POLYMERS FOR ADVANCED TECHNOLOGIES
·
2015
·Vol. 26
·期 11
·1340-1345
·
IF 1.757
Xiangming Hu,Weimin Cheng,Wen Nie,Zhenlu Shao
In this study, a temperature-sensitive hydrogel was synthesized using N-isopropylacrylamide (NIPAm), acrylic acid, sodium alginate (SA), and starch as the raw materials, ammonium persulfate as the initiator, and N,N′-methylenebisacrylamide as the crosslinker by the free radical polymerization. The structure and properties of the hydrogel were studied. The morphology and structure were characterized by scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy was used to investigate the effects of the amount of NIPAm, SA, crosslinker, and initiator on the swelling rate (SR) of the hydrogel. The SEM images show that the surface of the hydrogel was uneven and covered with pores, sockets, and laminated intervals, favoring the swelling. The pore size increased with increasing SA amount. The volume phase transition temperature of the hydrogel decreased at a higher NIPAm amount. The SR of the hydrogel stabilized with increasing amount of SA. Increasing amount of NIPAm decreased the SR, and increasing amount crosslinker and initiator increased SR initially, followed by a decrease. Copyright © 2015 John Wiley & Sons, Ltd.
✓ 已验证
产品关联
DOI
高影响因子
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
·
2015
·Vol. 17
·期 41
·27527-27533
·
IF 4.493
Tianxing Wu,Haimin Zhang,Xian Zhang,Yunxia Zhang,Huijun Zhao,Guozhong Wang
In this work, chitosan whiskers (CWs) were first extracted using low-cost and earth-abundant crab shells as materials by a series of chemical processes, and then assembled into chitosan whisker microspheres (CWMs) via a simple photochemical polymerization approach. Subsequently, a cementite (Fe3C) nanocrystal@N-doped graphitic carbon (Fe3C@NGC) nanocomposite was successfully fabricated by high temperature pyrolysis of CWMs adsorbed with ferric acetylacetonate (Fe(acac)3) at 900 °C. It was found that a suitable growth atmosphere generated inside CWMs during high temperature pyrolysis is critically important to form Fe3C nanocrystal cores, concurrently accompanying a structural transformation from chitosan whiskers to mesoporous graphitic carbon shells with natural nitrogen (N) doping properties, resulting in the formation of a core–shell structure Fe3C@NGC nanocomposite. The resulting samples were evaluated as electrocatalysts for oxygen reduction reaction (ORR). In comparison with sole N-doped graphitic carbon without Fe3C nanocrystals obtained by direct pyrolysis of chitosan whisker microspheres at 900 °C (CWMs-900), Fe3C@NGC showed significantly improved ORR catalytic activity. The tolerance to fuel cell molecules (e.g., methanol) and the durability of Fe3C@NGC are obviously superior to commercial Pt/C catalysts in alkaline media. The high ORR performance of Fe3C@NGC could be due to its large surface area (313.7 m2 g−1), a synergistic role of Fe3C nanocrystals, N doping in graphitic carbon creating more catalytic active sites, and a porous structure of the nanocomposite facilitating mass transfer to efficiently improve the utilization of these catalytic active sites.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD AND CHEMICAL TOXICOLOGY
·
2013
·
IF 3.01
Hui Dong,Demei Xu,Lihua Hu,Lingrui Li,Erqun Song,Yang Song
Tetrachlorobenzoquinone (TCBQ) is an active metabolite of pentachlorophenol (PCP). Although the genotoxic effect of PCP has been comprehensively investigated, there is little known about TCBQ’s genotoxic effects. In the current study, TCBQ was tested for its genotoxicity using HepG2 cells as experimental model. To select the exposure concentration of interest, cell viability was measured and three concentrations were used for further investigation. In single cell gel electrophoresis (SCGE) assay, concentration-dependent increase in tail length, tail DNA percentage and tail moment were detected following TCBQ exposure. Micronucleus (MN) assay indicated TCBQ gradually increased MN frequency and decreased nuclear division index (NDI). Enzyme-linked immunosorbent assay (ELISA) and western blotting analyses both showed TCBQ caused histone H2AX phosphorylation (γ-H2AX). Furthermore, the elevation of 8-hydroxydeoxyguanosine (8-OHdG) and reactive oxygen species (ROS) level indicated TCBQ-induced genotoxicity is associated with oxidative stress. On the other hand, N-acetyl-cysteine (NAC) administration significantly protected cells from the genotoxic effect of TCBQ. Overall, our data suggested TCBQ exerted genotoxic effect possibly via an oxidative damage mechanism in HepG2 cells and this toxicity is prevented by pretreatment with NAC.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2013
·
IF 2.206
Yan Liu,Zhenhu Cao,Yan Zhang,Zhengping Fang
Cerium N-morpholinomethylphosphonic acid (MMPA-Ce) with fibrous structure was synthesized via hydrothermal reaction between cerium nitrate hexahydrate and N-morpholinomethylphosphonic acid. The thermal stability and flame retardancy of high density polyethylene (HDPE) containing various amounts of MMPA-Ce was investigated by thermal gravimetric analysis and cone calorimeter. It is found that even at low addition of MMPA-Ce into HDPE could increase the thermal stability of HDPE. The results of cone calorimeter showed that the emission of CO decreased while the emission of CO2 increased instead.
