INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2018
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IF 3.141
Fan Cao,Hongxia Gao,Haipeng Li,Zhiwu Liang
N,N-Dimethylethanolamine (DMEA) is a promising absorbent due to the relative higher reaction rate and high capacity for CO2 capture. In this work, the CO2 absorption performance into aqueous DMEA solution using a polytetrafluoroethylene (PTFE) hollow-fiber membrane contactor (HFMC) was investigated experimentally and numerically. The CO2 absorption fluxes were determined under various important operating parameters, including liquid velocity, gas velocity, liquid feed temperature, CO2 partial pressure, and CO2 loading in liquid phase. In addition, a 2D steady-state mathematical model was established to predict the CO2 absorption flux in two operation modes, nonwetted and partially wetted modes, and was validated by using the CO2 absorption into water and aqueous MEA solution. The experimental and simulated results revealed that the CO2 absorption flux can be enhanced by increasing liquid velocity, liquid-phase temperature, and amine concentration in a moderate range. Also, the CO2 absorption flux will increase with the increasing gas velocity and CO2 partial pressure but decrease with increasing CO2 loading in the liquid phase. In addition, the membrane wetting can cause a severe deterioration in the CO2 absorption performance even with a slight membrane wetting. The CO2 absorption fluxes for CO2 absorption into DMEA solutions show the good agreement with or are closer to the simulated data with the membrane wetting of 10% under the same operational conditions, with the average absolute relative deviation (AARD) of 5.02%. Furthermore, the obtained radical and axial CO2 concentration profiles from the mathematical model were also discussed to further understand the CO2 absorption process.
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POLYMER DEGRADATION AND STABILITY
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2014
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IF 2.633
Si Chen,Xiaopeng Xu,Jiahuan Zhang,Wei Tang,Yingjun Qu,Xu Wang
A series of novel ureido organic stabilizers for poly(vinyl chloride) (PVC) with different length of alkyl chains, including N,N' -bis(phenylcarbamoyl)ethylenediamine (NA2), N,N' -bis(phenylcarbamoyl)butylenediamine (NA4) and N,N' -bis(phenylcar- bamoyl)hexamethylenediamine (NA6) were designed and synthesized, which have greater stabilizing efficiency compared with Ca/Zn stabilizers and phenylurea at the same concentration in PVC mixtures. The results of Congo red test, discoloration test, thermogravimetric analysis (TGA) and Fourier transform infrared (FTIR) spectra showed that the ureido moieties of NAn ( n = 2, 4, 6) have stronger ability to replace the labile chlorine atoms in PVC chains, but weaker ability to absorb hydrogen chloride (HCl) than those in phenylurea . On the other hand, longer alkyl chains in the synthesized organic stabilizers had positive effect in stabilizing efficiency for PVC, which was proved by the results that NA6 was the most efficient stabilizer among the present study, followed by NA4 and NA2. Furthermore, mixing the model compound NA6 with zinc stearate in different mass ratios led to a true synergistic effect, the “zinc burning” of PVC products was remarkably postponed.
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LANGMUIR
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2016
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IF 3.993
Ge Wang,Peiyi Wu
In this paper, one LCST-type thermoresponsive poly(ionic liquid) (PIL), poly(tetrabutylphosphonium styrenesulfonate) (P[P4,4,4,4][SS]), was introduced to poly(N-isopropylacrylamide) (PNIPAM) by two different ways, mixing and copolymerization. Interestingly, they show distinct thermoresponsive phase transition behaviors, evidenced by temperature-variable 1H nuclear magnetic resonance and Fourier transform infrared in combination with the perturbation correlation moving window (PCMW) technique. The PNIPAM/P[P4,4,4,4][SS] mixture exhibits a sharp and drastic phase transition, similar to that of pure PNIPAM. In the statistical copolymer, PNIPAM-co-P[P4,4,4,4][SS], the thermosensitivity of P[P4,4,4,4][SS] is largely suppressed, resulting in a linear, mild, and incomplete phase transition, which has never been reported before. This abnormal phenomenon is shown to arise from the outstanding hydration ability of P[P4,4,4,4][SS]. Our findings should be conducive to improving our understanding of the interaction between LCST-type polymers with distinct structures and provide a new perspective for preparing thermoresponsive materials with linear phase transition behavior.
