CHEMICAL ENGINEERING JOURNAL
·
2013
·
IF 3.473
C. Shen,Y.J. Wang,C. Dong,G.S. Luo
In this work, porous glass beads supported with TS-1 particles have been successfully prepared through in situ crystallization. TS-1 particles with uniform size and high crystallization are well dispersed on the surface of porous glass beads. As the support, porous glass beads exhibit the advantages of more manageable surface chemistry, better chemical and thermal stability, and larger specific surface area compared to that of conventional TS-1 films on flat or tubular supports. The experimental results show that the surface chemistry has profound influence on the morphology of TS-1 particles. The catalytic performance of the material was characterized with the reaction of ammoximation of cyclohexanone. Complete conversion was reached after 20 min in a stirred tank reactor with the selectivity of 100%. Compared with the commercial catalyst, the reaction rate was increased by 54 times. The prepared catalysts were packed in a bed reactor, and the effects of space time, content of catalyst, temperature and pressure were investigated. The conversion of 48.1% was reached by the catalyst with TS-1 loading of 0.183 wt.% at 353 K and the space time of only 1.57 min, and 100% recovery in catalytic activity after 5 cycles was demonstrated.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2022
·
IF 9.136
Wenbin Liu,Yiwei Huang,Guolin Huang,Lijiao Fan,Yuming Xie,Qin Zhang,Jeffery Shi
Uranium is both an important resource and an environmental hazard. It is vital to separate/enrich uranium from liquid for energy production as well as for environmental protection. Herein, the amidoxime-functionalized mesoporous silica/calcium alginates (Al/MS-AO) were synthesized by co-condensation and post-gluing process. The morphology and the characteristics of the Al/MS-AO were studied by using Scanning electron microscope (SEM), energy dispersive spectrometer (EDS), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), N 2 adsorption–desorption and X-ray photoelectron spectroscopy (XPS). These analyses have also revealed the in-depth information of the materials including function groups, structure, and Uranium adsorption mechanism. Batch experiments were conducted, and the results suggest that the adsorption of uranium by Al/MS-AO is a spontaneous and endothermic process. This process can be described with the combination of a pseudo second order kinetic model and a Langmuir isotherm model. The maximum adsorption capacity achieved is 328.68 mg·g −1 . Three possible adsorption mechanisms are proposed, which involve the chemical chelation of the N and O atoms of amidoxime.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2022
·
IF 9.965
Zhong Zhou,Qi Liu,Jiahui Zhu,Jingyuan Liu,Hongsen Zhang,Jing Yu,Rongrong Chen,Ying Li,Jun Wang
Amidoxime-based materials have made a great contribution to the selective adsorption process in the extraction of uranium from seawater. However, traditional adsorbents with amidoxime groups are limited by adsorption capacity and adsorption rate, which greatly hinder the development of uranium extraction from seawater. Based on this, we combined the amidoxime group with carbon nitride to synthesize the amidoxime group carbon nitride (NCN-AO), which is rich in nitrogen defects. Compared with ordinary carbon nitride (CN), NCN-AO has better selectivity and uranium reduction ability. In the process of extracting uranium from seawater, soluble hexavalent uranium (U(VI)) can be reduced to insoluble tetravalent uranium (U(IV)), to achieve high-efficiency extraction of uranium. The removal rate of uranium by NCN-AO in 100 mg/L uranium solution is 99 %, and NCN-AO has specific and selective adsorption of uranium. The band structure, density of states (DOS), highest occupied molecular orbital (HOMO), and lowest unoccupied molecular orbital (LUMO) of NCN-AO were calculated by Density Functional Theory (DFT) method, and adsorption reduction occurred on the surface and interface of NCN-AO. The above results show that NCN-AO may be a promising material for extracting uranium from seawater.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2022
·
IF 10.723
Yizhe Zhang,Tingting Cai,Zhiwei Zhao,Bing Han
