SURFACE ENGINEERING
·
2018
·
IF 1.978
G. Luo,Z. Jin,Y. Dong,J. Huang,R. Zhang,J. Wang,M. Li,Q. Shen,L. Zhang
The wear resistance and transparency properties of superhydrophobicity are most important issue essential for the application of superhydrophobic materials in industry. In this paper, we successfully prepared good wear resistance PU/SiO2 (polyurethane/silica) composite superhydrophobic coating with the double-step sol–gel route. The PU and SiO2 coating occurs crosslinking reaction forming composite superhydrophobic coating. The superhydrophobic coating surface is characterised by environmental scanning electron microscope and other testing methods, the results show that the PU/SiO2 composite superhydrophobic coating surface has excellent superhydrophobic properties and the Sa value was 332.5 nm. We used the pressure of 5 KPa to verify the wear resistance which the PU/SiO2 composite superhydrophobic coating surface exhibits good wear resistance, the water contact angle (WCA) still remains 138.7° after the abrasion resistance test. The PU/SiO2 composite superhydrophobic coating has high transparency in the visible light. The largest WCA of PU/SiO2 composite superhydrophobic coating could reach 162.1°.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS A-GENERAL
·
2020
·
IF 5.006
Hong Du,Xiuyun Ma,Miao Jiang,Peifang Yan,Z. Conrad Zhang
The production of furfuryl alcohol from furfural hydrogenation in gas phase is of great significance for the valorization of biomass. The existing catalyst for this transformation suffers from high cost and complex preparation process. Thus, a highly efficient copper catalyst was developed by a simple impregnation method using ethanolamine modified granular silica as carrier. The catalytic performance was related to the amount of ethanolamine used in modification. Highly dispersed copper with uniform particle size distribution was obtained from appropriate amount of ethanolamine modified granular silica. The ethanolamine modified granular silica (mass ratio between ethanolamine and silica was 3 in the initial modification mixture) supported copper catalyst exhibited the best performance in terms of catalyst lifetime thanks to its maximum amount of Cu 0 sites and largest amount of Cu + sites. A slow deactivation of the catalyst after extended time on stream evaluation is attributed to carbon deposition and slow copper sintering.
研究领域:
催化化学
·
材料科学
·
生物质转化
✓ 已验证
产品关联
DOI
高影响因子
Nanomaterials
·
2019
·Vol. 9
·期 3
·455
·
IF 4.034
Yuhao Zhao,Kai Xia,Zhenzong Zhang,Ziming Zhu,Yongfu Guo,Zan Qu
In order to avoid using toxic or harmful operational conditions, shorten synthesis time, enhance adsorption capacity, and reduce operational cost, a novel magnetic nano-adsorbent of CoFe2O4@SiO2with core–shell structure was successfully functionalized with polypyrrole (Ppy). The physical and chemical properties of CoFe2O4@SiO2-Ppy are examined by various means. The as-prepared CoFe2O4@SiO2-Ppy nanomaterial was used to adsorb Hg2+from water. During the process, some key effect factors were studied. The adsorption process of Hg2+onto CoFe2O4@SiO2-Ppy was consistent with the pseudo-second-order kinetic and Langmuir models. The Langmuir capacity reached 680.2 mg/g, exceeding those of many adsorbents. The as-prepared material had excellent regeneration ability, dispersibility, and stability. The fitting of kinetics, isotherms, and thermodynamics indicated the removal was endothermic and spontaneous, and involved some chemical reactions. The application evaluation of electroplating wastewater also shows that CoFe2O4@SiO2-Ppy is an excellent adsorbent for Hg2+ions from water.Keywords:adsorbent;polypyrrole;heavy metal;mercury;modification
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS AND MANUFACTURING PROCESSES
·
2019
·
IF 3.35
Tao Long,Yin Xu,Xiao-Jian Lv,Ming Li,Li Li,Lan-Ying Xu
A freestanding SiO2–TiO2 monolith with bicontinuous structure was prepared via a one pot sol-gel reaction. This monolith was fully characterized by using field emission scanning electron microscopy (FE-SEM), nitrogen adsorption and X-Ray diffraction (XRD). Synthesized SiO2–TiO2 monolith possesses great mechanical strength and interconnected macropores (throughpores, textural pores) on the micrometer scale as well as skeleton pores in nanoscale, and also possesses an anatase TiO2 crystalline structure. Photo-catalytic breakdown of aqueous methylene blue (MB) with UV light was chosen to evaluate photocatalytic efficacy of the SiO2–TiO2 catalyst. These photodegradation activities indicated that MB decomposed completely within 180 min and the SiO2-TiO2 catalyst was readily separated from the reaction system and easily regenerated. Moreover, the photocatalytic activity of the monolithic catalyst remained unchanged after four catalytic cycles and the morphology was still intact.
