JOURNAL OF SOLID STATE CHEMISTRY
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2023
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IF 3.3
Rui Zhao,Cheng Cheng,Xiurong Wu,Xueyan Bai,Fenghuan Wang
Due to the excellent pore structure , MOFs as the stationary phase was playing an important part in chromatography . In this work, the shell-core MIL-101(Al)@SiO 2 composites post-synthetic modified by ligands with different polarities were fabricated for separation of estrogens. The structure and morphology of these materials were characterized by X-ray diffraction (XRD), Fourier transform infrared spectrum (FTIR), scanning electron microscope (SEM) and Brunauer-Emmett-Teller (BET). In order to investigate the influence of the ligand polarity on chromatographic separation performance of estrogens, alkyl molecules with different chain length were introduced as the ligands. With the hydrophobicity and chain length of the ligands increasing, the resolutions of the MIL-101(Al)@SiO 2 columns for the separation of estrogens exhibited the tendency of a parabola. Best result was achieved on the C4-MIL-101(Al)@SiO 2 column. On that basis, the possible retention mechanism on C4-MIL-101(Al)@SiO 2 column was elucidated by studying the mobile phase effect on separation behavior.
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RSC Advances
·
2023
·Vol. 13
·期 19
·13142-13155
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IF 3.9
Jiancheng Li,Chi Wang,Yixing Ma,Kai Li,Yi Mei
A new heterojunction material BP/RP-g-C3N4/SiO2 was obtained by a one-step ball milling method, and its photocatalytic capacity was researched by the degradation of Rhodamine B (RhB) and ofloxacin (OFL) in simulated sunlight. The construction of an in situ BP/RP heterojunction can achieve perfect interface contact between different semiconductors and effectively promote the separation of photogenerated carriers. The composite material was well characterized, which proved that the multi-heterogeneous structure was prepared. Furthermore, the type II heterojunction was formed between the g-C3N4 and BP/RP interface, playing an important role in the degradation and promoting electron transfer. The degradation effect of BP/RP-g-C3N4/SiO2 on RhB reached 90% after 26 min of simulated solar irradiation, which was 1.8 times that of g-C3N4/SiO2. The degradation of OFL by BP/RP-g-C3N4/SiO2 reached 85.3% after illumination for 50 min, while the degradation of g-C3N4/SiO2 was only 35.4%. The mechanisms were further discussed, and ˙O2− and h+ were found to be the main active substances to degrade RhB. The catalyst also revealed distinguished stability of catalyst and recyclability, and the degradation effect of RhB can still realize 85% after 4 runs of experiment. Thus, this study provided a novel method for the design and preparation of multi-heterojunction catalysts in the removal of organic pollutants from wastewater.
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高影响因子
NEW JOURNAL OF CHEMISTRY
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2023
·Vol. 47
·期 21
·10455-10462
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IF 3.3
Mengting Chen,Qifeng Zhong,Jiao Ma,Zhiyang Zhang,Yingxin Liu,Zuojun Wei,Shuguang Deng
Hydrogenation of levulinic acid (LA) to γ-valerolactone (GVL) is a key reaction in the conversion of biomass to renewable fuels and value-added chemicals. Developing low-cost, highly efficient and reusable non-noble metal-based heterogeneous catalysts is vital but challenging. Herein, non-noble Ni–Mn/SiO2 catalysts with a low Ni loading (2.0 wt%) were designed for the selective hydrogenation of LA to GVL. The results showed that the optimal Ni–Mn/SiO2 (Ni/Mn = 2) catalyst with well-dispersed and small-sized metal nanoparticles (2.21 nm) and moderate acid sites exhibited excellent activity and selectivity and achieved a 100% yield of GVL in a 1,4-dioxane solvent under mild reaction conditions (e.g., 0.8 mol% Ni, 140 °C and 2.0 MPa H2) for 5.5 h and a 100% GVL yield at 180 °C for 2 h with a turnover frequency (TOF) of 190.2 h−1, which is better than most non-noble metal catalysts reported. Furthermore, the catalyst exhibited excellent reusability and could be recycled at least five times with only slight activity loss. This work provides new insights for the rational design of highly efficient and stable non-noble metal catalysts for the conversion of LA to GVL.
