MACROMOLECULES
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2019
·
IF 5.997
Ningwei Sun,Kaixin Su,Ziwei Zhou,Xuzhou Tian,Zhao Jianhua,Danming Chao,Daming Wang,Franziska Lissel,Xiaogang Zhao,Chunhai Chen
Electrofluorochromic (EFC) materials have aroused great interest owing to their interesting ability of tuning fluorescence in response to the applied potential. However, some crucial characteristics, such as response speed, fluorescence contrast, and switching stability, are still not well realized to meet the requirements of practical applications. Herein, we designed and synthesized a novel polyamide-bearing aggregation-induced emission (AIE)-active tetraphenylethylene (TPE) and a highly conjugated triphenylamine (TPA) pendant group. The rational combination of the highly conjugated TPA and TPE caused the resultant polymer to exhibit highly integrated electrochromic (EC) and EFC performances including multiple color-changing (colorless to green to blue), fast response speed (1.8/1.1 s for EC and 0.4/2.9 s for EFC process), high fluorescence contrast (82 at the duration time of 20 s), and excellent long-term stability over 300 cycles. The strategy of AIE functionality by combing a highly conjugated redox unit demonstrates a synergistic effect to prepare high-performance emission/color dual-switchable materials, greatly promoting their applications in sensors, smart windows, and displays.
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INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
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2019
·
IF 4.084
Kun Wang,Dongying Ju,Guiying Xu,Yongfei Wang,Shaobei Chen,Jian Zhang,Yuyuan Wu,Weimin Zhou
The new functional FeO/C composite carbon materials are successfully fabricated by controlling the adding amounts of Fe 3 O 4 particles in mixtures of coal tar pitch and Fe 3 O 4 particles. The structures of prepared FeO/C composite carbon materials were verified by XRD measurements. The excellent electrochemical performances of FeO/C composite carbon materials were evaluated in detail. For instance, the prepared materials show the high cycling performances at 679 mAh/g after carrying out charge-discharge 100 cycles. Meanwhile, the high rate performances and long cycle life characteristics of FeO/C composite materials were also observed. As a result, it is palpable that the carbon contents and specific area are the vital factors to improve the electrochemical performances of FeO/C composite materials, which effectively provides the reference to design the transition metal oxide/carbon composite materials as Li + ion storage materials.
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GREEN CHEMISTRY
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2019
·Vol. 21
·期 9
·2412-2427
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IF 9.405
Liang Qi,Zhigang Luo,Xuanxuan Lu
In this work, maize starch (MS) was successively modified via an esterification reaction with acetic anhydride (AA) and phthalic anhydride (PTA). Combined with the gelatinization–precipitation process, the formed starch nanoparticles at an AA/PTA ratio of 2 (MS-AP (2)) and 3 (MS-AP (3)) had similar regular spheres but distinct surface characteristics. In order to enhance the activity of lipase B from Candida antarctica (CALB) in an organic solvent, we designed an oil-in-water (o/w) and a water-in-oil (w/o) Pickering interfacial catalytic system simultaneously by utilizing MS-AP (2) and MS-AP (3) as robust Pickering emulsion stabilizers. Impressively, during the esterification of 1-butanol and vinyl acetate, the specific activity of CALB in the o/w (0.0843 U μL−1) or w/o (0.0724 U μL−1) Pickering interfacial catalytic system was much higher than that of free enzymes in the monophasic (0.0198 U μL−1) and biphasic (0.0282 U μL−1) system. Moreover, after preliminarily elaborating mass transfer discrepancies between the o/w and w/o Pickering interfacial catalytic systems and calculating their mass transfer resistance, we clarified the effects of the location of these two phases on the catalytic capacity of the Pickering emulsion. Impressively, both Pickering interfacial catalytic systems exhibited high effectiveness in product separation. It was found that the w/o Pickering emulsion enabled the organic product to be facilely isolated through a simple decantation, while the o/w Pickering emulsion achieved similar results after adjusting the system temperature. The bio-based nanomaterials and simple protocol, in conjunction with the stability to simultaneously achieve high catalysis efficiency and excellent recyclability, makes us believe that this starch nanoparticle-based Pickering interfacial catalytic system is a promising system for meeting the requirements of green and sustainable chemistry.