Adsorbents with highly efficient and selective recovery performance towards uranium are significantly demanded for the sustainable nuclear power production. Herein, poly(amidoxime)-graft-magnetic chitosan (P(AO)-g-MC) was synthesized through functionalizing magnetic chitosan with polyacrylonitrile followed by amidoximation process. Under magnetic field, P(AO)-g-MC can be separated from the solution in 10 s. Owing to the strong affinity of high-density amidoxime groups towards uranium, P(AO)-g-MC showed remarkable adsorption capacity, rapid kinetics and good regeneration performance in uranium spiked aqueous solution. Notably, the 7-day uranium adsorption capacity of P(AO)-g-MC from natural seawater in column mode was up to 5.14 mg/g, 12 times that of vanadium. The excellent uranium uptake performance over vanadium originated from the strong coordination by N and O in amidoxime groups according to theoretical simulation. The advantages of easy separating and high selectivity make P(AO)-g-MC a very potential uranium adsorbent in natural seawater.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2023
·
IF 9.9
Yanshao Yang,Zhenggong Wang,Zejun Song,Dixin Liu,Jiaqi Zhang,Lele Guo,Wangxi Fang,Jian Jin
Despite the commercial success of polyamide reverse osmosis (RO) membranes for desalination , shortcomings of the material intrinsic properties hinder the further improvement of RO membrane permselectivity towards more energy-efficient desalination. Exploring new polymer materials is thus important to overcome the limitation of existing RO membrane materials. This work reports an investigation on an amidoxime modified polymer of intrinsic microporosity (AOPIM-1) as a membrane material for reverse osmosis desalination. AOPIM-1 is casted into a defect-free dense membrane , and followed by a thermal treatment to finetune its structural feature for enhanced salt rejection. As a polymer with stiff and distorted backbone structure, thermal treated AOPIM-1 possesses a high free volume and highly connected 0.3–0.8 nm micropores that provide fast water transport routes while regulating the permeation of ions. The rapid transport through the microporous channels gives the AOPIM-1 membrane a water permeability of 1.92 × 10 −7 m·kg/m 2 ·h·bar with NaCl rejection as high as 98.5 %. The thickness-normalized water permeability of AOPIM-1 membrane exhibits order-of-magnitude improvement comparing to conventional polyamide-based desalination membranes , and the permselectivity of the membrane is also found to be on the high side. This study confirms the possibility of utilizing microporous polymers as reverse osmosis membrane materials for high performance desalination.
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
·
2023
·
IF 5
Pei Xiaolin,Xiao Qinjie,Feng Yumin,Chen Li,Yang Fengling,Wang Qiuyan,Li Nanxing,Wang Anming
Abstract Nitriles are of significant interest in the flavor and fragrance industries with potential application in cosmetics due to their higher stability than analogous aldehydes. However, the traditional methods to prepare nitriles need toxic reagents and hash conditions. This work aimed to develop a chemoenzymatic strategy to synthesize nitriles from natural aldehydes with aldoxime as the intermediate. A non-classical aldoxime dehydratase (Oxd) was discovered from the fungus Aspergillus ibericus (OxdAsp) to catalyze the dehydration of aldoximes to corresponding nitriles under mild conditions. The amino acid sequence of OxdAsp exhibits an approximately 20% identity with bacterial Oxds. OxdAsp contains a heme prosthetic group bound with the axial H287 in the catalytic pocket. The structure models of OxdAsp with substrates suggest that its catalytic triad is Y138-R141-E192, which is different from the classically bacterial Oxds of His-Arg-Ser/Thr. The catalytic mechanism of OxdAsp was proposed based on the mutagenesis of key residues. The hydroxyl group of the substrate is fixed by E192 to increase its basicity. Y138 acts as a general acid-based catalyst, and its phenolic proton is polarized by the adjacent R141. The protonated Y138 would donate a proton to the hydroxyl group of the substrate and eliminate a water molecule from aldoxime to produce nitrile. The recombinant OxdAsp can efficiently dehydrate citronellal oxime and cinnamaldoxime to citronellyl nitrile and cinnamonitrile in aqueous media, which are applied as fragrance ingredients in the food and cosmetic fields. Graphical abstract
Key points • A novel aldoxime dehydratase from the Aspergillus genus was first characterized as a heme-binding protein. • The catalytic mechanism was predicted based on the molecular interactions of the catalytic pocket with the substrate. • A chemoenzymatic strategy was developed to synthesize nitriles from natural aldehydes with aldoxime as the intermediate.
