Nanomaterials
·
2017
·Vol. 7
·期 5
·102
·
IF 3.553
Jinfeng Sun,Zhiqiang Xu,Weifeng Li,Xiaodong Shen
The impact of nano-SiO2on the early hydration properties of alite-sulphoaluminate (AC$A) cement was investigated with a fixed water to solid ratio (w/s) of one. Nano-SiO2was used in partial substitution of AC$A cement at zero, one and three wt %. Calorimetry, X-ray diffraction (XRD), thermogravimetric/derivative thermogravimetric (TG/DTG), mercury intrusion porosimetry (MIP) and scanning electron microscopy (SEM) analyses were used to characterize the hydration and hydrates of the blended cement. The hydration of the AC$A cement was significantly promoted, resulting in an increase of the heat released with the addition of nano-SiO2. Phase development composition analysis showed that nano-SiO2had no effect on the type of crystalline hydration products of the AC$A cement. Moreover, nano-SiO2showed significant positive effects on pore refinement where the total porosity decreased by 54.09% at three days with the inclusion of 3% nano-SiO2. Finally, from the SEM observations, nano-SiO2was conducive to producing a denser microstructure than that of the control sample.Keywords:nano-SiO2;AC$A cement;early hydration;properties
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
PubMed
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Chong Xu,Jian Fang,Ze-Xian Low,Shasha Feng,Min Hu,Zhaoxiang Zhong,Weihong Xing
Synthetic expanded polytetrafluoroethylene (ePTFE) membrane has a wide range of applications, including aerosol and dust removal, and exhibits high dust-removing efficiency, high air permeability, and cost-effectiveness. However, the intrinsic oleophilic surface of ePTFE limits its application in the oil-bearing gas–solid separation process. Herein, we report a surface modification method to prepare amphiphobic ePTFE membranes via coating of a layer of 1H,1H,2H,2H-perfluorooctyltrimethoxysilane (PFTMS) – modified nano-SiO2 onto the surface of ePTFE fibers. The oil contact angle of the modified ePTFE membranes was increased from 0 to 123°, while retaining the initial water contact angle of 142°. The amphiphobic membrane shows excellent oil aerosol filtration efficiency with a comparative low pressure drop and high oil rejection rate of 99.5%. Remarkably, the membrane can be reused after simple rinsing with water. The oil aerosol filtration efficiency of membrane remained as high as 98.5% after five cycles of filtration and cleaning.
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 Sciences-Basel
·
2023
·Vol. 13
·期 9
·5248
·
IF 2.7
Hao Lai,Wei Shi,Junqi Wang,Lei Tang,Nanjun Lai
A low-permeability reservoir contains many fine pore throat structures, which result in excessive injection pressure of the water injection well and difficult water injection in the production process of a low-permeability reservoir. In this study, a new silane coupling agent was synthesized via the ring-opening reaction between dodecyl amine and KH-560 (γ-propyl trimethoxysilane). The modified KH-560 was reacted with nano-SiO2to synthesize the modified nano-SiO2as an antihypertensive additive. Fourier infrared spectroscopy, thermogravimetric analysis and laser scattering were used to characterize this modified nano-SiO2. The results show that the particle size of the modified nano-SiO2is less than 60 nm. The test results of the water contact angle show that the dispersion system can increase the rock contact angle from 37.34° to 136.36°, which makes the rock surface transform from hydrophilicity to hydrophobicity and reduce the binding effect of rock with water. The dispersion test shows that the modified nano-SiO2has good dispersion stability under alkaline conditions with TX-100 (Polyethylene glycol octylphenyl ether) as the dispersant. The antiswelling test results show that the antiswelling rate of this modified nano-SiO2is 42.9%, which can efficiently prevent the clay expansion in the formation to reduce the injection pressure. The core displacement test results show that its depressurization rate reaches 49%. The depressurization rate still maintains 46% at a 20 PV water flow rate, indicating that its depressurization effect is remarkable and it has excellent erosion resistance.Keywords:nano-SiO2;hydrophobicity;ultra-low-permeability reservoir;pressure reduction
研究领域:
石油工程
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2024
·Vol. 35
·期 25
·1-13
·
IF 2.8
Xue Longlong,Xiong Shisheng
In the anti-wind–sand environment, it is challenging to find a single material that fulfills all the required functional application requirements, such as shielding performance, mechanical performance, chemical performance, reliability, and economic efficiency. Herein, a multi-layer electromagnetic shielding composite sheet specifically was designed for large military bases in anti-wind–sand environments. The composite material structure comprises laminated aluminum foil, PET film, and Oxford fabric, utilizing an acrylic emulsion pressure-sensitive adhesive that was modified with superior nano-SiO 2 . The results showed that the electromagnetic interference shielding of Al Mylar foil (0.03 mm) measured 88 dB, whereas the medium gauge foil recorded 84.7 dB after salt spray test for 288 h. The samples of Oxford fabric showed an increase in tensile and tearing strength as the fabric density increases, but the rate of increase decreases gradually. The shear and peel strengths of acrylic emulsion modified by hydrophobic nano-SiO 2 were 67.1 MPa and 24.3 N/m, respectively, with a blending ratio of 7 wt%. Finally, we handpicked 140 g/m 2 of Oxford cloth, 0.03 mm of aluminum foil with PET films, and acrylic emulsion pressure-sensitive adhesive containing 7 wt% hydrophobic nano-SiO 2 for the lamination. The samples have good aging performance, with electromagnetic shielding performance, shear strength, peel strength, and weight loss declining less than 10% at 85 °C and 85% RH for 1000 h.
