Polymers
·
2018
·Vol. 10
·期 10
·1090
·
IF 2.935
Jiling Zhao,Shixing Wang,Libo Zhang,Chen Wang,Bing Zhang
Industrial wastewater contains large amounts of silver ions. Here, a new adsorbent was synthesized by functionalizing poly(glycidyl methacrylate) with carboxymethyl groups. The adsorbent was used to recover Ag(I) in wastewater. Fourier transform infrared spectroscopy, zeta potential, scanning electron microscopy, and X-ray photoelectron spectroscopy were used to characterize the adsorbent. The experimental parameters affecting the adsorption are solution pH, contact time, and initial silver ion concentration. The optimum pH for adsorption of Ag(I) is pH 4. The maximum adsorption capacity at pH 4 is 157.05 mg/g, and the adsorption reaches equilibrium at 300 min. The kinetics and isotherms of the adsorption process were described by pseudo second-order, Langmuir and D-R models, respectively. The adsorption process was a single layer chemical adsorption, exothermic, feasible, and spontaneous. The adsorption mechanism is electrostatic or chelation. The adsorbent selectively absorbed Ag(I) from coexisting ions (Cu2+, Ni2+, Co2+, Zn2+). Finally, the removal rate of silver ions decreased from 79.29% to 65.01% after four repetitive experiments, which proved that the adsorbent had good reusability. The adsorbent has great potential benefit in removing Ag(I).Keywords:polymer;Ag (I), removal;mechanism;adsorption
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ANALYTICAL CHEMISTRY
·
2019
·
IF 6.35
Li Fu,Bin Zhang,Xiaoyan Long,Kena Fu,Xuwen Gao,Guizheng Zou
Screening a novel electrochemiluminescence (ECL) system is crucial to ECL evolution. Herein, an efficient ECL system with less interference and environmental concern under physiological condition is developed via a unique internal Cu(I)/Cu(II) couple cycling amplified strategy by employing the glutathione- and citrate-capped copper indium sulfide (CIS)/ZnS nanocrystals (NCs) as electrochemiluminophore and N2H4·H2O as co-reactant. CIS/ZnS NCs can be electrochemically injected with valence band (VB) hole at 0.46 and 0.87 V (vs Ag/AgCl), and then achieve the same hole-injected states by relocalizing VB holes with the Cu(I) species inside of CIS/ZnS NCs to form internal Cu(II) defects, while each N2H4·H2O molecule can be successively oxidized to two more reducing species N2H3• and N2H2 around 0.10 V, and inject conduction band (CB) electron onto CIS/ZnS NCs for triple times. The internal Cu(I)/Cu(II) couple cycling involved radiative-charge recombination between these VB hole and CB electron eventually enables two efficient near-infrared ECL processes (around 731 nm) at 0.55 and 0.87 V, in which each single nanocrystal may participate in multiple ECL reaction cycles to produce multiple photons for amplified ECL, similar to the tris(bipyridyl)ruthenium(III) based ECL system. The low-triggering-potential ECL process at 0.55 V can be utilized to selectively determine Cu(II) with a wide linear range from 10 and 1500 nM and a limit of detection of 5 nM (S/N = 3). This work presents a NCs engineering and co-reactant selecting combined strategy for further ECL evolution.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
·
2013
·
IF 1.977
Tianzhi Yu,Haifang Chai,Yuling Zhao,Chengcheng Zhang,Peng Liu,Duowang Fan
Two new mononuclear Cu(I) complexes based on 2-(2′-pyridyl)benzimidazolyl derivative ligand containing hole-transporting carbazole ( L ), [Cu(L)(DPEphos)](BF 4 ) and [Cu(L)(PPh 3 ) 2 ](BF 4 ), where L = (4-(9 H -carbazol-9-yl)phenyl)methyl-2-(2′-pyridyl)benzimidazole; DPEphos = bis[2-(diphenylphosphino)phenyl]ether and PPh 3 = triphenylphosphine, have been synthesized and characterized on the basis of elemental analysis, 1 H NMR and FT-IR spectra. The structures of the ligand L and the Cu(I) complexes were characterized by single crystal X-ray diffraction. The results reveal that in the Cu(I) complexes the central Cu(I) ions assume the irregular distorted tetrahedral geometry and are tetra-coordinated by the two nitrogen atoms from L ligand and two phosphorus atoms from ancillary ligands. The photophysical properties of the complexes were examined by using UV–vis, photoluminescence spectroscopic analysis. The complexes exhibit weak MLCT absorption bands ranging from 360 to 480 nm, and display strong orange phosphorescence in the solid states at room temperature, which is completely quenched in solutions.
