Environmental Pollutants and Bioavailability
·
2019
·
IF 0
Xiaona Li,Yang Song,Yongrong Bian,Fang Wang,Chenggang Gu,Xinglun Yang,Xin Jiang
The effect of oxalic acid on phenanthrene sorption was varied from that on pyrene sorption. 1.0 mg L-1 of oxalic acid inhibited phenanthrene sorption, whereas 20, 50 and 100 mg L-1 of oxalic acid enhanced the sorption. However, pyrene sorption onto biochar was all inhibited among different concentrations of oxalic acid. New functional groups and increased polarity were observed in the biochar coexisted with oxalic acid, moreover, a high concentration of oxalic acid led to an increased specific surface area of the biochar. These changed factors contributed to biochar sorption to phenanthrene, which was dominated by surface adsorption. Weakened aromaticity and increased release of dissolved organic carbon from biochar may have been the main reason for inhibited pyrene sorption onto biochar by oxalic acid. Therefore, this study suggested that root exudates could greatly influence the sorption behavior of biochar towards PAHs in soil rhizosphere, which deserves attention in agricultural systems.
研究领域:
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
CHINESE CHEMICAL LETTERS
·
2011
·Vol. 22
·期 12
·1497-1500
·
IF 0.775
Xiao Zheng Lan,Hai Rong Pei,Chuan Xian Cheng
Phase behavior of binary system of bromobenzene–chlorobenzene (C 6 H 5 Br–C 6 H 5 Cl) confined in SBA-15 and MCM-41 (pore diameter 8 nm, 3.8 nm, respectively) has been investigated by means of differential scanning calorimetry (DSC). Phase diagram of C 6 H 5 Br–C 6 H 5 Cl system confined in SBA-15 is a type of the complete miscible both in liquid and solid state, the same phase behavior as the bulk system. However, the phase diagram comprises only one boundary line, which is shifted down 22–36 K with respect to the bulk system. C 6 H 5 Br, C 6 H 5 Cl or the mixture within nanopores of MCM-41 is nonfreezing. The different phase behavior of the system confined in SBA-15 and MCM-41 is thought mainly due to the relative size of pore to molecule.
研究领域:
物理化学
·
材料科学
·
纳米科技
·
热力学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2021
·Vol. 47
·期 19
·26869-26876
·
IF 4.527
Shao-Min Lin,Ya-Ling Yu,Ming-Feng Zhong,Huan Yang,Chen-Yang Zhang,Zhi-Jie Zhang,Wei Xu,Jiong-Yan Xie,Yu-Chun Qiu
Converting the γ phase into the α phase completely is necessary in the presintering stage of industrial alumina (Al 2 O 3 ), which requires high temperature and energy consumption. To reduce the presintering temperature, γ-Al 2 O 3 was activated by oxalic acid . XRD , 27 Al-MAS-NMR and TG-DSC were used to characterize the γ - alumina before and after activation, and the phase transformation was studied. The formation temperature of α-Al 2 O 3 decreased to 1029 °C for oxalic acid activated γ-Al 2 O 3 , and the α-fraction was 100% for activated γ-Al 2 O 3 at 1300 °C. After oxalic acid activation , the diffraction peak intensity of γ-Al 2 O 3 decreased significantly; the results of 27 Al-MAS-NMR suggested that octahedral [AlO 6 ] in γ-Al 2 O 3 was easier than tetrahedral [AlO 4 ] to be attacked by oxalic acid , and the formation of pentavalent [AlO 5 ] with higher reaction activity, which was in favour of the lowering formation temperature of α-Al 2 O 3 . The dissolution concentration of Al increased after oxalic acid activation, and the dissolution process was controlled by surface reactions. Oxalic acid mainly attacked the octahedral aluminium in γ-Al 2 O 3 and extracted Al as three complexes of [Al(C 2 O 4 )] + , [Al(C 2 O 4 ) 2 ] - and [Al(C 2 O 4 ) 3 ] 3- . Oxalic acid activated γ - Al 2 O 3 with a lower phase transformation temperature has broad application prospects in the alumina industry.