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ENVIRONMENTAL RESEARCH
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2024
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IF 7.7
Yang Wang,Xiaoqing He,Peng Gao,Li Feng,Liqiu Zhang
Limited utilization of photogenerated charge carriers in titanium dioxide under visible light have hinder its application development. To address this challenge, a novel N-doped carbon quantum dots (N-CQDs) and oxygen vacancies (OVs) synergistically decorated on TiO 2 (P25) was synthesized through a facile one-step hydrothermal method. Under visible light irradiation, the first order reaction rate constants of formaldehyde (HCHO) photocatalytic oxidation by OVs-TiO 2 and N-CQDs/OVs-TiO 2 was significantly higher than that of pristine P25, with 10.1 and 16.7 folds increase, respectively. Characterization results confirmed the generation of OVs on the surface of N-CQDs/TiO 2 composite. The optical and electrochemical experiments suggested the electron capture center effect of OVs and the properties of N-CQDs in unique up-converted photoluminescence , efficient charge separation, as well as significant adsorption in visible light region. In addition, the work function also clarified that photoelectrons could transfer from N-CQDs to OVs-TiO 2 . Furthermore, different relative humidity and electron paramagnetic resonance (EPR) experiments demonstrated that the hydroxyl radical (•OH) was the dominant reactive radical in HCHO photodegradation . The •O 2 − could also enhance the photodegradation efficiency of HCHO. This work provides an in-depth understanding on the complementary roles of N-CQDs and OVs and is helpful for designing metallic oxide photocatalysts for volatile organic compounds removal.
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BIOSENSORS & BIOELECTRONICS
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2017
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IF 7.78
Yan Li,Junlin He,Jun Chen,Yazhen Niu,Yilin Zhao,Yuchan Zhang,Chao Yu
In this study, a dual-type responsive electrochemical immunosensor was developed for the quantitative detection of proprotein convertase subtilisin/kexin type 9 (PCSK9), a potential biomarker of cardiovascular disease in serum. N-doped graphene nanoribbons (N-GNRs) with good conductivity were used as the sensing matrix modifying the glassy carbon electrode. Palladium platinum alloy (PdPt) nanoparticles with high catalytic performance toward the reduction of hydrogen peroxide (H 2 O 2 ) were reduced onto amino-functionalized fullerene (n-C 60 -PdPt) and significantly amplified the electrochemical signal recorded by the amperometric i-t curve. Furthermore, staphylococcus protein A (SPA) with antibody orientation function was introduced to improve the immunoreaction efficiency. Accordingly, a label-free immunosensor was fabricated based on n-C 60 -PdPt/N-GNRs for the quick detection of PCSK9. Meanwhile, to realize ultrasensitive detection of PCSK9, Pt-poly (methylene blue) (Pt-PMB) nanocomposites synthesized by a one-pot method for the first time were used as a novel signal label, which exhibited uniform morphology as well as good conductivity and produced an electrochemical signal recorded by differential pulse voltammetry (DPV). Herein, a novel sandwich-type immunosensor was designed using n-C 60 -PdPt/N-GNRs as the sensing matrix and Pt-PMB as the signal label for sensitive detection of PCSK9. Under optimal conditions, the label-free immunosensor showed a linear range of 10 pg mL −1 to 100 ng mL −1 with a detection limit of 3.33 pg mL −1 (S/N=3), and the sandwich-type immunosensor exhibited a linear range of 100 fg mL −1 to 100 ng mL −1 with a detection limit of 0.033 pg mL −1 (S/N=3) for PCSK9 detection, indicating its potential application in clinical bioassay analysis.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
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2017
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IF 3.154
Lili Zhang,Hailong Lu,Juan Yu,Zhiguo Wang,Yimin Fan,Xiaofan Zhou
Lignocelluloses (LCs) with various amounts of lignin (even as high as 18.4%) were successfully dissolved in N-methylmorpholine-N-oxide monohydrate (NMMO/H2O) solution with stirring at 85 °C within 5 h. For the developmental dissolution methods of LCs with a high lignin content in NMMO/H2O solution, the following two pretreatment steps of LCs were necessary: (1) glycerol swelling and (2) mechanical extrusion. The mechanical extrusion pretreatment under glycerol swelling dissociated the fiber bundles of LCs to thinner fibers and, thus, enhanced the accessibility and solubility of the LCs in NMMO/H2O. The crystal structure of the pretreated LCs had no significant transformation during pretreatment, while the diameters of the fiber bundles were reduced from 50–60 to 10–12 μm, as investigated by X-ray diffraction and scanning electron microscopy. After the dissolution–regeneration process of LCs, the fiber bundles of the LCs disappeared and the crystal type of cellulose in the LCs was transformed from cellulose I to cellulose II, which indicated the complete dissolution of LCs.