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FITOTERAPIA
·
2013
·
IF 2.231
Ming Cong,Cui-Min Hu,Yun-Feng Cao,Zhong-Ze Fang,Shu-Hong Tang,Jia-Rui Wang,Jun-Sheng Luo
Danshen is one of the most famous herbs in the world, and more and more danshen–prescribed drugs interactions have been reported in recent years. Evaluation of inhibition potential of danshen's major ingredients towards UDP-glucuronosyltransferases (UGTs) will be helpful for understanding detailed mechanisms for danshen–drugs interaction. Therefore, the aim of the present study is to investigate the inhibitory situation of cryptotanshinone and dihydrotanshinone I towards UGT enzyme-catalyzed propofol glucuronidation. In vitro the human liver microsome (HLM) incubation system was used, and the results showed that cryptotanshinone and dihydrotanshinone I exhibited dose-dependent inhibition towards HLM-catalyzed propofol glucuronidation. Dixon plot and Lineweaver–Burk plot showed that the inhibition type was best fit to competitive inhibition type for both cryptotanshinone and dihydrotanshinone I. The second plot using the slopes from the Lineweaver–Burk plot versus the concentrations of cryptotanshinone or dihydrotanshinone I was employed to calculate the inhibition parameters (K i ) to be 0.4 and 1.7 μM, respectively. Using the reported maximum plasma concentration (C max ), the altered in vivo exposure of propofol increased by 10% and 8.2% for the co-administration of dihydrotanshinone I and cryptotanshinone, respectively. All these results indicated the possible danshen–propofol interaction due to the inhibition of dihydrotanshinone I and cryptotanshinone towards the glucuronidation reaction of propofol.
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Journal of Materials Chemistry C
·
2012
·Vol. 1
·期 6
·1160-1167
·
IF 0
Jinxing Yu,Na Xu,Qi Wei,Liyuan Wang
Polyaddition reactions of N-hydroxy maleopimarimide with divinyl ether compounds were carried out to give novel polymers with ester acetal linkages in the main chain. The polymers have good solubility in common organic solvents and relatively high Tg temperatures. The number-average molecular weights of the polymers range from 4000 to 5500, with Mw/Mn of 1.7–2.3. The thermal decomposition temperatures of the polymers are above 220 °C. The film of the obtained polymers showed excellent transparency to UV light above 230 nm. The ester acetal linkage of the polymer chain can be cleaved in the presence of strong acid under mild heating. Making use of the high acidolytic activity of the polymers, positive-tone chemically amplified i-line photoresists can be formed from them and 2,1-diazonaphthoquinone-4-sulfonate, in which the well known photoactive compound can also function as a photoacid generator. The photolithographic performance of the photoresists was evaluated using an i-line exposure system with high photosensitivity and resolution.
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JOURNAL OF COORDINATION CHEMISTRY
·
2015
·
IF 2.012
Xi-He Huang,Zu-Ping Xiao,Feng-Lan Wang,Ting Li,Meng Wen,Shu-Ting Wu
Two silver(I) compounds, [Ag(H2mbpz)(Hchda)]n (1) and [Ag2(H2mbpz)2(oba)]n (2) (where H2mbpz = 3,3′,5,5′-tetramethyl-4,4′-bipyrazole, H2chda = trans-cyclohexane-dicarboxylic acid and H2oba = 4,4′-oxy-bis-benzoic acid), have been synthesized and characterized by single-crystal X-ray diffraction analyses. In both cases, the Ag(I) centers are linked by H2mbpz ligands to form 1-D Ag(I)-H2mbpz chains; then, the Ag(I)-H2mbpz chains connect with two neighboring congeners through Ag⋯Ag interactions, forming 2-D supramolecular layers. In 1, the dicarboxylate is monodeprotonated and linked to form an anion chain through strong hydrogen bonding interaction. Such anion chains attach on two sides of the supramolecular layers via Ag–O bonds to form a neutral sandwich-like layered network. In 2, the dicarboxylate is fully deprotonated and adopts a μ2-η1:η1 mode to link two adjacent supramolecular layers to form a twofold interpenetrating 3-D supramolecular network. The thermal stability and luminescence of 1 were also studied.
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APPLIED SURFACE SCIENCE
·
2015
·
IF 2.711
Kaihang Chen,Zuguang Shen,Jiwen Luo,Xiaoying Wang,Runcang Sun
There is an urgent need to develop a highly sensitive detection system for detecting trace amounts of food contaminants. In this study, optimal synthesis of silver nanoparticles (Ag NPs) with stable and narrow size distribution in the range of 15–25 nm was performed under microwave irradiation, using quaternized chitosan (QCS) as reducing and stabilizing agent. The results showed that the ratio of QCS to [Ag(NH 3 ) 2 ] + , reaction temperature, irradiation time, the degree of substitution ( DS ) and molecular weight ( Mw ) of QCS had obvious effects on the formation, particle size and size distribution of Ag NPs. In addition, utilizing QCS/Ag NPs composite as SERS substrate, tricyclazole and Sudan I could be rapidly and sensitively detected with the limit of detection (LOD) as low as 50 ppb and 10 ppm, respectively. Compared with previously reported works, our detection system are of great stability and operability. The QCS was coated on the surface of Ag core, avoiding aggregation of Ag NPs and creating hot spots, in turn, providing superior amplification of SERS. Thus, it is believed that the QCS/Ag NPs composite could be considered as an ideal SERS-active substrate for detection of food contaminants.
