ACS Sustainable Chemistry & Engineering
·
2023
·
IF 8.4
Hong Du,Xiuyun Ma,Miao Jiang,Siyuan Zhao,Qi Fang,Xiumei Liu,Zongchao Conrad Zhang
Xylitol is a value-added health product from the hemicellulose component in biomass. In this work, highly efficient Cu–Ni/SiO2 catalysts are developed for the production of xylitol by means of xylose hydrogenation. The bimetallic catalysts exhibit higher activity compared to the corresponding monometallic nickel or copper catalyst and the currently used industrial Raney nickel catalyst. The bimetallic catalyst with a higher ratio of nickel to copper shows a better performance. The 5Cu15Ni/SiO2 catalyst exhibits a xylose conversion of 96% accompanied by higher than 99% selectivity to xylitol under the moderate conditions of 100 °C and 3MPa H2. The bimetallic catalysts show improved performances when they are activated at a low temperature. The apparent activation energies of xylose hydrogenation over the 5Cu15Ni/SiO2 and 20Ni/SiO2 catalysts are 16.6 and 25.2 kJ/mol, respectively. The formation of the Cu–Ni alloy leads to a lower activation energy and thus superior performance for xylose hydrogenation to xylitol.
研究领域:
生物化学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 5
·期 10
·7773-7780
·
IF 3.708
Junping Zhang,Fuyao Liu,Tao Li,Xiuxia He,Zhenxin Wang
Taking advantage of the unique optical properties of upconversion nanoparticles (NP) and the feasibly modified nature of SiO2, NaYF4:Yb3+, Er3+@SiO2 core@shell (UCNP@SiO2) NPs with excellent morphology have been synthesized to investigate the surface charge effect on the interactions of NPs with cells. The cellular uptake behaviors, cytotoxicities and intracellular metal ion release of the as-prepared NPs have been investigated in two cell lines (HeLa and HepG-2) by fluorescence microscopy, MTT assay and inductively coupled plasma mass spectrometry (ICP-MS), respectively. It is found that the UCNP@SiO2 NPs with positive surface charge have much higher cell internalization ability and cytotoxicity than those with negative surface charge. The experimental results also demonstrate that the cytotoxicity of UCNP@SiO2 NP is closely related to the increase of intracellular reactive oxygen species (ROS) and metal ion release of internalized NPs.
研究领域:
纳米技术
·
细胞生物学
·
材料科学
·
毒理学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Nano Materials
·
2024
·
IF 5.3
Tingting Yang,Qingqing Lu,Fangyuan Ren,Shengkang Xin,Hailong Zhang,Hong Qiao,Zuankai Wang,Libin Liu
The icing phenomenon in nature can cause serious economic losses and security concerns. Eco-friendly anti-icing and deicing surfaces have been developed to address these issues. In this study, a photothermal superhydrophobic coating was fabricated by a facile polymerization process in the presence of micro–nano structured SiO2/TiN particles followed by a two-step spraying technology. The optimal coating displays remarkable superhydrophobic performance with a water contact angle of 159.1° and a water roll-off angle as low as 1.2°; it survives tape peeling, Taber abrasion, and solution immersion and demonstrates weather and corrosion resistance. More importantly, the SiO2/TiN coating shows excellent anti-icing/deicing property and can withstand multiple icing/thawing cycles. The excellent anti-icing/deicing performance is attributed to the robust superhydrophobic surface and the photothermal effect of TiN nanoparticles. Our fluorine-free design strategy provides important guidance for actual large-scale eco-friendly anti-icing/deicing application.