研究领域:
材料科学
·
电子工程
✓ 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
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
ELECTROCHIMICA ACTA
·
2018
·
IF 5.116
Hao Yang,Fusheng Li,Xiujuan Wu,Peili Zhang,Wenlong Li,Suyan Cao,Yu Shan,Licheng Sun
The electrochemical splitting of water requires efficient functional electrodes. Herein, we report the fabrication of electrocatalyst consisted of an electrodeposited NiFeP alloy film which was composite plated with nano-SiO 2 on nickel foam. The structure and morphology of the film were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the surface area of this NiFeP -SiO 2 co-deposition alloy film can be significantly increased after electrochemical etching in a KOH solution. The water splitting properties of the alloy film were evaluated using electrochemistry . By using the NiFeP -SiO 2 / NF (Etched) as a bifunctional electrode, total water splitting has been demonstrated in a two-electrode cell with a current density of 10 mA cm −2 at an applied voltage of 1.57 V, which exhibited enhanced water splitting activity in comparison to the analogue cell using the pristine NiFeP / NF electrode.
研究领域:
材料科学
·
电化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
POWDER TECHNOLOGY
·
2019
·
IF 3.413
Xuechen Tang,Wanli Kang,Bobo Zhou,Yongbo Gao,Changxiao Cao,Shujun Guo,Muhammad Wassem Iqbal,Hongbin Yang
Polymer/nano-SiO 2 composite microspheres (PNSCMs) were synthesized via inverse suspension polymerization with 3-methacryloxypropyltrimethoxysilane (MPS) modified SiO 2 as the reinforcing filler. The influences of these polymerizable nanoparticles on the swelling behavior, mechanical property, thermal stability, viscoelasticity and dispersion stability were examined in detail. Moreover, the plugging behaviors were investigated by sand pack tests. The results indicate that the introduction of these modified nanoparticles revealed a significant enhancement on the comprehensive properties of PNSCMs. By varying the content of MPS-modified SiO 2 , the environmental sensitivity of the microspheres’ swelling behavior was reduced. Besides, the mechanical property, thermal stability and viscoelasticity were greatly improved by increasing the SiO 2 loading. Compared with SiO 2 -free ones, PNSCMs exhibited better dispersion stability and plugging performance, and the maximum plugging rate reached 93.64%, which was increased by 14.69%. These PNSCMs studied can realize in-depth profile control in reservoirs and have great application prospects in the further enhanced oil recovery research.
研究领域:
石油工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS SURVEYS FROM ASIA
·
2020
·Vol. 24
·期 2
·115-122
·
IF 2.194
Gao Meixiang,Jiang Haoxi,Zhang Minhua
This paper has systematically investigated the structures and properties of the ZrO 2 , Nano-SiO 2 and their composition. The catalysts were prepared by impregnation, characterized by N 2 adsorption–desorption, TEM, XRD, Raman, temperature-programmed desorption of NH 3 and CO 2 , FTIR spectroscopy of adsorbed pyridine and CO 2 , and UV–vis spectra. Compared with dry-mixed samples, these catalysts have larger average pore diameter, enabling ZrO 2 to be dispersed more uniformly on the surface of Nano-SiO 2 . With the Zr–O–Si bonds, ZrO 2 could interact intensely with Nano-SiO 2 . The catalyst prepared shows the best performance, with the selectivity of 93.18% and conversion of 58.52%. The preparation methods have a significant influence on the interaction between ZrO 2 and Nano-SiO 2, which then affects the acid–basic properties. This paper finds that weak acid–basic sites with moderate-intensity are more suitable for ethanol conversion to BD, with the amount of acid and basic sites as close as possible.