研究领域:
生物化学
·
生物催化
·
有机化学
·
香精香料行业
·
酶学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MINERALS ENGINEERING
·
2024
·
IF 4.9
Kangjing Wu,Yuxi Lu,Shuai Wang,Xin Ma,Hong Zhong
The weak collection ability of conventional benzohydroxamic acid (BHA) impedes its widespread application in the direct flotation of copper oxide minerals. Conversely, octyl hydroxamic acid (OHA) with enhanced hydrophobicity demonstrated superior collecting ability while exhibiting weak selectivity in malachite flotation. In order to achieve a balance between collecting ability and selectivity, we synthesized a novel N -cyclohexyl- N -hydroxyacetamide collector (ECHA) that featured similar structure of hydroxamate compounds and improved selectivity for the direct flotation of malachite. The bench-scale flotation results demonstrated that ECHA exhibited stronger collecting ability and excellent selectivity, 14.66% and 15.17% of copper recoveries increased than sodium butyl xanthate (SBX) and BHA, respectively. Contact angle tests, Zeta potential tests and solution chemistry analysis revealed that the interaction intensity of ECHA with malachite was significantly stronger than that of calcite and quartz. FTIR and XPS analysis showed that the reaction sites of ECHA were primarily located on the [–N(OH)CO–] group, suggesting possible chemisorption on the malachite surface. Additionally, DFT calculations indicated that the ECHA anion could potentially form a five-membered structure chelate complex with a Cu atom on the malachite surface through its [–N(OH)CO–] functional group. ECHA proved to be promising as an attractive collector in the direct flotation of malachite.
研究领域:
矿物加工工程
·
化学工程
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2024
·
IF 4.9
Rong Huang,Aoshuang Yang,Ziyu Liu,Fangxing Liu,Tian Fang,Fangfang He,Yongsheng Li,Zhuoni Jiang,He Lan,Kai Zhang,Wenbin Yang
Traditional poly(ethylene glycol)-based polyurethane phase change materials (PUPCMs) are difficult to reprocess and non-recyclable because of their permanently cross-linking structure, leading to issues of resource waste. To overcome this problem, this study introduces dynamic bonds in PUPCMs to develop dynamic cross-linking networks. A series of polyurethane phase change materials containing dynamic oxime-urethane bonds (DOU-PUPCMs) are prepared using poly(ethylene glycol) (PEG), dimethylglyoxime (DMG) and hexamethylene diisocyanate (HDI) as raw materials. It has been shown that the obtained DOU-PUPCMs exhibit good heat storage capability and outstanding thermal stability. Importantly, the introduction of oxime-urethane groups provided DOU-PUPCMs with processibility. After multiple reprocessing cycles, the chemical structure and energy storage capacity of the DOU-PUPCMs essentially remain consistent with the original samples. The breaking and restructuring of oxime-urethane bonds and hydrogen bonds in DOU-PUPCMs makes them recyclable. This is not only significant for the development of recyclable and sustainable energy storage materials , but also complements studies such as the application of oxime-urethane bonds to PCMs.
研究领域:
材料科学
·
能源工程
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2025
·
IF 4.7
Junxiang Lu,Yuting Liu,Shasha Zhang,Juhong Nie,Bing Tang,Jia Guan,Jian Zhang
Regulating the strength of coordination bonds plays an important role in synergizing the activity and stability of single-atom catalysts (SACs) but is often limited due to coordination atoms from the inorganic carrier lattice being tough to modify. It is fascinating yet rarely explored to immobilize organic molecules on lattice atoms for modulating the character of coordination bonds. Herein, a valid inorganic–organic coupling strategy is developed to enhance Pd–O coordination bonds within Pd-SAC for reconciling activity and stability. Nickel hydroxide enriched with Ni2+ vacancies is utilized to bind Pd centers, and dimethylglyoxime (DMG) bonds with its OH groups by H2 reduction, forming a Pd–O-DMG structure. Compared with the pristine Pd–O structure, whose activity descends greatly during the recycling process, the Pd–O-DMG structure makes the activity unchanged after 6 used times for the Suzuki–Miyaura reaction. The Pd-SAC has mild and economic reaction conditions (at 70 °C under air in ethanol without excess base) and good substrate tolerance. Further theoretical calculations show that coupled DMG induces hydrogen bonds on O atoms of the oxazole around Pd centers and thus strengthens Pd–O coordination bonds to exhibit good stability and activity.