研究领域:
材料科学
·
表面工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
POLYMER COMPOSITES
·
2021
·Vol. 43
·期 1
·84-93
·
IF 3.171
Jiaming Guo,Tingtian Qiu,Chengxingzi Yu,Yu Liu,Chen Ning,Lingqiang Kong,Yan Ma,Liu Liu,Yuhui Ao
An unprecedented electrostatic self-assembly of MXene and SiO 2 on carbon fiber (CF) to enhance the interfacial properties of CF-reinforced epoxy resin composites is disclosed. MXene with negative charge was anchored on the cationized CF surface via a strong electrostatic interaction, followed by synergistic effect of amine-modified SiO 2 (positive charge) to furnish a stable MXene/SiO 2 material with three-dimensional structure, which takes the advantages of high modulus, large specific surface area, and high-surface activity. The involvement of the two nano-materials with different dimensions and morphologies results in synergistic enhancement on mechanical interlocking, leading to excellent chemical bonding connection between CF and resin, which could transfer stress and dissipate energy effectively. Moreover, the surface energy of CF increased from 26.67 to 48.12 mJ/m 2 after assembly of MXene/SiO 2 . Compared with unsized CF/EP composites, the interfacial shear strength, interlaminar shear strength, and flexural strength of CF/MXene/SiO 2 /epoxy (EP) composites were increased by 73.2%, 61.2%, and 39.2%, respectively. Dynamic mechanical analysis poxy (DMA) tests showed that the storage modulus of the CF/MXene/SiO 2 /EP composites was enhanced by 64% compared with CF/EP composites, and the glass-transition temperature of composites was elevated from 147.9 to 151.8°C. This protocol provides a promising strategy for designing advanced CF/EP composites with three-dimensional structure.
研究领域:
材料科学
·
复合材料工程
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Chen Zhang,Benzheng Gao,Houyang Yu,Xin Wang,Jianliang Xie
CaO–B 2 O 3 –SiO 2 (CBS) is a promising lightweight, low-dielectric matrix material for high-temperature microwave-absorbing coatings. However, the comprehensive study of absorbent morphology evolution within such coatings and its influence on electromagnetic (EM) performance has not been conducted. In this work, a series of FeSiAl (FSA)/CBS composite coatings with various FSA contents were fabricated using atmospheric plasma spraying. The morphological evolution of the FSA phase and the resulting EM properties of the coatings were systematically analyzed. Experimental findings show that during the spraying process, when the size of FSA clusters in the composite powder exceeds the thickness of CBS splats, FSA clusters form a rigid contact with the underlying solidified coating, leading to the development of a lamellar structure. This lamellar FSA phase creates local conductive networks, which significantly increase the complex permittivity of the coating. These results provide valuable guidance for controlling absorbent morphology and optimizing the EM properties of CBS-based coatings.
研究领域:
材料科学
·
电磁学
✓ 已验证
产品关联
DOI
高影响因子
IONICS
·
2023
·Vol. 30
·期 2
·1075-1087
·
IF 2.8
Zhou Jingkai,Xiao Lijuan,Zhou Song,Liu Jiaqin,Huang Lvhang,Chen Yan
Obtaining electrode materials with excellent electrochemical properties is always a challenge in the research of new energy materials. This paper presents a novel composite material prepared using a simple method, which involves embedding core–shell Co 3 O 4 @SiO 2 nanoparticles onto highly conductive reduced graphene oxide (rGO) with excellent electrochemical performance. The results indicate that the encapsulation of the polymer with the core–shell material enhances the electrochemical performance. In this process, graphene oxide is reduced to reduced graphene oxide (rGO) by the hydrothermal method, and then the prepared core–shell Co 3 O 4 @SiO 2 nanoparticles are embedded into the network structure of reduced graphene oxide (rGO). In addition, we investigate the optimal mass ratio of the core–shell material Co 3 O 4 @SiO 2 and rGO in the Co 3 O 4 @SiO 2 /rGO composite. We prepare composites with different ratios of 4:1, 2:1, 4:3, 1:1, and 4:5, Co 3 O 4 @SiO 2 /rGO. The experimental results illustrate that when the current density is 0.4 A/g, the specific capacitance of the composite Co 3 O 4 @SiO 2 /rGO (1:1) is up to 216 F/g, and the volumetric capacitance is 372 F cm −3 , which is more than fivefold higher than that of the core–shell material Co 3 O 4 @SiO 2 . Such large performance improvement is mainly attributed to the addition of rGO which can improve the conductivity of the entire composite material and the aggregation of Co 3 O 4 @SiO 2 , thus providing more active sites. This study confirms that the electrochemical properties of graphene oxide can be greatly improved by the combination of hydrothermal reduction graphene oxide with core–shell material Co 3 O 4 @SiO 2 , which provides a certain reference value for the further research of high-performance electrode materials.