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES B-BIOINTERFACES
·
2014
·
IF 4.287
Wei Wei,Xinyu Hu,Xiaoliang Qi,Hao Yu,Yucheng Liu,Junjian Li,Jianfa Zhang,Wei Dong
Salecan is a novel microbial polysaccharide produced by Agrobacterium sp. ZX09. The salt-tolerant strain was isolated from a soil sample in our laboratory and the 16S rDNA sequence was deposited in the GenBank database under the accession number GU810841 . Salecan is suitable to fabricate hydrogel for biomedical applications due to the excellent hydrophilicity and biocompatibility. Here, salecan has been introduced into poly(N-isopropylacrylamide) (PNIPAm) network to form novel thermo-sensitive semi-interpenetrating polymer networks (semi-IPNs). The structure of salecan/PNIPAm semi-IPNs was confirmed by Fourier transformation infrared spectroscopy (FTIR) and X-ray diffraction (XRD). Thermogravimetric analysis (TGA) proved the stability of the semi-IPNs. Rheological and compressive tests revealed an elastic solid-like behavior and good mechanical properties of the hydrogels. Swelling behavior test showed the hydrogels possessed high water content at room temperature. An excellent thermo-sensitive property of fast response rates to temperature had been demonstrated as well. In vitro degradation measurements ensured the semi-IPNs were degradable. Cytotoxicity and cell adhesion study suggested the synthesized salecan/PNIPAm hydrogels were non-toxic and biocompatibility. The results indicated the novel thermo-responsive hydrogels could be a suitable candidate for biomedical applications.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 21
·16368-16375
·
IF 3.84
Yupeng Sun,Chen Shen,Jing Wang,Yun Lu
A facile, simple, effective and green method has been developed to synthesize nitrogen and sulfur co-doped carbon dots (N, S-CDs) from heparin sodium. The as-prepared N, S-CDs possess naked-eye observable blue-green luminescence, good biocompatibility, low toxicity and strong fluorescence in live cell imaging, indicating their great potential to serve as high quality optical imaging probes. Besides, the N, S-CDs can also be used as a competitive fluorescent sensing platform for the detection of Fe3+.
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2016
·
IF 7.145
Rong Bai,Qing Zhang,Lanlan Li,Ping Li,Yan-Jie Wang,Oudjaniyobi Simalou,Yanling Zhang,Ge Gao,Alideertu Dong
N-Halamine-based antibacterial materials play a significant role in controlling microbial contamination, but their practical applications are limited because of their complicated synthetic process and indistinct antibacterial actions. In this study, novel antibacterial N-halamine-containing polymer fibers were synthesized via an one-step electrospinning of N-halamine-containing polymers without any additives. By adjusting the concentration of precursor and the molecular weight of polymers, the morphology and size of the as-spun N-halamine-containing fibers can be regulated. The as-spun fibers showed antibacterial activity against both Gram-positive and Gram-negative bacteria. After an antibacterial assessment using different biochemical techniques, a combined mechanism of contact/release co-determined killing action was evidenced for the as-spun N-halamine-containing fibers. With the aid of contact action and/or release action, this combined mechanism can allow N-halamines to attack bacteria, making the as-spun fibers wide in the application of antibacterial fields, whatever it is in dry or wet environment. Also, a recycle antibacterial test demonstrated that the as-spun fibers can still offer antibacterial property after five recycle experiments.
