ENERGY & FUELS
·
2021
·
IF 3.605
Jing Wang,Yv Chen,Shun Wang,Huiqing Liu,Fengming Zhao
Foam stability is significantly important for enhancing oil recovery and sequestration of carbon dioxide underground. Nanoparticles have been widely used to improve foam stability, but traditional experiments cannot well reveal the mechanisms of nanoparticles on stabilizing foams and the interactions among nanoparticles, surfactants, and liquid films. In order to clarify the mechanisms of enhancing foam stability by nanoparticles, the adsorption behaviors of nanoparticles with different modification degrees on the liquid film and the effects of different compounded systems of nanoparticles and surfactants on the foam stability were studied by molecular simulation. Moreover, the foam stability of the compounded systems was evaluated by experiments. The results show that the foam stability of single nanoparticles increases first and then decreases with the increase of hydrophobic properties. The electrically charged properties of nanoparticles can significantly affect the foam stability of the compound system with nanoparticles and surfactants. The electrostatic repulsion between hydrophilic nanoparticles and anionic surfactants results in irregular arrangement of surfactants in the liquid film, which reduces foam stability. On the contrary, the electrostatic attraction between cationic surfactants and hydrophilic nanoparticles can promote the orderly arrangement of cationic surfactants and thus enhance the foam stability. Amphiphilic nanoparticles can interact with anionic or cationic surfactants, which not only strengthens the regular arrangement of surfactants on the interface but also fills the interface cavity and improves the foam stability. In addition, the experimental results show that there is an optimal ratio between nanoparticles and surfactants. Nanoparticles can reduce the foaming volume to a certain extent, but appropriate nanoparticles can effectively prolong the foam half-life. This study elucidates the mechanism of the nanoparticles/surfactant system in enhancing foam stability and provides an important theoretical basis and guidance for nanoparticle modification and optimization of foam flooding.
研究领域:
石油工程
·
化学工程
·
纳米技术
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2020
·Vol. 8
·期 48
·17403-17409
·
IF 7.059
Cuifang Meng,Dandan Yang,Ye Wu,Xuejia Zhang,Haibo Zeng,Xiaoming Li
Encapsulating cesium lead halide (CsPbX3, X = Cl, Br, and I) perovskite quantum dots (PQDs) into stable shells has been proved to be an effective strategy for improving their stability, which however usually forms agglomerated particles or alters PQDs’ original morphology and optical properties. Herein, we propose a surface activation strategy to prepare single CsPbBr3@SiO2 core–shell particles. (3-Aminopropyl)triethoxysilane (APTES) is used as a bifunctional surface ligand, which not only effectively passivates the surface defects of PQDs, but also provides –SiOCH3 and –SiOH groups for the formation of Si–O–Si covalent bonds with the subsequently introduced silanes. Furthermore, by controlling the hydrolysis rate of silanes, we realized the preparation of single CsPbBr3@SiO2 core–shell particles with an average shell thickness from 1 to 2.7 nm, and the PQDs maintained their initial cubic morphology and optical properties after coating. The stability of CsPbBr3@SiO2 in harsh environments has been effectively improved owing to the complete encapsulation of the SiO2 shell. As a result, the emission peak of CsPbBr3@SiO2 remains constant at 515 nm after being heated at 60 °C for 84 h, and the photoluminescence (PL) intensity still remains 90% after storage for 6 h in a high humidity environment. This work not only enhances the stability of PQDs for practical applications but also provides a reliable method to synthesize single core–shell particles, which can be instructive to other PQD systems.
研究领域:
材料科学
·
纳米技术
·
化学
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2023
·Vol. 24
·期 12
·4279-4286
·
IF 2.5
Zhou Jianhua,Niu Zhuanli,Xiao Anguo,Li Xiang
Materials with passive daytime radiative cooling (PDRC) have drawn more attention as a result of their potential for energy savings. We prepared SiO 2 -encapsulated ZnO@ZIF-8 (ZZS) particles and a radiative cooling coating containing ZZS particles. Owing to the polyhedron structure and the phonon-polarization resonance of ZZS particles, the ZZS fabric coating could reflect sunlight with 83% and radiate heat to outer space with 0.96. Compared with the ambient air, its average temperature decreased by 6.4 °C, and the human body under direct sunlight could avoid overheating 3.9 °C. In addition, the ZZS coated fabric after rubbing still had good PDRC and its average temperature increased by 1.38℃ higher than the original ZZS coated fabric. Owing to good PDRC property, hydrophobicity, mechanical properties and simple methods, the widespread usage of ZZS coated fabric for personal thermal management appears to be promising.
