Polymers
·
2019
·Vol. 11
·期 6
·985
·
IF 3.164
Yidong Liu,Lingfeng Jian,Tianhua Xiao,Rongtao Liu,Shun Yi,Shiyang Zhang,Lingzhi Wang,Ruibin Wang,Yonggang Min
CO2has been regarded as one of the most promising blowing agents for polystyrene (PS) foam due to its non-flammability, low price, nontoxicity, and eco-friendliness. However, the low solubility and fast diffusivity of CO2in PS hinder its potential applications. In this study, an attapulgite (ATP)/polypyrrole (PPy) nanocomposite was developed using the in situ polymerization method to generate the hierarchical cell texture for the PS foam based on the supercritical CO2foaming. The results demonstrated that the nanocomposite could act as an efficient CO2capturer enabling the random release of it during the foaming process. In contrast to the pure PS foam, the ATP/PPy nanocomposite reinforced PS foam is endowed with high cell density (up to 1.9 × 106) and similar thermal conductivity as the neat PS foam, as well as high compression modulus. Therefore, the in situ polymerized ATP/PPy nanocomposite makes supercritical CO2foaming desired candidate to replace the widely used fluorocarbons and chlorofluorocarbons as PS blowing agents.Keywords:supercritical CO2;polystyrene foam;blowing agent;in situ polymerization;attapulgite/polypyrrole nanocomposite
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMISTRY OF MATERIALS
·
2019
·
IF 10.159
Kui Wang,Zhe Zhang,Lin Lin,Jie Chen,Kai Hao,Huayu Tian,Xuesi Chen
Photodynamic therapy (PDT) still faces a key challenge associated with its oxygen-dependent property, which limits its therapeutic efficiency against hypoxic tumor. To address the problem, covalent organic nanosheets (CONs) are prepared with a donor–acceptor molecular heterostructure. CONs can address the hypoxic-tumor PDT by two strategies, that is, type I PDT and type I PDT combined with photothermal therapy (PTT). On the one hand, the molecular heterostructure of CONs can afford highly efficient charge carrier separation, a long lifetime of electrons and holes can be obtained, the electrons can reduce O2 to form O2·–, and at the same time, the holes can oxidize water to produce ·OH. Therefore, type I PDT is obtained, which can be used to diminish the limits of hypoxia in type II PDT. On the other hand, the recombination of photoexcited species results in an important nonradiative attenuation, and thus the energy is emitted as heat. A combination of type I PDT and PTT serves as an effective way to get around the difficulties of hypoxia in PDT. Intravenous injection of CONs in nude mice followed by the combination of type I PDT and PTT under single-wavelength irradiation achieves significant tumor ablation.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2020
·Vol. 10
·期 4
·1858-1869
·
IF 3.119
Yuanming Deng,Xiaoman Zhao,Junxuan Luo,Zhong Wang,Jiaoning Tang
Here we present a magnetic recyclable photo-Fenton catalyst CoFe2O4@PPy with uniform morphology and excellent dispersibility prepared via simple in situ Fenton oxidization polymerization. The CoFe2O4 core provides good magnetic recyclability for the catalysts as well as the ion source for catalyzed decomposition of H2O2 in PPy coating. The optimal catalytic effect can be obtained by adjusting the ratio of CoFe2O4 and PPy. Methylene blue, Methyl orange and Rhodamine B (RhB) employed as model pollutants certificated that the catalyst exhibits a wide range of photodegradability. The decoloration rates reach nearly 100% in the photodegradation of 10 mg L−1 RhB after 2 h visible-light irradiation and only low toxicity small molecules are detected by LC-MS. Moreover, the catalytic activity remains after 5 cycles with decoloration rates up to 90%. The degradation measurement in the presence of scavengers of reactive species reveals that the positive holes (h+) and hydroxyl radical (·OH) are the main reactive oxygen species in the CoFe2O4@PPy system. The performance enhancement may be attributed to the combination of improved Fenton activity by coordinated Fe2+ and PPy redox pairs and photo-catalytic activity by broaden adsorption and photo-generated charge separation.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2020
·
IF 5.774
Zhongde Wang,Sihang Tian,Junjian Niu,Wei Kong,Jianying Lin,Xiaogang Hao,Guoqing Guan
Desalination is an important way to provide fresh water for our life. In this study, an electrochemically switched ion exchange (ESIX) process based on self-electrical-energy recuperation concept was designed and realized for desalination, in which the self-generated electricity could provide the required energy for the ESIX process. As iron hexacyanoferrate (FeHCF) and polypyrrole (PPy) were used as electroactive Na + and Cl − ion exchange materials respectively, NaCl was successfully removed from the aqueous solution with a low energy consumption of 0.14 kWh·m −3 and a high ion exchange capacity of 79.6 mg·g −1 . Moreover, the system also exhibited an excellent stability. It is expected that such an ESIX process with self-electrical-energy recuperation could enable more efficient desalination applications.
