SEPARATION AND PURIFICATION TECHNOLOGY
·
2018
·
IF 3.927
Yuwei Pan,Minghua Zhou,Ying Zhang,Jingju Cai,Bing Li,Xuejie Sheng
An efficient heterogeneous catalyst, pre-magnetized Fe 0 (pre-Fe 0 ) could significantly activate persulfate (PS) to remove Rhodamine B (RhB). The effect of pH, Fe 0 and PS dose on the RhB removal in the pre-Fe 0 /PS and Fe 0 /PS processes were investigated, and optimized by response surface methodology (RSM) to analyze the rate constants of the RhB removal in the pre-Fe 0 /PS process and Fe 0 /PS process ( f ). High RhB removal was obtained at low pH and high dose of Fe 0 and PS in both systems. Low Fe 0 and high PS dose and large pH would result in big value of f , and the simulated maximum f of 44.3 was achieved at 2 mM Fe 0 , 16 mM PS and pH 9. The synergetic factor of pre-Fe 0 /PS (45.6) was larger than that of Fe 0 /PS (21.4). The pre-Fe 0 /PS process presented 2.1–37.5 folds enhancement than the Fe 0 /PS process for the degradation of RhB. The RhB removal in the pre-Fe 0 /PS process was 1.5–11.2 folds enhancement than that of the Fe 0 /PS process in the presence of different anions and cations. Scanning Electron Microscope (SEM) results and the larger intensity of DMPO-SO 4 − adduct signal in the Electron Paramagnetic Resonance (EPR) confirmed the primary role of sulfate radicals generated from the reaction of PS with Fe 0 in the contaminant degradation. The pre-Fe 0 /PS process exhibited advantages over other processes to remove RhB in terms of contaminant removal, working pH range and chemical dose. Therefore, the pre-Fe 0 /PS process is a cost-effective approach for degrading RhB.
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JOURNAL OF APPLIED PHYSICS
·
2014
·Vol. 116
·期 23
·
IF 2.185
Li Muye,Li Fang,He Zhicong,Zhang Junpei,Han Junbo,Lu Peixiang
Two-photon excited fluorescence resonance energy transfer (FRET) between CdTe quantum dots with different emission peaks and Rhodamine B in aqueous solution are investigated both experimentally and theoretically. The photoluminescence and lifetime are measured using a time-resolved fluorescence test system. The two-photon excited FRET efficiency is found to increase as the degree of spectral overlap of the emission spectrum of CdTe and the absorption spectrum of Rhodamine B increases, which is due to the increase of Forster radius of the sample. Moreover, FRET efficiency increases when the ratio of acceptor/donor concentration increases. The two-photon excited FRET efficiency was found to reach 40%.
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高影响因子
AICHE JOURNAL
·
2014
·Vol. 61
·期 1
·35-45
·
IF 2.581
Feng Xu,Jing-Wen Xu,Bi-Xia Zhang,Luo Yan-Ling
Novel tri-armed star polystyrene-block-poly(N-isopropylacrylamide) block copolymers with trimesic acid as central molecules were synthesized by successive two-step atom transfer radical polymerization, and confirmed by Fourier-transform infrared spectra, 1 H nuclear magnetic resonance, and laser light scattering gel chromatography system. The copolymers could self-assemble into spherical core-shell micelles in aqueous media independent on drug loading. Physicochemical properties of the blank and drug-loaded micelles were examined by surface tension, fluorescence spectroscopy, UV-vis, transmission electron microscope, and dynamic light scattering measurements. The copolymer micelles exhibited thermo-triggered phase transition, with low critical solution temperature of 33.7 and 34.6°C, varying with copolymer compositions. The critical aggregate concentrations were 11.62 and 47.61 mg L −1 , and hydrodynamic diameters from 200 to 220 nm. Water-insoluble 10-hydroxycamptothecine was encapsulated into the micelle aggregates to investigate the change in the resulting physicochemical parameters, thermo-triggered in vitro drug release, and the applicability as drug targeting release carriers. MTT assays were carried out to uncover cytotoxicity of the newly developed micelle-based drug formulations. © 2014 American Institute of Chemical Engineers AIChE J , 61: 35–45, 2015
