ADVANCES IN POLYMER TECHNOLOGY
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2018
·Vol. 37
·期 8
·3650-3658
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IF 2.073
Zhengping Fang,Xingning Zhang,Meng Xia,Wei Luo,Huiling Hu,Zhiguo Wang,Peixin He,Yuhong Zhang
By multicomponent mechanical blending technology, water-swelling rubber (WSR) was prepared through choosing chlorinated polyethylene (CPE), a superabsorbent polymer (cross-linking poly(sodium acrylate), CPNaAA), and compatibilizer (poly(methyl methacrylate-co-maleic anhydride), P (MMA-co-MAH)) along with other minor additives. P (MMA-co-MAH) was synthesized by grafting maleic anhydride (MAH) onto methyl methacrylate (MMA). Microstructure, water-absorbent properties, and mechanical properties of WSR were investigated. The results showed that P (MMA-co-MAH) boosted the dispersibility between CPNaAA and CPE and led to the increase in Shore A hardness, tensile strength, tensile stress at 100%, and water-swelling behavior, whereas the elongation at break and weight loss were decreased with P (MMA-co-MAH) content. When the content of P (MMA-co-MAH) reached 8 phr, the tensile strength, hardness, and water-swelling ability of dry-state WSR exhibited a maximum value and the percentage loss ratio of CPNaAA reached a relatively low value.
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高影响因子
MINERALS ENGINEERING
·
2019
·
IF 3.315
Wenjie Zou,Lu Gong,Jun Huang,Mingfei Pan,Zhenzhen Lu,Chunbao Sun,Hongbo Zeng
Selective flocculation is an efficient separation method for processing fine coal. In this work, one type of hydrophobically modified polyacrylamide, poly(AM-NaAA-C 16 DMAAC) (HMPAM), was synthesized and used as flocculants of coal. The adsorption and interaction of HMPAM on model coal surface under the influence of KCl concentration were compared with a commercial polyacrylamide (PAM) using quartz crystal microbalance with dissipation monitoring (QCM-D), multi-angle laser light scattering (MALLS) and atomic force microscope (AFM). The QCM-D results showed that the adsorption amounts of both PAM and HMPAM on model coal surface increased with increasing KCl concentration, and the amount of HMPAM was much higher than that of PAM in 100 mM KCl solution. This result could be due to the fact that the high salinity (e.g., 100 mM KCl) led to the compressed conformation of the polymers and significantly compressed electric double layer repulsion. The conformational changes were determined using MALLS. The AFM force measurement results showed that the adhesion between the polymers and model coal surface increased with increasing the KCl concentrations due to the compressed electric double layer, and the average adhesion of PAM was about one order of magnitude smaller than that of HMPAM. Such difference was mainly ascribed to the hydrophobic attraction between the hydrophobic chain of HMPAM and model coal surface. Meanwhile, the attractive hydrophobic interaction between the hydrophobic chains induced the formation of multiple layers of HMPAM, which was in consistence with the QCM-D results. The fundamental insights into the interaction mechanisms of HMPAM/PAM on model coal surface will benefit the rational development of effective polymer additives for fine coal preparation.
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ACS Applied Materials & Interfaces
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2019
·
IF 8.456
Lunlun Gong,Heng Yin,Chengming Nie,Xuran Sun,Xiuli Wang,Mei Wang
Although hybrid photocathodes built by immobilizing molecular catalysts to the surface of semiconductors through chemical linkages have been reported in recent years, systematic and comparative studies remain scarce about the impact of various anchoring groups on the performance, stability, and charge-transfer kinetics of molecular catalyst-decorated hybrid photocathodes for photoelectrochemical (PEC) H2 production. In this study, the molecular cobaloxime catalysts, CoPy-4-X (Py = pyridine, X = PO3H2, COOH, and CONH(OH)), bearing different anchoring groups were synthesized and covalently immobilized to the surface of the porous TiO2 layer coated on a p-Si plate or a fluorine-doped tin oxide glass. The influence of the anchoring groups on the performance of p-Si/TiO2/CoPy-4-X photocathodes was comparatively studied for PEC H2 evolution. Among the tested hybrid photocathodes, the one with a hydroxamate as an anchoring group displayed higher activity and lower charge-transfer resistance than that observed for the electrode with a carboxylate or a phosphonate as the anchoring group. Notably, the catalytic current of p-Si/TiO2/CoPy-4-CONH(OH) was attenuated only by 2.9% in the controlled potential photoelectrolysis tests in borate buffer solution at pH 9 at 0 V versus a reversible hydrogen electrode over 6 h. Moreover, the influence of anchoring groups on the interfacial electron transfer from the TiO2 layer to the immobilized cobaloxime catalyst and electron–hole recombination was studied by transient absorption spectroscopy. These results revealed that the hydroxamate as an anchoring group is superior to the carboxylate and phosphonate groups for speeding up the interfacial electron transfer and firmly immobilizing the molecular catalysts to the metal oxide semiconductors to build efficient and stable hybrid photoelectrodes.
