CELLULOSE
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2015
·Vol. 22
·期 4
·2365-2374
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IF 3.573
Ge Wenjiao,Guo Yanzhu,Zhong Haoquan,Wang Xiaohui,Sun Runcang
In response to the shortage of petroleum resources and the growing need for sustainable development, cellulose-based amphiphilic copolymers have emerged as a new generation of value-added functional nanostructures from biomass resources. In this article, 17 amphiphilic hydroxyethyl cellulose-based graft copolymers with different side chains, including poly(lactide), poly( ε -caprolactone) and poly( p -dioxanone), were synthesized via homogeneous ring opening polymerization in ionic liquid 1-butyl-3-methylimidazolium chloride and characterized by FT-IR, 1 H NMR, thermogravimetric analysis and gel permeation chromatography. The resultant copolymers can self-assemble into micelles with a low critical micelle concentration that varies in the range of 0.03–0.24 mg/ml. TEM observations revealed the obtained micelles had a spherical and well-distributed morphology, and DLS analysis showed the nanoscaled sizes were between 40 and 150 nm. These HEC-based micelles can be used as nano-sized vesicles and have great latent forces in drug delivery systems.
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BIOMATERIALS
·
2014
·
IF 8.312
Xiaoying Wang,Yihang Chen,Fatima Zohra Dahmani,Lifang Yin,Jianping Zhou,Jing Yao
An amphiphilic carboxymethyl chitosan-quercetin (CQ) conjugate was designed and synthesized for oral delivery of paclitaxel (PTX) to improve its oral bioavailability by increasing its water solubility and bypassing the P-gp drug efflux pumps . CQ conjugate had low critical micelle concentration (55.14 μg/mL), and could self assemble in aqueous condition to form polymeric micelles (PMs). PTX-loaded CQ PMs displayed a particle size of 185.8 ± 4.6 nm and polydispersity index (PDI) of 0.134 ± 0.056. The drug-loading content (DL) and entrapment efficiency (EE) were 33.62 ± 1.34% and 85.63 ± 1.26%, respectively. Moreover, PTX-loaded CQ PMs displayed similar sustained-release profile in simulated gastrointestinal fluids (pH 1.2/pH 6.8) and PBS (pH 7.4). In situ intestinal absorption experiment showed that PTX-loaded CQ PMs significantly improved the effective permeability of PTX as compared to verapamil ( P < 0.01). Likewise, PTX-loaded CQ PMs significantly enhanced the oral bioavailability of PTX, resulting in strong antitumor efficacy against tumor xenograft models with better safety profile as compared to Taxol ® and Taxol ® with verapamil. Overall, the results implicate that CQ PMs are promising vehicles for the oral delivery of water-insoluble anticancer drugs.
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PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2017
·
IF 6.216
Qin Wang,Zhuo Chen,Sufen Deng,Shaokun Song,Chuanxi Xiong,Lijie Dong
The non-flow property for rigid-rod polymers remains a serious problem that limits their application on a massive scale. Based on a water-in-oil microemulsion method and one pot in situ “grafting to” strategy, a series of novel poly(p-phenylene terephthalamide)-based materials containing controllable graft density of long-chain tertiary amine are prepared. Consequently, the materials’ rheology behaviors are controllable at the level of an order of magnitude and are well-matched with the tunable condensed state structures. Several significant micro-structures of such liquid-like poly(p-phenylene terephthalamide)-based materials are obtained. Additionally, the excellent solubility conforms to the liquid crystal states, solving the key problem of only dissolving concentrated sulfur acid. Additionally, we further investigated the liquid crystal states in different solvents, mass ratios and temperature. This state-of-the-art material with its established property-structure relationship, especially regarding how the structure determines the rheology behavior and solubility, can be treated as a prototype for guiding future research on ionic liquids and in the field related to functional polymer science and technology . Furthermore, the dielectric properties of f -PPTA/PVDF composite membranes have been investigated and show great potential for use in capacitor applications.
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COMPOSITES COMMUNICATIONS
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2017
·
IF 0
Ying Bai,Xue Mao,Jun Song,Xia Yin,Jianyong Yu,Bin Ding
Study of high-efficiency and free secondary pollution TiO 2 based photocatalyst has become the one of the most urgent problems in improving the decolorization effect of the waste water from printing and dyeing mill. In this work, a novel self-standing Ag 2 O@YSZ-TiO 2 p-n nanoheterojunction nanofibrous membrane was designed for ultraviolet (UV) photocatalyst by a facile combination of electrospinning technique and precipitation process. Moreover, the UV photocatalytic performance of the flexible AZT p-n nanoheterojuction nanofibrous membranes with a band gap energy of 2.89 eV and good reversibility of 5 cycles, was superior to the commercial catalyst P25 for photocatalytic degradation of methylene blue. Furthermore, the photocatalytic mechanism of the flexible Ag 2 O@YSZ-TiO 2 nanofibrous photocatalyst was proposed by the electron transition in Ag 2 O/TiO 2 p-n nanoheterojunction, which showed a new insight to development of flexible and high-efficiency nanoheterojunction nanocrystalline photocatalytic membranes.