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高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2013
·Vol. 52
·期 2
·188-199
·
IF 3.543
Yan Zhang,Jinhong Li,Zhengzhen Du,Meidong Lang
pH-responsive methoxy poly(ethylene glycol)- b -poly(ε-caprolactone) bearing pendant carboxyl groups mPEG- b -P(2-CCL- co -6-CCL) was synthesized based on our newly monomer benzyloxycarbonylmethly functionalized ε-caprolactone. Their structure was confirmed by 1 H NMR, 13 C NMR, and Fourier transform infrared spectrum spectra. In addition, SEC results indicated that the copolymers had a relatively narrow polydispersity. WXRD and DSC demonstrated that the introduction of carboxymethyl groups had significant effect on the crystallinity of the copolymers. Furthermore, the solution behavior of mPEG- b -P(2-CCL- co -6-CCL) has been studied by various methods. The results indicated that mPEG- b -P(2-CCL- co -6-CCL) had a rich pH-responsive behavior and the micelles could be formed by pH induction, and the mPEG- b -P(2-CCL- co -6-CCL) could existed as unimers, micelles or large aggregates in different pH range accordingly. The mechanism of which was supposed to depend on the counteraction between the hydrophobic interaction from PCL and the ionization of the carboxyl groups along the polymer chain. Moreover, the mPEG- b -P(2-CCL- co -6-CCL) copolymers displayed good biocompatibility according to the preliminary cytotoxicity study. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 188–199
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RSC Advances
·
2015
·Vol. 5
·期 23
·17905-17914
·
IF 3.84
Jin Wang,Chenchen Guo,Yongqiang Yu,Huabing Yin,Xueting Liu,Yang Jiang
A new self-doped 3-hexylthiophene-b-sodium styrene sulfonate block copolymer (P3HT-b-PSSNa) was obtained via solution copolymerization of sodium styrene sulfonate (SSNa) with vinyl end-group poly(3-hexylthiophene) (v-P3HT), which was synthesized under Grignard metathesis (GRIM) reaction conditions. The self-doping structure can be controlled by altering the feed amounts of SSNa monomer, and it exhibited tunable properties. In comparison with v-P3HT, P3HT-b-PSSNa shows good solubility, broad absorption, higher electrical conductivity and good donor/acceptor (D/A) interface binding with CdSe quantum dots (QDs). Composites of P3HT-b-PSSNa and CdSe exhibit uniform dispersion, good compatibility and highly efficient fluorescence quenching, and surface chemical state analysis confirmed the chemical bonding between copolymer and QDs. This is helpful for rapid charge transfer of different semiconductors in the two-phase D/A interface. Here, we developed a strategy for producing a conjugated polymer with both doped stability during repeated electric cycles and compatibility with inorganic semiconductor materials.
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高影响因子
CHINESE JOURNAL OF CHEMICAL ENGINEERING
·
2014
·
IF 0.872
Jingyun Wang,Fangling Ji,Jishuang Xing,Shuang Cui,Yongming Bao,Wenbo Hao
A block copolymer of 2-dimethylaminoethyl methacrylate (DMAEMA) and glycidyl methacrylate (GMA) was grafted onto the surface of magnetic nanoparticles (Fe 3 O 4 ) via atom transfer radical polymerization . The resultant PGMA-b-PDMAEMA-grafted-Fe 3 O 4 magnetic nanoparticles with amino and epoxy groups were characterized by Fourier transform infrared spectroscopy, powder X-ray diffraction, thermo-gravimetric analysis, and scanning electron microscopy. Lipase from Burkholderia cepacia was successfully immobilized onto the magnetic nanoparticles by physical adsorption and covalent bonding. The immobilization capacity of the magnetic particles is 0.5 mg lipase per mg support, with an activity recovery of up to 43.1% under the optimum immobilization condition. Biochemical characterization shows that the immobilized lipase exhibits improved thermal stability, good tolerance to organic solvents with high lg P , and higher pH stability than the free lipase at pH 9.0. After six consecutive cycles, the residual activity of the immobilized lipase is still over 55% of its initial activity.
