Current Issue

Previous Issue | Next Issue

July 15,2016
Volume 9,Issue 13
Pages -
Subject Area:Functional Polymer (including Liquid Crystal Polymer Chemistry),Catalytic Chemistry,Analytical Chemistry

Title: Optimal design of triangular piezoelectric cantilever beam energy harvester

Authors: HU Dingcong, SHI Yang, YAO Hong, GAO Yuanwen
PP: 1377-1385
Abstract: A theoretical model of the triangular piezoelectric bimorph cantilever beam was established and then the output voltage expression was derived. At the same time, the finite element model was established using finite element software ANSYS and some simulation analysis were given. The output voltage of the energy harvesting device was obtained. The simulation results are in good agreement with the theoretical ones. Meanwhile, using modal analysis and harmonic response analysis, we analyzed the triangular piezoelectric vibrator’s operating state. The energy harvester was optimized by changing piezoelectric and substrate parameters. The result shows that the voltage reaches its highest value near the beam’s natural frequency; resonant frequency can be well adjusted by changing material’s size in order to match environment’s frequency. At the same time, the structure’s parameters are very important in adjusting frequency and optimizing.
Keywords: solid mechanics; triangle; piezoelectric; ANSYS; voltage

Title: Mechanical properties of short fiber reinforced shape memory polymer

Authors: GUO Jianming, WANG Zhenqing
PP: 1372-1376
Abstract: As a new kind of smart materal, shape memory polymer has some advantages, such as low density, large recovery ability, superior fabrication property and low cost and which has been widely used in textile industry, medical, aerospace and microelectronics engineering. In this paper, short carbon fiber reinforced trans-1,4-polyisoprene shape (TPI) memory polymer composites was fabricated with the weight fraction of 0, 5%, 7%, 9%, 11%, 13%, respectively, using a new preparation technology. The mechanical properties of short carbon fiber reinforced shape memory polymer composites are analyzed by tensile tests and their failure mechanism was also studied based on the fracture surface morphology of composites.
Keywords: solid mechanics; shape memory polymer; composites; mechanical property; failure mechanism

Title: Preparation and characterization of ultrathin SPES-C nanoporous membranes

Authors: ZHANG Qiugen, DENG Chao, LIN Zhen
PP: 1367-1371
Abstract: In this paper, we reported a method to fabricate ultrathin SPES-C nanoporous membranes for size-selective separation. Copper hydroxide nanostrands are employed as templates to prepare the about 79 nm-thick nanoporous layer on microfiltration filters by adsorption of SPES-C chains on nanostrands’ surface. The newly developed method is facile, universal, and can be applied to negatively charged polymers. The membrane fabrication, structure and separation performances are investigated in detail. The resulting membrane has an ultrathin SPES-C nanoporous layer covering on the macroporous support, and shows ultrafast water permeation, low fouling and tiny permeation resistance during pressure-driven filtration. The membrane has high pure water flux of up to 856 L•m−2•h−1•bar−1 and good rejection (93.9%) for 5 nm gold nanoparticles, which will have a wide application in controlled release, selective separation.
Keywords: functional polymer; separation membrane; nanowire templates; ulrathin film

Title: Preparation of imido-acetic acid type composite nanofibers by electrospinning

Authors: YANG Jiali, ZHANG Zhu, LIAO Minhui, LI Lingxing, HE Huirong, CHEN Shijin, CHEN Jida
PP: 1359-1366
Abstract: In this study, the composition of imido-acetic acid type polymer spinning solution was investigated, and the influences of spinning conditions (voltage intensity, velocity and distance between syringe needle and drum) on the morphology of nanofiber were also investigated. Furthermore, the effect of crosslinking on the morphology and dissolve-loss percentage of nanofibers were also investigated. The results showed that the average diameter of nanofibers was (150±77) nm, with uniform diameter distribution and relatively good morphology, when the optimized conditions of voltage 24 kV, working distance 8.0 cm, flowing rate 0.5 mL/h were applied. And the stability of nanofibers in the aqueous solution was improved, where the dissolve-loss percentage of nanofibers was considerably decreased to 4.31%, without significantly change in morphology, when pre-crosslinked with glutaraldehyde vapor and cross-linked with epichlorohydrin.
Keywords: polymer chemistry; nanofiber; imido-acetic acid type polymer; polyvinyl alcohol; electrospinning

Title: Ionic liquid-assisted solvothermal synthesis of highly active Bi2WO6 photocatalyst and its photocatalytic activity