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ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY
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2016
·
IF 3.13
Qiang Liu,Qinze Liu,Zining Ruan,Xiaoqing Chang,Jinshui Yao
A novel poly(catechol-diethylenetriamine-pphenylenediamine)(PCEA) adsorbent was synthesized in methanol, with chelating groups supplied by catechol and diethylenetriamine, which showed a strong removal performance and efficient adsorption toward Cu(II) ions in aqueous solution. The adsorbent was characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA). Besides, factors such as adsorbent dosage, pH, initial ionic and metal concentrations, contact time, and temperature on the adsorption of Cu(II) were studied. The data revealed that the adsorption followed a pseudo-second order kinetic model and the adsorption rate was influenced by the intra-particle diffusion. Furthermore, the adsorption process followed the Langmuir isotherm model, and the maximum adsorption capacity ( Q m ) was 44.2 mg/g at 298 K in simulated wastewater. The value of Δ G (kJ/mol) and Δ H (kJ/mol) also demonstrated that the adsorption process was spontaneous and endothermic. Studies revealed that PCEA particles were powerful and stable for the removal of Cu(II) in water, and it could be directly applied to the Cu(II)-contaminated water.
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PubMed
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JOURNAL OF ELECTROCERAMICS
·
2017
·Vol. 40
·期 1
·65-71
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IF 1.238
Huang Qiao,Luo Hang,Chen Chao,Zhou Kechao,Zhang Dou
Dielectric composites are of great demand in the micro-electronics industry. To enhance the energy storage density of the composites, TiO 2 nanowire clusters was synthesized by a hydrothermal method and incorporated into the P(VDF-HFP) polymer matrix in this work. The microstructure, dielectric properties of the prepared film were discussed and the effects of TiO 2 loading on the energy density were investigated. The results shows that the TiO 2 clusters were tightly blended to the P(VDF-HFP) matrix owing to the dopamine-modified interface. The dielectric constant increased with the loading of TiO 2 , the maximum dielectric constant reached 12.04 with 7.5 vol% TiO 2 loading at 1 kHz, as compared to 5.01 for the neat P(VDF-HFP). The enhanced dielectric constant was attributed to the interface polarization originated from the large interface area between the TiO 2 nanowire and polymer matrix. The discharged energy density of the composite significantly increased to 1.35 J/cm 3 with 7.5 vol% TiO 2 nanowire clusters, which was two times higher than that of the neat P(VDF-HFP) at the same condition. The findings of this work can shed a light on improving the energy density of energy storage device via morphology modification.
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Molecular Catalysis
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2017
·
IF 0
Junlei Zhang,Zhen Ma
Ag 3 VO 4 /BiOBr n-p heterojunctions were prepared via chemical deposition. Ag 3 VO 4 /BiOBr consists of Ag 3 VO 4 nanoparticles with sizes ranging from several to tens nanometers and flower-like BiOBr microspheres composed of irregular nanosheets. The photocatalytic performance of Ag 3 VO 4 /BiOBr and relevant samples was investigated in the visible-light-driven degradation of Rhodamine B (RhB), methylene blue (MB), methyl orange (MO), and tetracycline hydrochloride (TC). Ag 3 VO 4 /BiOBr heterojunction with a BiOBr/Ag 3 VO 4 mass ratio of 10% was more active than a physical mixture of Ag 3 VO 4 and BiOBr, showing the importance of forming the heterojunction. Photogenerated holes (h + ) and superoxide radical anions ( O 2 − ) were found to be the primary active species. A possible mechanism for the enhanced photocatalytic performance was proposed.
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RSC Advances
·
2017
·Vol. 7
·期 17
·10564-10569
·
IF 3.108
Xiaowen Zhang,Yang Li,Zhongliang Hu,Zhi Chen,Jianrong Qiu
The second near-infrared window (NIR-II, 1000–1400 nm) is ideal for fluorescence imaging owing to negligible tissue scattering and minimal autofluorescence. NIR-II luminescence nanophosphors are promising materials for fluorescence imaging. Mn5+ is emerging as a new luminescent indicator owing to its typical NIR-I (800 nm) to NIR-II (1190 nm) downconversion luminescence. Herein, we report a facile synthesis approach to prepare Mn5+ doped Ba3(MO4)2 (M = V, P) nanoparticles with a remarkably sharp emission peak around 1190 nm in the NIR-II region for the first time to our knowledge. The developed two-step approach based on efficient anion exchange reaction is able to not only stabilize the valence but also keep the controlled morphology and uniform size. It is highly possible that the general approach will provide a new perspective on synthesizing special valence ion doped nanosized materials.