✓ 已验证
产品关联
DOI
高影响因子
CHEMISTRY OF MATERIALS
·
2019
·
IF 10.159
Qin Wang,Jin Li,Xianjun Tu,Hongbo Liu,Miao Shu,Rui Si,Calum T. J. Ferguson,Kai. A. I. Zhang,Run Li
Generation of efficient light-induced charge separation inside the photocatalyst is an essential factor for a high catalytic efficiency. The usual immobilization of metal or metal oxide particles on semiconductor photocatalysts offers an uncontrolled assembly of active sites during the reaction. The introduction of single metal atoms on photocatalysts can lead to extremely high atomic utilization and precise active sites. However, this approach is limited because of the lack of suitable photosensitizers for single atom immobilization. Here, we have designed photocatalytic carbon quantum dots with anchoring sites for single cobalt atoms in a defined Co–N4 structure via facile pyrolysis of vitamin B12. Carbon dots functioned as both light-harvesting antenna and support for the cobalt atom with high atom loadings up to 3.27 wt %. This new photocatalytic material demonstrated enhanced visible light absorption, efficient charge separation, and reduced electrochemical impedance, while single Co atoms acted as the active site with strong oxidative ability. As a result, the photocatalysts showed excellent visible light-promoted photocatalytic efficiency with oxygen evolution rates up to 168 μmol h–1 g–1 via water oxidation, imine formation with high conversion (∼90%) and selectivity (>99%), and complete photodegradation of organic dyes.
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Ying Xu,Jiaxiang Ma,Yu Han,Hongbo Xu,Yu Wang,Dianpeng Qi,Wei Wang
Solar-driven distillation is now considered as a rising technology for the supply of fresh water in the rare areas. As the crucial part of solar distillation, photothermal materials have been flourished investigated. Herein, we report a universal and facile method to construct a photothermal layer on various substrates to enhance the interfacial water evaporation via polypyrrole (PPy) polymerization and silver nanoparticles (Ag NPs) deposition. The photothermal Ag/PPy layer was firmly coated on six different substrates with an average solar absorption of 95.4% and Ag loading of 94.3 mg/L. One of the optimized resultant membranes (substrate is cellulose fibers) presents the ultrahigh solar evaporation rate of 1.55 kg m −2 h −1 and a corresponding light-to-vapor efficiency of 92.6% with a silver loading of 74 μg cm −2 . Bacterial diffusion inhibition zone experiments revealed clear antibacterial effects of the Ag/PPy membrane on bacteria. Furthermore, the Ag NPs deposited membrane had a rechargeability for multiple times upon their depletion, indicating sustainable anti-bacteria potential. Hence, our facial fabricated photothermal Ag/PPy layer can apply to substrates with different types for enhanced photothermal and anti-biocorrosion capacity, and may pave a new way to the long-term practical sustainable technique for the clean water production application.