研究领域:
材料化学
·
无机化学
·
固态化学
·
工业催化
·
陶瓷材料
✓ 已验证
DOI
高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2016
·Vol. 17
·期 2
·536-542
·
IF 2.206
Zhang Jinyang,Li Chuxian,Wang Dingyong,Zhang Cheng,Liang Li,Zhou Xiong
Purpose The environmental safety of both nano-TiO 2 particles and mercury (Hg) pollution has been of widespread concern. Soils and sediments were the main receiving environments of nano-TiO 2 and Hg. There was a strong association between nano-TiO 2 with Hg compounds. Very limited research has been carried out on the impact of nano-TiO 2 on the environmental behavior of Hg in sediments. The objective of this study was to investigate the effects of nano-TiO 2 on the release and transformation of Hg in sediments. Materials and methods Two types of TiO 2 nanoparticles were employed. Sediment samples were collected in the water level fluctuating zone of the Three Gorges Reservoir, China. Sediment samples spiked with HgCl 2 solution were taken as Hg-contaminated sediments. The flooding experiments were conducted using capped borosilicate glass bottles containing 300 ml TiO 2 suspensions (0.2 g L −1 and 0.4 g L −1 ) and 30 g original or Hg-contaminated sediment samples outdoors. All experiments were conducted in triplicate. Water samples were collected at determined interval times over a 60-day period. Sediments were collected on the 60th day. Total Hg (THg) and methylmercury (MHg) in both water and sediment samples and Hg speciation just in sediment samples were determined. A series of control samples without TiO 2 addition were also prepared. Results and discussion The results showed that nano-TiO 2 particles at high content (4 g kg −1 ) promoted the release of Hg in sediments, and the anatase particles showed a stronger effect. Methyl Hg concentrations in waters of nano-TiO 2 treatments significantly decreased by the 10th day. The effect of nano-TiO 2 greatly depended on anatase and rutile particles. After that, methyl Hg concentrations had no significant difference between nano-TiO 2 treatments and the control, except 2 g kg −1 rutile treatment by the 20th day. The changes of Hg speciation in sediments demonstrated that nano-TiO 2 inhibited the transformation of Hg-bound organic matter into the oxidated state, especially upon 2 g kg −1 rutile treatment. This was consistent with the lower MHg concentrations in the 2 g kg −1 rutile treatment. Conclusions Both anatase and rutile nano-TiO 2 were found to affect the release of Hg in sediment. Nano-TiO 2 promoted THg release in sediments and posed an increased risk of Hg contamination in waters, especially for anatase particles. Moreover, nano-TiO 2 inhibited the methylation process of Hg in sediments at the initial stage of flooding and could affect the transformation of Hg speciation in sediments, especially for low-content rutile particles.
研究领域:
环境科学
·
地球化学
·
水体生态学
·
污染控制
·
环境毒理学
✓ 已验证
DOI
高影响因子
MATERIALS AND CORROSION-WERKSTOFFE UND KORROSION
·
2019
·Vol. 70
·期 6
·1044-1055
·
IF 1.458
Junwei Sheng,Xixun Shen,Yaxue Wang,Qunjie Xu,Xiaoxue Zhang
In this paper, the pure Zn coating and Zn-TiN composite coatings containing four different concentrations of TiN particles were prepared on the carbon steel by direct current electrodeposition. The X-ray diffraction and scanning electron microscopy were used to study the crystal size, preferred orientation, and surface morphology of these coatings. The results show that the incorporation of TiN particles refines the crystal size of the Zn coating and results in the formation of a special surface morphology with papillary-shaped clusters structure that preferentially grows along the (100) crystallographic plane. Such a surface provides better hydrophobicity for the Zn-TiN composite coatings. The corrosion behavior of these coatings was evaluated by potentiodynamic polarization, electrochemical impedance spectroscopy and the long-term immersion test. The results show that the incorporation of TiN nanoparticles leads to a significant increase in corrosion resistance of the Zn coating and there is an optimal addition of TiN nanoparticles to provide a best corrosion resistance for the composite coatings. Additionally, the microhardness of prepared coatings was also evaluated.
研究领域:
材料科学
·
表面工程
·
腐蚀与防护
·
金属功能涂层
·
电化学
✓ 已验证
DOI
高影响因子
EUROPEAN POLYMER JOURNAL
·
2018
·
IF 3.741
Yue Han,Donghao Tang,Guangxing Wang,Ying Guo,Heng Zhou,Wenfeng Qiu,Tong Zhao
Low melting phthalonitrile monomers containing allyl and/or methoxyl groups were designed, synthesized and characterized. In order to evaluate their potential application in phthalonitrile resins, these monomers were blended with 1,3-bis(3,4-dicyanophenoxy)benzene and 4-(4-aminophenoxy)phthalonitrile, then cured into polymers. Curing mechanisms of different prepolymers were proposed and compared, and processability, thermal and mechanical properties were characterized. The introduction of methoxyl units was found to postpone the curing, and thermal properties were slightly compromised. On the contrary, the usage of allyl was beneficial to both processability and thermal properties. More importantly, the impact strength for allyl-containing polymers could be as high as 13.63 kJ m −2 , indicating such resin could be applied as high temperature structural composite matrices.