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ANALYTICAL AND BIOANALYTICAL CHEMISTRY
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2025
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IF 3.8
Xie Baogang,Zhan Dujuan,Wu Le,Wang Lele,Lei Yongrong,Liu Meng,Liu Xiaodan,Li Suping
Congenital heart disease (CHD) poses significant clinical challenges due to limitations in early prenatal diagnosis. This study aimed to identify serum metabolic biomarkers for CHD using a combined metabolomics approach. Serum samples from 55 pregnant women carrying fetuses with confirmed CHD (CHDP group) and 49 healthy controls (ZCP group) were analyzed via non-targeted 1 HNMR metabolomics, revealing distinct metabolic profiles. Six choline pathway metabolites were further quantified by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). Among these, N,N-dimethylglycine (DMG) exhibited the most significant reduction in the CHDP group (1.07 ± 0.03 vs. 1.55 ± 0.04 µg/mL, p < 0.001), with an area under the ROC curve (AUROC) of 0.883 in the discovery cohort. Validation in an independent cohort (58 CHDP vs. 62 ZCP) confirmed DMG’s diagnostic potential (AUROC = 0.818). While betaine-homocysteine methyltransferase 2 (BHMT2) activity showed no intergroup differences, DMG’s consistent performance highlights its utility as a non-invasive biomarker. This study underscores the clinical value of metabonomics in prenatal CHD screening and establishes DMG as a promising diagnostic marker, potentially improving early detection and perinatal management. Graphical abstract
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JOURNAL OF SOLID STATE CHEMISTRY
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2019
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IF 2.291
Hongjie Li,Yi He,Qiangbing Yang,Jizhuang Wang,Siming Yan,Chunlin Chen,Jingyu Chen
Electrospinning and carbonization have been combined to fabricate urchin-like nickel nanoparticle@ nitrogen doped carbon composites electrocatalysts for efficient oxygen evolution reaction (OER), in which bamboo-like and graphic N-doped carbon nanotubes encapsulated nickel nanoparticles can be detected on the substrates’ surface. The catalyst has superior performance in OER shows a low overpotentials of 305 mV at 10 mA cm −2 , small Tafel slope of 62 mV·dec −1 and outstanding durability. In addition, the research opens a simple route to develop high-efficient OER electrocatalyst from earth-abundant materials.
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ChemPlusChem
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2014
·Vol. 79
·期 7
·907-913
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IF 3.242
Xiang Wang,Pengcheng Huang,Ping Yu,Lifen Yang,Lanqun Mao
In this study, a new method was developed for the rapid and cost-effective synthesis of nanosized zeolitic imidazolate framework-7 (ZIF-7) nanocrystals with a high yield and a low molar ratio of benzimidazole ligand to metal salt (2:1) by using N , N′- dimethylformamide (DMF) as the solvent and zinc acetate dihydrate (Zn(OAc) 2 ⋅2 H 2 O) as the metal source. The synthesized ZIF-7 nanocrystals have a size of approximately 50–80 nm, and tend to aggregate or become intergrown to form irregular nanoparticles of about 200–300 nm in size. The morphology and yield of the ZIF-7 nanocrystals can be tuned easily by changing the synthetic parameters such as the composition of the solvent and concentrations of reagents. The synthesized ZIF-7 nanocrystals exhibit good thermal and chemical stability, CO 2 capture capability, and fluorescent properties. Remarkably, we find that the synthetic strategy developed here can be extended to the syntheses of other kinds of ZIFs including ZIF-69 and ZIF-90. This study offers a new, simple synthetic strategy for the high-yield preparation of ZIF materials. Graphical Zeolitic nanocrystal control : We have developed a new method for the rapid and cost-effective synthesis of nanosized zeolitic imidazolate framework (ZIF-7) nanocrystals with a high yield and a stoichiometric molar ratio of ligand to metal salt (2:1) by using N , N ′-dimethylformamide (DMF) as the solvent and zinc acetate as the metal source (see figure). This strategy can also be extended to the synthesis of ZIF-69 and ZIF-90.