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2019
·Vol. 150
·期 2
·493-504
·
IF 2.372
Wang Yong,Wang Jinghua,Zhang Yuan,Song Feng,Xie Yujiao,Wang Ming,Cui Hongyou,Yi Weiming
Abstract Fructose is not only an important food and beverage ingredient, but also a renewable resource for production of bio-chemicals. In this paper, a series of N doped mesoporous carbon materials (MCNs) were prepared and evaluated as heterogeneous catalysts for catalytic isomerization of glucose to fructose. The MCNs were prepared through carbonization of p -phenylenediamine disulfate and the effects of desulfonation with NaOH and hydrogenation treatments were examined. It is found that the molar ratio of H 2 SO 4 /pPDA crucially affects the porous structure and the nitrogen content. Desulfonation with NaOH treatment could largely eliminate the sulfonic groups on the carbon edges and thus enhance the basicity of the MCN materials, whereas hydrogenation reduction could modify the N atom species and reinforce the strength of the basic sites, as a result enhancing the catalytic activities in glucose isomerization to fructose. Among all of the prepared MCN samples, MCN-2-DH showed an excellent activity in aqueous solution, which afforded a fructose yield of 31.6% with 84.6% selectivity. Graphic Abstract
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2019
·
IF 6.361
Chao Wang,Ming Yang,Lihong Liu,Yingming Xu,Xianfa Zhang,Xiaoli Cheng,Shan Gao,Yuan Gao,Lihua Huo
In order to enhance the gas response of polypyrrole to NO 2 , the polypyrrole/Fe 2 O 3 nanocomposites are synthesized by one-step hydrothermal route. The presence of ferric oxide in composites is demonstrated by XPS, HRTEM and TG analyses. The polypyrrole/Fe 2 O 3 sensor exhibits high selectivity and response to NO 2 at 50 °C. Compared with other polypyrrole/metal oxide materials, the polypyrrole/Fe 2 O 3 materials are easy to be synthesized, and the gas sensor has a higher response of 220.7%, lower detection limit of 0.1 ppm and good linear relationship when the NO 2 concentrations range from 0.1 ppm to 10 ppm. The gas response is greatly improved in comparison with the pure polypyrrole and Fe 2 O 3 . The reason for the improved response is also discussed.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MICROCHIMICA ACTA
·
2019
·Vol. 187
·期 1
·1-9
·
IF 5.479
Zhang Wanqing,Fan Shumin,Li Xinli,Liu Shanqin,Duan Dawei,Leng Leipeng,Cui Chengxing,Zhang Yuping,Qu Lingbo
A glassy carbon electrode (GCE) was modified with a composite prepared from phytic acid, polypyrrole and a ZIF type metal-organic framework (PA/PPy)/ZIF-8@ZIF-67). The nanocomposite was prepared by in-situ chemical polymerization in the presence of ferric chloride and subsequently functionalized with PA to form PA/PPy/ZIF-8@ZIF-67. The materials were characterized by XRD, FT-IR, BET, XPS, SEM and TEM. The modified GCE was applied to individual and simultaneous detection of Pb(II) and Cu(II), with peak voltages of −0.6 and − 0.1 V, respectively (vs. SCE). The amount of PPy, the ZIF-8@ZIF-67 concentration, polymerization potential, polymerization time and pH value were optimized. Under optimized conditions, the calibration plots have two linear ranges. These are from 0.02 to 200 μM and from 200 to 600 μM for Pb(II), and from 0.2 to 200 μM and 200 to 600 μM for Cu(II). The detection limits are 2.9 nM and 14.8 nM, respectively. Simultaneous detection of Pb(II) and Cu(II) is also demonstrated. The good performance of the electrode is attributed to the large surface area of ZIF-8@ZIF-67, the good electrical conductivity of PPy, and the metal complexation power of PA. The modified GCE was successfully applied to the determination of Pb(II) and Cu(II) in real samples and gave satisfactory recoveries.
