MICROPOROUS AND MESOPOROUS MATERIALS
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2022
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IF 5.876
Maosheng Zhang,Zhiqiang Shi,Yongcun Zou,Zongtao Zhang,Runwei Wang,Shilun Qiu
Porous carbons with controlled pore structure have attracted great interest owing to their excellent application potential. Herein, we report a simple synthetic route to synthesize the core-shell C@SiO 2 spheres with various pore structures by calcining core-shell structured RF@SiO 2 (RF = resorcinol-formaldehyde resin). The obtained C@SiO 2 spheres had high surface areas (238.5–732.5 m 2 /g), large pore volume (0.111–0.647 cm 3 /g) and abundant micro-mesoporous structure. The mesopore size of C@SiO 2 spheres can be easily turned in the range of 8–15 nm, by simply modifying the carbonization temperature, size and heating rate of RF@SiO 2 spheres. Among these, S–C@SiO 2 -400 spheres had higher mesopore volume of 0.207 cm 3 /g, this was related to internal carbon slices structure. Meantime, the toluene adsorption capacity of S–C@SiO 2 -400 spheres could reach 448.2 mg/g, which increased by 88.73% compared to ordinary carbon spheres. Moreover, the formation mechanism of the mesopore carbon slices structure was evaluated based on controlled experiments. This work provides a new synthetic method of micro-mesoporous carbon spheres, which can further enrich the application of carbon materials.
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高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
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2022
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IF 24.319
Fang Dong,Weigao Han,Weiliang Han,Zhicheng Tang
Configuring Ni-based catalyst with superior activity and stability is one efficient strategy in achieving its application for VOCs catalytic combustion. Here, we report the rational design and synthesis of core-shell SiO 2 @Ni a Co b O x nanotube derived from three-layered C@SiO 2 @NiCo-Phyllosilicate nanofiber. Through a typical hydrothermal strategy, the hierarchical NiCo-Phyllosilicate ultrathin nanosheets are fitly grown on the surface of order mesoporous SiO 2 nanotube, which is obtained through thermal treatment of core-shell C@SiO 2 nanofiber in air. Whereafter, a core-shell SiO 2 @Ni 2 Co 1 O x nanotube is obtained to achieve the highly efficient conversion of VOCs in the presence of 5vol%H 2 O. We observe this special structural design can own superior redox ability, provide active oxygen species (O ads ), and generate the abundant acid sites. Ideally, the low-temperature catalytic combustion of toluene over the core-shell SiO 2 @Ni 2 Co 1 O x nanotube is realized through the combined action of Marse-van Krevelen (MvK) and Langmuir-Hinshelwood (L-H) mechanism. Simultaneously, a good thermal stability and water resistance is also achieved, which benefits from the guided growth of order mesoporous SiO 2 nanotube, the presence of strong interactions (Ni-O-Si band) and the contribution of surface -OH groups in the special “fibrous” structure of phyllosilicate.
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高影响因子
ANALYST
·
2022
·Vol. 147
·期 12
·2851-2858
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IF 5.227
Xiuhui Liang,Zhenzhen Lin,Ling Li,Dianping Tang,Jinfeng Kong
Molecular tags such as fluorophores are increasingly being replaced with nanoparticles thanks to their superior optical properties, substantial chemical stability, and stability against photobleaching. Herein, we innovatively constructed a new ratiometric fluorescence enzyme-linked immunosorbent assay (RF-ELISA) for the screening of alpha-fetoprotein (AFP) in early hepatocellular carcinoma in vitro diagnostics using carbon dots@SiO2@CdTe quantum dots (CDs@SiO2@CdTe QDs). Carbon dots with blue fluorescence were initially encapsulated into SiO2 nanospheres through the typical Stöber method. Thereafter, CdTe QDs with red fluorescence were modified onto the surface of CDs@SiO2 nanospheres. Dual-emission nanotags with blue and red fluorescent signals were utilized to design a RF-ELISA method for the determination of AFP on the anti-AFP capture antibody-coated microplate using glucose oxidase (GOx)-labeled anti-AFP secondary antibody. After the formation of the sandwiched immunocomplex, GOx catalyzed glucose to generate hydrogen peroxide (H2O2), which could quench the red fluorescence of CdTe QDs on the surface of nanotags. Meanwhile, the encapsulated carbon dots in the nanotags could still maintain the initial blue fluorescence intensity. The ratio between red fluorescence intensity and blue-emission intensity could be used for the quantitative monitoring of AFP concentration under optimum conditions. The experimental results indicated that CDs@SiO2@CdTe QDs-based RF-ELISA could exhibit a good fluorescence signal with a dynamic linear range of 0.05–60 ng mL−1 at a low detection limit of 8.7 pg mL−1. Moreover, the fluorescence color of the solution including CDs@SiO2@CdTe QDs changed from pink to purple to blue with the increasing AFP level when viewed by the naked eye. Good reproducibility, high specificity, and acceptable stability were achieved for the analysis of target AFP. Importantly, the accuracy of ratiometric fluorescence immunoassay was evaluated to determine human serum samples, giving well-matched results relative to commercially usable human AFP ELISA method.