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ANALYTICA CHIMICA ACTA
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2012
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IF 4.555
Tao Li,Haoyue Xie,Zhifeng Fu
A facile, sensitive and universal method was established for analysis of biogenic amines using micellar electrokinetic chromatography coupled with chemiluminescent (CL) detection. It was found that diperiodatocuprate (III) (K 5 [Cu(HIO 6 ) 2 ], DPC), a transition metal chelate at unstable high oxidation state, could effectively enhance the reaction between luminol-type compound and hydrogen peroxide, to produce very strong CL signal. In addition, triethylamine was found to be able to effectively improve the yield of the derivatization reaction between biogenic amines and a luminol-type derivatization reagent, N -(4-aminobutyl)- N -ethylisoluminol (ABEI). Based on these facts, three biogenic amines were pre-column derivatized with ABEI, and post-column detected using high sensitive luminol-hydrogen peroxide-DPC CL system. Since the background was quite low, and the signal was quite strong, a considerable improved sensitivity was obtained. The presented method had been successfully applied to simultaneously analyze glycine, proline and phenylalanine with the detection limits (S/N = 3) of 0.030 μmol L −1 , 0.23 μmol L −1 and 0.21 μmol L −1 , respectively. To evaluate its potential application value, glycine in saliva and urine samples was detected using this method, and satisfied results were obtained. This approach can be further extended to detection of many other compounds such as peptides and drugs by using luminol-type derivatization reagent.
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JOURNAL OF ORGANIC CHEMISTRY
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2017
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IF 4.849
Xiaoxia Wang,Na Li,Zhongfeng Li,Honghua Rao
A dehydrogenative C(sp2)–N bond-forming strategy via copper-catalyzed intramolecular C–H/N–H coupling has been developed, which systematically unraveled the feasibility and practicality for benzoimdazo[1,2-a]indole formations through oxidative anilidic N–H activation. The merit of this strategy is illustrated by the broad tolerance of functionalities, as well as the utilization of extremely cheap copper catalysis to realize potentially useful indole-fused tetracycles in a step- and atom-economical manner.
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ACS Applied Polymer Materials
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2022
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IF 4.855
Yun Huang,Weida Zeng,Peirong Li,Qiang Liao,Ao Xia,Xianqing Zhu,Xun Zhu
Microalgal biofilm is one of the most promising candidates for renewable feedstock accumulation and carbon neutralization. To synergistically enhance cell adhesion during the microalgal biofilm formation stage and detachment during the harvesting stage, a surface possessing controllable properties is expected. However, the enhancement of the adhesion capacity of a conventional N-isopropylacrylamide (NIPAM) coating to microalgal cells only happens when the temperature reaches its lower critical solution temperature (LCST) of 33 °C, but at the optimum growth temperature of microalgae (25 °C) its adhesion capacity is dramatically weakened. In this study, a nondependent and environment-friendly thermoresponsive coating with a flexible LCST (22.3–25.0 °C) was prepared by cross-linking poly(NIPAM-co-N-tert-butylacrylamide) onto polydopamine to accelerate the adhesion of microalgal cells onto the coating at the optimum growth temperature of microalgae (25 °C). The coatings exhibited outstanding temperature-switchable performance due to competition between hydrophobic groups and hydrophilic groups in polymer molecules. Based on the temperature-switchable characteristic, the adhesion density of Chlorella sorokiniana MB-1 (C. sorokiniana) on the coating was increased by 49.4% compared to the conventional coating at 25 °C. Meanwhile, at 15 °C, the detachment efficiency of these cells on the coating reached 96.5%. The energy barrier between the C. sorokiniana and the coating was reduced by 54.8% compared to that of these cells on conventional coating, resulting in excellent cell adhesion and release. This report not only designs smart polymers for adjusting the adhesion of microalgal cells but also provides a sustainable strategy for microalgal biofilm cultivation.
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