Selective adsorption of Pd(II) over interfering metal ions (Co(II), Ni(II), Pt(IV)) from acidic aqueous phase by metal-organic frameworks

Lin, Shuo,Bediako, John Kwame,Cho, Chul-Woong,Song, Myung-Hee,Zhao, Yufeng,Kim, Jeong-Ae,Choi, Jong-Won,Yun, Yeoung-Sang Elsevier 2018 Chemical Engineering Journal Vol.345 No.-

<P><B>Abstract</B></P> <P>Metal-organic frameworks (MOFs) have successfully employed as a class of adsorbents for selective separation of CO<SUB>2</SUB> and some organics from gas and liquid phases; however, little attention has been paid to MOFs applications for selective adsorption of ionic targets from aqueous solutions. Besides, selective separation of precious metals is of great importance from the standpoint of realizing a new sustainable development concept of “urban mining”. While, separation of precious metals is challenging, as they are often present in acidic solutions with many interfering metal ions. Herein, Zr(IV)-cluster-based MOFs were synthesized in this study for the selective adsorption of Pd(II), as a model precious metal ion, from acidic aqueous solutions containing Co(II), Ni(II), Pd(II), and Pt(IV). Among the various Zr-MOFs synthesized (i.e. UiO-66, UiO-66-NH<SUB>2</SUB> and UiO-66-NHCOCH<SUB>3</SUB>), UiO-66-NH<SUB>2</SUB> showed the highest Pd(II) selectivity, with the Pd(II) uptake in the mixture-metals solution being around 181 times higher than that of Pt(IV). The Pd(II) selectivity of UiO-66-NH<SUB>2</SUB> was attributed to higher binding affinity of the protonated amino groups (–NH<SUB>3</SUB> <SUP>+</SUP>) for PdCl<SUB>4</SUB> <SUP>2−</SUP> and more convenient diffusion of the PdCl<SUB>4</SUB> <SUP>2−</SUP> through the apertures (pores) of the UiO-66-NH<SUB>2</SUB> – which have the appropriate inner sizes befitting PdCl<SUB>4</SUB> <SUP>2−</SUP> penetration – than for Pt(IV) ions (PtCl<SUB>6</SUB> <SUP>2−</SUP>).</P> <P><B>Highlights</B></P> <P> <UL> <LI> This is the earliest report of selective MOFs (UiO-66-NH<SUB>2</SUB>) for an ionic target (PdCl<SUB>4</SUB> <SUP>2−</SUP>). </LI> <LI> The protonated amino groups show high affinity for PdCl<SUB>4</SUB> <SUP>2−</SUP>. </LI> <LI> The convenient diffusion of the PdCl<SUB>4</SUB> <SUP>2−</SUP> through the apertures of the UiO-66-NH<SUB>2</SUB> are found. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Highly Effective Removal of Nonsteroidal Anti-inflammatory Pharmaceuticals from Water by Zr(IV)-Based Metal-Organic Framework: Adsorption Performance and Mechanisms

Lin, Shuo,Zhao, Yufeng,Yun, Yeoung-Sang American Chemical Society 2018 ACS APPLIED MATERIALS & INTERFACES Vol.10 No.33

<P>Nonsteroidal anti-inflammatory pharmaceuticals are emerging organic micropollutants in surface water, groundwater, and wastewater, whose removal is very important yet challenging. As a new class of porous functional materials, metal-organic frameworks (MOFs) have attracted extensive attention for their adsorption applications. Here, we report that Zr(IV)-based MOFs (defective UiO-66, and MOF-808) have extraordinary adsorption ability to remove nonsteroidal anti-inflammatory pharmaceuticals from water. Excellent adsorption performances are obtained for UiO-66 and MOF-808, particularly for UiO-66, of which the adsorption capacities are the highest in a wide series of adsorptive materials previously reported. It is elucidated that the incomplete-coordinated cationic Zr in the cluster has high affinity for the anionic pharmaceutical (chemical adsorption) and that the adsorption interaction between the benzene ring of the pharmaceutical and MOF’s ligand is involved to enhance or as an alternative to the adsorption interactions (π-π interaction). In particular, adsorption of ibuprofen, ketoprofen, naproxen, indomethacin, and furosemide by UiO-66 and MOF-808 and the synergetic effect of chemical adsorption and π-π interaction are outstanding, leading to extremely higher binding energies (<I>E</I><SUB>bind</SUB>) and sorption abilities.</P> [FIG OMISSION]</BR>

Adsorptive interaction of cationic pharmaceuticals on activated charcoal: Experimental determination and QSAR modelling

