Environmental Technology & Innovation
·
2025
·
IF 7.1
Yonglin Yang,Jiangyong He,Shuaige Shi,Long Yan,Jian Li,Xiaoyong Fan,Bi Chen,Guohui Dong,Hongrui Ma
There is a key issue about formation of highly toxic and easily dissoluble Cr(VI) during heat treatment of Cr-bearing solid waste, resulting in a prominent increase of environmental risk of incineration product. In this study, the effects of CaO and SiO 2 on formation and reduction of Cr(VI) were investigated during heating of Cr-bearing simulated sludge (Cr-SS) and Cr 2 O 3 , exploring Cr(III) oxidation mechanism. The findings indicates that doping CaO significantly promotes Cr(III) oxidation to Cr(VI), and chromium speciation vary with temperature. At 300℃, leaching amount of Cr(VI) in Cr-SS samples increases sharply to 9.3 % of total Cr. In contrast, no Cr(VI) was detected in Cr 2 O 3 samples. Above 300℃, oxidation rates of Cr(III) in different samples of Cr-SS and Cr 2 O 3 exhibit the same trend with temperature increasing. Above 1000℃, new Cr-containing crystalline phases were observed, like CaCr 2 O 4 and Ca 3 (CrO 4 ) 2 . The oxidation rate of Cr(III) is positively connected with the adding amount of CaO. Besides, doping SiO 2 to sludge prominently inhibits Cr(III) oxidation or facilitate Cr(VI) reduction at 600℃-1200℃, which is also confirmed by thermodynamic calculation, attributing to formation of Ca 5 Cr 2 SiO 12 and CaCr 2 O 4 . The number of holes in valence band will be changed through substitution of Cr(III) ions by cations of different valence states, thus facilitate or inhibit Cr(III) oxidation. The ions (III) can inhibit Cr(III) oxidation and promote Cr(VI) reduction. Introducing SiO 2 or Si-enriched materials to chromium-bearing wastes may be a promising alternative to solve the problem of highly toxic Cr(VI) formation during heat treatment.
研究领域:
环境科学
·
化学
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2016
·
IF 2.567
Jing Chen,Bo Zhang,Guangw Miao,Jun Men
SiO2–NiO aerogels with different molar ratios of Si/Ni (n(Si/Ni)) were prepared by a sol–gel method and atmospheric pressure drying technology. The morphology and structure of SiO2–NiO aerogels were characterized by XRD, BET, XRF, and SEM methods. The equilibrium adsorption performance of thiophene or benzothiophene on the SiO2–NiO aerogels were studied at three different adsorption temperatures (298, 313, 333 K). The adsorption equilibrium data of thiophene on SiO2–NiO aerogels were more in line with the Temkin model at the lower temperature, while they were well fitted with both Langmuir and Temkin isotherms at the higher temperature. The maximum saturation adsorption capacities obtained by the Langmuir isotherms at different temperature decreased in the order qm(298 K) > qm(313 K) ≈ qm(333 K). The maximum saturation adsorption capacities of thiophene or benzothiophene on SiO2–NiO aerogels with different n(Si/Ni) values at 298 K decreased in the order SiO2–NiO-23 > SiO2–NiO-74 > SiO2–NiO-6. The maximum saturation adsorption capacities of thiophene and benzothiophene on SiO2–NiO-23 aerogels are 6.4564 and 2.1316 mgS/g, respectively. Both the amount of adsorption active sites and the textural structure of aerogels could significantly affect the adsorption performance. The higher the nickel content, specific surface area, pore volume, and larger pore size of the aerogel, the larger the adsorption capacity. The absolute value of adsorption heat of thiophene on SiO2–NiO aerogels increased gradually with the increase of n(Si/Ni) (the reduction of the Ni content).