研究领域:
材料科学
·
能源存储与转换
✓ 已验证
DOI
高影响因子
JOURNAL OF NON-CRYSTALLINE SOLIDS
·
2024
·
IF 3.2
Bo Wang,Zihao Pan,Ziyan Zhao,Bo Zhou,Xuejian Liu,Zhengren Huang,Yan Liu
In this paper, we designed two series of the ZnO-B 2 O 3 -SiO 2 (ZBS) glass to explore their applicability for joining AlN ceramic. The density, flexural strength, structure, characteristic temperature, coefficient of thermal expansion (CTE) and crystallization behavior of the ZBS glass with varying ZnO and B 2 O 3 content were systematically studied. The results show that as B 2 O 3 content increase, the glass network is disrupted with the transition from three-dimensional shelf-like structure [BO 4 ] to two-dimensional layers [BO 3 ], increasing the number of the broken bonds, while an increase in ZnO results in a more compact glass network structure. We also found that both glass transition temperature (T g ) and softening temperature (T S ) exhibit a declining trend with the increase in B 2 O 3 and ZnO. Zn 2 SiO 4 and ZnAl 2 O 4 , began to precipitate after heat treatments in all the samples except 60ZnO-30B 2 O 3 –10SiO 2 (abbreviated as B30), where the diffraction peaks do not appear in Zn 2 SiO 4 but in Zn 4 B 6 O 13 . Notably, Zn 2 SiO 4 is the main phase for most samples while the main phase of B30 sample is ZnAl 2 O 4 . The CTE increases from 4.6 to 5.03 (× 10 –6 / °C) and 4.23 to 4.73 (× 10 –6 / °C) with an increase of B 2 O 3 and ZnO content, respectively. Among these, the CTE of B30 sample is compatible with that of AlN ceramic substrate. The optimal shear strength, 60.32±10.26 MPa, was achieved with B30 samples at 750 °C. The high strength was attributed to the interfacial reaction that leads to strong chemical bonding and the uniform distribution of the ZnAl 2 O 4 in the interlayer, which reinforces the strength of the interlayer itself.
研究领域:
材料科学
·
无机非金属材料
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
·
IF 8.2
Pangpang Li,Jingyi Jiang,Han Yan,Yuexin Zhai,Wanlin Fu,Yueming Sun,Yunqian Dai
Ultrafine Pt clusters exhibit superior activity for propane dehydrogenation compared to larger Pt nanoparticles; however, they are prone to sintering at high operating temperatures, leading to a decline in both activity and selectivity. In this work, porous ZrOx/SiO2 nanofibers featuring highly dispersed ZrOx nanodomains within a SiO2 matrix were successfully fabricated via a high-throughput blow-spinning process. The abundant and thermal-stable 1.6 nm micropores significantly stabilize 1.5 nm PtGa clusters against sintering at temperatures over 800 °C, due to the pore confinement. Moreover, the electron transfer from Ga to Pt is significantly enhanced in close proximity to ZrOx, contributing to metallic Pt with exceptional activity toward C–H bond activation. Thereby, the sinter-resistant PtGa/ZrOx/SiO2 nanofibers maintained 98.8% propylene selectivity and 43.2% propane conversion rate over 100 h of reaction, with a deactivation rate constant down to 0.0045 h–1. This work explores a sinter-resistant catalytic system based on oxide nanofibers and elaborates a new logic for the design of high-performance propane dehydrogenation catalysts with long-term stability.