研究领域:
催化化学
·
材料科学
·
理论计算
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Inorganic Chemistry Frontiers
·
2024
·Vol. 11
·期 18
·6156-6167
·
IF 6.1
Shiliang Qin,Jianang Sha,Peipei Yang,Songwei Li,Chuntai Liu,Changyu Shen
The advancement of the extraction of uranium(VI) (U(VI)) from seawater holds significant strategic importance for the sustainable progression of nuclear energy. In this study, the photocatalyst heterojunction of graphene oxide/graphitic carbon nitride (GO/g-C3N4) was encapsulated by the spinning of fiber to obtain a graphene oxide/graphitic carbon nitride/polyamide oxime (GO/g-C3N4/PAO) film with adsorption and photoreduction ability toward U(VI). The enhanced adsorption capacity of the GO/g-C3N4/PAO nanofiber was achieved through the synergistic effects of the aminoxime group in PAO and the photocatalytic performance of GO/g-C3N4. The GO/g-C3N4/PAO composite exhibited an adsorption capacity of 190.7 mg g−1 (pH = 6, t = 600 min, C0 = 99.9 mg L−1, and m/v = 0.5 g L−1) under light conditions. GO/g-C3N4/PAO showed good recycling reproducibility following five cycles of adsorption. After 30 days of adsorption in natural seawater, the adsorption capacity of GO/g-C3N4/PAO for U(VI) was 10.39 mg g−1, representing a 38.6% increase compared to its performance in the absence of light. The favorable adsorption characteristics exhibited by the GO/g-C3N4/PAO composite suggest its potential as a viable option for the extraction of uranium from seawater.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2020
·
IF 3.104
Xiaoyan Cao,Qing Wang,Shuai Wang,Ruilin Man
A novel polystyrene-poly(hydroxamic acid) interpenetrating network resin (PS-PHA IPNs) was successfully synthesized by suspension polymerization and interpenetrating network technology. The effects of various experimental parameters, including pH, contact time and initial concentrations of rare earth ions on the adsorption capacity were discussed in detail. Under the condition of pH 4.0 (La 3+ ), 1.0 (Ce 3+ ) and 3.0 (Y 3+ ), respectively, PS-PHA IPNs can reach equilibrium adsorption in 6 h and get maximum adsorption capacities (1.08, 1.43 and 1.36 mmol/g). The adsorption process of PS-PHA IPNs for La(III), Ce(III) and Y(III) ions can be described by liquid membrane diffusion, particle diffusion and chemical reaction. The adsorption process is a spontaneous and endothermic process and can be better simulated by Langmuir adsorption isotherm . The studies of SEM-EDS indicate that rare earth ions are adsorbed on the surface of PS-PHA IPNs. Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis further prove that rare earth ions are chemisorbed on the surface of PS-PHA IPNs. These results reveal that the as-prepared PS-PHA IPNs is a promising adsorbent for adsorption of rare earth ions due to their higher adsorption capacity than other adsorbents.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2020
·
IF 9.038
Xiang Hu,Tingting Sun,Lanjun Jia,Jie Wei,Zhirong Sun
Metal-organic framework based carbon material UC-X was prepared by template method, and adopted to remove cephalosporins from aqueous solution. The effect of templates including cetyltrimethyl ammonium bromide and sodium laurate was discussed. The UC-0.1 with the pore size of 5.38 nm has the best adsorption. According to FTIR spectrum, with the gradual increase of sodium laurate, the functional groups like C O increased, which promoted the adsorption capacity of cefepime in UC-X materials from 42.52 to 84.23 mg⋅g −1 . The optimal conditions for the adsorption of cefepime were determined by the response surface method: the adsorption temperature was 25.8 °C, the initial pH value was 6.11, and the ionic strength was 1.13 g·L −1 . Under the best adsorption condition, the adsorption-desorption experiments showed that the adsorption capacity of UC-0.1 material decreased by less than 10 % after five times usage, which indicated that its recycling property was competitive. The adsorption process conformed to the mixed-order kinetic model, and the error of equilibrium adsorption capacity between model fitting and actual experiments is not more than 1 %. The overall results of adsorption isotherm model and thermodynamic analysis demonstrated that Redlich-Peterson isothermal model could describe the adsorption process better.
研究领域:
环境科学
·
材料科学
·
药学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）