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JOURNAL OF POLYMER SCIENCE PART B-POLYMER PHYSICS
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2015
·Vol. 54
·期 3
·385-396
·
IF 3.83
Qiuwen Wang,Hui Tang,Peiyi Wu
Dynamic phase transition and self-assembly mechanism of thermosensitive poly(ethylene oxide)- b -poly( N -vinylcaprolactam) (PEO- b -PVCL) copolymer are explored deeply. A gradual dehydration process with predominated hydrophobic interactions among copolymer chains in the phase transition process distinguishes the copolymer from homopolymer. PVCL in the inner zone is restricted and counter-balanced by the PEO segments based on the sequence order of representative groups during the heating-cooling cycles. Remarkably, PEO shell experiences unusual hydration process, which is first discovered. This hydrophilic shell plays as water absorption sponge layer and captures expelled water from PVCL core, accompanied by gradient distribution of water existed in the assembly structures. Peculiarly, pseudo-linear changes of the integral area of free CO are presented compared with inflection point in the hydrated CO integral area, which propose that a part of hydrated CO forms incomplete dehydrated states. During the cooling process, perfect reversibility is observed without obvious hysteresis. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54 , 385–396
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JOURNAL OF INDUSTRIAL AND ENGINEERING CHEMISTRY
·
2015
·
IF 3.512
Haochi Liu,Xiaohui Ren,Ligang Chen
Adsorptive removal of Rhodamine B (RhB) on a novel kind of magnetic metal–organic framework (MOF) was studied in view of adsorption isotherm, thermodynamics and kinetics. The adsorbent was characterized by physical property measurement system, X-ray diffraction and scanning electron microscopy. The adsorption isotherm of RhB on magnetic MOF followed the Freundlich model. The resultant kinetics data was well described by the pseudo-second-order model. Most of the RhB was removed from the aqueous solution within 30 min. Thermodynamic parameters including Gibbs free energy, enthalpy, and entropy of adsorption were obtained. The result confirmed that the adsorption is controlled by an entropy effect rather than an enthalpy change. The maximum removal has been achieved in the pH range of 4–8 at 150 rpm. The sorbent can be used at least five times after washing with methanol including HCl (0.001 mol L −1 ). The π−π stacking interaction and electrostatic interaction may play an important role in the adsorption of RhB onto magnetic MOF. Compared with other adsorbents, this kind of magnetic material demonstrated a superior dye adsorption capability.
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Oncology Letters
·
2015
·Vol. 9
·期 4
·1940-1946
·
IF 1.554
Ling Wang,Xianglu Li,Xinyu Liu,Kang Lu,Na Chen,Peipei Li,Xiao Lv,Xin Wang
The aim of the present study was to investigate the indirubin‑enhanced effects of arsenic disulfide (As2S2) on the proliferation and apoptosis of diffuse large B‑cell lymphoma (DLBCL) cells in order to identify an optimum combination therapy. The human DLBCL cells, LY1 and LY8, were treated with different concentrations of indirubin for 24, 48 and 72 h. Next, the cells were treated with 10 µM As2S2 or a combination of 10 µM As2S2 and 20 µM indirubin for 48 h. Cell proliferation inhibition was detected using cell counting kit‑8 and cell apoptosis was determined using flow cytometry. The expression levels of Bcl‑2, Bcl‑2‑associated X protein (Bax) and caspase‑3 were analyzed by quantitative polymerase chain reaction (qPCR) and western blotting. The DLBCL cell viability exhibited no significant changes at 24, 48 or 72 h with increasing indirubin concentration. In addition, the apoptotic rates of the LY1 and LY8 cells demonstrated no noticeable effects at 48 h with increasing indirubin concentration. Following treatment with the combination of indirubin and As2S2, the inhibitory and apoptotic rates of the cells were notably increased compared with those of the As2S2‑treated group. The qPCR results revealed that indirubin alone had no enhancing effect upon the Bax/Bcl‑2 mRNA expression ratio and caspase-3 mRNA expression. Western blot analysis revealed that indirubin alone had an enhancing effect upon the Bax/Bcl‑2 protein ratio and procaspase‑3 protein expression. In addition, the results demonstrated that the 21‑KDa Bax protein was proteolytically cleaved into an 18‑KDa Bax in the DLBCL cells treated with the combination of indirubin and As2S2. Indirubin alone did not inhibit proliferation or induce the apoptosis of the LY1 and LY8 cells. However, the combination of indirubin and As2S2 yielded enhancing effects. Therefore, the results of the present study demonstrated that with regard to antitumor activities, As2S2 served as the principal drug, whereas indirubin served as the adjuvant drug. The enhancing effect was due, in part, to the induction of the mitochondrial apoptotic pathway, which involves the cleavage of Bax.