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PubMed
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2022
·Vol. 33
·期 23
·18345-18355
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IF 2.779
Gao Liang,Zhang Jiaqi,Song Lingyun,Bai Xilong,Yu Changxing
Polymer film capacitors have a high power density and great application potential in high-power electronic devices; however, high-energy storage density of polymer composites is usually obtained via doping high-content ceramic filler. An efficient approach to solve this issue is to dope polymers with an ultralow-content ceramic filler to improve their energy storage density. In this work, one-dimensional (1D) TiO 2 nanobelts@SiO 2 (TO nb@SO) are prepared via the hydrothermal reaction, muffle calcination, and hydrolysis. Extremely low-content TO nb@SO/poly(vinylidene fluoride) (TO nb@SO/PVDF) composites are prepared. The microstructure, crystalline structure, dielectric properties, electric breakdown strength, and discharge energy density are systematically investigated. The results show that the nanobelts have a width of 250 nm, a length of 1–2 μm, and a uniform shell layer at the edge with a thickness of ∼25 nm. The relative dielectric constant of the composites is significantly enhanced; it reaches 11 for PVDF at 100 Hz, and 12.03 for 0.5 wt% TO nb@SO/PVDF. The theoretical dielectric constant is calculated based on a mathematical model and compared with the measured value. 1D materials with a large aspect ratio are beneficial in the improvement of the dielectric properties. The Weibull breakdown field strength is 381.3 MV/m for 0.5 wt% TO nb@SO/PVDF. A discharge energy density of 8.86 J/cm 3 is obtained at 390 MV/m, while a high charge/discharge efficiency of 66.28% is achieved. To conclude, this work provides a valuable method for increasing the energy storage density and charge/discharge efficiency of dielectric capacitors.
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高影响因子
DIAMOND AND RELATED MATERIALS
·
2022
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IF 3.806
Miaomiao Li,Dening Zou,Bifang Zhao,Jinghui Chu,Libo Tong
The extensive application of Mg alloys is restricted by their poor corrosion, wear resistances and long-term service performance. Although the low-cost epoxy (EP) coating has excellent corrosion resistance , many pores and cracks are easily formed during the curing process, leading to the deterioration of barrier capacity. This study reports an epoxy-based nanocomposite coating, fabricated through the hybridization of γ-(2, 3-epoxypropoxy) propytrimethoxy silane modified silica nanoparticles and graphene oxide (mSiO 2 /GO). The insulating SiO 2 particles can isolate the direct contact between Mg alloy substrate and GO sheets, avoiding the formation of micro-cells and preventing the galvanic corrosion . The SiO 2 /GO in EP coating with “crack pinning and bridge” structure has reduced porosity and enhanced consistency, which effectively prevents crack propagation and electrolyte penetration. The corrosion rate of SiO 2 /GO/EP coating is 374 and 10 times lower than that of pure EP coating and individual GO/EP coating, respectively. The wear rate of GO/EP and SiO 2 /GO/EP coating specimens is 81.2 % and 70.4 % less than that of the pure EP coating, which is related to the favorable lubricating performance and high hardness of GO nanosheets . The results show that the embedding of well-distributed mSiO 2 -GO hybrids can remarkably improve the barrier effect and anti-corrosion of EP coating.
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高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2021
·Vol. 32
·期 22
·26655-26665
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IF 2.478
Yang Chengyu,Li Junkai,Lu Yang,Shan Yiting,Xian Qianqian,Zhou Hongqing
CaO-B 2 O 3 -SiO 2 (CBS) glass ceramic with various glass network modifiers were synthesized to develop a kind of material sintered at low temperature for multi-layer ceramic substrates. The influence of double alkali metal oxides (Na 2 O and K 2 O) on sintering characteristics, microstructures and dielectric properties of CBS glass ceramic were investigated. XRD analysis showed that the major crystalline phase was β-CaSiO 3 and CaB 2 O 4 , and the strength of the peak increased with the addition of network modifiers. DSC curve revealed that the process of crystallization and softening were obviously affected. SEM photographs exhibited that the microstructures were composed of amorphous phases, pores and crystalline phases. FTIR showed that the additives changed the continuity of CBS glass structure. An appropriate amount of Na 2 O and K 2 O additives could significantly improve the sintering characteristics and dielectric properties. CBS samples with 1.5 wt% (Na 2 O + K 2 O) sintered at 850 °C for 15 min presented the best performances with the bulk density of 2.53 g/cm 3 , ε r = 5.94 and tan δ = 1.22 × 10 −3 at 10 GHz.