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Journal of Physical Chemistry C
·
2015
·
IF 4.772
Junwei Yang,Jin Wang,Ke Zhao,Takuya Izuishi,Yan Li,Qing Shen,Xinhua Zhong
Surface trap defects are the limited factor for quantum dots (QDs) application in solar cells. The trapping states can be efficiently suppressed by coating a shell of wider band gap material around the core QDs. We choose CdSe0.65Te0.35 (simplified as CdSeTe) as a model core material, and CdS shell was then overcoated around the CdSeTe core QD to decrease surface defect density and to increase the stability of the core QDs. By optimizing the thickness of the CdS shell, the power conversion efficiency (PCE) of the CdSeTe/CdS quantum dots sensitized solar cells (QDSCs) is enhanced by 13% in comparison with that of plain CdSeTe QDSCs. Transient absorption (TA), incident-photo-to-carrier conversion efficiency (IPCE), open-circuit voltage decay (OVCD), and electrochemical impedance spectroscopy (EIS) measurements confirmed the suppressed charge recombination process in internal QDs and QD/TiO2/electrolyte interfaces with the overcoating of CdS shell around CdSeTe core QDs. With the further overcoating of a-TiO2 and SiO2 barrier layers around the QD-sensitized photoanode, the PCE of champion CdSeTe QDSCs achieved 9.48% (Jsc = 20.82 mA/cm2, Voc = 0.713 V, FF = 0.639) with average PCE 9.39 ± 0.09% under AM 1.5 G one full sun illumination.
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CARBOHYDRATE POLYMERS
·
2016
·
IF 4.219
Lei Tao,Fei Song,Naiyu Xu,Duxin Li,Robert J. Linhardt,Zhenqing Zhang
Hyaluronic acid (HA), a glycosaminoglycan, is a linear polysaccharide with negative charge, composed of a repeating disaccharide unit [→4)-β- d -glucopyranosyluronic acid (1 → 3)-β- d - N -acetyl- d -glucoaminopyranose (1 → ] n ([→4) GlcA (1 → 3) GlcNAc 1 → ] n ). It is widely used in different applications based on its physicochemical properties associated with its molecular weight. Enzymatic digestion by polysaccharides lyases is one of the most important ways to decrease the molecular weight of HA. Thus, it is important to understand the action patterns of lyases acting on HA. In this study, the action patterns of two common lyases, Flavobacterial chondroitinase AC I and Streptomyces hyaluronidase, were investigated by analyzing HA oligosaccharide digestion products. HA oligosaccharides having an odd-number of saccharide residues were observed in the products of both lyases, but their distributions were quite different. Chondroitinase AC acted more efficiently at the β 1–4 glycosidic bond linking GlcNAc and GlcA. Oligosaccharides, having an even number of saccharide residues, and with an unsaturated uronic acid (4-deoxy-α- l - threo -hex-4-enepyranosyluronic acid, △UA) residue at their non-reducing end represent the major product. A minor amount of oligosaccharides having an odd number of saccharide residues resulted from the irregular terminal residues of HA substrate chains. Hyaluronidase showed a more complicated product mixture. Its minimum recognition and digestion domain is HA heptasaccharide and it could cleave both β 1–4 and β 1–3 glycosidic linkages. The HA oligosaccharides, generated with a 2-acetamido-2,3-di-deoxy-β- d - erythro -hex-2-enopyranose (△HexNAc) at the non-reducing end, are believed to be unstable and undergo breakdown immediately after their generation, and the oligosaccharides with △UA residue at the non-reducing end are formed. Thus, oligosaccharides having both an even and odd-number saccharide residues with a △UA residue at their non-reducing ends, represent the major products of hyaluronidase acting on HA.