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高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
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2016
·
IF 3.014
Qiao Huang,Hang Luo,Chao Chen,Xuefan Zhou,Kechao Zhou,Dou Zhang
Dielectric capacitors are of urgently demand in modern micro-electric industry. The surface modified inorganic filler introduced to polymer matrix represents a promising avenue for the dielectric material's enhancement of energy storage density. To ease the electric field concentration of the composite induced by permittivity difference between ceramic fillers and polymer matrix, the specific dielectric fillers of TiO 2 nanowires modified BT particles were synthesized in this study. Gradient dielectric composite consisting of poly(vinylidene fluoride-co-hexafluoropylene) [P(VDF-HFP)] matrix ( ε r ∼10), TiO 2 shell ( ε r ∼40), and BaTiO 3 (BT) core ( ε r ∼1000) were focused to investigate the electric field contribution and interface polarization. The results revealed that the permittivity of the composites increased as a result of large interfacial polarization induced by the large specific surface area of the nanowires as compared to the composite with randomly mixed TiO 2 /BT fillers. The breakdown strength of the composite was slightly improved with 20 vol% fillers, attributed to the fact that the electric field intensification was weakened by the BT@TiO 2 /Dop gradient dielectric fillers. The composite could endure up to 10 6 times of field cycling at the applied cycling field and the leakage current density was rather low. The composites with 20 vol% fillers exhibited a discharged energy density of 2.8 J/cm 3 at a low electric field, which was much higher than that of the neat P(VDF-HFP). The findings of this research introduced a new inorganic particle with large specific surface area and gradient dielectric permittivity as filler in composite for energy storage application.
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JOURNAL OF APPLIED POLYMER SCIENCE
·
2017
·Vol. 134
·期 41
·45400
·
IF 1.86
Ting Liu,Ernest Koranteng,Zhengshun Wu,Wang Xiao,Qiangxian Wu
Biodegradable composites from starch and hydrophobic polymer usually show poor compatibility. A novel p -phthaloyl chloride-based prepolymer (PCP) compatibilizer based on p -phthaloyl chloride and polycaprolactone (PCL) diol (2000) was synthesized successfully and the chemical structure was characterized by Fourier transform infrared spectra and 1 H nuclear magnetic resonance (NMR). The PCP compatiblizer was mixed with starch granules to form a coating layer, and then the coated starch granules were melt-compounded with PCL plastic to prepare compatible starch-PCL composites with enhanced properties. The structural, mechanical, thermal properties, and water absorption of the composites were then investigated. It was found that the composites containing the PCP compatibilizer showed better interfacial interaction and compatibility between starch and PCL domains compared to the pure starch-PCL composite, which led to the improved mechanical properties of the composites. The results were attributed to the ester linkage between the PCP compatibilizer and starch as well as the strong physical crosslinking between the PCP compatibilizer and PCL plastic through PCL-PCL crystallinity. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 45400.
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高影响因子
POLYMER ENGINEERING AND SCIENCE
·
2017
·Vol. 57
·期 11
·1252-1261
·
IF 1.449
Yuan Zong,Hao Tang,Ling Zhao
Poly(p-phenylene terephthalamide) (PPTA) is a typical high-performance fiber and usually synthesized by low temperature solution polycondensation in twin screw extruder. During the reactive extrusion, flow behavior, rheokinetics, and temperature are highly coupled, which makes it difficult to ensure the quality of product. In the present work, the rheokinetics of the PPTA solution is established by experiments and its reactive extrusion is investigated via 3-D numerical simulation. The flow pattern, molecular weight distribution and temperature have been investigated for the extruders with three different elements, i.e., full flight screw (FF), kneading block (KB), and screw mixing element (SME). The results indicate that the unique flow characteristic of different screw elements affects mixing experience of the reactants and further the PPTA qualities. By numerical simulation, it shows the temperature increase within the tested extrusion stage is 7 K and reaction heat is found the main energy source for extrusion stage. Furthermore, heat removal method is verified with consideration of industrial production process. The numerical simulation work also discusses the reaction and mixing process in the extruders with three combined screws. The results show the introduction of more reverse FF and KB elements can lead to higher quality of PPTA. POLYM. ENG. SCI., 57:1252–1261, 2017. © 2017 Society of Plastics Engineers
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RSC Advances
·
2016
·Vol. 6
·期 110
·109023-109029
·
IF 3.289
Lijuan Lan,Fanglin Du,Chuanhai Xia
Carbon nanotubes (CNTs) supported Pd catalysts (1 wt% and 5 wt%) were prepared by a conventional impregnation method and tested in liquid-phase hydrodechlorination (HDC) of para-chlorophenol (p-CP) under mild conditions (313 K and atmospheric pressure) with H2. CNTs as a catalyst support offered better performance than activated carbon (AC). The conversion of p-CP reached 72% and 82% over 5 wt% Pd/AC and 5 wt% Pd/CNTs, respectively, within 30 min. When the content of Pd was reduced to 1 wt%, the conversion of p-CP over Pd/AC and Pd/CNTs was 55% and 83%, respectively. The mechanism of this phenomenon was studied through catalyst characterization (XRD, TEM, and BET). The abovementioned results indicated that the different activities of the catalysts over different supports mainly resulted from the porous structure of the supports and nanoparticle diameters of the active metal.
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危险品化学品经营许可证（带存储）