Zhao, Yufeng,Choi, Jong-Won,Bediako, John Kwame,Song, Myung-Hee,Lin, Shuo,Cho, Chul-Woong,Yun, Yeoung-Sang Elsevier 2018 Journal of hazardous materials Vol.360 No.-

<P><B>Abstract</B></P> <P>Due to high mobility and specific toxic actions of the ionizable pharmaceuticals in surface water with a normal range of pH, the pharmaceuticals should be removed before being discharged. Therefore, this study investigated the adsorptive interactions between cationic pharmaceuticals and a popular adsorbent (i.e., activated charcoal) frequently used in water treatment processes. For that, we performed isotherm experiments and then the results were plotted by Langmuir model to determine the adsorption affinity (<I>b</I>) and capacity (<I>q<SUB>m</SUB> </I>). Afterwards, to interpret the adsorption behaviors, two simple prediction models were developed based on quantitative structure-activity relationships (QSAR). In the modelling, molecular weight (MW), polar surface area (PSA), and octanol-water partitioning coefficient (log <I>P</I>) were used as model parameters. In the results, the combinations of these three parameters could predict the adsorption affinity and capacity in <I>R</I> <SUP>2</SUP> of 0.85 and 0.80, respectively. The robustness of models was validated by leave-one-out cross-validation (<I>Q</I> <SUP>2</SUP> <SUB>LOO</SUB>) and the estimated <I>Q</I> <SUP>2</SUP> <SUB>LOO</SUB> values were 0.60 and 0.55 for the adsorption affinity and capacity, respectively, which are higher than the acceptability of standard i.e., 0.5.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Adsorptive interactions between cationic pharmaceuticals and activated charcoal were obtained at natural pH. </LI> <LI> Simple and easy parameters were used to predict adsorptive behavior through QSAR-based modelling. </LI> <LI> Major factors influencing the adsorption include log <I>P</I>, polar surface area, and molecular weight of pharmaceuticals. </LI> <LI> The log <I>P</I> value of pharmaceutical was the most important factor. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Novel high-Q × f (1 − x)CeO2–xCaF2 (0.2 ≤ x ≤ 0.6) microwave dielectric ceramics sintered at medium temperatures

Gao Yufeng,Jiang Juan,Wang Jinzhao,Gan Lin,Zhang Tianjin 한국세라믹학회 2022 한국세라믹학회지 Vol.59 No.6

In this work, a new binary microwave dielectric ceramic system of (1 − x)CeO2–xCaF2 (0.2 ≤ x ≤ 0.6) was fabricated at medium sintering temperatures. The compositional eff ects of on the sintering behavior, phase compositions, microstruc- tures, and microwave dielectric properties of the samples were studied. High relative density levels (> 95%) were achieved in the (1 − x)CeO2–xCaF2 samples at the sintering temperatures ranging from 1100 to 1350 °C. An increase in the content of CaF 2 resulted in a decrease in the dielectric constant, an increase in the Q × f level, and a negative shift of the τf value. The optimal microwave dielectric properties of εr = 11.3, Q × f = 53,000 GHz, and τf = − 102 ppm/°C were obtained in the sample of (1 − x)CeO2–xCaF2 with x = 0.6 when sintered at 1300 °C.

Experimental and QSAR studies on adsorptive interaction of anionic nonsteroidal anti-inflammatory drugs with activated charcoal

Zhao, Yufeng,Choi, Jong-Won,Lin, Shuo,Kim, Jeong-Ae,Cho, Chul-Woong,Yun, Yeoung-Sang Elsevier 2018 CHEMOSPHERE - Vol.212 No.-