研究领域:
材料科学
·
能源工程
·
纺织科学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2019
·
IF 8.355
Jinxin Xie,Xukai Li,Weirui Chen,Xianglin Sun,Kexin Chen,Yiming Tang,Laisheng Li
The mesoporous core-shell CeO x @SiO 2 was synthesized and characterized by XRD, pyridine-FTIR, BET, SEM, TEM and XPS. CeO x @SiO 2 was the hollow nanosphere with high surface area of 1291.4 m 2 g −1 , which benefited for mass transfer of reactants. CeO x @SiO 2 exhibited the excellent catalytic activity for oxidizing oxalic acid (OA) in O 3 /H 2 O 2 /CeO x @SiO 2 . The greatest OA mineralization (91.2%) was achieved at pH = 3.2 in O 3 /H 2 O 2 /CeO x @SiO 2 , which was 5.5 times higher than that in peroxone (O 3 /H 2 O 2 , 15.9%). Influence of pH, HSO 3 − , PO 4 3− and detection of ozone and H 2 O 2 concentration were conducted to explore the mechanism. The interface reaction played vital role for OA removal in O 3 /H 2 O 2 /CeO x @SiO 2 process. Protonated surface hydroxyl groups (Ce-OH 2 + ) was the active sites, where OA, O 3 and H 2 O 2 were chemi-absorbed. The peroxide-like species (≡(Ce(IV)-O 2 H 2 )) formed by the complex of H 2 O 2 with active sites were the important intermediates, which initiated ozone decomposition into hydroxyl radical (·OH) and led to the high OA mineralization. Moreover, Lewis acid sites and electron transfer effect of Ce(III)/Ce(IV) also accounted for the high catalytic activity of CeO x @SiO 2 . In addition, CeO x @SiO 2 maintained stable structure and catalytic activity in three cycles.
研究领域:
环境科学
·
化学工程
✓ 已验证
DOI
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Zhaokuan Cui,Hui Zhao,Jiale Song,Wei Liu,Shuheng Zhang,Weiguang Li
Surface treatment protective technology is a cost-effective approach to prevent harmful ions from infiltrating concrete, avoiding the deterioration of performance and increasing longevity. Here, a novel coupling agent with ester group (MA-KH-550) is synthesized from γ-aminopropyltriethoxysilane (KH-550) and methyl acrylate (MA) to modify nano-SiO 2 particles. Subsequently, the ester-modified nano-SiO 2 can be successfully dispersed in alkaline composite silicate solutions to fabricate nano-SiO 2 /silicate coatings, improving the impermeability of concrete. The incorporation of nano-SiO 2 particles can fill microscopic pores in cementitious materials, which improves the compactness of the concrete. Furthermore, nano-SiO 2 particles can also accelerate secondary hydration of cement and synergistically generate more calcium silicate hydrate gel with silicates to further boost the compactness of the concrete. High-compactness coatings reduce the penetration of the medium, thereby enhancing the impermeability performance of the concrete. When the nano-SiO 2 particle content is 1.0 wt%, the optimal performance of concrete is achieved. Compared with the original C30 concrete, the C30 concrete treated with the nano-SiO 2 /composite silicate (nano-SiO 2 /CSC) shows a 31.1 % decrease in chloride ion resistance, a 35.5 % reduction in carbonization resistance, a loss rate of 1.08 % for anti-freezing quality. This work charts a new course for designing and developing high-performance composite silicate coatings for concrete.