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
Journal of Materials Chemistry C
·
2021
·Vol. 9
·期 37
·12581-12589
·
IF 7.393
Yixuan Liu,Lulu Zhang,Xuemi Long,PanPan Jiang,Chong Geng,Shu Xu
Perovskite nanocrystals (PNCs) are promising luminescent materials but suffer severe stability issues due to their ionic surface nature. SiO2 encapsulation is widely adopted for stabilizing PNCs in LED lighting and display applications. However, PNCs commonly lose ligands during the SiO2 encapsulation process, leading to fluorescence quenching and agglomeration. Here, CsPbBr3 PNCs with lead-carboxylate capping motif, which shows extraordinary ethanol and moisture resistance, were developed to facilitate fast and controlled growth of PNC–SiO2 nanocrystals using ethanol to accelerate the hydrolysis of tetramethoxysilane. Surface analysis revealed the preservation of the original carboxylate ligands after the reaction. Carboxylate and SiO2 form uniform dual-encapsulation that provides PNCs with superior air and water resistance, excellent photoluminescence maintenance, and high miscibility in silicone resin. Finally, saturated green LED and white-light LED with a wide color gamut were fabricated through on-chip packaging of the PNC–SiO2 on the blue LED chip. LEDs retained >85% of their light intensity after continuous illumination for 1000 h, demonstrating the high potential of the encapsulation method and the materials in light-emitting applications.
研究领域:
材料科学
·
光学工程
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
CATALYSIS LETTERS
·
2021
·Vol. 151
·期 8
·2291-2301
·
IF 3.186
Fan Xizheng,Yang Jingyi,Pang Qingqing,Liu Zhongyi,Zhang Panke,Yang Jing-He
Abstract Construction of heterogeneous Pd/SiO 2 catalyst via the pollution-free strategy marked strong electrostatic adsorption has been reported for the application to Suzuki–Miyaura cross-coupling reactions. The exposed negatively charged oxygen groups, which were converted from the hydroxyl groups on the surface of silica under the alkaline atmosphere, could effectively anchor palladium species to form ultrafine Pd nanoparticles (Pd NPs) with an average particle size of 1.3 nm and high dispersion (43%). Pd/SiO 2 catalyst was endowed with the excellent catalytic performance which was that the yield of the Suzuki–Miyaura reaction between bromobenzene and phenylboronic acid at 40 °C was > 99% for 30 min and the TOF was ~ 80,000 h −1 . The catalyst could be easily recovered and recycled by facile procedure without a significant decrease in catalytic activity, which was able to maintain the 90% yield after repeated for 8 times. In addition, a continuous flow reaction device was designed using the Pd/SiO 2 catalyst to effectively improve the production efficiency of biphenyl. Graphic Abstract Pd/SiO 2 catalyst constructed with the strategy of strong electrostatic adsorption (SEA) possesses uniformly dispersed and highly exposed Pd sites which can be easily transformed into electron-deficient Pd δ+ and strengthened stability for itself due to its strong interaction with the front surface of the carrier, and has been endowed the outstanding catalytic performance for Suzuki − Miyaura cross-coupling reaction.
研究领域:
催化化学
·
材料科学
·
有机合成
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2021
·
IF 5.161
Junchao Fu,Haojie Yu,Li Wang,Ruixue Liang,Chuyin Zhang,Meijin Jin
To achieve the high dispersion of SiO 2 nanoparticles in polyurethane acrylate resin, the titanate coupling agent, PN-102, was used as the surface modifier to prepare the modified SiO 2 nanoparticles (Si-PN102-5) with small particle size and good dispersion ability in PUA-6 resin. Accordingly, hydrophilic SiO 2 (Si-380) and hydrophobic SiO 2 (Si-115) were introduced into PUA-6 resin to prepare the corresponding composite coatings, so as to investigate the effects of SiO 2 nanoparticles modified with different surface modifiers on the properties of PUA / SiO 2 composite coatings. The properties of PUA / SiO 2 composite coatings were characterized by the tests of FT-IR, AFM, SEM, DMA, TG and so on. The FT-IR and XPS results show that PN-102 had functionalized the Si-PN102-5 particle surface successfully. The TEM test displays that the particle size of SiO 2 was almost unchanged before and after modification, maintaining at about 20–30 nm. The SEM, DMA and tensile test reveal that Si-PN102-5 not only blocks the interaction and accumulation of nanoparticles, but also enhances the interface interaction with polymer chains through chain entanglement, which endows Si-PN102-5-5% composite coatings with highest mechanical strength among the other prepared coatings, reaching to 11.0 ± 0.1 MPa in tensile strength and 9.4 ± 3.0% in elongation at break. The pencil hardness of the prepared Si-PN102-5-5% composite coating could reach to 5H which is higher than the commercial PUA-6 based coating, and it also displayed good adhesion (4B) and flexibility (3 mm). The TG results show that all of prepared composite coatings display good thermal stability with a decomposition temperature of higher than 250 °C.