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CELLULOSE
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2019
·Vol. 26
·期 5
·3285-3297
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IF 3.917
Gao Hejun,Du Jia,Liao Yunwen
Abstract A novel biological magnetic adsorbent was successfully constituted with sugarcane bagasse (SCB), polyetherimide (PEI) and Fe 3 O 4 . The physicochemical properties of the adsorbent (Fe 3 O 4 @PEI/SCB) were investigated by SEM, BET, VSM, XRD, TGA, FT-IR, XPS, TEM and UV–Vis. The adsorption capacity was measured using Cr(VI) and orange II as adsorbates. The effects of initial pH, dosage, contact time, and ionic strength on the adsorption capacity were investigated in detail. Fe 3 O 4 @PEI/SCB is a mesoporous material and the mass ratio of Fe 3 O 4 :PEI:SCB is about 5:2:15. Adsorption capacity could reach 182.28 mg/g and 1893.57 mg/g for Cr(VI) and orange II at room temperature, respectively. Fe 3 O 4 @PEI/SCB is a green and economical material, which is very easily regenerated, reused, and separated in the adsorption. The most important factor is the ionic strength and major adsorption interaction was electrostatic in this work. Graphical abstract
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CELLULOSE
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2019
·Vol. 26
·期 5
·3271-3284
·
IF 3.917
Li Wei,Wang Shuangfei,Wang Wei,Qin Chengrong,Wu Min
Abstract Due to energy crisis and environmental pollution, biopolymer-based packaging materials have been extensively investigated. Cellulose nanofibrils (CNFs), due to their good oxygen barrier performance and excellent mechanical as well as film-forming properties, have emerged as interesting packaging materials. However, the problem of the resulting films is the highly hygroscopic character of the cellulose fibers themselves, which would further lead to a decrease of the films’ mechanical and barrier properties. Herein, a facile preparation of hydrophobic CNF films was carried out by the attachment of 10-undecylenoyl chloride onto CNFs followed by vacuum filtration. The modified CNFs became thicker and rougher compared with the pristine CNFs and were easy to disperse in ethanol. The resulting CNF film showed a higher surface roughness and a tensile strength of (47 ± 4) MPa. Additionally, the modified CNF film was hydrophobic, leading to an obvious barrier improvement with the WVP value decreasing by 62.4% in comparison to the pristine CNF film. Since this hydrophobic CNF film is easy to prepare with a good vapor barrier property, it should be promising for packaging applications. Furthermore, the generated CNF film demonstrated good reactivity with thiol groups, which can be applied for further functionalization to enrich their application fields. Graphical abstract
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Journal of Materials Chemistry B
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2019
·Vol. 7
·期 9
·1469-1474
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IF 5.047
Zhixiang Lu,Yanxiong Liu,Xiaolan Liu,Shuhan Lu,Yuan Li,Shaoxiong Yang,Yu Qin,Liyan Zheng,Hongbin Zhang
Covalent organic frameworks (COFs) are a class of crystalline porous materials utilized in various potential applications. However, the development of hollow-structured COFs with defined morphology is important for their further applications, which is rare. Herein, COF with unique hollow shuttle morphology was prepared by a Schiff condensation reaction between 4-(4-aldehyde phenyl)ethylene (TPE) and tetra-(4-aminophenyl) porphyrin (TAP). A detailed mechanistic investigation reveals that an initial self-assembly followed by a similar inside–out Ostwald ripening process is responsible for the hollow capsule formation. The hollow microshuttle-shaped capsule COF is used for studying hemoglobin adsorption, which shows an uptake of 550.82 mg g−1 of hemoglobin. These studies could foreshadow new avenues for the development of porous materials with defined morphologies for the adsorption of biomolecules.