研究领域:
材料科学
·
土木工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2019
·Vol. 43
·期 16
·6234-6241
·
IF 3.069
Xinfu Zhao,Wei Ju,Jian Zhang,Benxue Liu,Jing Zhang,Xibin Yi
TiO2/SiO2-Based nanocomposites with highly porous structures have received increasing attention due to their excellent photocatalytic activity. In this work, a TiO2/SiO2/Ag ternary composite aerogel with enhanced visible-light photocatalytic activity has been successfully synthesized through a facile sol–gel method combined with a supercritical drying technique. The specific surface area and pore structure of TiO2/SiO2/Ag aerogel could be controlled by adjusting the Si content. The TiO2/SiO2/Ag aerogel with pore size of 9.2 nm achieved the maximum adsorption capacity of oxytetracycline. The presence of SiO2 in TiO2/SiO2/Ag improved the compression strength of the aerogel and thus achieved long-term stability in photocatalysis. Furthermore, the addition of Ag particles in TiO2/SiO2/Ag effectively decreased the recombination of photo-electrons and holes. The photocatalytic degradation rates of oxytetracycline over the TiO2/SiO2/Ag aerogel with a mole ratio of Ag : Si : Ti = 0.1 : 10 : 4 were 3.1 and 2.3 times those over P25 and a TiO2/SiO2 aerogel. The enhanced photocatalytic performance of the TiO2/SiO2/Ag aerogel is attributed to the large specific surface area, 3-D porous structure, high electrical conductivity and compression strength of this novel composite aerogel.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
Catalysis Science & Technology
·
2019
·Vol. 9
·期 13
·3454-3468
·
IF 5.726
Huixian Zhong,Jiaming Wang,Kang An,Kegong Fang,Yuan Liu
A catalyst with a novel composition for direct ethanol synthesis from syngas was prepared and investigated in this work, which is Rh nanoparticles (NPs) highly dispersed on La2O3 modified LaFeO3, and the Rh NPs/La2O3–LaFeO3 was loaded on SiO2 with high surface area. The catalyst was prepared by using LaFe1−xRhxO3 in the perovskite phase as the precursor, which was transformed to Rh/La2O3–LaFeO3/SiO2 after reduction. The results showed that, compared to Rh–La2O3/SiO2, the activity and selectivity to ethanol were improved markedly, which was ascribed to the well-matched catalyzing process by the active sites of Rh0, Rh+ (or Rhδ+) and the oxygen vacancies on the surface of LaFeO3; of those, Rh0 dissociatively adsorbed CO and the latter two associatively adsorbed CO. Moreover, the interaction of La2O3 and LaFeO3 donated electrons to rhodium, which effectively adjusted the ratio of CO adsorbed associatively and dissociatively, and thus improved the selectivity to ethanol and lowered the selectivity to methanol. The catalyst also exhibited excellent resistance to the sintering of Rh NPs and to carbon deposition, which was attributed to the confinement of Rh NPs by La2O3 and LaFeO3, the eliminating effect of La2O3 and LaFeO3 and the very high dispersion of Rh NPs.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 37
·17461-17474
·
IF 3.591
Shuili Lai,Gong Chen,Wen Hu,Baojian Liu,Xin Yang,Kai Gao
Aiming to reduce coal dust pollution and spontaneous coal combustion during coal mining, storage, and transportation, a kind of DOPO-nano-SiO2 modified polyacrylic acid-based polymer flame retardant dust suppressant for coal was fabricated using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO), γ-aminopropyl triethoxysilane (KH550), nano-SiO2, sodium alginate (SA), and acrylic acid (AA) as raw materials, potassium persulfate (K2S2O8) and sodium bisulfite (NaHSO3) as initiator, and N,N′-methylenebisacrylamide (MBA) as a cross-linking agent by the aqueous solution polymerization method. The product was characterized and analyzed by FT-IR, XPS, XRD, GPC, TG, and DSC techniques. Its flame retardant property, thermal stability, and dust suppression performance were tested, and the activation energy of the pyrolysis reaction was calculated using Flynn–Wall–Ozawa (FWO) method. Compared with the coal sample sprayed with water, the CO mass concentration of the coal sample sprayed with flame retardant dust suppressant was decreased by 80.6%, inhibition rate reached 82.8%, LOI value was 26.1%, and the UL-94 rating was V-0. Moreover, the initial degradation temperature and pyrolysis activation energy were increased by 10.6% and 108%, respectively. After spraying the flame retardant dust suppressant, the pulverized coal particles were tightly bonded together to form a flexible consolidation layer, thereby inhibiting coal dust pollution and loss. The water loss rate, wind erosion loss rate, and oscillation loss rate were decreased by 56.9%, 98.7%, and 97.5%, respectively. These results revealed that the pulverized coal sprayed with the flame retardant dust suppressant exhibited better flame retardant property, thermal stability, and dust suppression performance than that sprayed with water. In summary, the flame retardant dust suppressant prepared in this work could play a key role in inhibiting coal dust pollution and spontaneous coal combustion.