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THERMOCHIMICA ACTA
·
2023
·
IF 3.5
Lei Liu,Runfeng Li,Min Guo,Linjun Wang,Mei Zhang
In this manuscript, CuS-ZnS/SiO 2 @n-octadecane nanocapsules were prepared by a simple one-step Cu 2+ and Zn 2+ co-deposition method. The results of XRD, SEM, TEM, FTIR and XPS show that nanocapsules composed of CuS-ZnS/SiO 2 shell and n-octadecane core material were successfully prepared, and the particles deposited was proved to be composite structure of CuS-ZnS. The solution concentration, reaction temperature and pH value have significant effects on the morphology of the nanocapsules prepared. The appropriate conditions are 0.02 mol/L CuSO 4 , 0.02 mol/L Zn(CH 3 COO) 2 , 60 °C, and no additional pH adjustment. Under the optimum conditions, the melting enthalpy reached 45.11 J/g, and after 100 times of cold and hot cycles, the melting enthalpy of the sample only decreased by 3.2%, showing good thermal stability. The CuS-ZnS composite structure makes CuS-ZnS/SiO 2 nanocapsules exhibit a wider spectrum absorption performance. The absorption effect of CuS-ZnS/SiO 2 nanocapsules to ultraviolet light is significant, compared to the slight reducing of the visible light, while the absorption of near-infrared light is strong. The photothermal conversion efficiency of the samples is significantly improved from 9.7% to 86.6%. Hence, the prepared nanocapsules achieve full spectral absorption, which has a broad application prospect in solar thermal utilization.
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POLYMER
·
2023
·
IF 4.6
Jianchun Niu,Shuomeng Zhang,Yunqi Li,Xiaoyu Li,Jialin Zhang,Shanfu Lu,Qinggang He
The operating temperature of modified Nafion membranes remains too low to satisfy the requirements for high-temperature proton exchange membrane fuel cells (HT-PEMFCs) because most can only operate well below 120 °C. In this article, we prepare a series of Nafion/SiO 2 composite membranes with different contents of doped silica nanoparticles by in situ growth of SiO 2 nanoparticles near the –SO 3 H group. The water dynamic change process and the functional properties of Nafion/SiO 2 composite membranes are studied and found to correlate well with structural parameters, such as crystallinity and average chain spacing. Also, microstructure information including the phase separation structure changes, structural complexity, and ion cluster fraction of Nafion/SiO 2 composite membranes at different temperatures are investigated using synchrotron-based in situ small angle X-ray scattering (SAXS). Differing from expectations, the amount of water in the Nafion/SiO 2 composite membranes may not be the decisive factor to maintain proton conductivity at relatively high temperatures. Instead, the complexity or connectivity of the proton transport channel may play a more important role in the effective proton transfer inside the composite membranes, which also provides valuable guidance and insight for the development of novel HT-PEM materials with well-designed ion transport pathways in the future.
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COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2023
·
IF 5.2
Lili Tian,Miaomiao Sun,Yinglin Liu,Bingyu He,Guangli Dong,Hong Hao
The development of superhydrophobic and highly oleophobic nanocomposites that are highly adhesive to substrates is a major challenge in surface-related technologies. In this study, litchi-like polystyrene (PS) particles were prepared by soap-free emulsion polymerization with styrene (St) as monomer , KH-570 as crosslinking agent and KPS as initiator. Dual-sized litchi-like 1H,1H,2H,2H-perfluorodecyltriethoxy silane-SiO 2 -PS (PFDTES-SiO 2 -PS) particles was sol–gel synthesized using TEOS, PS, and PFDTES. Special superhydrophobic , highly oleophobic, and highly adhesive FDA-SiO 2 -PS (fluoride hdroxyl acrylate-resin-SiO 2 -PS copolymer) coatings were fabricated by embedding fluorosilane-modified litchi-like SiO 2 particles in fluoride hdroxyl acrylate-resin (FHA resin) followed by curing through cross-linking using free radical polymerization . The structure, surface morphology , and properties of the coatings were examined by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM) and contact angle measurements, and chemical analysis. The measured Ra roughness value was 181 nm for FDA-SiO 2 -PS coating. The fluorine-containing groups have a strong tendency to direct themselves to the coating surface , resulting in a superhydrophobic and highly oleophobic coating (water and CH 2 I 2 contact angles of 169.61° and 137.04°, respectively, and a water rolling angle of 4.35°) that is also highly adhesive to substrates (adhesion 5B). Exposing to air for 24 months, the coating possessed long air-stability with contact angles of 159.31° and 135.04° for water and CH 2 I 2 , independently. Furthermore, the FDA-SiO 2 -PS coating endows it with excellent antifouling and self-cleaning abilities, and resistance to E. coli and platelet adhesion; hence, FDA-SiO 2 -PS is a promising coating for use in biomedical and marine antifouling applications.