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2015
·
IF 2.288
Weicheng Xu,Jianzhang Fang,Ximiao Zhu,Zhanqiang Fang,Chaoping Cen
A series of novel p−n junction photocatalysts BiOI/Bi 2 Sn 2 O 7 (BiOI/BSO) were successfully fabricated via a facile hydrothermal method. The phase structures, morphologies and optical properties of the as-prepared samples were studied by XRD, TEM, HRTEM, BET, XPS, UV–vis DRS and photoluminescence (PL) spectroscopy. The results showed that BiOI/BSO heteronanostructures displayed much higher photocatalytic activity than pure BSO and BiOI for the degradation of rhodamine B (RhB). The best photocatalytic activity of BiOI/BSO with almost 99.9% RhB degradation situated at molar percentage ratio of 4% after 6 h irradiation. The enhanced photocatalytic performance of BiOI/BSO could be mainly attributed to the formation of the heterojunction between p-BiOI and n-BSO, which effectively restrains the recombination of photoinduced electron–hole pairs. Moreover, the study of radical scavengers affirmed that h + and •O 2 − were the primary reactive species for the degradation of RhB.
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 5
·期 5
·3122-3129
·
IF 3.708
Jinjuan Xue,Shuaishuai Ma,Yuming Zhou,Zewu Zhang,Xin Wu,Chenguang She
Novel Ag2O/N-doped helical carbon nanotubes (Ag2O/N–HCNTs) were successfully synthesized via a simple coprecipitation method and were well characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). The photocatalytic activities were evaluated in the degradation of methylene blue (MB) aqueous solution. The results showed that Ag2O nanoparticles sized 3–10 nm were highly anchored on the surface and inner tubes of the N–HCNTs support, and significantly enhanced the visible-light photocatalytic activity compared to bare Ag2O. It was attributed to the combined effects, including highly dispersed smaller Ag2O particles and higher charge separation efficiency. The possible mechanism for the photocatalytic activity of Ag2O/N–HCNTs was also tentatively proposed. In particular, the rate of degradation of the as-prepared Ag2O/N–HCNTs was 3.9 times faster than that of using bare Ag2O nanoparticles under visible light irradiation. Furthermore, the Ag2O/N–HCNTs could be easily recycled in visible photocatalytic activity. In addition, the Ag2O/N–HCNTs could also degrade MB dye in different water sources like Changjiang River water and tap water with high efficiency as well as in deionized water and that will greatly promote their application in the area of environmental remediation.
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2017
·Vol. 7
·期 7
·200
·
IF 3.082
Hui Dai,Mingyuan Zhu,Haiyang Zhang,Feng Yu,Chao Wang,Bin Dai
Recently, many scientists have focused on the development of green industrial technology. However, the process of synthesizing vinyl chloride faces the problem of Hg pollution. Via a novel approach, we used two elements Mo and Ti to prepare an inexpensive and green binary transition metal nitride (BTMN) as the active ingredient in a catalyst with nano-sized particles and an excellent degree of activation, which was supported on activated carbon. When the Mo/Ti mole ratio was 3:1, the conversion of acetylene reached 89% and the selectivity exceeded 98.5%. The doping of Ti in Mo-based catalysts reduced the capacity of adsorption for acetylene and also increased the adsorption of hydrogen chloride. Most importantly, the performance of the BTMN excelled those of the individual transition metal nitrides, due to the synergistic activity between Mo and Ti. This will expand the new epoch of the employment of transition metal nitrides as catalysts in the hydrochlorination of acetylene reaction.Keywords:binary transition metal nitride;acetylene hydrochlorination
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2017
·
IF 9.446
Yi Wang,Hanyu Liu,Kun Wang,Shuqin Song,Panagiotis Tsiakaras
In the present work, a novel metal-free ORR electrocatalyst, with large specific surface area (2600 m 2 g −1 ), high content of N dopants (3.12 at.%) and 3D cross-linking hierarchically porous structure (abbreviated as LHNHPC) is readily prepared by using a modified classical carbon-aerogel method with NH 3 as the activating agent. Compared with benchmark Pt/C catalyst, it is found that, LHNHPC exhibits similar electrocatalytic activity towards oxygen reduction reaction (ORR), superior durability and excellent methanol tolerance in basic media. The above electrochemical properties of LHNHPC are mainly attributed to the synergistic contribution of its unique hierarchical pore structure, the rich N doping and the large surface area. It can be anticipated that the proposed two-step process could be used for mass production of metal free electrocatalysts for a wide range of electrochemical devices including fuel cells and metal-air batteries.
✓ 已验证
产品关联
DOI
高影响因子
Molecular Catalysis
·
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.
✓ 已验证
产品关联
DOI
危险品化学品经营许可证（带存储）