<P><B>Abstract</B></P> <P>Adsorptive interactions, namely adsorption capacity (<I>q</I> <SUB>m</SUB>) and affinity (<I>b</I>), between nonsteroidal anti-inflammatory drugs (NSAIDs) in anionic forms and commercial activated charcoal (AC), were estimated by isotherm experiment in a batch, and the properties were modeled based on the concept of quantitative structure–activity relationship (QSAR). Experimental results showed that AC had a high <I>q</I> <SUB>m</SUB> (0.38–0.67 mmol g<SUP>−1</SUP>) and <I>b</I> (14.03–930.8 L mmol<SUP>−1</SUP>) for the selected NSAIDs. In QSAR modeling, linear free energy relationship (LFER) descriptors of excess molar refraction (<I>E</I>), dipolarity/polarizability (<I>S</I>), and Coulombic interactions of anions (<I>J</I> <SUP>−</SUP>) were highly related to log <I>q</I> <SUB>m</SUB>, and the combination of the three terms could predict log <I>q</I> <SUB>m</SUB> in <I>R</I> <SUP>2</SUP> of 0.97 and SE of 0.015 log unit. In the case of <I>b</I>, only single <I>B</I> term showed a good correlation with log <I>b</I> in <I>R</I> <SUP>2</SUP> of 0.81. Additionally, the combination of hydrogen-bonding acceptors (HBAs) and molar volume (MV), which are easily calculable parameters, could also derive good predictability in <I>R</I> <SUP>2</SUP> = 0.81 and SE = 0.26 log unit. Afterwards, validation of the QSAR models based on the leave-one-out cross-validation (<I>Q</I> <SUP> <I>2</I> </SUP> <SUB> <I>LOO</I> </SUB>) method showed that the models were acceptable.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Adsorption properties between NSAIDs and AC were investigated by experimental and theoretical methods. </LI> <LI> The adsorption capacity can be predicted with linear free energy relationship model in <I>R</I> <SUP>2</SUP> of 0.97. </LI> <LI> Adsorption capacity is strongly related to excess molar refraction, dipolarity/polarizability, and ionic interactions. </LI> <LI> Molecular volume and HBAs of NSAIDs correlate with adsorption affinity on AC in <I>R</I> <SUP>2</SUP> of 0.81. </LI> <LI> Adsorption affinity is strongly related to H-bonding acceptability (<I>B</I>) of anionic NSAIDs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Monitoring moisture content of timber structures using PZT-enabled sensing and machine learning

Qingzhao Kong,Lin Chen,Hai-Bei Xiong,Yufeng He,Xiuquan Li 국제구조공학회 2022 Smart Structures and Systems, An International Jou Vol.29 No.4

Timber structures are susceptible to structural damages caused by variations in moisture content (MC), inducing severe durability deterioration and safety issues. Therefore, it is of great significance to detect MC levels in timber structures. Compared to current methods for timber MC detection, which are time-consuming and require bulky equipment deployment, Lead Zirconate Titanate (PZT)-enabled stress wave sensing combined with statistic machine learning classification proposed in this paper show the advantage of the portable device and ease of operation. First, stress wave signals from different MC cases are excited and received by PZT sensors through active sensing. Subsequently, two non-baseline features are extracted from these stress wave signals. Finally, these features are fed to a statistic machine learning classifier (i.e., naive Bayesian classification) to achieve MC detection of timber structures. Numerical simulations validate the feasibility of PZT-enabled sensing to perceive MC variations. Tests referring to five MC cases are conducted to verify the effectiveness of the proposed method. Results present high accuracy for timber MC detection, showing a great potential to conduct rapid and long-term monitoring of the MC level of timber structures in future field applications.

The near wake of three circular cylinders in an equilateral triangular arrangement at a low Reynolds number Re=100

Honglei Bai,Yufeng Lin,Md. Mahbub Alam 한국풍공학회 2020 Wind and Structures, An International Journal (WAS Vol.30 No.5

Two-dimensional numerical simulations are conducted at a low Reynolds number Re = 100 to investigate the near wake of three identical circular cylinders that are arranged in an equilateral triangular configuration. The incident angle of the three-cylinder configuration with respect to incoming flow is varied from  = 0o to 60o, while the spacing between adjacent cylinders (L) covers a wide range of L/D = 1.25-7.0, where D is diameter of the cylinder. Typical flow structures in the near wake of the three-cylinder configuration are identified, including a single Karman vortex street, bistable flip-flopping near wake, anti-phase and/or in-phase vortex shedding, shear layer reattachment, and vortex impingement, depending on the configuration (L/D, ). The behavior of Strouhal number (St) is discussed in detail, echoing the distinct structures of near wake. Furthermore, fluid forces on the individual cylinders are examined, which, though highly depending on (L/D, ), exhibit a close correlation to the near wake behavior.

Two new triterpenoid saponins derived from the leaves of Panax ginseng and their antiinflammatory activity

Fuli Li,Yufeng Cao,Tingwu Liu,Guilong Yan,Liang Chen,Lilian Ji,Lun Wang,Bin Chen,Aftab Yaseen,Ashfaq A. Khan,Guo-Lin Zhang,Yunyao Jiang,Jianxun Liu,Gongcheng Wang,Ming-Kui Wang,Weicheng Hu 고려인삼학회 2019 Journal of Ginseng Research Vol.43 No.4