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JOURNAL OF ORGANOMETALLIC CHEMISTRY
·
2019
·
IF 2.066
Yi Zhou,Xuelian He,Ting Fu,Ning Zhao,Boping Liu
A series of novel Cr/Ti bimetallic polyethylene catalysts were successfully synthesized for the first time through introduction of chromium species into the (SiO 2 /MgR 2 /MgCl 2 )·TiCl x Ziegler-Natta catalysts. The bimetallic catalysts , which showed high activity, were simply prepared by refluxing titanium choloride with chromium modified silica gel/alkyl Mg adducts. Moreover, the effects of chromium content and calcination temperature were investigated in detail. The results obtained in the study were used to systematically discuss a clear relationship between the catalyst preparation condition and the relative performance of different metal active centers. Factors including surface hydroxyl content, catalyst performance in homo-polymerization, ethylene/1-hexene copolymerization were systematic investigated. Comparably, the chromium modified catalyst shows catalytic performance with 89% higher activity, 41.5% higher hydrogen response and 46.3% higher 1-hexene incorporation than the original (SiO 2 /MgR 2 /MgCl 2 )·TiCl x Ziegler-Natta catalyst. A new schematic model was proposed to explain the accelerated activation process of the bimetallic catalysts with kinetic and SEM results: chromium active sites on the outer surface of support react 10 times quicker than Ti active sites initially and help to crack the catalyst particle in the first stage; then the released inner surface active sites start to accelerate the polymerization reaction in the second stage.
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COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2019
·
IF 6.282
Gang Li,Tao Zhao,Pengli Zhu,Yachuan He,Rong Sun,Daoqiang Lu,Ching-ping Wong
SiO 2 nanoparticles are attractive components for formulating highly filled underfill adhesives in the electronic packaging field. However, achieving uniform dispersion of inorganic SiO 2 nanoparticles into an organic polymer matrix to obtain desired rheological and thermo-mechanical properties remains a significant challenge in nanocomposites engineering. To address the issue, previous studies mainly focused on tailoring the filler morphology and size, volume fraction and filler distribution. Here, in this work, in-situ modification of SiO 2 nanoparticles by using organosilanes with different functional groups was conducted. We demonstrated the structure-property relationships between microscopic surface state of SiO 2 nanofillers and macroscopic rheological, coefficient of thermal expansion (CTE) and adhesive properties of the resulting amine curing epoxy-based nanocomposite underfills. Our experimental results show that the modification of filler surface effectively enables the decrease of viscosity of underfill, and methacryl-terminated silane exhibits the highest efficiency among various organosilanes. Moreover, surface modification improves the adhesion strength between the underfill and substrate evidently, and nonpolar groups function better than their polar counterparts. In addition, modification with nonpolar methacryloxy and phenyl groups is capable of reducing CTE of nanocomposites effectively while other groups have no significant contribution to CTE reduction. These properties improvement can be attributed to the alteration of interfacial compatibility and adhesion in the SiO 2 nanocomposites. Overall, our work provides a useful guideline for the rational surface chemistry design of SiO 2 filler and optimizing the overall performance of underfill adhesives.
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HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Wenluan Zhang,Zijun Wang,Xiaobo Liu
In this work, poly(arylene ether nitrile) (PEN) was utilized to fabricate a separation membrane to remove dye molecules and oil/water emulsions for the very first time. Specifically, 15 wt% polyethylene glycol (Mw = 800 Da) was added to the casting solution as a pore-forming agent to enhance the flux. In situ-generated SiO2 nanoparticles (NPs) were utilized to improve the membrane surface hydrophilicity by the hydrolyzation of tetraethyl orthosilicate under weak acid conditions. However, the surface hydrophilicity improvement was not significant. It may be because the strong mechanical strength of PEN caused most of the SiO2 NPs to be buried within the polymer matrix or SiO2 NPs were lost by dissolution in the acidic water bath. Fourier-transform infrared spectroscopy and X-ray photoelectron spectroscopy were performed to study the membrane surface chemical features. Scanning electron microscopy images were obtained to observe the membrane cross-section morphology.
