RENEWABLE ENERGY
·
2022
·
IF 8.634
Wenjing Song,Mengxue Song,Wenqing Cai,Weichu Li,Xingmao Jiang,Weiping Fang,Weikun Lai
Development of highly active and stable catalyst for C–O bonds cracking is important in biomass conversion , in this work, we report a SiO 2 -encapsulated NiPt/HY core-shell catalyst for phenethoxybenzene (PEB) catalytic cracking . The as-grown silica shell with defined pores serves as a ‘storage’ to enhance local concentration of PEB and intermediate isomers and promotes catalytic cracking on NiPt/HY core. With the increase of silica shell thickness from 0 to 40 nm, PEB reaction rate has increased more than five times, and the major cracking product selectivity is raised to above 90%, which is attributed to the continuous conversion of PEB isomers within the shell. This designed structure endows the NiPt/HY@SiO 2 with a high activity and no obvious deactivation in PEB cracking to corresponding phenol and aromatics. The outstanding performance benefit from the enrichment effect on the unique core-shell structure, as well as the moderate acidity originated from silica regulation. This work can be extended to the modulation of microenvironment to promote the catalytic behavior of core-shell catalysts.
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高影响因子
Journal of Energy Storage
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2022
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IF 8.907
Lei Liu,Xiwang Miao,Xiang Cheng,Huigang Wang,Min Guo,Fangqin Cheng,Mei Zhang
In this work, PCM nanocapsules composed of ZnO/SiO 2 shell and n-octadecane core were successfully synthesized by emulsion polymerization and hydrothermal method . The crystallinity of ZnO was enhanced on the SiO 2 shell by MPTS modification. The granule-like ZnO were distributed on the SiO 2 shell. The encapsulation rate of n-octadecane in nanocapsules was about 45.2 % with enthalpy of 95.0 J/g melting at room temperature 28.3 °C. Furthermore, due to the presence of ZnO, the synthesized PCM nanocapsules had excellent UV absorption properties for whole wavelengths, and the absorbed UV light can be converted into heat energy for storage, and the photothermal conversion efficiency had reached 25.0 %. Hence, the prepared ZnO/SiO 2 @n-octadecane nanocapsules had broad application prospects due to its thermal energy storage , UV protection and photothermal conversion performance.
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高影响因子
POLYMER COMPOSITES
·
2022
·Vol. 43
·期 11
·8228-8238
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IF 3.531
Zhongying Wang,Huan Wang,Xiaomei Shen,Qingfu Wang,Zhiqian Wang,Fanghui Wang,Hong Zhu
In this work, a series of C 3 N 4 /SiO 2 nanohybrids were prepared and incorporated to solution polymerized styrene-butadiene rubber/butadiene rubber (SSBR/BR) to prepare “green tire” tread rubber. As expected, C 3 N 4 /SiO 2 nanohybrids are uniformly dispersed in SSBR/BR, and SiO 2 possesses a small average particle size of ~15 nm. In addition, the interfacial interaction between C 3 N 4 /SiO 2 nanohybrids and rubber matrix are significantly enhanced. Hence, the mechanical properties of C 3 N 4 /SiO 2 -SSBR/BR nanocomposites are greatly improved. The tensile strength of 5% C 3 N 4 /SiO 2 -SSBR/BR nanocomposites (5 wt% C 3 N 4 in C 3 N 4 /SiO 2 ) improved 1580% compared to pristine SSBR/BR. Furthermore, dynamic mechanical analyses indicate the increasing wet skid resistance (10.8% higher) and decreasing rolling resistance (50.5% lower) of 5% C 3 N 4 /SiO 2 -SSBR/BR nanocomposites compared with SiO 2 -SSBR/BR. In addition, the wear volume and heat built-up are reduced at the same time. This work paves the way to prepare high comprehensive performance “green tire” and could be extend to the reinforcement of elastomer composites.