研究领域:
高分子化学
·
材料科学
·
复合材料
·
热固性树脂
·
高性能聚合物
✓ 已验证
DOI
高影响因子
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
·
2014
·Vol. 52
·期 17
·2442-2453
·
IF 3.245
Bingyan Jiang,Lei Zhang,Jie Yan,Qingquan Huang,Bing Liao,Hao Pang
A series of well-defined thermoresponsive graft polymers with different lengths and graft densities, poly(glycidyl methacrylate)- graft -poly( N -isopropylacrylate) (PGMA- g -PNIPAM), were successfully prepared by combination of controlled/living free radical polymerization and click chemistry. Effects of grafting length and density on the thermoresponsive behavior, aggregating mean diameter, and self-assembly morphology are systematically investigated. The thermosensitive characteristics of graft polymers in aqueous solution prove that the length and graft density had positive co-relationship with the lower critical solution temperature value and mean diameter of micelles as well as the size distribution, while the effect of graft length of polymers is more significant than that of density. Transmission electron microscopy analysis shows that the conformations of PGMA 45 - g -PNIPAM 20 and PGMA 45 - g -PNIPAM 46 with longer length and bigger grafting density in aqueous solutions are spherical nanoparticles with the increasing trend of the diameters, while that of PGMA 45 - g -PNIPAM (73, 50%) shows a spherical-like morphology, which indicates that the graft length and density have a significant effect on the mean diameter of micelle but not on the self-assembly morphology. These results reveal that to obtain desired thermoresponsive behavior and self-assembly morphology of functional polymers, it is essential to design and fabricate the structure of graft polymers with proper length and graft density. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52 , 2442–2453
研究领域:
高分子化学
·
材料科学
·
纳米医学
·
药物递送
·
生物材料
·
智能响应材料
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2021
·
IF 3.498
Yaxin Feng,Guilin Wei,Yi Liu,Wenhong Han,Yan Chen,Runjie Sun,Lin Peng,Meihua Ma,Yu Zhang,Zhentao Zhang,Xirui Lu
The immobilization of iodine waste is a challenge in the field of nuclear waste . In this work, iodine waste (silver-coated silica gel with different iodine loadings) was immobilized at low-sintering temperatures (500, 550, and 600 °C). XRD represented that the crystallized phases of the sintered matrix consist of AgI and B 2 O 3 . The crystallization behavior of boron can be found as the sintering temperature increased from 500 °C to 600 °C. FT-IR results proved that in the process of crystallization, part of the microstructure related to B–O stretching transformed from [BO 4 ] to [BO 3 ] units, which benefits low-temperature iodine waste immobilization due to the bonding energy of [BO 3 ] is higher than that of [BO 4 ]. Our work reveals the B-related microstructure transition in low-temperature immobilization iodine waste.
研究领域:
核废物处理
·
材料科学
·
无机化学
·
放射化学
·
环境工程
✓ 已验证
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2019
·Vol. 136
·期 27
·47723
·
IF 2.188
Yayun Zheng,Yaofang Hu,Xing Yang,Meng Yuan,Jie Zhang,Yaodong Zhang,Jujie Luo
We synthesized novel polyurethane (PU) membranes from isophorone diisocyanate (IPDI), poly(ethylene glycol) (PEG) with a molecular weight of 2000, aminopropyl-terminated poly(dimethyl siloxane) (PDMS) with a molecular weight of 2000, and 1,4-butanediol (BDO) via a two-step polymerization. The structure of each synthesized membrane was studied through Fourier transform infrared spectroscopy and gel permeation chromatography. The effect of the thermal behavior was determined by differential scanning calorimetry and thermogravimetric analysis. The gas-permeability characteristics of the PU membranes were then tested for a single gas. The results show that the permeability of CO 2 ( P CO2 ) gradually increased with PDMS content. Among these PU membranes, PU-d (PEG/PDMS = 1:1, PEG/PDMS/IPDI/BDO = 1:3:2) showed the best P CO2 (132.6 Barrer) at 25°C and 1 bar pressure. The gas-permeability coefficients of each PU membrane at different operating temperatures were investigated, and the results show that P CO2 reached 302.6 Barrer at 65°C and 1 bar. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136 , 47723.
