to photocatalytic activity. In this work, we explore the electronic interfacial characteristics of pseudomorphic rutile(110) heterostructures, such as SnO₂/TiO₂, NbO₂/TiO₂, and MnO₂/TiO₂, using density functional theory (DFT)-based computations. The nature of the electronic structure and the band alignment are studied, which helps to identify the heterostructure. The internal electric field created at the interface of the heterostructure is crucial for defining the flow of electron and hole charge carriers, which is understood by the charge density difference plots. The enhancement of optical absorption of the heterostructure toward the visible region of the solar spectrum is further confirmed. From our analysis, we conclude that the nature of the electronic structure and band alignment of the rutile heterostructure are explored. Here, SnO₂/TiO₂ shows a type II heterostructure, MnO₂/TiO₂ shows a type I heterostructure, and NbO₂/TiO₂ shows a metal–semiconductor interface. From the heterostructure model, we proved that the band gap can be reduced toward the visible light absorption, and also, the electron and hole recombination can be avoided by generating the internal electric field along the interface of the heterostructure. From our analysis, we conclude that the pseudomorphic rutile(110) heterostructure will act as a potential photocatalyst for environmental pollution reduction.