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高影响因子
SENSORS
·
2022
·Vol. 22
·期 12
·4595
·
IF 3.847
Haiyang Sha,Zhengkun Wang,Jie Zhang
In this paper, a monolayer SiO2microsphere (MS) array was self-assembled on a silicon substrate, and monolayer dense silver nanoparticles (AgNPs) with different particle sizes were transferred onto the single-layer SiO2MS array using a liquid–liquid interface method. A double monolayer “Ag@SiO2” with high sensitivity and high uniformity was prepared as a surface-enhanced Raman scattering (SERS) substrate. The electromagnetic distribution on the Ag@SiO2substrate was analyzed using the Lumerical FDTD (finite difference time domain) Solutions software and the corresponding theoretical enhancement factors were calculated. The experimental results show that a Ag@SiO2sample with a AgNPs diameter of 30 nm has the maximal electric field value at the AgNPs gap. The limit of detection (LOD) is 10−16mol/L for Rhodamine 6G (R6G) analytes and the analytical enhancement factor (AEF) can reach ~2.3 × 1013. Our sample also shows high uniformity, with the calculated relative standard deviation (RSD) of ~5.78%.Keywords:Raman scattering;SiO2microsphere array;Ag nanoparticles
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DOI
PubMed
高影响因子
POLYMER COMPOSITES
·
2022
·Vol. 43
·期 10
·7200-7210
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IF 3.531
Feng Gao,Jiahao Shi,Xiaorui Zhang,Xuan Wang,Ling Weng,Xue Sun,Lida Yu,Chenhao Li
Bismaleimide resin (BMI) is a thermosetting resin with excellent properties. However, due to its poor toughness as a cured product, this paper uses hyperbranched polyimide (HBPI) and nano-SiO 2 in a synergistic manner to improve the performance of BMI. Isophorone diisocyanated tripolymer (IPDI trimer) and methyl nadic anhydride (MNA) were used to synthesize HBPI, and then we investigated the effect of the synergistic modification on the mechanical and thermal properties and the modification mechanism of HBPI and nano-SiO 2 . The experiments showed that the most significant improvements were achieved at the addition of 40 and 3 wt% of HBPI and nano-SiO 2 respectively, with the impact strength of the materials increasing by 97.2%, fracture toughness indexes G IC and K IC increased by 36.7% and 34.6% respectively and glass transition temperature ( T g ) was reduced. The SEM results showed that the nanoparticles were uniformly dispersed and further validated the synergistic modification mechanism.
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高影响因子
APPLIED SURFACE SCIENCE
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2022
·
IF 7.392
Jiafei Su,Qinfei Ke,He Xu
Catalytic oxidation of toluene by employing manganese dioxide (MnO 2 ) as catalysts has shown great potential, however, the huge energy demands during the MnO 2 catalytic process limits its application. Herein, a new type of MnO 2 /SiO 2 nanocomposites with outstanding solar light-driven photo-thermo catalysis activity was successfully fabricated. The MnO 2 nanoparticles in homogeneous dispersion state were decorated on the surface of SiO 2 nanofiber. The abundant hydroxyl groups on the surface of SiO 2 nanofiber facilitated toluene enrichment. Moreover, abundant oxygen vacancies were generated through the substitution between the Mn 4+ and Si 4+ , which improved the concentration and mobility of active oxygen. An excellent photo-thermo catalytic activity of MnO 2 /SiO 2 nanocomposites on toluene degradation was observed with a significant CO 2 yield (100 %) and high value of CO 2 production rate under simulated sunlight, which was much superior to that of P25 and MnO 2 powders. The mechanism of the enhanced catalytic performance of MnO 2 /SiO 2 nanocomposite is ascribed to the synergism of photo-activation and solar light-driven thermo-catalytic oxidation. This work demonstrates a new route to develop MnO 2 -based photo-thermo catalyst and provides an energy-saving way for toluene removal on overall utilization of solar energy.
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高影响因子
ACS Applied Materials & Interfaces
·
2021
·
IF 9.229
Xunxun Deng,Xiaobo Liu,Shuo Wu,Shiyu Zang,Xiaotong Lin,Yanqiu Zhao,Chunying Duan
Accurate and sensitive fluorescence imaging of intracellular miRNA is essential for understanding the mechanism underlying some physiological and pathological events, as well as the prevention and diagnosis of diseases. Herein, a highly sensitive ratiometric fluorescent nanoprobe for intracellular miRNA imaging was fabricated by integrating a Ru-SiO2@polydopamine (Ru-SiO2@PDA) nanoplatform with a near-infrared light (NIR)-assisted DNA strand displacement signal amplification strategy. The Ru-SiO2@PDA spheres have excellent biosafety, high photothermal effect, and unique photophysical properties that can both emit a stable red fluorescence and well quench the fluorophores getting closer to them. So, when the fuel DNA and carboxyfluorescein (FAM)-labeled signal DNA are co-assembled on their outer surfaces, the FAM’s green fluorescence is quenched, and a low ratiometric signal is obtained. However, in the presence of miRNA, the target displaces the signal DNA from the capture DNA, releasing the signal DNA far away from the Ru-SiO2@PDA. Then, the green fluorescence recovers and leads to an enhanced Igreen/Ired value. Under NIR light irradiation, the Ru-SiO2@PDA increases the local temperature around the probe and triggers the release of fuel DNA, which thus recycles the target miRNA and effectively amplifies the ratiometric signal. Using A549 cells as a model, the nanoprobe realizes the highly sensitive ratiometric fluorescence imaging of miRNA let-7a, as well as its in vivo up- and down-regulation expressions. It provides a facile tool for highly sensitive and accurate intracellular miRNA detection through one-step incubation and may pave a new avenue for single-cell analysis.