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PubMed
高影响因子
ENERGY & FUELS
·
2018
·
IF 3.024
Qian Zhao,Wenbo Zhao,Muyuan Chai,Ling Chen,Yang Wang,Qingming Jia,Yuan Chen
As SO2 removal via traditional aqueous amine scrubbing requires large amounts of energy for absorbent regeneration, phase-change absorption was considered to be a promising alternative, as regeneration of only the SO2-rich phase is needed. The SO2-lean phase can be directly reused, thus greatly reducing energy requirements. We herein investigated the phase-change absorption behavior of N,N,N′,N′-tetramethyl-p-phenylenediamine (TPD) in organic solvents. In general, the TPD absorption rate in organic solvents followed the order: dimethylformamide > diethylene glycol dimethyl ether > propylene carbonate > butanol, which is related to their Henry’s constant. Our results indicated that TPD reacted with SO2 to form the charge-transfer complex TPD·SO2, which was further converted into TPD·2SO2 upon increasing the absorption time. Furthermore, the addition of H2O promoted the formation of TPD·2SO2, but it exhibited a negative effect on the absorption rate. Moreover, in the presence of O2 and H2O, TPD·SO2 in solution was converted slowly into [H2TPD][HSO4]2. TPD·SO2 decomposed into TPD and SO2 at ∼100 °C and exhibited a relatively stable recyclability for SO2 absorption. At last, TPD·SO2 was used as a surrogate of SO2 to synthesize sulfonamide; its activity was higher than that of a reported complex of triethylenediamine and SO2.
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JOURNAL OF CATALYSIS
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2018
·
IF 6.759
Yuqing Wang,Li Yan,Cunyao Li,Miao Jiang,Ziang Zhao,Guangjin Hou,Yunjie Ding
Porous organic copolymer (designated as CPOL-BP&P(OPh) 3 ) containing vinyl biphephos moieties and tris(4-vinylphenyl)phosphite (P(OPh) 3 ) moieties was synthesized through a solvothermal copolymerization technique. After metalation with Rh precursor, an efficient heterogeneous catalyst Rh/CPOL-BP&P(OPh) 3 for the hydroformylation of 1-butene is presented with high activity (TOF = 2490.3 h −1 ) and regioselectivity (l:b = 40.0). The Rh/CPOL-BP&P(OPh) 3 catalyst has been investigated by using solid-state 13 C MAS NMR, in situ FT-IR spectroscopy, nitrogen sorption measurements, SEM, TEM, and XPS. Interestingly, in situ FT-IR spectra showed that Rh species tended to coordinate with both two kinds of P species from biphephos and P(OPh) 3 ligands in the Rh/CPOL-BP&P(OPh) 3 polymer frame rather than one kind of them. Therefore, the synergistic effect of three kinds of coordination compound formed between Rh species and both ligands could be responsible for the high activity and regioselectivity observed in hydroformylation of 1-butene.
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APPLIED CATALYSIS B-ENVIRONMENTAL
·
2018
·
IF 11.698
Hui-Fang Ye,Rui Shi,Xiao Yang,Wen-Fu Fu,Yong Chen
Photocatalytic water splitting over semiconductors without using of any electron sacrificial agents is essential to the conversion of solar energy into chemical energy. Herein, we report remarkable photocatalytic hydrogen production from pure water without the assistance of electron sacrificial agents by using P-doped Zn x Cd 1−x S with rich S vacancies (Zn x Cd 1−x S-P) as the photocatalyst. It is found that interstitial P doping in Zn x Cd 1−x S solid solutions with rich S vacancies can prolong the lifetime of charge carriers and enhance the generation and separation of photogenerated electrons-holes, resulting in a H 2 evolution rate of up to 419 μmol h −1 g −1 , which is 72 and 7.5 times higher than those of ZnS-P (5.8 μmol h −1 g −1 ) and CdS-P (56 μmol h −1 g −1 ), respectively. Furthermore, the introduction of biomass-derived compound 5-hydroxymethylfurfural (HMF) into this system further promotes the photocatalytic hydorgen evolution reaction and simultaneously obtains value-added HMF oxidation products.
