INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
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IF 3.375
Dan-Lei Yang,Qian Sun,Yong-Hong Duan,Hao Niu,Rui-Li Wang,Dan Wang,Mei-Fang Zhu,Jie-Xin Wang
The size and structure of inorganic fillers have a significant effect on the mechanical properties of dental resin composites. In this work, we report the use of spray-drying for the efficient construction of SiO2 colloidal nanoparticle clusters (SCNCs) as novel dental fillers, yielding spherical and closely packed structures with diameters of 1–3 μm. The superior performance of the resin composites can be obtained by filling 70 wt % SCNCs assembled with 60 nm silica colloids as building blocks in the dental resin matrix. As compared to silica microparticles with a similar average size and primary monodispersed silica nanoparticles, SCNCs have a better strengthening effect on the mechanical properties of resin composites owing to their unique nano–micro secondary structures. This spray-drying strategy enables the construction of multicomponent fillers. This is very promising for the development of multifunctional high-performance restorative resin composites.
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Polymers
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2019
·Vol. 11
·期 9
·1483
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IF 3.164
Nanjun Lai,Lei Tang,Na Jia,Dongyu Qiao,Jianlin Chen,Yong Wang,Xubin Zhao
To improve oil recovery significantly in low-mid permeability reservoirs, a novel modified nano-SiO2hyperbranched copolymer (HPBS), consisting of polyacrylamide as hydrophilic branched chains and modified nano-SiO2as the core, was synthesized via an in situ free radical polymerization reaction. The structure and properties of the hyperbranched copolymer were characterized through a range of experiments, which showed that HBPS copolymers have better stability and enhanced oil recovery (EOR) capacity and also smaller hydrodynamic radius in comparison with hydrolyzed polyacrylamide (HPAM). The flooding experiments indicated that when a 1000 mg/L HPBS solution was injected, the resistance factor (RF) and residual resistance factor (RRF) increased after the injection. Following a 98% water cut after preliminary water flooding, 0.3 pore volume (PV) and 1000 mg/L HPBS solution flooding and extended water flooding (EWF) can further increase the oil recovery by 18.74% in comparison with 8.12% oil recovery when using HPAM. In this study, one can recognize that polymer flooding would be applicable in low-mid permeability reservoirs.Keywords:modified nano-SiO2;hyperbranched copolymer;enhanced oil recovery;low-mid permeability reservoir
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ANALYTICAL CHEMISTRY
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2019
·
IF 6.35
Shanshan Wang,Chuanping Li,Muhammad Saqib,Guohua Qi,Chunhua Ge,Haijuan Li,Yongdong Jin
Signal amplification for electrochemiluminescence (ECL) plays a significant role in ultrasensitive detection of disease biomarkers. We report herein a new signal amplification strategy–quasi-photonic crystal nanomembrane-based light scattering enhancement for ECL signal amplification, via fabricating a novel close-packed monolayered SiO2-nanomembrane as solid-state ECL electrodes. In the system, the quasi-photonic crystal structure of the monolayered SiO2-nanomembrane led to intense light scattering within the nanofilm, which significantly increases the photon flux and then definitely improves the excitation number of the luminescent molecules (Ru(bpy)32+). Reinforced by the nanostructured electrode surface of the nanomembrane, the as-prepared ECL electrode exhibited significant ECL enhancement, ∼77-fold enhancement in the classic Ru(bpy)32+-TPrA system. We further constructed a sandwich-type SiO2-nanomembrane based solid-state ECL immunobiosensor for ultrasensitive detection of cardiac troponin I (cTnI). Under optimal conditions, the immunobiosensor exhibited a very low limit of detection (LOD) of 5.6 fg mL–1 for cTnI. Due to the cheap and easy availability of the materials, this study and findings not only provide an efficient way to improve the ECL intensity but also benefit the design of novel ECL electrodes for various biomarker detections.