研究领域:
材料科学
·
环境工程
·
矿业工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Lixin Zhou,Shengdong Pan,Xiaohong Chen,Yonggang Zhao,Baobo Zou,Micong Jin
A novel core–shell covalently functionalized Fe 3 O 4 coated SiO 2 decorated multi-walled carbon nanotubes (Fe 3 O 4 @SiO 2 –MWCNTs) adsorbent was synthesized and characterized by scanning electron microscopy, transmission electron microscopy, Fourier Transform Infrared Spectrum (FTIR), Thermogravimetry, X-ray diffraction and magnetic measurements. The pentachlorophenol (PCP) adsorption effect factors of initial concentration, contact time, solution pH and temperature were investigated in detail. It was found the absorption capacity was strongly depended on pH, and the maximum adsorption value for PCP (96.4 mg/g) was obtained at pH 2.5. The equilibrium was attained within 30 min, and the adsorption kinetics was better described by pseudo-second-order kinetic model. The data pointed out excellent fit to Freundlich isotherm model. Thermodynamic parameters such as standard enthalpy (Δ H θ ), standard entropy (Δ S θ ) and standard free energy (Δ G θ ) showed that the adsorption of PCP onto Fe 3 O 4 @SiO 2 –MWCNTs was spontaneous, endothermic and random within the temperature range of 288–318 K. The results indicate that the Fe 3 O 4 @SiO 2 –MWCNTs adsorbent is a potential low-cost effective material for PCP removal from contaminated wastewater.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2018
·Vol. 33
·期 5
·1176-1185
·
IF 0.524
Lu Guosen,Deng Min,Mo Liwu
C3S pastes containing 0%, 5%, 10%, and 15% nano-SiO2 mixed with de-ionized water and alkali solutions were prepared. When C3S was completely hydrated, the pastes were ground into powders with a particle size less than 80 μm. Adsorption and desorption characteristics of alkali ions adsorbed by C 3 S-nano SiO 2 pastes mixed with de-ionized water immersed in alkali solutions and those in C 3 S-nano SiO 2 pastes mixed with alkali solutions, were investigated. Meawhile, the adsorption mechanisms of alkali ions were discussed. Results showed that the contents of alkali ions adsorbed by C 3 S-nano SiO 2 pastes mixed with de-ionized water increased with increasing substitution levels of nano-SiO 2 and/or the initial alkali concentrations. In C 3 S-nano SiO 2 pastes mixed with de-ionized water, each paste was characterized by having a fixed alkali-adsorption capacity that was essentially independent of alkali concentration. No obvious difference between the adsorption capacity of a given paste for K + and Na + was observed. Adsorption of alkali ions in the pastes is considered to be caused by surface force which is related to the BET specific surface area of the paste, and charge compensation of C-S-H gel, mainly by electrostatic interactions. In C 3 S-nano SiO 2 pastes mixed with alkali solutions, alkali ions may enter the structure of C-S-H gel to replace a part of Ca 2+ in the interlayer. This assumption is supported by the structural characterization of C-S-H gel using 29 Si MAS NMR.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
CORROSION SCIENCE
·
2018
·
IF 4.862
Lian-Kui Wu,Wei-Yao Wu,Jia-Lin Song,Guang-Ya Hou,Hua-Zhen Cao,Yi-Ping Tang,Guo-Qu Zheng
Thickness controllable SiO 2 film was prepared on γ-TiAl alloy by cathodic electrodeposition . The oxidation behaviour of the specimens at 900 °C was studied. The effects of SiO 2 electrodeposition parameters, such as electrolysis time and deposition current density, on the morphology, structure and high temperature oxidation performance of the film were investigated. Results shown during thermal oxidation, the electrodeposited SiO 2 film could react with the TiAl alloy to form an alumina- and silicon-enriched glass-like oxide scale, which can prevent the inward diffusion of oxygen from air to the film/alloy interface, resulting in the remarkable decreased oxidation rate of the alloy.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
RSC Advances
·
2022
·Vol. 12
·期 52
·33626-33633
·
IF 4.036
Xiaoru Hao,Jun Xie,Yu Zhang,Zhihao Cheng,Wei Sheng
Among different types of anti-icing coatings, superhydrophobic surfaces have attracted extensive attention due to their excellent water repellency and low thermal conductivity. We report facile spraying time tuning to optimize the superhydrophobic (SHP) surface coating fabrication by a one-step spraying method of mixing SiO2 nanoparticles with epoxy resin (EP), polyamide resin (PAI), and HFTMS. The wettability performance was optimized by adjusting spraying time from 0 s to 25 s to control surface morphology by adjusting surface morphology and line roughness. With spraying time of 20 s, SiO2 molecular clusters on the superhydrophobic surface showed a maximum water contact angle (WCA) of 160.4° ± 1.3° and a sliding angle (SA) of 4.1° ± 1.0°. What's more, the effect of the coatings' icing behavior were studied by icing heat conduction; SHP-20 delayed the icing time for 410 s at −15 °C, and the icing performance of SHP-20 also declined with the decrease of temperature to −9 °C, −12 °C, −15 °C, and −18 °C. The WCA of SHP-20 can remain above 140.9° ± 1.8° after 40 abrasive 1000# sandpaper wear cycles. The results also provide a basis for the preparation of SHP and anti-icing characteristics.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）