Authors: PAN Gaifang, HUO Yuning, LI Hexing
PP: 1352-1358
Abstract: Photocatalyst Bi2WO6 has been synthesized by using solvothermal process assisted with ionic liquid, and its photocatalytic activity was investigated. In the glycol-ethanol system and [Cn-mim]BF4 (n=2, 4, 8, 16) ionic liquid acts as structure-directing agent, Bi2WO6 with hollow microspheres presents the greatly enhanced photocatalytic activity. By changing the solvothermal time, the amount of ionic liquid and alkyl chain length of ionic liquid, the optimal reaction conditions during the photocatalytic degradation of rhodamine B organic pollutants as a probe has been demonstrated as 20 h, 15 μL and [C16mim] BF4.
Keywords: catalytic chemistry; Bi2WO6; visible-light photocatalysis; ionic-liquid-assisted solvothermal process; degradation of organic compound

Title: Isopiestic investigation and ion-interaction model of system NiCl2-NH4Cl-H2O at 308.15 K

Authors: JIANG Bingchuan, LIU Shijun, DING Zhiying, ZHANG Weili
PP: 1345-1351
Abstract: The isopiestic equilibrium molalities of NiCl2-H2O system, the concentration of which ranges from 0.045 3-4.948 8 mol•kg−1, and the NiCl2-NH4Cl-H2O system, the ion strength of which ranges from 0.216 6-6.316 9 mol•kg−1 were determined by isopiestic at 308.15 K. The osmotic coefficient, water activity and the rule of the osmotic coefficient varying with ionic strength were obtained through thermodynamic calculation of solution systems at different concentrations. The experiment results were parametrically studied by the Pitzer ion-interaction model. The ion-interaction parameters of the NiCl2-NH4Cl-H2O system and the NiCl2-H2O system were obtained by multiple nonlinear regression. The average activity coefficients of NiCl2 were calculated in the system. The pure salt parameters β(0), β(1) and Сφ of NiCl2-H2O system were 0.386 0, 1.269 2 and −0.054 2. The parameters of the mixed salt θNiNH4, ψNiNH4Cl were −0.026 0, −0.023 1. The osmotic coefficients which obtained by fitting Pitzer model agreed well with the experiment results.
Keywords: physical chemistry; isopiestic measurement; Pitzer model; osmotic coefficient; activity coefficient

Title: Determination of 8 heavy metal elements in soil by ICP-MS using graphite digestion

Authors: TONG Wei, HAN Jichang, WANG Huanyuan
PP: 1338-1344
Abstract: Graphite furnace digestion and infrared heating digestion pretreatment method were compared in this experiment by HNO3-H2O2-HF digestion system using national standard substances GBW07454 (GSS-25) as the standard soil samples. The Sc, Rh and Lu were chosen as the internal standard elements and a method of using inductively coupled plasma mass spectrometry (ICP-MS) to measure the heavy metals contents of Cr, Ni, Cu, Zn, As, Cd, Hg and Pb was established. The results showed that the correlation coefficients of graphite furnace digestion method for all heavy metals were more than 0.999, except for Hg. Meanwhile, for graphite furnace digestion method, the relative standard deviation (RSD) was 0.31%-7.32%, and the recovery rate was 99.2%-103.3%, and the relative deviation was 0.36%-9.14%. Compared to the infrared heating digestion method, the graphite furnace digestion method proved to be uniform heating, rapid digestion, less pollution, simple operation and was suitable for the mass sample treatment. Besides, the Cr, Ni, Cu, Zn, As, Cd, Hg and Pb contents of soil samples in Guanzhong plain were measured in this experiment with the constructed method. Results indicated that the Cr, Ni, Cu, Zn, As, Cd, and Pb contents of soil in Guanzhong plain met the secondary-rate standard of the National Soil Environmental Quality.
Keywords: analytical chemistry; inductively coupled plasma mass spectrometry; graphite digestion; infrared digestion; soil; heavy metal

Title: Design and synthesis of uranium-responsive DNA hydrogel for distance-based visual detection with microfluidics