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INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
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2019
·
IF 3.375
Ping Hu,Yan Chen,Xi Yan,Wan-Zhong Lang,Ya-Jun Guo
VOX-SiO2 catalysts have been synthesized by the one-pot method using different vanadium precursors, namely, ammonium metavanadate (NH4VO3; VO3–, V5+), vanadium acetylacetonate [V(acac)3; organic complex, V3+], and vanadyl sulfate (VOSO4; VO2+, V4+). The influence of different vanadium precursors on the structure–performance relationship of these catalysts is studied on the propane dehydrogenation (PDH) reaction. The catalysts derived from VO3– attain a mesoporous structure with fairly high specific surface area and large pore volume, while those prepared with V(acac)3 or VOSO4 display a microporous structure. It is noted that VOX-SiO2 catalysts derived from NH4VO3 present a better catalytic performance, and low-polymerized VOX species display better intrinsic activity compared with isolated species. This study may contribute to the selection of vanadium precursors for the one-pot synthesis.
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FOOD CHEMISTRY
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2019
·
IF 5.399
Lijun Luo,Shuai Ma,Libo Li,Xiaohong Liu,Jiayi Zhang,Xia Li,Dong Liu,Tianyan You
Accurate and early diagnosis of mycotoxin is particularly significant to the food and agricultural product safety. In the present work, a sensitive and effective monitoring method for zearalenone (ZEN) was exploited based on a novel self-enhanced electrochemiluminescence (ECL) aptasensor. The self-enhanced lumonophore was compounded by electrostatically combining amine-functionalized Ru(bpy) 3 2+ -doped silica nanoparticles (NH 2 [email protected] 2 NPs) and nitrogen doped graphene quantum dots (NGQDs) together. Since the emitter and co-reactant simultaneously existed in the same nanoparticle, shortened electron-transfer distance and decreased energy loss was obtained. Therefore, self-enhanced ECL aptasensor based on the novel complex expressed the widest linear range of 10 fg mL −1 –10 ng mL −1 and the lowest detection limit of 1 fg mL −1 for ZEN detection. More importantly, ZEN produced during the mildew process of corn flour was monitored by the developed aptasensor, which exhibited superior determination and potential application in real samples.
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COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
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2019
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IF 6.282
Tao Zhang,Yue Xu,Hongfu Li,Boming Zhang
In this study, the effect of carbon fiber (CF) surface chemistry and grafting of nano-SiO 2 on CF surface with respect to the interfacial adhesion of CF-reinforced nylon 6 composites was investigated. CFs were oxidized and reacted with poly(oxypropylene) diamines to modify the surface chemistry. The oxidized CFs were modified with 3-aminopropyltriethoxysilane and then grafted with SiO 2 nanoparticles. Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), scanning electron microcopy (SEM), and atomic force microscopy (AFM) were used to characterize the chemistry and topographies of the CF surface. The transverse fiber bundle strength of CF oxidized and grafted nano-SiO 2 increased to 31.92 MPa and 39.35 MPa, respectively, from 12.57 MPa for untreated CF. The results indicated that the reaction between the carboxyl group and nylon 6 led to chemical bonding at the interface and it meanwhile was strengthened and toughened by uniformly distributed SiO 2 nanoparticles on the CF surface.
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Advanced Science
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2019
·Vol. 6
·期 18
·1900943
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IF 15.804
Pan Xue,Chuang Sun,Hongpeng Li,Jiajie Liang,Chao Lai
Lithium (Li) metal anodes have garnered increasing interest in recent years as its high theoretical capacity and low electrochemical potential promises a myriad of opportunities for various applications. However, one critical issue to overcome is the inhomogeneous deposition of Li + during the plating and stripping process. This inhomogeneous deposition could result in uncontrollable dendrite growth, further leading to poor coulombic efficiency, shorter lifecycles, and safety concerns due to internal short circuit and thermal runaways. To address these issues, a 3D porous core–shell fiber scaffold is presented, comprising of well-dispersed SiO 2 , TiO 2 , and carbon, as superlithiophilic host materials for lithium anodes. The amorphous SiO 2 and TiO 2 allow for controllable nucleation and deposition of metal Li inside the porous core–shell fiber even at ultrahigh current densities of 10 mA cm −2 . In addition, the interconnected conductive fiber with high porosity enables good electrical conductivity with fast ion transport and excellent mechanical strength to withstand massive Li loading during repeated cycles of stripping and plating. As a result, excellent cycling performance and high rate capability are observed in both symmetric cells and full cells, highlighting the feasibility of the proposed Li anode composite.