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PubMed
高影响因子
ANALYTICAL CHEMISTRY
·
2015
·
IF 5.636
Wei Zhang,Wei Liu,Ping Li,Fang Huang,Hui Wang,Bo Tang
Hydrogen peroxide (H2O2) as a reactive oxygen species (ROS) plays a crucial role in oxidative stress and signal transduction of organisms. Currently, a fluorescence probe has proven to be a powerful tool for the H2O2 analysis. However, the common problem is the slow response, causing difficulty in tracking H2O2 in situ. Herein, we describe a novel aggregation-induced emission (AIE) fluorescence probe based on increased polarity of C–B bonds that is well suited for monitoring H2O2 rapidly and selectively. Importantly, the probe was successfully applied to visualize H2O2 levels in living cells, which provides a rapid-response and highly selective fluorescence tool for monitoring of the H2O2 levels in biological process.
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PubMed
高影响因子
Soft Matter
·
2015
·Vol. 12
·期 5
·1411-1418
·
IF 4.029
Haixia Li,Wei Wei,Huiming Xiong
A metallo-supramolecular triblock copolymer polystyrene-b-polyisoprene–[Ni2+]–polystyrene (SI–[Ni2+]–S′) has been efficiently prepared using a one-pot, two-step procedure, where the blocks are held by bis-terpyridine complexes at the junction of SI–S′. This specific metallo-supramolecular chemistry is demonstrated to be a robust approach to potentially broaden the diversity of block copolymers. The location of the metal–ligand complexes has a profound influence on the phase separation of the triblock copolymer in the bulk, which results in a distinctive phase segregation between the end blocks and leads to an unexpected asymmetry of the triblock copolymer. The metal–ligand complexes are found to be preferentially located on the adjacent spherical domain and form a core–shell structure. The resulting multiphase material exhibits distinct elastomeric properties with significant toughness and creep recovery behavior. This type of triblock copolymer is anticipated to be a novel class of hybrid thermo-plastic elastomeric material with wide tunability and functionality.
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高影响因子
ORGANIC & BIOMOLECULAR CHEMISTRY
·
2013
·Vol. 11
·期 41
·7192-7198
·
IF 3.568
Ru Jia,Yi Hu,Luo Liu,Ling Jiang,He Huang
Various imidazolium-functional ionic liquids (ILs) composed of different cations and anions were grafted onto Candida antarctica lipase B (CALB) through lysine coupling, and 4–6 of the 9 primary amino groups of the lysine residues were modified. The catalytic activity and stability were investigated in a p-nitrophenyl palmitate hydrolysis reaction. After modification, CALB was activated and achieved a high catalytic efficiency in the aqueous phase (e.g., [HOOCMMIm][Cl] modification showed a 1.5-fold increase in the catalytic efficiency). The thermostability and organic solvent tolerance were significantly increased with the ILs modification (e.g., [HOOCBMIm][Cl] owned kosmotropic cation and chaotropic anion modification showed a 7-fold thermostability increase at 70 °C, 1-fold increase in 50% aqueous dimethylformamide and 5-fold increase in 50% aqueous methanol). Conformation changes were confirmed by fluorescence spectroscopy, circular dichroism spectroscopy and attenuated total reflection Fourier transform infrared spectroscopy.
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高影响因子
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