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高影响因子
ACS Applied Bio Materials
·
2018
·
IF 0
Yang Zhang,Guohua Jiang,Wenjie Hong,Mengyue Gao,Bin Xu,Jiangying Zhu,Gao Song,Tianqi Liu
Herein, an NIR-responsive polymeric microneedle (MN) system incorporated with metformin-loaded and polydopamine/lauric-acid-coated (PDA/LA-coated) hollow mesoporous SiO2 has been developed for transdermal delivery of antidiabetic drug (metformin). First, an antidiabetic drug was loaded within hollow mesoporous SiO2 nanoparticles (HMSNs) by a diffusion method. Then, PDA as photothermal conversion agent and lauric acid (LA) as phase change material (PCM) were coated onto the HMSN to form NIR-responsive drug nanocarriers. Finally, these metformin-loaded and PDA/LA-coated HMSNs were encapsulated into poly(vinylpyrrolidone) (PVP) MNs. After insertion into skin tissue, LA could melt with the photothermal conversion of PDA under NIR light, thus enabling release of encapsulated metformin from MNs. The in vivo release behavior of metformin from MNs into skin was further studied to investigate its hypoglycemic effect on diabetic rats. Compared with the subcutaneous injection of metformin, the bioavailability of MN–NIR groups was 95.8 ± 2.7%. The antidiabetic drug can be precisely released by adjustment of exposure time and power densities of NIR light.
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MOLECULAR PHARMACEUTICS
·
2019
·
IF 4.396
Yanyan Yu,Min Zhou,Wei Zhang,Lei Huang,Dandan Miao,Hongyan Zhu,Gaoxing Su
Rattle-type nanostructures with movable cores, porous shells, and hollow interiors have become attractive nanoplatforms in the field of nanomedicine, especially for targeted and stimuli-responsive drug delivery. In this work, rattle-type gold nanorods@void@porous-SiO2 (GVPS) nanocomposites were fabricated facilely using the surface-protecting etching method and exhibited high photothermal conversion efficiency. Taking advantage of the porous shell and hollow interior, the nanocomposites have abundant space for drug loading and successfully improved the drug loading capacity up to ∼19.6%. To construct a multifunctional drug delivery system, GVPS was further functionalized with polyethylene glycol (PEG) and cyclic RGD peptides to improve biocompatibility as well as selectivity toward the targeted cancer cells. Besides, to achieve precise regulation and near-infrared laser activation of the drug release, a phase-changing material, 1-tetradecanol (1-TD, Tm: 39 °C), was employed as gatekeepers in this system. After incubation with an αVβ3 integrin receptor-overexpressed cell line, the as-prepared GVPSPR-DOX/TD nanocomposites exhibited great performances in combined photothermal therapy and chemotherapy. It is worth noting that the combined therapy showed superior efficiency in cancer cell killing to chemotherapy or photothermal therapy alone.
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PubMed
高影响因子
COMPOSITES PART B-ENGINEERING
·
2019
·
IF 6.864
Jiangtao Xu,Songmin Shang,Shouxiang Jiang
Conventionally, the surface-enhanced Raman spectroscopy (SERS) measurement is performed by dispersing noble metal nanoparticles onto the target sample directly or assembling noble metal nanoparticles onto a micro-sized substrate. Despite it is flourishing, this method is not adequate for various samples, mainly limited by either a defined confinement of the test position or the complex extraction process of the target sample on the irregularly shaped surface, besides the costive materials, complex and uncontrollable fabricating processes. Herein, we demonstrate that the α-Fe 2 O 3 thin film is decorated with Ag nanoparticles constructed on SiO 2 fibers as a flexible SERS-active substrate, which yields a functional optical enhancement of the signal at 532 nm laser excitation . It shows a high enhancement factor of 4.71 × 10 5 , ultrahigh sensitivity of 10 −15 M, and excellent signal stability with a relative standard deviation (RSD) of 1.22% and reproducibility with a RSD of 0.258%.
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高影响因子
危险品化学品经营许可证（带存储）