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POLYMER COMPOSITES
·
2018
·Vol. 40
·期 6
·2346-2356
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IF 1.943
Zhujun Wang,Qian Li,Zheming Chen,Huayi Li,Shuirong Zheng,Xiaobin Tang
Functionalization of boron nitride nanosheets (BNNSs) has always been a challenge due to its chemical inertness and anti-oxidative properties. In a concentrated base environment, the B-N bonds on the surface of BNNSs were broken to produce a large number of B-OH and N-H functional groups. Afterwards, aniline carbocation produced by decomposition of the diazonium salt was utilized to achieve high grafting content of Ph-NH 2 groups onto the surface of BNNSs. Further, the amide reaction between amino and stearyl chloride verified the reactivity of Ph-NH 2 groups on the surface of BNNSs, with the result that BNNSs were abundantly decorated by aliphatic chains at 22.9 wt% grafting yield. The surface aliphatic chains of BNNSs strongly improved the interfacial adhesion between the High-density polyethylene (HDPE) matrix and the filler and provided an excellent dispersion of SC-BNNSs in the HDPE matrix. Therefore, HDPE/SC-BNNSs nanocomposites showed improved thermal stability, thermal conductivity, neutron shielding property and flexural modulus with no apparent reduction in tensile strength. When filler content exceeded 5 wt%, the HDPE/SC-BNNSs nanocomposites showed a higher thermal decomposition temperature than the composites with pristine BNNSs fillers. POLYM. COMPOS., 40:2346–2356, 2019. © 2018 Society of Plastics Engineers
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ELECTROPHORESIS
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2019
·
IF 2.754
Yuan-Yuan Cui,Huan Yao,Cheng-Xiong Yang,Xiu-Ping Yan
Microporous organic networks (MONs) are a new class of porous materials synthesized via Sonogashira coupling reactions between organic building blocks. Here we report an in situ synthesis approach to fabricate MONs coated capillary column for high resolution GC separation of hydrocarbons. The McReynolds constant evaluation reveals the MONs coated capillary is a non-polar column. The MONs coated capillary column shows good resolution for GC separation of diverse important industrial hydrocarbons such as linear and branched alkanes, alkylbenzenes, pinene isomers, ethylbenzene and styrene, cyclohexane and benzene. The MONs coated capillary column gave a high column efficiency of 1542 plates per meter for hexane and good precision for replicate separations of the selected hydrocarbons with the RSDs of 0.2–0.3, 1.5–3.1, and 1.9–3.3% for retention time, peak height and peak area, respectively. The MONs coated capillary also offered better resolution than commercial Inert Cap-1 and Inert Cap-5 capillary columns for hexane and heptane isomers. These results reveal the potential of MONs as novel stationary phases in GC.
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ANALYTICAL CHEMISTRY
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2019
·
IF 6.35
Juan Li,Xu Zhao,Li-Jian Chen,Hai-Long Qian,Wen-Long Wang,Cheng Yang,Xiu-Ping Yan
Aflatoxin B1 (AFB1) contamination is one of the most critical global issues in food safety. The high carcinogenic nature necessitates rapid and specific methods for the determination of AFB1 in foodstuffs at ultratrace levels. Here, we report an enhanced bienzymatic chemiluminescence competitive immunoassay for ultrasensitive and high-throughput determination of AFB1. In this assay, protein G was first coated on the wells of a microplate for recognizing the Fc fragment of anti-AFB1 mAbs to reduce the antibody dosage and guarantee high immunological reaction efficiency. The target AFB1 competed with glucose oxidase labeled AFB1 for the limited anti-AFB1 mAbs in the wells of the microplate. p-Bromophenol was employed as an enhancer to obtain intense and long-lasting chemiluminescence. The utilization of an enhancer and bienzymatic catalysts effectively improved the detection sensitivity. The developed method offered a good linearity over 5 orders of magnitude, a detection limit of 5 pg L–1, and a relative standard deviation of 1.9% for AFB1. The application of the developed method to the analysis of grain samples gave quantitative recoveries from 94.0% to 97.0%. The developed method provides a universal platform for high-throughput, ultrasensitive, and high specific detection of pollutants or nutrients in foods.