Authors: HUANG Yishun, FANG Luting, ZHU Zhi, YANG Chaoyong
PP: 1327-1337
Abstract: In this paper, a uranyl ion (UO22+) responsive smart hydrogel was constructed for rapid, portable, sensitive detection of uranyl ion. The uranyl ion dependent DNAzyme composing of enzyme strand and substrate strand complex was utilized to crosslink the DNA grafting polyacrylamide chains to form DNA hydrogel. Colorimetric analysis was done by encapsulating gold nanoparticles (AuNPs) in the hydrogel to indicate the concentrations of uranyl ion. Without uranyl ion, the enzyme strand was not active. The presence of uranyl ion would trigger the cleaving reaction of enzyme strand to substrate strand which would decrease the density of crosslinkers to destabilize the hydrogel and thus release the encapsulated AuNPs. As low as 100 nmol/L uranyl ion was visually detected by naked eye. Furthermore, to avoid the visual errors which may be caused by naked eye observation, a previously developed volumetric bar-chart chip (V-chip) was used to quantitatively detect and verify the results of uranyl ion concentrations in natural water by encapsulating Au-Pt nanoparticles in the hydrogel. The method can be used for portable and quantitative uranyl ion quantitation in field applications without skilled operators and sophisticated instruments.
Keywords: analytical chemistry; portable detection; uranyl ion; DNAzyme; DNA hydrogel; volumetric bar-chart chip

Title: Synthesis and luminescence properties of Zn3(PO4)2: Eu3+, Gd3+ phosphor for microwave-assistant co-precipitation method

Authors: XU Mengjiao, WANG Luxiang, JIA Dianzeng
PP: 1322-1326
Abstract: Novel orange-red light emitting phosphor Zn3(PO4)2: Eu3+, Gd3+ was synthesized by the microwave-assistant co-precipitation method and we investigated phase and photoluminescence properties by X-ray powder diffraction and spectroscopy. The Gd3+-Eu3+ in Zn3(PO4)2 system in the energy transfer process are also discussed in detail. When the calcination temperature is 900℃ and holding for 15 min, Zn3(PO4)2: 0.24Eu3+, 0.30Gd3+ orange red phosphor can be prepared. The Eu3+ ion emission intensity can be improved via the non-radiation energy transfer between Gd3+-Eu3+ and Eu3+-O2− charge transfer transition synergies. Besides, the novel phosphor showed excellent luminescence properties under the test temperature of 77 K to 423 K.
Keywords: inorganic chemistry; microwave-assistant method; rare earth doped; energy transfer

Title: Free radical cyclization: effects of chain structures

Authors: JIANG Yuanye, XU Zhengyang, FU Yao
PP: 1314-1321
Abstract: Radical cyclizations are efficient methods for the construction of cyclic compounds. Herein density functional theory (DFT) methods were used to investigate the effects of chain structure on the radical cyclization of 1-hexene, 1-pentene and their derivatives. Calculation results reveal that substitution on the alkyl chain by gem dimethyl groups generally promotes cyclization and increases reaction energies. Replacing the methylene group adjacent to carbon radical by NH, O and S increases the energy barriers of cyclization while the same replacements on the methylene group adjacent to the double bond decreases the energy barriers of 5-endo cyclization. Meanwhile, changing the methylene group not adjacent to neither the carbon radical nor the double bond to NH, O and S facilitates the cyclization in general. Furthermore, it is found that there is a good linear relationship between the energy barriers and reaction energies in endo cyclization whereas no such linear relationship found in exo cyclization.
Keywords: organic chemistry; free radical; cyclization; regioselectivity

Title: Synthesis and self-assembly of soluble thiophene-fused polycyclic aromatic hydrocarbons

Authors: YIN Jianghui, ZHANG Dengqing, XIANG Yunjie, LI Xianying, JIN Wusong
PP: 1308-1313
Abstract: Compared with full carbon ones, polycyclic aromatic hydrocarbon (PAH) derivatives containing rich electronic or strong electronegative heteroatom, such as fluorine, nitrogen, sulfur, oxygen in the skeleton exhibited a changed electron density, polarity and so on, which present unique physical and chemical properties in crystal growth, liquid crystal phase and photoelectric properties. So we designed and synthesized a soluble sulfur-fused PAH. The solubility and self-assembly were discussed. The results showed that the PAH could self-assemble into inhomogeneous spherical nanostructures in the solution through π-π stacking.
Keywords: organic chemistry; supramolecular chemistry; polycyclic aromatic hydrocarbon; self-assembly; synthesis

Title: Ag-catalyzed [6+3] cycloaddition of tropone with homoserine lactone derived azomethine ylides: synthesis of tricyclic spiropiperidine