研究领域:
催化化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
DESALINATION
·
2017
·
IF 5.527
Heiyan Zhang,Bingbing Li,De Sun,Xiaoling Miao,Yunlei Gu
In this study, hydrophobic asymmetric SiO 2 -PDMS-PVDF hollow fiber membranes were prepared for the vacuum membrane distillation (VMD). To make PVDF dope solution, hydrophobic nano-fumed silica (SiO 2 ) and polydimethylsiloxane (PDMS) were used. The effects of SiO 2 concentration on membrane parameters such as membrane morphology, hydrophobicity , porosity, thickness, pore size, liquid entry pressure , burst pressure, Fourier transformed infrared spectroscopy , thermal property, mechanical property and permeability were investigated. With the increasing of nano-particle concentration, membrane hydrophobicity, mechanical property and thermal stability improved. Furthermore, membrane VMD properties under various operation conditions were studied, the membranes showed a stable substantial flux of 44.27 LMH and a stable high salt rejection of over 99.9% under the optimum operation conditions of 75 °C, 35 g/L, 87 kPa, and 50 L/h. The results of our research demonstrated that the prepared hydrophobic asymmetric SiO 2 -PDMS-PVDF hollow fiber membranes not only had high permeability and good anti-wetting property but also exhibited a satisfying stability for the vacuum membrane distillation of 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
JOURNAL OF THE ENERGY INSTITUTE
·
2017
·
IF 3.204
Qifu Huang,Wenzhi Li,Qizhao Lin,Xusheng Zheng,Haibin Pan,Dong Pi,Chunyu Shao,Chao Hu,Haitao Zhang
In this paper, the catalyst of Pd–NiCo 2 O 4 /SiO 2 was prepared and applied to the catalytic combustion of lean methane. Pd and NiCo 2 O 4 nanoparticles were uniformly distributed on the SiO 2 support, so that every Pd or NiCo 2 O 4 nanoparticle was separated from each other by another component. Comparing with Co 3 O 4 /SiO 2 , NiCo 2 O 4 /SiO 2 , Pd–Co 3 O 4 /SiO 2 and Pd#NiCo 2 O 4 /SiO 2 (catalysts without uniform distribution of Pd and NiCo 2 O 4 nanoparticles), Pd–NiCo 2 O 4 /SiO 2 had the highest catalytic activity in the catalytic combustion of lean methane, with a methane total conversion temperature at 378 °C. In addition, the high activity did not decrease during the long time reaction, which showed good thermal stability . TEM and BET results showed that the nanoparticle sizes of Pd and NiCo 2 O 4 were very small. The XRD patterns indicated that the Pd nanoparticles were highly dispersed on the surface of SiO 2 . The XPS spectra demonstrated the formation of NiCO 2 O 4 , the presence of enough active oxygen species on the catalyst surface and the high ratio of PdO/Pd 0 . The enhanced influence of Ni introduction was also proved by comparison tests. All these results indicated that the high catalytic activity of Pd–NiCo 2 O 4 /SiO 2 mainly comes from the nanoparticle distribution and the Ni cation enhancement.
研究领域:
催化化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Sustainable Cement-Based Materials
·
2017
·
IF 0
Xiuzhi Zhang,Xiaoha Du,Xiaoyan Zhao,Rui Zhang,Pengkun Hou,Zonghui Zhou,Xin Cheng
To understand the synergistic effect of nano-SiO2(NS) and silica fume (SF) on cement-based material, the hydration process, the compressive strength development, and the pore structure of cement-based materials with the addition of nano-SiO2 and SF were investigated. The results showed that the compressive strength of cement paste increased with the increase of NS, especially at the early ages. Compared with 10% SF, the incorporation of 3% NS in the cement pastes with 7%wt dosage of SF has the highest compressive strength (51.93 MPa). When replace SF with 3% NS, the hydration of cement was promoted, C–S–H gel increased as more calcium hydroxide was consumed. Three percent NS and 7% SF can significantly reduce the porosity of the cement matrix, which is also an explanation of the phenomenon of increased compressive strength.
研究领域:
土木工程
·
材料科学
✓ 已验证
DOI
FIBERS AND POLYMERS
·
2015
·Vol. 16
·期 8
·1772-1780
·
IF 0.881
Zhou Yingsong,Yu Junrong,Wang Xuexin,Wang Yan,Zhu Jing,Hu Zuming
Melamine-formaldehyde/polyvinyl alcohol (MF/PVA) composite membranes modified by nano silica (SiO 2 ) and silane coupling agent KH570 modified SiO 2 (KH570-SiO 2 ) were prepared. The surface properties and morphology of KH570-SiO 2 were characterized using fourier transform infrared spectrometer (FTIR), thermogravimetric analysis (TGA), contact angle measurement instrument and X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM) and particle size analyzer. The morphology and properties of nanoparticles modified MF/PVA membranes were also studied with scanning electron microscopy (SEM), TGA, dynamic mechanical analysis (DMA) and tensile tester. The results show that KH570 is grafted on the surface of nano SiO 2 . KH570-SiO 2 has better dispersion in MF/PVA resin than that of unmodified SiO 2 . The thermal stability, mechanical and crystallizing properties of MF/PVA membrane are increased after modified with nano SiO 2 . KH570-SiO 2 makes MF more compatible with PVA resin, and further increases the mechanical properties and thermal stability of MF/PVA membrane.
研究领域:
材料科学
·
化学工程
✓ 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）