Hye-Young Cho

CO2 capture and conversion using Mg-MOF-74 prepared by a sonochemical method

Mg-MOF-74 crystals were successfully prepared in 1 h by a sonochemical method (Mg-MOF-74(S)) after triethylamine (TEA) was added as a deprotonating agent. Mg-MOF-74(S) (1640 m2 g−1 BET surface area) displayed similar textural properties to those of a high-quality MOF sample synthesized in 24 h by the solvothermal method (Mg-MOF-74(C), 1525 m2 g−1). However, mesopores were formed, probably due to the competitive binding of TEA to Mg2+ ions, and the average particle size of the former (ca. 0.6 μm) was significantly smaller than that of the latter (ca. 14 μm). The H2O adsorption capacity was 593 mL g−1 at 298 K for Mg-MOF-74(S), displaying higher hydrophilicity than Zeolite 13X. The adsorption isotherms of Mg-MOF-74(S) for CO2 showed high adsorption capacity (350 mg g−1 at 298 K) and high isosteric heats of adsorption for CO2 (42 to 22 kJ mol−1). The breakthrough experiment confirmed excellent selectivity to CO2 over N2 at ambient conditions (saturation capacity of ca. 179 mg g−1). Ten consecutive adsorption–desorption cycles at 298 K established no deterioration of the adsorption capacity, which showed reversible adsorbent regeneration at 323 K under helium flow for a total duration of 1400 min. Mg-MOF-74(S) also demonstrated excellent catalytic performance in cycloaddition of CO2 to styrene oxide under relatively mild reaction conditions (2.0 MPa, 373 K) with close to 100% selectivity to carbonate, which was confirmed by GC-MS, 1H-NMR, and FT-IR. Mg-MOF-74(S) could be reused 3 times without losing catalytic activity and with no structural deterioration.

Synthesis and Adsorption/Catalytic Properties of the Metal Organic Framework CuBTC

CuBTC (Copper(II) benzene-1,3,5-tricarboxylate) is one of the most well characterized and widely studied metal organic framework (MOF) structures for potential use in industrial applications due to its relatively easy synthesis and excellent textural and physicochemical properties. In this comprehensive review, a different perspective on MOF materials for future sustainability is presented by critically examining the recent works that have considered the synthesis and adsorption/catalytic applications of CuBTC as a model case.

Facile synthesis of covalent organic frameworks COF-1 and COF-5 by sonochemical method

Covalent organic frameworks COF-1 and COF-5 crystals with excellent textural properties were obtained for the first time in a 0.5 L synthesis vessel within 1–2 h by a sonochemical route.

Objective evaluation of the pulling sound for a seat belt in a vehicle

This paper presents the objective method to evaluate the subjective evaluation of the pulling sound of the seat belt. The physical quantification is required to objectively evaluate the subjective response of the pulling sound. This is called the “sound quality metric.” The sound quality metric should be correlated with the subjective rating of the pulling sound. In this paper, not only is the sound quality metric extracted from the measured interior sound when a passenger pulls the seat belt but also the subjective evaluation is performed for the pulling sound of the seat belt in the 18 vehicles. The pulling sound index is developed through a linear regress analysis of the sound quality metric and the subjective rating. The developed index is used for the objective evaluation of the subjective evaluation of the pulling sound of a seat belt with after modifications of seat belt components.