Authors: WU Yang, LIU Honglei, ZHANG Lei, SUN Zhanhu, HUANG Jiaxing, WANG Min, GUO Hongchao
PP: 1299-1307
Abstract: Ag-catalyzed [6+3] cycloaddition of tropone with homoserine lactone derived azomethineylides has been achieved. The reaction works efficiently under mild conditions to give tricyclic spiropiperidine products in moderate to good yields with excellent diastereoselectivity. These products have been characterized by nuclear magnetic resonance (NMR), infrared spectroscopy (IR) and high resolution mass spectrum (HRMS) data whose relative configurations were confirmed by X-ray crystallographic data. The reaction will find potential application in synthesis of natural products and biologically important compounds.
Keywords: organic chemistry; cycloaddition; tropone; azomethine ylide; homoserine lactone; spiropiperidine

Title: Expeditious synthesis of 3,4-dihydro-1,8-naphthyridin-2(1H)-one derivatives

Authors: ZHOU Jun, LING Pengxiang, LI Bo, SHI Bingfeng
PP: 1293-1298
Abstract: 3,4-dihydro-1,8-naphthyridine derivatives are important heterocyclic compounds which have special biological and chemical properties. We reported herein the synthesis of 3-alkenyl-2-aminopyridines via Rh-catalyzed C—H olefination of the C3 position of pyridines. Subsequently, a series of 3,4-dihydro-1,8-naphthyridin-2(1H)-ones have been prepared from 3-alkeny pyridines in one pot via two steps, including catalytic hydrogenation and intramolecular cyclization. This protocol proceeded under mild reaction conditions and was operationally simple.
Keywords: organic chemistry; 3,4-dihydro-1,8-naphthyridin-2(1H)-one; hydrogenation; cyclization

Title: Synthesis of methyl 11(S)-jalapinolate

Authors: SHU Penghua, SUN Jiuchang, FANG Jing, ZENG Jing, WAN Qian
PP: 1288-1292
Abstract: Methyl 11(S)-jalapinolate is a common intermediate for the synthesis of many resin glycosides and plays a very important role in organic synthesis. This study aimed at developing a new synthetic method for methyl 11(S)-jalapinolate to afford the intermediate more efficiently. In this newly developed technology, commercially available (R)-glycidol and 1,9-nonanediol were chosen as the starting materials, with Grignard reaction as the key step for carbon chain extension. Methyl 11(S)-jalapinolate was successfully obtained via a eight-step procedure in an overall yield of 21.3%. The improved approach exhibits advantages such as short synthetic route, simple operation and high overall yield, and has potential value in organic synthesis.
Keywords: organic chemistry; methyl 11(S)-jalapinolate; total synthesis; (R)-glycidol; 1,9-nonanediol

Title: Progress in the studies of production of valerate esters

Authors: LIU Xinxin, YAN Long, CHEN Mengyuan, FU Yao, GUO Qingxiang
PP: 1281-1287
Abstract: With the increasing depletion of fossil resources, preparing the liquid fuel from renewable biomass resources attracts people’s attention. The catalytic conversion of fuel molecules by biomass platform molecule levulinic acid (LA) is a hot topic. Comparison with the traditional biomass-based fuel molecules (γ-valerolactone, methyl tetrahydrofuran, ethanol, etc.), the property of valerate esters is more compatible than existing fossil fuels. Many processes for conversing LA into valerate esters have been reported. The summary of the valerate esters synthesis provides a reference for exploring more efficient synthesis method to valerate esters.
Keywords: organic chemistry; valeric acid; review; heterogeneous catalysis

Alert Name:
Alerting to:
Authentication email will be sent to your email address in 24 hours
Frequency:
Email Message Format:	Plain text Graphical(HTML)

Complete the form below and we will recommend the selected titles to your friends on your behalf. * Indicates a required field.
Your name*:
Your email address*:
Recipient's name*:
Recipient's email address*:
(multiple recipient's names and email addresses should be separated with semicolons)
Your comments:	I thought you would find the page(s) useful.

Your name:
Your email address:
Recipient's name:
Recipient's email address:
(multiple recipient's names and email addresses should be separated with semicolons)
Your comments:	I thought you would find this page useful.

Disclaimer: This message was sent to your friend using the "Send it to a friend" facility on the Sciencepaper Online’ WWW site, http://www.paper.edu.cn/en. The Sciencepaper Online is not responsible for the content of this email, and anything said in this email does not necessarily reflect the Sciencepaper Online's views.

	Check out RSS, or use RSS reader to subscribe this item