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
DALTON TRANSACTIONS
·
2011
·Vol. 40
·期 48
·12818-12825
·
IF 3.647
Xuefeng Zhai,Min Yu,Ziyong Cheng,Zhiyao Hou,Ping'an Ma,Dongmei Yang,Xiaojiao Kang,Yunlu Dai,Dong Wang,Jun Lin
Rattle-type hollow nanocapsules are among of the most promising candidates as drug carriers owing to their huge inner space and multifunctional material combination. In this paper, rattle-type hollow CaWO4:Tb3+@SiO2 nanocapsules with a diameter of 100–110 nm and a wall thickness around 10 nm were fabricated. The hollow silica nanospheres were used as nano-reactors and the luminescent core of CaWO4:Tb3+ was post-filled into the nano-reactors by a vacuum nano-casting route combined with a Pechini-type sol–gel method. Subsequently, doxorubicin hydrochloride (DOX), a model of an anti-cancer drug, is loaded into the CaWO4:Tb3+@SiO2 nanocapsules and their cell cytotoxicity, cancer cell uptake and drug release behavior are investigated in vitro. The prepared multifunctional inorganic nanocapsules show a loading capacity for DOX as high as 124 mg g−1 and sustained-release properties. The release profile of the drug from DOX-loaded nanocapsules can last over five days. Besides, the blank CaWO4:Tb3+@SiO2 shows very low cytotoxicity against cancer cell lines (HeLa cell) while the DOX-loaded nanocapsules exhibit relatively high efficiency for killing of HeLa cells. The rapid cancer cell uptake process is observed by confocal laser scanning microscopy. The results indicate that a rattle-type hollow CaWO4:Tb3+@SiO2 nanocapsule has the potential to be used as drug carrier in therapy. Moreover, it is possible to extend the synthetic strategy in this study to other rattle-type multifunctional composites to meet various demands.
研究领域:
纳米医学
·
肿瘤学
·
药剂学
·
生物材料
·
分子影像
✓ 已验证
DOI
高影响因子
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
·
2018
·
IF 3.141
Hui Wang,Zewen Chen,Xingyu Deng,Shengji Wu,Qinqin Yu,Wei Yang,Jie Zhou
Catalytic combustion is considered as one of the most efficient methods for soot removal. However, the limited contact area between soot and active site is a key restrictive factor for the present reaction, as soot particles (particle size > 25 nm) are usually difficult to enter the inner pores of general catalysts. In this work, we report a simple and economic strategy to synthesize macroporous SiO2 as the support for combustion catalysts so as to facilitate the mass transfer in the inner surface of the catalysts. The macroporous SiO2 could be synthesized rationally through controlling and adjusting the Si–OH dehydration condensation and neck growth during the sol–gel preparation process. The porosity of SiO2 influences catalytic activity greatly in the reaction of soot catalytic combustion. Furthermore, macroporous SiO2 supported Ag and K catalysts exhibit superior soot oxidation activity, showing important potentiality for future applications.
研究领域:
材料科学
·
环境催化
✓ 已验证
产品关联
DOI
高影响因子
FIBERS AND POLYMERS
·
2019
·Vol. 20
·期 10
·2017-2024
·
IF 1.439
Ding Yadan,Xu Dan,Shao Hong,Cong Tie,Hong Xia,Zhao Huiying
SiO 2 /polystyrene porous micro/nanofibers with superhydrophobic and superoleophilic properties were prepared by facile electrospinning method. The spindle-beads-on-string structured fibers were found to be more hydrophobic than those without the beads. The doping of nano-SiO 2 endowed the fibers with porous structure, and thus further increased the water contact angle from 139° to 153°. Simultaneously, the oil contact angle of 0° was obtained. The superhydrophobic-superoleophilic micro/nanofibers could selectively absorb oil from water within eight seconds. The oil sorption process followed pseudo-first order kinetic model. The absorption mechanism was proved to be physical encapsulation by Fourier transform infrared technique. The maximum sorption capacity for highly viscous silicone oil was up to 122.7 g/g. It is higher than many recently reported values. The porous micro/nanofibers exhibit significant value in oil-water separation.
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
MATERIALS & DESIGN
·
2017
·
IF 4.364
Ran Zhang,Rongrong Xie,Deping Liu,Xiaolong Jia,Qing Cai,Xiaoping Yang
Porous silica fibers were fabricated aiming to broaden the applications of SiO 2 nanosphere materials. The fibers were built with SiO 2 nanospheres via electrospinning and calcinations . At first, SiO 2 nanospheres (synthesized by Stober method) were surface-modified using γ-aminopropyltriethoxysilane to obtain SiO 2 -NH 2 nanospheres, which dispersed homogeneously in the solvent. Then, polyacrylonitrile (PAN) and polymethylmethacrylate (PMMA) were introduced in different weight ratios into the suspension. Subsequently, PAN/PMMA/SiO 2 composites were electrospun , followed by preoxidization and calcination to transfer PAN into carbon form and to remove PMMA component. Thus, porous silica fibers were fabricated with SiO 2 nanospheres binding together during carbonization and porous structure was formed. The porosity, pore size and pore volume of porous silica fibers were controllable by adjusting the content of SiO 2 nanospheres and the weight ratio of PAN/PMMA. Accordingly, the drug adsorption and release performance of these porous silica fibers depended on their micro-structural features. The thus-obtained porous silica fibers displayed great potentials in applications such as drug carriers and adsorbents.