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高影响因子
CHEMICAL ENGINEERING JOURNAL
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2021
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IF 13.273
Pu Mao,Qinzhao Sun,Lixue Zhang,Zepeng Wang,Liqiang He,Ruirui Kang,Gang Lu,Bing Xie,Zhiyong Liu,Jiping Wang
The development of excellent performances polymer-based nanocomposite films with high discharge energy density and high discharge efficiency are eagerly desirable for promoting their electric energy storage applications. However, the high discharge energy density and efficiency of polymer-based nanocomposite films are usually not compatible above intermediate electric fields. To address this issue, here we propose a newly designed multilayer-structured nanocomposite film with a combination of introducing the BaTiO 3 /CaCu 3 Ti 4 O 12 @SiO 2 (BT/CCTO@SO) hybrid nanoparticles with core–shell structure in middle layer and the poly(methyl methacrylate) (PMMA) linear polymer with low loss in outer layers. These motivations of introducing the core–shell structured hybrid nanoparticles with high dielectric constant and designing the multilayered structure give rise to an enhancement of maximum electric displacement while maintaining a relatively high breakdown strength. Also importantly, bring the PMMA polymer into top and bottom layers results in the low energy loss of whole nanocomposite film. Benefiting from these merits, a larger maximum electric displacement of 11.7 μC/cm 2 and a higher discharge energy density of 18.84 J/cm 3 accompanied with an ultrahigh discharge efficiency of 79.81% under an intermediate electric field of 418.13 MV/m are achieved in multilayer-structured nanocomposite film even at a very low filler loading of 2 wt% BT/CCTO@SO hybrid nanoparticles in middle layer, and these enhanced values are far higher than that of the monolayer nanocomposite films. This work validates the advantages of multilayered structure to integrate multiple components and presents outstanding overall performances of nanocomposite films in further applications of the dielectric capacitors with miniaturization and integration.
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高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 152
·期 8
·2524-2532
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IF 3.186
Jiang Haoxi,Jiang Angjiong,Gao Qiang,Yang Guochao,wang Lingtao
In this work, Ta was firstly reported as an efficient promoter of MgO–SiO 2 for the conversion of ethanol and acetaldehyde to 1,3-butadiene. The doping of Ta into MgO–SiO 2 forms Ta–O–Si bonds and generates more strong Lewis acid sites, which not only promote the aldol condensation reaction but also significantly facilitate the Meerwein–Ponndorf–Verley reduction, the total conversion around 80% which drops to 65% after 24 h. In addition, the catalyst showed desirable stability in 24 h long-term stability evaluation, the selectivity remained stable at 80%. Graphic Abstract
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高影响因子
LUMINESCENCE
·
2021
·Vol. 37
·期 2
·348-356
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IF 2.464
Shilin Shen,Zerong Long,Yi Lu,Jia Chen
A novel double-windows fluorescence sensor for carbofuran (CF) detection was successfully developed based on rare-earth Eu,Tb-doped Y 2 O 3 @SiO 2 -based molecularly imprinted nanoparticles (MINs) with a multilayer core-shell structure. The recognition process of the MINs for CF was fairly fast and needed only ~8 min to reach a dynamic equilibrium. Interestingly, one fluorescence attenuation window was found with an increase in CF concentration ( Q ) from 0.1 to 10 μg ml −1 and with a limit of detection (LOD) of 0.04 μg ml −1 at 544 nm belonging to the Tb 3+ emission, as well as another fluorescence enhanced window within the CF concentration range 10–100 μg ml −1 (LOD = 4 μg ml −1 ) at 617 nm of Eu 3+ emission in the dispersed rare-earth-doped MIN colloidal aqueous solution. Luminescence resonance energy transfer from CF to Eu 3+ and an inner filter effect of CF towards Tb 3+ , as well from the two independent detection windows were clearly observed simultaneously. The competition experiment displayed hardly any marked interference during detection of CF following addition of its analogues (carbaryl, isoprocarb, aldicarb, methomyl, and etofenprox). Moreover, the MINs could also be applied to accurately detect CF in rhubarb and wolfberry samples with recoveries of 85.7–92.2%. This sensing system has high specific recognition and a wide detection range for CF and provides new opportunities for pesticide detection.
