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In this study, two-dimensional (2D) and exfoliated FeIII nanosheets are prepared using a fast and facile fluid-dynamics-induced exfoliation method for large-scale production. The resulting FeIII nanosheet is ultrathin and of 2D morphology with a high surface area. The FeIII nanosheet exhibits excellent glycolysis-catalytic performance for polyethylene terephthalate (PET) degradation to produce a bis(hydroxyethyl) terephthalate (BHET) monomer. A high PET conversion of 100% and a high BHET yield of 100% using the FeIII nanosheet catalyst are achieved within a short reaction time (30 min) at a reaction temperature of 200 °C. Furthermore, the FeIII nanosheet catalyst shows excellent recyclability for the glycolysis of PET, and a high BHET yield of 96.7% was obtained after five cycles.

Composite materials have been extensively studied to optimize properties such as lightness and strength, which are the advantages of plastics. We prepared a highly concentrated (30 wt %) nylon/chitosan nanowhisker (CSW) masterbatch by blending nylon 6,10 and CSW by solvent casting to achieve high dispersion efficiency while considering an industrial setting. Subsequently, 0.3 wt % nylon/CSW nanocomposites were prepared with a large quantity of nylon 6,10 via melt blending. During preparation, the materials were stirred in the presence of formic acid at different times to investigate the effect of stirring time on the structure of the CSW and the physical properties of the composite. The formation of nanocomposites by the interactions between nylon and CSW was confirmed by observing the change in hydrogen bonding using FT-IR spectroscopy and the rise in melting temperature and melting enthalpy through differential scanning calorimetry. The results demonstrated increases in complex viscosity and shear thinning. The rheological properties of the composites changed due to interactions between CSW and nylon, as indicated by the loss factor. The mechanical properties produced by the nanocomposite stirred for 1.5 h were superior, suggesting that formic acid caused minimal structural damage, thus verifying the suitability of the stirring condition.

Two-dimensional (2D) materials have been extensively studied as promising heterogeneous catalysts because of their high surface area, outstanding mechanical strength, and excellent chemical and thermal stability. Herein, we report an efficient and simple two-step strategy for the synthesis of 2D holey and ultrathin MnO2/graphene oxide nanosheets. As a 2D nanoporous support, holey graphene oxide (HGO) nanosheets are prepared by an oxidative etching method. The uniform and conformal deposition of MnO2 onto the HGO surface is performed by a solution-based self-limiting redox reaction, resulting in nanoporous MnO2/HGO nanosheets with a high surface area. The resulting MnO2/HGO shows outstanding catalytic performance for the glycolysis of polyethylene terephthalate (PET). A high conversion of PET (100%) and a high yield of a bis(hydroxyethyl) terephthalate (BHET) are achieved within a short reaction time of 10 min at a reaction temperature of 200 °C. Furthermore, the MnO2/HGO catalyst shows excellent recyclability for the glycolysis of PET; a BHET yield of 100% is obtained after 5 cycles.

We report on the high-throughput production of heterogeneous catalysts of RuO2-deposited graphene using a hydrodynamic process for selective alcohol oxidation. The fluid mechanics of a hydrodynamic process based on a Taylor–Couette flow provide a high shear stress field and fast mixing process. The unique fluidic behavior efficiently exfoliates graphite into defect-free graphene sheets dispersed in water solution, in which ionic liquid is used as the stabilizing reagent to prevent the restacking of the graphene sheets. The deposition of RuO2 on a graphene surface is performed using a hydrodynamic process, resulting in the uniform coating of RuO2 nanoparticles. The as synthesized RuO2/IL–graphene catalyst has been applied efficiently for the oxidation of a wide variety of alcohol substrates, including biomass-derived 5-hydroxymethylfurfural (HMF) under environmentally benign conditions. The catalyst is mechanically stable and recyclable, confirming its heterogeneous nature.