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JOURNAL OF CHEMICAL AND ENGINEERING DATA
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2019
·
IF 2.298
Wenjun Tu,Weiquan Cai,Yihong Jiang,Fanxin Kong,Jiabin Zhou
The rare-earth elements (La, Ce, and Y)-modified SiO2 films for effective Cr(VI) removal from electroplating effluent were synthesized by a convenient sol–gel method successfully. X-ray diffraction, Fourier transform infrared spectra (FT-IR), scanning electron microscope, energy-dispersive system, and X-ray photoelectron spectroscopy (XPS) were applied to characterize their physicochemical properties. The adsorption isotherms showed that the adsorption capacity of SiO2 modified by La3+ (64.43 mg g–1) is the best, followed by Ce3+ (53.45 mg g–1) and Y3+ (47.83 mg g–1) because of the different ion-exchange capacities of La/Ce/Y–(OH), whereas that of SiO2 film without modification is only 38.54 mg g–1. Their adsorption processes could be well depicted by the pseudo-second-order kinetic model. The thermodynamics study showed that the adsorption process of the La/SiO2 film is spontaneous. The adsorption mechanism includes the ion exchange and electrostatic effect. Furthermore, the conversion of Cr(VI) to Cr(III) during the in situ reduction process was verified by both macro (optical photographs) and micro (FT-IR and XPS) levels. Importantly, the La/SiO2 film showed high adsorption selectivity and high removal efficiency of 97.4% toward Cr(VI) from initial concentration of 41.7 mg L–1 to residual concentration of 1.1 mg L–1 in the real electroplating effluent, indicating its potential industrial value for pretreatment of heavy metal wastewater.
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CERAMICS INTERNATIONAL
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2019
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IF 3.45
Xiaoqian Song,Qianyi Guo,Zhenlu Cai,Jianrong Qiu,Guoping Dong
Carbon quantum dots (CQDs) with multi-color emission are synthesized through hydrothermal method by varying the ratio of citric acid (CA) and urea, the solvent (water, ethyl alcohol, and dimethylformamide), the hydrothermal temperature, and reaction time. The CQDs emit bright fluorescence which can be gradually tuned from blue to red continuously, almost covering the whole visible spectrum. The emission peaks of the CQDs shift from 450 nm to 650 nm with the surface groups and structures changing. Importantly, all solid state CQDs@SiO 2 nanophosphors are successfully synthesized by reversed-phase micromulsion method. Based on these solid state phosphors, multi-color CQDs@SiO 2 phosphors-based light-emitting diodes (LED) and white light-emitting diode (WLED) with a Commission Internationale de L’ Eclairage (CIE) value of (0.3497, 0.3045) are fabricated in a low-cost, environment-friendly way.