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PubMed
高影响因子
Engineering
·
2021
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IF 7.553
Xianbin Huang,Jinsheng Sun,He Li,Ren Wang,Kaihe Lv,Haichao Li
Wellbore stability is essential for safe and efficient drilling during oil and gas exploration and development. This paper introduces a hydrophobic nano-silica (HNS) for use in strengthening the wellbore wall when using a water-based drilling fluid (WBF). The wellbore-strengthening performance was studied using the linear swelling test, hot-rolling recovery test, and compressive strength test. The mechanism of strengthening the wellbore wall was studied by means of experiments on the zeta potential, particle size, contact angle, and surface tension, and with the use of a scanning electron microscope (SEM). The surface free energy changes of the shale before and after HNS treatment were also calculated using the contact angle method. The experimental results showed that HNS exhibited a good performance in inhibiting shale swelling and dispersion. Compared with the use of water, the use of HNS resulted in a 20% smaller linear swelling height of the bentonite pellets and an 11.53 times higher recovery of water-sensitive shale—a performance that exceeds those of the commonly used shale inhibitors KCl and polyamines. More importantly, the addition of HNS was effective in preventing a decrease in shale strength. According to the mechanism study, the good wellbore-strengthening performance of HNS can be attributed to three aspects. First, the positively charged HNS balances parts of the negative charges of clay by means of electrostatic adsorption, thus inhibiting osmotic hydration. Second, HNS fabricates a lotus-leaf-like surface with a micro-nano hierarchical structure on shale after adsorption, which significantly increases the water contact angle of the shale surface and considerably reduces the surface free energy, thereby inhibiting surface hydration. Third, the decrease in capillary action and the effective plugging of the shale pores reduce the invasion of water and promote wellbore stability. The approach described herein may provide an avenue for inhibiting both the surface hydration and the osmotic hydration of shale.
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高影响因子
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
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2021
·
IF 5.302
Chong He,Xinger Liu,Cong Ma,Yueqi Cao,Feng Hou,Liwen Yan,Anran Guo,Jiachen Liu
Nowadays, 3D polymer-derived silicon oxycarbide ceramics (SiOC) can be fabricated by the stereolithography method successfully. However, due to their intrinsically poor ceramic content and the large thermal shrinkage during the pyrolysis, it is difficult for the bulk 3D polysiloxane precursors to be pyrolyzed into dense 3D-ceramics. Herein, the ceramic content of the photocurable polysiloxane precursors was increased by adding a large amount of SiO 2 powders into the low solid content epoxy-acrylic siloxane. After being added with proper dispersant, the viscosity of the high solid loading polysiloxane/SiO 2 slurry can reach a proper level. Bulk 3D-silica ceramics with the wall-thickness around 8 mm can be conveniently fabricated from the polysiloxane/SiO 2 slurry by stereolithography and a two-step sintering process. The addition of a proper sintering aid NaF can promote the 3D-PSO/SiO 2 precursor to be converted into dense and crack-free 3D-silica ceramics with good mechanical proprieties.
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高影响因子
JOURNAL OF DISPERSION SCIENCE AND TECHNOLOGY
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2021
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IF 2.262
Li Chao,Haiwang Wang,Xinfang Wei,Jinlong Li,Cheng Ji,Xiwei Qi
At present, the polymer flocculation technology has been widely used in the treatment of oil sand tailings. However, the current composite flocculant still has the problems of low flocculation efficiency and serious secondary pollution after using. In this article, cationic composite flocculant SiO2-TiO2-P(AM-DMC) with self-degrading characteristics was prepared by the surface photoinitiated polymerization technique. Above all, in order to study the synthesis process of SiO2-TiO2-P(AM-DMC), cationic composite flocculant was characterized by FTIR, TG, TEM, XPS, etc. Furthermore, the central composite design (CCD) and response surface methodology (RSM) were used to optimize the preparation parameters of the cationic composite flocculant. And the optimization results of preparation parameters of cationic composite flocculant showed that the optimal preparation parameters of SiO2-TiO2-P(AM-DMC) were as follows: mDMC: mAM = 5, monomer concentration was 35% and reaction time was 100 min. Ultimately, the flocculation parameters of SiO2-TiO2-P(AM-DMC) were optimized by CCD and RSM. Moreover, the optimization results of flocculation parameters of cationic composite flocculant showed that the optimal flocculation parameters of SiO2-TiO2-P(AM-DMC) were as follows: pH = 5, flocculant dosage was 30 ppm, kaolin concentration was 1.36%. In summary, this work had greatly enriched the knowledge of oil sand tailings treatment, and had the extremely important reference significance for realizing the parameter regulation of high-efficiency flocculation of oil sand tailings.
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高影响因子
危险品化学品经营许可证（带存储）