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DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2021
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IF 6.953
Jumin Hou,Xiaoxia Yan
The ultrasonic treatment could decrease the particles size of chitosan-SiO 2 particles. The EDS of samples with ultrasonic treatment for 0 min and 10 min indicated that the SiO 2 was present in prepared chitosan-SiO 2 particles. When the ultrasonic time reached 10 min, the chitosan-SiO 2 nanoparticles formed and the mean size was 506.7 ± 3.42 nm and the Zeta potential of the chitosan-SiO 2 nanoparticles was greater than 30 mV, showing the suspension was a stable dispersed liquid. The chitosan-SiO 2 nanoparticles were used as reinforcement in thermoplastic starch films to further verify their performance in enhanced films. The water contact angle of thermoplastic starch film reinforced with chitosan-SiO 2 nanoparticles was 44.13 ± 5.02° and had a good mechanical property with tensile strength of 8.91 ± 0.49 MPa. This study indicates that chitosan-SiO 2 nanoparticles could be used as a reinforcement to prepare thermoplastic starch films and promote the application of chitosan nanoparticles in nanocomposite films.
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DOI
PubMed
高影响因子
NEW JOURNAL OF CHEMISTRY
·
2021
·Vol. 45
·期 37
·17461-17474
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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.
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高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2021
·
IF 7.312
Yijie Feng,Wenjiao Sang,Zhiyi Deng,Shiyang Zhang,Cuihua Li
Co-N-C@SiO 2 with Co, N doped carbon as core and SiO 2 as shell was successfully synthesized by template method, and SiO 2 shell was about 43 wt%. Impressively, the SiO 2 shell increased the active sites of the core in Co-N-C@SiO 2 preparation, and reduced the loss of active sites during use. Co-N-C@SiO 2 /PMS was a 1 O 2 dominated non-radical reaction, which was less interfered by solution pH and water constituents. In addition, Co-N-C@SiO 2 possessed better cycling performance compared with Co-N-C. Finally, the possible SMX degradation pathways were presented based on the identified intermediate products.
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高影响因子
Membranes
·
2021
·Vol. 11
·期 11
·803
·
IF 4.106
Qianqian Xu,Yuchao Chen,Tonghu Xiao,Xing Yang
The use of poly(vinylidene fluoride) (PVDF) microfiltration (MF) membranes to purify oily water has received much attention. However, it is challenging to obtain high-performance PVDF microfiltration membranes due to severe surface fouling and rapid decline of permeability. This study explored a new approach to fabricate high-performance PVDF/silica (SiO2) composite membrane via the use of a polymer solution featuring lower critical solution temperature (LCST) characteristics and the non-solvent thermally induced phase separation method (NTIPS). Coupling with morphological observations, the membrane formation kinetics were analyzed in depth to understand the synergistic effect between the LCST solution properties and fabrication conditions in NTIPS. Utilizing such a synergistic effect, the transition from finger-like macrovoid pores to bi-continuous highly connected pores could be flexibly tuned by increasing the PVDF concentration and the weight ratio of SiO2/PVDF in the dope solution and by raising the coagulation temperature to above the LCST of the solution. The filtration experiments with surfactant-stabilized oil-water emulsion showed that the permeation flux of the PVDF/SiO2composite membranes was higher than 318 L·m−2·h−1·bar−1and the rejection above 99.2%. It was also shown that the PVDF/SiO2composite membranes, especially those fabricated above the LCST, demonstrated better hydrophilicity, which resulted in significant enhancement in the anti-fouling properties for oil/water emulsion separation. Compared to the benchmark pure PVDF membrane in oily water purification, the optimal composite membrane T70 was demonstrated via the 3-cycle filtration experiments with a significantly improved flux recovery ratio (Frr) and minimal reduced irreversible fouling (Rir). Overall, with the developed method in this work, facile procedure to tune the membrane morphology and pore structure was demonstrated, resulting in high performance composite membranes suitable for oil/water emulsion separation.Keywords:PVDF/SiO2composite membrane;lower critical solution temperature (LCST);nonsolvent thermally induced phase separation (NTIPS);structural control;oil-in-water emulsion
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PubMed
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2021
·
IF 4.158
Dandan Li,Han Peng,Zaiwen Lin,Jiahui Zhu,Jing Yu,Jingyuan Liu,Rongrong Chen,Qi Liu,Jun Wang
Taking advantage of the excellent barrier properties of reduced graphene oxide (rGO) sheets and the loading capacity of mesoporous silica (SiO 2 ), silane-functionalized rGO/SiO 2 nanocontainers are synthesized and, after loaded with benzotriazole (BTA), composite corrosion protection coatings are prepared. The XRD , FTIR, XPS , SEM , and TEM are used to confirm the successful preparation of silane-functionalized rGO/SiO 2 nanocontainers, and BET and UV–visible measurements are used to estimate the loading and release behavior of BTA. Dispersion stability of the nanocontainers is observed, the surface morphology , wettability , and water absorption of coatings are characterized by SEM, water contact angle, and weight method, respectively. The corrosion behavior of pristine and scratched composite coatings is characterized by EIS , the effect of released BTA is further confirmed. The results show that silane-functionalized rGO/SiO 2 nanocontainers possess excellent dispersibility and load capacity, reduce defects and micropores in composite coatings, and provide improved permeability resistance, corrosion resistance , and self-repairing performance.
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高影响因子
危险品化学品经营许可证（带存储）