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JOURNAL OF COLLOID AND INTERFACE SCIENCE
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2019
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IF 6.361
Hao Zheng,Zhuyi Wang,Liyi Shi,Yin Zhao,Shuai Yuan
Electric vehicles have very strict requirements for lithium ion batteries (LIBs). However, the commercial polyethylene (PE) separators cannot meet the demands of high safety and electrochemical performance for LIBs. This work aims to enhance the electrochemical and safety performance of LIBs by coating the separator with multifunctional particles. First, the colloidal SiO 2 nanoparticles were etched by LiOH to form porous shell and lithium silicate (LSO) species simultaneously. Then, the SiO 2 nanoparticles with porous shell were coated on PE separator by dip-coating method in the presence of binder. The experiment results indicate that SiO 2 nanoparticles with porous shell can endow PE separator excellent thermal stability (thermal shrinkage is almost 0% at 150 ℃ for 30 min) and electrochemical properties (improved ionic conductivity and Li + ion transference number). Moreover, the Li/LiCoO 2 cell employing the PE separator coated by SiO 2 with porous shell exhibits the best cycle life and C-rate performance. The discharge capacity retention of the cell assembled with LSO-SiO 2 @PE separator increase from 69% (cells assembled with pristine PE separator) to 86% after 100 cycles at 0.2C.
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SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
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2019
·
IF 2.931
Xinchun Zhou,Jing Shi,Jing Zhang,Kang Zhao,Anping Deng,Jianguo Li
A novel, rapid and convenient competitive immunoassay for ultrasensitive detection of chloramphenicol residues in shrimp and honey was established combined with flow injection chemiluminescence. The carboxylic resin beads were used as solid phase carriers to load with more coating antigen due to their larger specific surface area and good biocompatibility. The surface of the silica dioxide nanoparticles was modified with aldehyde group to combine with more horseradish peroxidase and the chloramphenicol antibody. There was a competitive process between the chloramphenicol in solution and the immobilized coating antigen to combine with the limited binding site of antibody to form the immunocomplex. Silica dioxide nanoparticles played an important role in enhancing chemiluminescence signal, because the horseradish peroxidase on SiO 2 effectively catalyzed the system of luminol-PIP-H 2 O 2 . Under optimal conditions, the chemiluminescence intensity decreased linearly with the logarithm of the chloramphenicol concentration in the range of 0.0001 to 100 ng mL −1 and the detection limit (3σ) was 0.033 pg mL −1 . This immunosensor demonstrated acceptable stability, high specificity and reproducibility. The horseradish peroxidase-silica dioxide nanoparticle-chloramphenicol antibody complex successfully prepared in this article was firstly applied to the detection of chloramphenicol, and had extremely important meanings for the application of nanoparticles and enzymatic catalysis in the field of chemiluminescence.
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CHEMICAL ENGINEERING JOURNAL
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2019
·
IF 8.355
Qiang Zeng,Yongji Huang,Leiming Huang,Liang Hu,Daoling Xiong,Hui Zhong,Zhiguo He
The reduction of Cr(VI) by iron-based materials was inhibited under neutral and alkaline conditions due to the production of precipitates. In this work, a novel composite with a wide pH range application in the remediation of Cr(VI) contamination, SiO 2 /nano-FeC 2 O 4 composite (SNFC), was prepared from natural biotite-containing minerals. Transmission electron microscope (TEM) analysis indicated that nano-FeC 2 O 4 with average particle size of 10.08 nm was uniformly coated on the surface of layered minerals. Batch experiments results showed that Cr(VI) was completely removed in the pH range of 2–10 within 60 min at an initial Cr(VI) concentration of 20 mg/L. The removal rate of Cr(VI) was decreased when the initial pH value increased from 2 to 6 and then kept at constant when the initial pH value increased from 6 to 10. Furthermore, continuous fixed bed column studies showed that simulated permeable reactive barriers (PRB) with SNFC was considerably effective for in situ removal of Cr(VI) from groundwater under alkaline conditions. Characterizations of X-ray diffraction (XRD) and scanning electron microscope (SEM) suggested that the reactive component in the composite for Cr(VI) removal was nano-FeC 2 O 4 rather than biotite itself. The Cr(VI) removal mechanisms of SNFC involved reduction, precipitation and surface complexation. These results plus the preliminary cost analysis indicated that the composite was an efficient, economical, and easy for mass production material with application for remediation of Cr(VI) polluted groundwater in a wide pH range.
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