研究领域:
高分子材料科学
·
膜分离技术
·
气体分离
·
功能高分子
·
环境化工
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2015
·
IF 7.435
Peng Yi-Zhu,Ma Wan-Hong,Jia Man-Ke,Zhao Xiao-Rong,David M. Johnson,Huang Ying-Ping
In this study, a weakly polar pesticide acetochlor in water was tried to degrade by BiOBr catalysts under visible light irradiation. Its degradation reaction rate increased exponentially with increasing catalyst dosage, which was significantly different from conventional photocatalytic patterns established for polar or water-soluble pollutants. Thus, the rate-dosage relationship of BiOBr/acetochlor was compared to that of BiOBr/Rhodamine B (RhB) (a typical strong polar dye pollutant in water) at different BiOBr dosages. The degradation rate of RhB increased with the BiOBr dosage and then plateaued due to more catalyst particles blocking the light into the inner solution, which is a typical behavior for heterogeneous photocatalysis of polar organic compounds in aqueous solution. While acetochlor behaved differently, its degradation rate increased exponentially with the BiOBr dosage, and no plateau was observed even up to 9.0 g/L BiOBr dosage. This special rate-dose relationship for weakly polar acetochlor was correlated with a unique adsorption property of BiOBr to acetochlor in water solution. There was a re-distribution effect that always exclude excessive acetochlor adsorbed on BiOBr surface regardless either substrates or BiOBr overdose. This finally resulted in every BiOBr particle having enough adsorption sites available for dissolved dioxygen to function thereby accelerate the degradation of weakly polar organic compounds in water.
研究领域:
环境化学
·
光催化
·
水污染控制
·
环境功能材料
·
污染物降解机制
✓ 已验证
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 98
·55256-55262
·
IF 3.708
Zhijian Wu,Ya Xiong,Guoqiang Guan,Lingjun Kong,Shuanghong Tian
A new pyrolytic process was successfully used to prepare hollow-like spherical sludge chars (HSC). In the process, pre-formed cotton spheres with a low density were firstly coated by a layer of sludge paste containing ZnCl2 to form cotton fiber@sludge spheres and then pyrolyzed at 500 °C for 2 h. The resulting HSC possessed a diameter of about 3 mm, a low density of 0.1008 g cm−3 and a high surface area of 1008 m2 g−1. The column adsorption behavior showed that the adsorption capacity and rate constant of HSC for methylene blue reached 186.4 mg g−1 and 0.232 mL min−1 mg−1. The adsorption capacity is about 8.4 and 12 fold of the adsorption capacities of GAC (22.28 mg g−1) and SC (15.26 mg g−1), respectively, and the adsorption rate constant is about 1.3 fold of that of GAC and SC. The great adsorption capacity and rate constant can be considerably dependent on the special hollow-like spherical structure of HSC.
研究领域:
环境科学
·
材料科学
·
化学工程
·
污染控制
·
吸附技术
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2016
·
IF 2.76
Caili Dai,Zhe Yang,Huili Yang,Yifei Liu,Jichao Fang,Wenxia Chen,Weitao Li,MingWei Zhao
Micelle-to-vesicle aggregate transition is investigated in this work through the addition of β-cyclodextrin 1 (β-CD) in mixed catanionic surfactant aqueous solutions. The catanionic system is composed of 1-hexadecyl-3-methylimidazolium chloride (C 16 mimCl) and sodium oleate (NaOle) which are cationic surfactant and anionic surfactant, respectively. The mixed surfactant solutions can self −assemble into micelles, which are studied by dynamic light scattering measurements and the calculation of molecular interaction parameter. The inclusion complexation of β-CD to C 16 mimCl-NaOle surfactants is studied by surface tension measurements and the calculation of association constants. The dynamic light scattering (DLS), rheological measurements, freeze-fracture transmission electron microscopy(FF-TEM)were conducted to indicate that micelles can transform into vesicles with the addition of β-CD. Finally, the transformation mechanism is proposed. The main reason for micelle-to-vesicle aggregate transition is the inclusion complexation of β-CD to surfactants and it will alter the composition of mixed C 16 mimCl-NaOle surfactant systems which should be responsible for the phase behavior.
研究领域:
胶体化学
·
纳米材料
·
药物递送
·
自组装体系
·
物理化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）