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International Journal of Nanomedicine
·
2016
·
IF 4.32
Yunzhu Qian,Hanbang Chen,Yang Xu,Jianxin Yang,Xuefeng Zhou,Feimin Zhang,Ning Gu
Constructing biomimetic structure and incorporating bioactive molecules is an effective strategy to achieve a more favorable cell response. To explore the effect of electrospinning (ES) nanofibrous architecture and collagen I (COL I)-incorporated modification on tuning osteoblast response, a resorbable membrane composed of poly(lactic-co-glycolic acid)/poly(caprolactone) (PLGA/PCL; 7:3 w/w) was developed via ES. COL I was blended into PLGA/PCL solution to prepare composite ES membrane. Notably, relatively better cell response was delivered by the bioactive ES-based membrane which was fabricated by modification of 3,4-dihydroxyphenylalanine and COL I. After investigation by field emission scanning electron microscopy, Fourier transform infrared spectroscopy, contact angle measurement, and mechanical test, polyporous three-dimensional nanofibrous structure with low tensile force and the successful integration of COL I was obtained by the ES method. Compared with traditional PLGA/PCL membrane, the surface hydrophilicity of collagen-incorporated membranes was largely enhanced. The behavior of mouse preosteoblast MC3T3-E1 cell infiltration and proliferation on membranes was studied at 24 and 48 hours. The negative control was fabricated by solvent casting. Evaluation of cell adhesion and morphology demonstrated that all the ES membranes were more favorable for promoting the cell adhesion and spreading than the casting membrane. Cell Counting Kit-8 assays revealed that biomimetic architecture, surface topography, and bioactive properties of membranes were favorable for cell growth. Analysis of β1 integrin expression level by immunofluorescence indicated that such biomimetic architecture, especially COL I-grafted surface, plays a key role in cell adhesion and proliferation. The real-time polymerase chain reaction suggested that both surface topography and bioactive properties could facilitate the cell adhesion. The combined effect of biomimetic architecture with enhanced surface activity by 3,4-dihydroxyphenylalanine-assisted modification and COL I incorporation of PLGA/PCL electrospun membranes could successfully fill osteogenic defects and allow for better cell proliferation and differentiation.
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NANO
·
2017
·
IF 1.025
Xiqing Liu,Xiao Wei,Yeqing Xu,Hongji Li,Kai Lu,Kun Wang,Yongsheng Yan
In this paper, a novel fluorescent nanoswitch based on carbon dots (CDs) was developed for the sensitive and selective determination of Hg 2 + and I − . The CDs were obtained by simple hydrothermal process and had a strong fluorescence emission at 440 nm. The fluorescence of the CDs can be selectively quenched by Hg 2 + ion, and then the I − was added into the system, which can interact with Hg 2 + and recover fluorescence of the CDs. Under optimal conditions, the quenching fluorescence intensity on addition of Hg 2 + has obtained a satisfactory linear relationship covering the linear range of 0–50 μ M with the linear relationship ( R 1 2 = 0 . 9 9 9 1 ), and the limit of detection is 0.047 μ M. The additions of I − could lead to the fluorescence intensity of the solution of CDs and Hg 2 + (50 μ M) recover rapidly, which is linearly related ( R 2 2 = 0 . 9 9 5 7 ) to the concentration of I − in the range from 0 to 70 μ M, the detection limit for I − was calculated to be 0.084 μ M. Moreover, the developed method to detect Hg 2 + and I − was evaluated in real examples, and the fluorescence switching can sensitively and selectively detect Hg 2 + and I − over some potentially interfering ions, the recoveries were up to 97.8–107.0% and 96.7–106.6%, respectively.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2024
·
IF 2.7
Yuejiao Wu,Jian Yang,Ke Shen,Liyan Liu,Jing Cao,Zhaomei Wang
Curcumin (Cur) is a bioactive nutraceutical with great potential in biological, nutritional, and medical applications. However, these applications are limited by various factors such as insufficient ingestion, low aqueous solubility, and relatively high toxicity to normal cells. To tackle these obstacles, we synthesized a novel Cur-modified-rhamnogalacturonan (RG-C) nano-micelle carrier to target-deliver Cur to hepatocellular carcinoma HepG2 cells via specific recognition of RG-I by the overexpressed surface galactin-3 receptor. Fourier transfer infrared, UV–vis, and 1 H NMR analyses confirmed the conjugation between RG and Cur RG-C loaded with Cur (RG-CC) was formed via self-assembly in an aqueous solution with a drug loading efficiency of 12.2%. RG-CC micelle was ellipsoidal or cubic with a size ranging between 100 and 200 nm by scanning electron microscopy observation. Cur release from RG-CC exhibited a controlled and pH-dependent manner with 50% at pH 5.0 in contrast to 5% at pH 7.4 after 24 h exposure. RG-CC possessed more potent anti-proliferative activity against HepG2 cells than normal embryonic kidney 293T cells. Compared to free Cur, both the anti-proliferative effect and uptake of RG-CC were significantly higher in HepG2 cells as revealed from laser confocal microscopy and flow cytometry analyses. RG-CC was a promising anticancer candidate and deserves further preclinical and clinical investigations.
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