研究领域:
材料科学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2020
·Vol. 44
·期 5
·2122-2128
·
IF 3.288
Lei Ding,YiFan Chen,Zibo Hua,Li Liu,Haixu Chen,Zhengxiang Zhong,Yunzhe Du,Yudong Huang
ZnO quantum dots@SiO2 (ZnO QDs@SiO2) was synthesized by a modified sol–gel method, and then added to polyvinyl alcohol (PVA) to form an ink-absorbing coating with ultraviolet shielding performance on poly(ethylene terephthalate) (PET) films. A layer of silica encapsulated on the surface of ZnO QDs not only reduces the photocatalytic activity significantly, but also prevents the agglomeration of ZnO QDs in aqueous solution. The UV-vis transmittance spectrum of the as-prepared ink-absorbing coating displayed excellent shielding performance in the ultraviolet region (<355 nm) and high transmittance in the visible region. Even when exposed to 30 W ultraviolet for 100 h, no obvious changes were observed in its UV-vis transmittance spectrum, showing long-term durability. Notably, the ink absorption of the ink-absorbing coating prepared using ZnO QDs@SiO2 is higher than that of the ink-absorbing coating prepared using commercially available silica. Therefore, a durable, highly transparent and ultraviolet shielded inkjet printing coating on PET can be prepared with ZnO QDs@SiO2 nanoparticles.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2017
·
IF 4.055
Meiqi Chang,Yanhua Song,Jie Chen,Lei Cui,Ye Sheng,Zhan Shi,Haifeng Zou
SiO2@TiO2:Eu3+ core–shell structure was synthesized by a surfactant-free solvothermal method, and its luminescence intensities were increased through a coating SiO2 layer. Furthermore, SiO2@TiO2:Eu3+@SiO2 core double-shell structures with different coating thicknesses have been prepared to examine the relationship between luminescence intensity and thickness. In addition, luminescence enhancement mechanisms including the surface repair effect and excitation/emitted light absorption effect were proposed. Moreover, the luminescence properties and photocatalytic behaviors of SiO2@TiO2:Eu3+ core–shell structure and its derivatives SiO2@TiO2:Eu3+ yolk–shell structure and TiO2:Eu3+ hollow structure have been investigated in detail. It is worth mentioning that yolk–shell and hollow structures could be obtained by changing the order of the calcination and etching process of the SiO2@TiO2:Eu3+ core–shell structure. Herein, the hollow structure showed the highest luminescence intensity, and the core–shell structure exhibited excellent photocatalytic efficiency for the degradation of methyl orange.
研究领域:
材料科学
·
光学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS RESEARCH
·
2017
·Vol. 33
·期 9
·1219-1225
·
IF 1.673
Linmin Cao,Jilin Huang,Zhipeng Lin,Xiang Yu,Xiaoxian Wu,Bodong Zhang,Yunfeng Zhan,Fangyan Xie,Weihong Zhang,Jian Chen,Hui Meng
This work designed a facile preparation for an SiO2/C composite as the anode material for lithium ion battery. Both SiO2 and carbon are amorphous. SiO2 and carbon are mixed uniformly. The SiO2/C composite shows high specific capacity, cycle stability, and rate capability in lithium ion battery charge–discharge test. A stable reversible capacity of 1024 mA h/g at the current density of 100 mA/g is reached. The capacity retains 83% after 100 cycles. The uniform mixture of SiO2 and carbon leads to reduced volume change during the lithiation and delithiation of SiO2, together with the amorphous nature of SiO2 explains the high cycling stability. The carbon coating is a key factor for the high capacity and stability due to the increased electrical conductivity and reduced volume change. The resistance of the solid electrolyte interface film and charge transfer resistance of the SiO2/C composite are much smaller than those of pure carbon, which is a direct proof of the improved conductivity of the material by the carbon coating.