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APPLIED ORGANOMETALLIC CHEMISTRY
·
2018
·Vol. 32
·期 12
·e4534
·
IF 3.581
Mingliang Ma,Yuying Yang,Renjun Feng,Li Jia,Guopeng Chen,Wenting Li,Ping Lyu
A highly effective and stable hollow Fe 3 O 4 /P(GMA-EGDMA)-SO 3 H/Au-PPy catalyst was prepared. Monodisperse hollow Fe 3 O 4 microspheres were synthesized using a hydrothermal method. As the catalyst support, magnetic hollow Fe 3 O 4 /P(GMA-EGDMA) microspheres with core–shell structure were prepared by distillation precipitation polymerization. Then sulfonic acid groups (─SO 3 H) were introduced into the surface of the support by surface modification. Au 3+ could be adsorbed by coordination with ─SO 3 H and underwent redox reactions with added pyrrole monomers. Finally, an Au–polypyrrole (PPy) layer was formed on the surface of the Fe 3 O 4 /P(GMA-EGDMA)-SO 3 H microspheres. The synthesized material was characterized using various techniques. Results indicated that the as-prepared hollow Fe 3 O 4 /P(GMA-EGDMA)-SO 3 H/Au-PPy catalyst had excellent catalytic activity and exhibited reusability for the reduction reaction of 4-nitrophenol. In addition, the catalyst was reusable for at least ten successive cycles.
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ACS Applied Energy Materials
·
2018
·
IF 0
Linghao He,Bingbing Cui,Bin Hu,Jiameng Liu,Kuan Tian,Minghua Wang,Yingpan Song,Shaoming Fang,Zhihong Zhang,Qiaojuan Jia
Electrocatalytic water splitting requires the development of attractive and earth-abundant catalysts. In this work, a novel four-part electrocatalyst of mesoporous cobalt/iron phosphorus–selenide nanocomposite (CoFe–Se–P) was derived from hollow CoFe Prussian blue analogues (CoFe-PBA) and combined by phosphatization and selenylation. This novel electrocatalyst displays an efficient and durable bifunctional catalysis performance for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). In view of strong electron interaction among Co, Fe, Se, and P, this four-part electrocatalyst exhibits a lower onset potential of −35.9 mV and an overpotential of −172.5 mV at a current density of 10 mA cm–2 in acidic solution for HER. In alkaline solution, the onset potential and the overpotential are maintained at approximately −33 and −183.1 mV, respectively. Moreover, the proposed CoFe–Se–P catalyst possesses superior OER performance with a lower onset potential of 1.07 V and overpotential of 1.44 V at a current density of 10 mA cm–2 in 0.1 M KOH solution. The versatile electrocatalyst can catalyze water splitting in a two-electrode system at a potential of 1.59 V. The proposed strategy offers insight into the rational design and development of promising electrode materials with distinct architectures for electrochemical energy storage and conversion.
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CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Xuan Zhou,Rongzhi Li,Fei Fu,Minggui Shen,Qiaoguang Li,He Liu,Xu Xu,Zhanqian Song
Most epoxy resins on the market have low thermal stability and flammable defects. As a potential curing agent for epoxy resin, polybenzoxazine (PBz) can effectively improve the thermal properties of the resin due to its low heat release capacity (HRC) and rigid aromatic ring support, and its raw materials can be derived from renewable resources. Here, we have successfully developed a molecular design strategy to obtain a trifunctional benzoxazine monomer with phosphate ester. Firstly, guaiacol-ethanolamine benzoxazine monomer (GE) was synthesized by Mannich condensation using guaiacol and ethanolamine as raw materials. Then trifunctional benzoxazine phosphate ester (TBP) was synthesized by the nucleophilic reaction of GE with phosphorus oxychloride. Finally, the epoxy resin DGEBA was cured by TBP to obtain a PBz modified epoxy resin (EP-TBP polymer) with T g of 113.7 °C and char yield of 37.4 %. Due to the introduction of TBP rich in phosphorus and nitrogen, it releases phosphorus radicals and nitrogen-containing inert gases during combustion, which leads to quenching effect and dilution effect. In addition, TBP can also promote the dehydration and dehydrogenation of the polymer and accelerate the formation of the aromatic hybrid char layer. Therefore, the THR of TBP modified epoxy resin is 49.3 % lower than that of epoxy resin without TBP, and the char yield is 47 times higher. And when the phosphorus content is 1.76 %, the flame-retardant grade can reach V-0. In addition, the introduction of TBP also enhanced the mechanical properties, adhesion properties and hydrophobicity properties of the polymer. It is worth mentioning that under alkaline conditions, the phosphate ester in the structure of EP-TBP polymer will undergo ammonolysis reaction with ethanolamine, and the resulting oligomers will be dissolved in it, thereby achieving rapid degradation of EP-TBP polymer. This work is to develop a high-performance multifunctional epoxy resin flame retardant curing agent based on renewable raw materials, and provide important insights for the subsequent development of halogen-free bio-based PBz flame retardant materials.