Schematic presentation of the construction process of PA/PPy/ZIF-8@ZIF-67/GCE sensor, and the mechanism of Pb(II) and Cu(II) at the prepared sensor.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Sustainable Energy & Fuels
·
2019
·Vol. 4
·期 1
·407-416
·
IF 4.912
Xinyang Ji,Kaixuan Wang,Yao Zhang,Haohao Sun,Yuanyuan Zhang,Tiange Ma,Zhuo Ma,PingAn Hu,Yunfeng Qiu
Searching for promising HER electrocatalysts is an urgent task for the practical application of hydrogen production by water electrolysis. The Mott–Schottky effect between a metal with larger work function and n-type semiconductor with a higher Fermi level will facilitate the electron transfer from the semiconductor toward the metal. As a result, it is possible to design optimal H* adsorption active sites with thermoneutral hydrogen adsorption free energy (ΔGH*). Herein, MoC nanoparticles with a diameter of about 3.4 nm embedded in N, P-codoped carbon were converted from well-defined polyoxometalates (around 1 nm) and polypyrrole nanocomposites by carbonization and further wrapped on the surface of CNTs. On the basis of improved electron transfer rate, increased carrier densities, and enhanced active site activities on MoC after lowering the work function due to the Mott–Schottky effect with n-type domains in N, P-codoped carbon, our electrocatalysts could drive the current density of 10 mA cm−2 at 175 mV with a Tafel slope of 62 mV dec−1 and TOF value of 1.49 s−1 at 150 mV, as well as long-term H2 production stability. The present study provides a new guideline for the design and preparation of Mott–Schottky HER electrocatalysts.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RADIOANALYTICAL AND NUCLEAR CHEMISTRY
·
2019
·Vol. 323
·期 1
·431-438
·
IF 1.186
Li Zhiyang,Xiao Xilin,Su Changlin,Hu Nan,Nie Changming,Liu Yong,Zhang Di,Wang Zhimei,Liao Lifu
In this paper, a novel method was established for determination of fructose 1,6-diphosphate (F-1,6-BP) based on resonance light scattering (RLS), and a type of bipolar tetradentate schiff base H 4 L was synthesized. The study showed that under the optimization condition with the ligand concentration of 5 nmol mL −1 , pH 6.5, the reaction temperature of 25 °C, the reaction time of 30 min, RLS intensity had good linearity with the concentration of F-1,6-BP within the range of 0.4–5.0 nmol mL −1 , the limit of detection was 0.16 nmol mL −1 and the relative standard deviation (RSD) was 1.83%. In vitro feasibility study, four groups of medical injections and two groups of human urine were analyzed, the RSD of six parallel experiments was approximately 2%, and the recovery value changed from 98.0 to 102.5%. As shown herein, this method has high sensitivity, good precision and recovery.
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2019
·Vol. 31
·期 2
·1483-1490
·
IF 2.195
Zhang Nan,Li Jinfeng,Men Xiusen,Li Zhigang,Zhao Hongtao
A novel electromagnetic functionalized Ni@PPy composite was synthesized with a cleaning method. XRD and FTIR analyses showed that the Ni@PPy composite was successfully prepared. SEM, TEM, and HRTEM results proved that Ni nanoparticles, produced by the γ-irradiation-induced reduction method, were wrapped with polypyrrole (PPy) shell to form core–shell structure. There existed many Ni cores in a PPy shell, which could induce more interfacial and dipolar polarization than the structure with one core in a shell. With an increase in Ni content, the dielectric loss was obviously decreased and the magnetic loss had little change. Attenuation constant decreased gradually, which was influenced jointly by conductivity loss and dipolar and interfacial polarization loss. When nPy/nNi/nAPS was 1.75:1:1.75, the as-prepared Ni@PPy composite exhibited the highest microwave absorption (RL max of − 48 dB at 7 GHz and EAB of 3.8 GHz) owing to suitable impedance matching as well as attenuation ability. Therefore, such core–shell structured Ni@PPy composite would be a promising microwave absorber.
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）