研究领域:
材料科学
·
能源存储
·
纳米技术
✓ 已验证
DOI
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2017
·Vol. 17
·期 1
·370-376
·
IF 1.483
Xia Guo-Hua,Liu Wei,Jiang Xiao-Ping,Wang Xiang-Yu,Zhang Ye-Wang,Guo Jianyong
Magnetic Fe3O4 nanoparticles were prepared through hydrothermal method and coated with silica on the surface to obtain Fe3O4@SiO2 core–shell nanoparticles. After modification with different functional groups including aldehyde,
amine and diimide, the nanoparticles were used as carrier for covalent immobilization of lipase. The nanoparticles with aldehyde groups showed highest immobilization yield (52.8%) and efficiency (86.5%). And the immobilization conditions including pH, temperature and the concentration of enzyme
were optimized. After immobilization, the K
m of lipase was altered from 2.3 to 3.2 mM. The thermal stability and pH stability were enhanced by immobilization at the investigated conditions: pH 5.0–8.0 and temperature 30–70 °C. After 10 batches conversion of
4-Nitrophenyl palmitate into p-Nitrophenol, the immobilized lipase retained over 75% of the original activity. Compared with the commercial lipase Novozym435, the immobilized lipase showed better stability and higher catalytic efficiency. These results demonstrate that the immobilized lipase
on the modified Fe3O4@SiO2 magnetic nanoparticles has enhanced stability and reusability, which make lipase of potential interest in a number of industrial applications.
研究领域:
生物化学
·
纳米材料科学
·
酶工程
✓ 已验证
DOI
PubMed
高影响因子
Processes
·
2025
·Vol. 13
·期 3
·596
·
IF 2.8
Weiyou Zhang,Yongpeng Sun,Xianghua Meng,Rutong Dou
During oilfield production, organic substances such as asphaltenes and resins present in crude oil are prone to adsorb onto the surfaces of reservoir rocks. This adsorption process can lead to the conversion of hydrophilic rock surfaces into more oleophilic interfaces, which in turn reduces the permeability and porosity of the reservoir, ultimately affecting the overall recovery efficiency. Consequently, targeted modification of reservoir wettability presents a promising strategy for enhancing recovery rates. In this study, a polymer layer comprising large molecular side chains and hydroxyl groups was synthesized on the surface of nano-SiO2to enhance the thermal stability of the polymer. Additionally, the hydroxyl groups were employed to improve the wettability of the core material and reduce interfacial tension. The polymers were characterized using techniques such as FTIR and TG, and the results revealed that the modified SiO2exhibited superior performance in reducing both interfacial tension and contact angle when compared to the SiO2. Injection of a 0.4 wt% EP-HMTA-SiO2solution resulted in an increase in recovery rates by 16.4% and 13.2% in medium- and low-permeability cores, respectively.
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
WATER AIR AND SOIL POLLUTION
·
2024
·Vol. 235
·期 10
·1-15
·
IF 3.8
Liu Xu,Kong Xiaomin,Wen Hao,Wang Yue,Wu Meili,Yin Hongwei,Qin Wei,Wang Manli,Pei Jun,Qu Miaoming
Coal gangue, a byproduct of coal mining with massive generation, presents a major challenge for resource utilization. In this study, SiO 2 aerogel was successfully fabricated from coal gangue, via a facile and cost-effective approach. The aerogel boasts an intricate network framework structure internally and functions as a mesoporous material with measurements of 154.5662 m 2 ·g −1 for specific surface area and 7.9557 nm for average pore size. Additionally, exploring the adsorption capabilities of SiO 2 aerogel concerning Pb(II) in wastewater, the research revealed insights. The results demonstrated that the maximum Pb(II) removal efficiency reached 94.09% under pH 6, aerogel dosage of 1.5 g·L⁻ 1 , and initial Pb(II) concentration of 80 mg·L⁻ 1 . The adsorption process followed the Langmuir isotherm model and pseudo-second-order kinetic model, suggesting a favorable and predominantly monomolecular layer chemisorption, and the intraparticle diffusion model suggests internal diffusion behavior during adsorption. The SiO 2 aerogel exhibited specific adsorption behavior towards Pb(II). This study offers a promising avenue for repurposing coal gangue while addressing the issue of Pb(II)-contaminated wastewater.
研究领域:
环境科学
·
材料科学
✓ 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）