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
Materials
·
2023
·Vol. 16
·期 24
·7576
·
IF 3.4
Tianlei Chen,Rong Zhong,Zhengjie Wang
In this study, a hydrophobic, wear-resistant ultraviolet (UV)-curable coating was investigated as an alternative to traditional coatings with low hardness and high susceptibility to scratching. The SiO2nanoparticles were ground and modified using high-energy ball milling, during which the surface energy of nano-SiO2particles rapidly increased as their particle size decreased. Different proportions of modified nano-SiO2particles were added to the coating and cured into a film. The structure of the composite coating was analyzed via infrared spectroscopy, scanning electron microscopy, and X-ray diffraction, which confirmed the successful preparation of the composite coating. The mechanical and optical property tests of the coating were investigated. With a 5% nano-SiO2content, the hardness of the coating reached 5H, whereas the adhesion was poor (2B), and the flexibility was 1. The overall comprehensive performance of the coating was best when the addition amount was 3%. The coating exhibited good hardness, flexibility, and adhesion. The hardness of the coating reached 4H, the adhesion was 4B, the flexibility was 5, the coating haze was 12.38 HZ, and the contact angle was 118°.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CORROSION
·
2022
·Vol. 78
·期 12
·1190-1202
·
IF 2.094
Xu Yangshuhan,Chen Feng,Wang Shufen,Li Minghua
In this work, ordinary epoxy coatings were modified by hydrophobic nanoSiO 2 and hydroxyl PDMS to construct ultrahydrophobic epoxy coatings for corrosion protection and self-cleaning of phosphatized Q235 carbon steel. Ordinary epoxy polymer coating was fabricated via polyaddition reaction between E44 (bisphenol A epoxy resin oligomer) and DDM (4,4-diaminodiphenyl methane). The microscopic morphologies of coatings showed that many SiO 2 nanoparticles were presented on the surface of ultrahydrophobic epoxy coating. Through static water contact angle measurement, the modified epoxy coating displayed ultrahydrophobicity with a water contact angle of approximately 150°. However, adding too much nanoSiO 2 caused cracks on the modified epoxy coating, which deteriorated the corrosion resistance of the coating. According to the corrosion test results, the modified coating added with 6.7 wt% hydrophobic nanoSiO 2 and chemically modified with hydroxyl PDMS showed the best corrosion protection performance, which was reflected by the high impedance of approximately 10 9 Ω·cm 2 after 50 d immersion in 3.5 wt% NaCl (aq.). Besides, the coating also presented good self-cleaning performance. The coating extracted from the slurry still remained clean without any contamination.
研究领域:
材料科学
·
表面工程
✓ 已验证
DOI
高影响因子
MATERIALS AND STRUCTURES
·
2019
·Vol. 53
·期 1
·1-12
·
IF 2.548
Liu Xin,Feng Pan,Shu Xin,Ran Qianping
The agglomeration of nano particles in cement systems remains a major challenge for their wide use in construction materials. A method of preparing highly dispersed nano-SiO 2 in cement paste is introduced in this paper, and the effects of modified nano-SiO 2 (SiO 2 @PCE) with a core–shell structure on cement hydration and microstructure development were investigated by isothermal calorimetry, quantitative X-ray diffraction, thermogravimetric analysis, scanning electron microscopy and nanoindentation. The results show that well-dispersed nano-SiO 2 @PCE particles in a cement system can significantly accelerate cement hydration at an early age. The highly dispersed nano-SiO 2 @PCE particles refine the pore structure of the hardened cement paste. More specifically, the number of harmless and less-harmless pores is increased, whereas the number of harmful and more-harmful pores is reduced. In addition, the proportion of high-density C–S–H and low-density C–S–H in the hardened cement paste at an early age increases by 69% and decreases by 27%, respectively, with the addition of 1.5% nano-SiO 2 @PCE. Through the seeding effect, cement hydration is accelerated pronouncedly with the addition of highly dispersed SiO 2 @PCE nano particles. In addition, the stiffness of the paste is enhanced by the pozzolanic reaction between SiO 2 @PCE and portlandite.
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
危险品化学品经营许可证（带存储）