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APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Yan Li,Fang-Ting Liu,Yin Chang,Jian Wang,Cheng-Wei Wang
Structuring the materials in the form of photonic crystals is a new strategy for photocatalytic applications. Herein, a new concept of photonic crystal-induced p-n coaxial heterojunction film photocatalyst of Cu 3 SnS 4 /TiO 2 (CTS/PhC-TNAs) was well-designed and successfully fabricated by combining periodic pulse anodic oxidation and in-situ self-assembling methods Such nanostructured CTS/PhC-TNAs exhibited significantly improved photocatalytic degradation activity under simulated sunlight irradiation with methyl orange (MO) as the target pollutants. Within 120 min, 82% of the MO (10 mg/L) was photodegraded and its kinetic constant per specific surface area reached 0.05332 μmol/m 2 h, which is 1.6 and 12.8 times more quickly than that of PhC-TNAs and CTS, respectively. Its significantly enhanced photocatalytic activity could be mainly attributed to a joint effect of the unique photonic crystal property of PhC-TNAs and the nanostructured hollow p-n coaxial hetero-junction, which result in an increased efficiency of charge separation and transfer and also an improved spectral response capability. This photonic crystal film photocatalyst has the potential for enhancing the photocatalytic activity via further optimizing the photonic stop band of PhC-TNAs. The study presents a new means to design the kind of photonic crystal structural-induced novel photocatalysts with high photocatalytic activities in pollution treatment.
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RSC Advances
·
2016
·Vol. 6
·期 37
·31101-31106
·
IF 3.289
Ailing Hui,Shijing Zhu,Huayang Yin,Li Yang,Zheng Zhang,An Zhou,Jian Pan,Wencheng Zhang
A series of ginkgolide B derivatives (GBD) were designed for delivery of ginkgolide B (GB) across the blood–brain barrier to the brain. Three GBD had shown considerable brain-targeting ability in our previous study. Among them, the ginkgolide B pyrazine (PGB) derivative was selected as a promising novel GB derivative because of its highest brain distribution. Further investigations with regard to PGB and GB's effects on inhibiting the expression of P-gp and attenuating the efflux function of P-gp were reported in this study. They were considered a big step towards better understanding the relationship between GBD's brain-targeting behavior and P-gp regulation. Western blot analysis indicated that PGB was more effective in inhibiting the expression of P-gp than GB in rat brain microvessel endothelial cells (rBMECs) and rat cerebral cortexes and hippocampus. Moreover, the efflux function of P-gp via the transportation of rhodamine 123 was significantly inhibited in PGB-treated rat brains. Preventive medication with PGB induced a better protection of the integrity of the BBB in incomplete ischemia mice. Our findings revealed that an attenuated expression level and efflux function of P-gp and improved protective effect could be realized by the ginkgolide B derivative. These investigations will pave the way for designing more efficient brain-targeting derivatives of ginkgolide and some other central nervous system drugs.
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高影响因子
CARBOHYDRATE POLYMERS
·
2017
·
IF 4.811
Yongjun Sun,Chengyu Zhu,Wenquan Sun,Yanhua Xu,Xuefeng Xiao,Huaili Zheng,Huifang Wu,Cuiyun Liu
In this work, a highly efficient and environmentally friendly chitosan-based graft flocculant, namely, acrylamide- and dimethyl diallyl ammonium chloride-grafted chitosan [CS-g-P(AM-DMDAAC)], was prepared successfully through plasma initiation. FTIR results confirmed the successful polymerization of CS-g-P(AM-DMDAAC) and P(AM-DMDAAC). P(AM-DMDAAC) was the copolymer of acrylamide- and dimethyl diallyl ammonium chloride. SEM results revealed that a densely cross-linked network structure formed on the surface. XRD results verified that the ordered crystal structure of chitosan in CS-g-P(AM-DMDAAC) was changed into an amorphous structure after plasma-induced polymerization. The flocculation results of low-algal-turbidity water further showed the optimal flocculation efficiency of turbidity removal rate, COD removal rate, and Chl-a removal rate were 99.02%, 96.11%, and 92.20%, respectively. The flocculation efficiency of CS-g-P(AM-DMDAAC) were significantly higher than those obtained by cationic polyacrylamide (CPAM) and Polymeric aluminum and iron (PAFC). This work provided a valuable basis for the design of eco-friendly naturally modified polymeric flocculants to enhance the flocculation of low-algal-turbidity water.
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高影响因子
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