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ACS Sustainable Chemistry & Engineering
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2019
·
IF 6.97
Mingjie Chen,Rui-Min Li,Troy Runge,Jin Feng,Jing Feng,Songnan Hu,Qing-Shan Shi
Cellulose acetate is one of the oldest synthetic thermoplastic polymers and has various applications including usage as films, fibers, and membrane products. Traditionally, cellulose acetate is prepared by reacting cellulose with acetic anhydride in acetic acid using sulfuric acid as a catalyst. This process suffers from extensive depolymerization of the cellulose molecules and corrosion of the equipment from the use of the acidic solvent and catalyst. Herein we present an acid-free cellulose acetylation process using vinyl acetate as both the reactant and reaction medium and 1-ethyl-3-methylimidazolium acetate as the catalyst. The obtained cellulose acetate was confirmed by FTIR, NMR, and XRD studies. Additionally, the reaction kinetics, mechanism of the process, and properties of the obtained cellulose acetate were studied. Cellulose triacetate was obtained by our process within 2 h at 90 °C. The reaction kinetics was described with the classical pseudo-first-order rate expression of heterogeneous cellulose acetylation. The reaction mechanism was shown to be a peel-off mechanism similar to that of cellulose acetylation by the traditional acetic acid process. The molecular weight of the cellulose acetate produced by this new process was significantly higher than that from the traditional acetic acid process because of the absence of strong acids, which can depolymerize cellulose. In summary, we describe a new acid-free process to produce cellulose acetate that limits cellulose depolymerization and avoids the use of corrosive chemicals.
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BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY
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2019
·Vol. 103
·期 5
·683-688
·
IF 1.65
Lu Tao,Zhou Zhigao,Zhang Qi,Zhang Zhenyan,Qian Haifeng
Extensive use of the fungicides azoxystrobin (AZ) and pyraclostrobin (PYR) can have negative effects on aquatic environments, but comprehensive studies on their effect on aquatic microbial communities are still lacking. We found that AZ and PYR could both inhibit the growth of Chlorella vulgaris , but PYR also inhibited Microcystis aeruginosa more strongly than did AZ. High-throughput sequencing analysis showed that AZ promoted the growth of Cyanobacteria in microcosms, and both PYR and AZ disturbed the ecological balance in the aquatic bacterial community and created distinct ecological risks. Our study suggests that the ecological risk of fungicides is complex, and fungicide use should be better managed to reduce potential risks to the environment.
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JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
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2018
·Vol. 56
·期 10
·1058-1066
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IF 2.588
Kai Ma,Guofei Chen,Wei Wang,Anjiang Zhang,Yingying Zhong,Yajie Zhang,Xingzhong Fang
Two novel bio-based diamines are synthesized through introduction of renewable 2,5-furandicarboxylic acid (2,5-FDCA), and the corresponding aromatic polyimides (PIs) are then prepared by these diamines with commercially available aromatic dianhydrides via two-step polycondensation. The partially bio-based PIs possess high glass transition temperatures ( T g s) in the range from 266 to 364 °C, high thermal stability of 5% weight loss temperatures ( T 5% s) over 420 °C in nitrogen and outstanding mechanical properties with tensile strengths of 79–138 MPa, tensile moduli of 2.5–5.4 GPa, and elongations at break of 3.0–12.3%. Some colorless PI films (PI-1-b and PI-1-c) with the transmittances at 450 nm over 85% are prepared. The overall properties of 2,5-FDCA-based PIs are comparable with petroleum-based PI derived from isophthalic acid, displaying the potential for development of innovative bio-based materials. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2018 , 56 , 1058–1066
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