Background: The leaves and roots of Panax ginseng are rich in ginsenosides. However, the chemical compositionsof the leaves and roots of P. ginseng differ, resulting in different medicinal functions. In recent years,the aerial parts of members of the Panax genus have received great attention fromnatural product chemistsas producers of bioactive ginsenosides. The aim of this study was the isolation and structural elucidation ofnovel, minor ginsenosides in the leaves of P. ginseng and evaluation of their antiinflammatory activity in vitro. Methods: Various chromatographic techniques were applied to obtain pure individual compounds, andtheir structures were determined by nuclear magnetic resonance and high-resolution mass spectrometry,as well as chemical methods. The antiinflammatory effect of the new compounds was evaluated onlipopolysaccharide-stimulated RAW 264.7 cells. Results and conclusions: Two novel, minor triterpenoid saponins, ginsenoside LS1 (1) and 5,6-didehydroginsenoside Rg3 (2), were isolated from the leaves of P. ginseng. The isolated compounds 1and 2 were assayed for their inhibitory effect on nitric oxide production in LPS-stimulated RAW 264.7cells, and Compound 2 showed a significant inhibitory effect with IC50 of 37.38 mM compared with that ofNG-monomethyl-L-arginine (IC50 ¼ 90.76 mM). Moreover, Compound 2 significantly decreased secretionof cytokines such as prostaglandin E2 and tumor necrosis factor-a. In addition, Compound 2 significantlysuppressed protein expression of inducible nitric oxide synthase and cyclooxygenase-2. These resultssuggested that Compound 2 could be used as a valuable candidate for medicinal use or functional food,and the mechanism is warranted for further exploration.

Removal and fate of carbamazepine in the microbial fuel cell coupled constructed wetland system

Jingyi Xie,Haixiao Li,Shiyu Wang,Hao Chen,Wei Jiang,Lin Zhang,Lianjie Wang,Yufeng Wu,Lirong Li,Xueqiang Lu 대한환경공학회 2022 Environmental Engineering Research Vol.27 No.3

Carbamazepine (CBZ), which is difficult to remove in the wastewater treatment system and easily forms toxic transformation products during the treatment process, is one of the priority pollutants of pharmaceuticals and personal care products (PPCPs). Increasing attention has been paid to explore their treatment technology without side effects from the treatment products. This study aims to reveal the removal and transformation of CBZ in the microbial fuel cell coupled constructed wetland (CW-MFC) system. The CW-MFC system was operated continuously at room temperature for nearly 80 days. The results show that CW-MFC system can effectively remove CBZ with an average removal rate of 97%. Three transformation products were identified by liquid chromatography−high-resolution mass spectrometry: 2-(2-oxoquinazolin-1(2H)-yl) benzoic acid (TP267), methyl 2-(2-oxoquinazolin-1(2H)-yl) benzoate (TP281), 2-(2,4-dioxo-3,4-dihydroquinazolin-1(2H)-yl) benzoic acid (TP283). Except TP281 in the influent, the other transformation products were formed in the system, which indicated that TP267 and TP283 were the main transformation products of CBZ. The formation pathway of transformation products could be explained by reactions including oxidation, hydrolysis, bond rupture and intramolecular reaction. The results also indicate that the CW-MFC system might be a promising technology for PPCPs treatment.

Monolayer Molybdenum Disulfide Transistors with Single-Atom-Thick Gates

Zhu, Yibo,Li, Yijun,Arefe, Ghidewon,Burke, Robert A.,Tan, Cheng,Hao, Yufeng,Liu, Xiaochi,Liu, Xue,Yoo, Won Jong,Dubey, Madan,Lin, Qiao,Hone, James C. American Chemical Society 2018 NANO LETTERS Vol.18 No.6

<P>Two-dimensional transition-metal dichalcogenides (TMDs) are unique candidates for the development of next-generation electronic devices. However, the large contact resistance between metal and the monolayer TMDs have significantly limited the devices’ performance. Also, the integration of ultrathin high-<I>k</I> dielectric layers with TMDs remains difficult due to the lack of dangling bonds on the surface of TMDs. We present monolayer molybdenum disulfide field-effect transistors with bottom local gates consisting of monolayer graphene. The atomic-level thickness and surface roughness of graphene facilitate the growth of high-quality ultrathin HfO<SUB>2</SUB> and suppress gate leakage. Strong displacement fields above 8 V/nm can be applied using a single graphene gate to electrostatically dope the MoS<SUB>2</SUB>, which reduces the contact resistances between Ni and monolayer MoS<SUB>2</SUB> to 2.3 kΩ·μm at low gate voltages. The devices exhibit excellent switching characteristics including a near-ideal subthreshold slope of 64 millivolts per decade, low threshold voltage (∼0.5 V), high channel conductance (>100 μS/μm), and low hysteresis. Scaled devices with 50 and 14 nm channels as well as ultrathin (5 nm) gate dielectrics show effective immunity to short-channel effects. The device fabricated on flexible polymeric substrate also exhibits high performance and has a fully transparent channel region that is desirable in optical-related studies and practical applications.</P> [FIG OMISSION]</BR>