研究领域:
材料科学
·
表面化学
✓ 已验证
产品关联
DOI
高影响因子
COLLOID AND POLYMER SCIENCE
·
2017
·Vol. 295
·期 7
·1223-1232
·
IF 1.723
Yao Jia,Cao Zhihai,Chen Qun,Zhao Shuning,Zhang Yushang,Qi Dongming
Poly(styrene- co -methyl methacrylate) (poly(St- co -MMA))/SiO 2 nanocomposite particles (NCPs) were prepared through miniemulsion polymerization by using polyoxyethylene (20) sorbitan monolaurate (commercial name: Tween-20) as the sole surfactant. The number fraction of poly(St- co -MMA)/SiO 2 NCPs in the as-synthesized emulsion could exceed 90% in some well-designed systems, indicative of high efficiency of poly(St- co -MMA)/SiO 2 NCP formation. Each poly(St- co -MMA)/SiO 2 NCP contained many SiO 2 NPs, thus exhibiting a high composite efficiency between the poly(St- co -MMA) and SiO 2 NPs. The mechanistic investigation indicated that the enhanced efficiency of the poly(St- co -MMA)/SiO 2 NCP formation is due to the improved homogeneity in the distribution of SiO 2 among the monomer droplets and the effectively suppressed nucleation of plain monomer droplets through controlled coalescence of the monomer droplets with the latex particles.
研究领域:
材料科学
·
化学工程
·
高分子化学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Advanced Materials Interfaces
·
2017
·Vol. 4
·期 15
·1700062
·
IF 4.279
Aijaz Ahmed Babar,Xianfeng Wang,Nousheen Iqbal,Jianyong Yu,Bin Ding
Liquid moisture (sweat) transport properties of textile materials play critical role in maintaining the comfort of body which are mainly controlled by surface chemistry, structure, and morphology of substrate. Herein, a dual layer surface treated nonwoven (NW)/electrospun nanofiber membrane with excellent differential liquid moisture transport characteristics is reported. NW is used as inner layer for its high moisture releasing and low moisture absorbing features, and polyacrylonitrile (PAN) as outer layer because of its decent hydrophilic nature. Wettability of NW is tailored by surface treatment with polydopamine, and the wicking characteristics of PAN nanofibers are enhanced by inducing hydrophilic SiO 2 nanoparticles (PAN-SiO 2 ). Performance of resultant surface treated NW (TNW)/PAN-SiO 2 nanofiber composite membranes is thoroughly characterized by moisture management tester (MMT). Subsequent composite membranes offer high wettability gradient which leads to their marvelous MMT performance with an outstanding one-way transport capacity of 1413%, excellent overall moisture management capacity of 0.99, and a decent water vapor transfer rate of 12.73 kg m −2 d −1 , indicating a potential candidate for faster sweat release applications.
研究领域:
材料科学
·
纺织工程
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Qiang Huang,Meiying Liu,Jiao Zhao,Junyu Chen,Guangjian Zeng,Hongye Huang,Jianwen Tian,Yuanqing Wen,Xiaoyong Zhang,Yen Wei
Polyethylenimine-tannins coated SiO 2 (SiO 2 @PEI-TA) hybrid materials have been prepared via a single-step multifunctional coating with polyethylenimine (PEI) and tannins (TA), and characterized by transmission electron microscope (TEM), Fourier transform infrared spectroscopy (FT-IR), thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS). The as-prepared SiO 2 @PEI-TA composites were examined as adsorbents to remove the Cu 2+ from aqueous solution. The effects of contact time, initial Cu 2+ concentration, solution pH and temperature, on Cu 2+ adsorption have been investigated. The results show that the adsorption of Cu 2+ onto SiO 2 @PEI-TA is dependent on the contact time, Cu 2+ concentration, pH and temperature. The SiO 2 @PEI-TA composites show a 2.4-fold increase in adsorption capacity, implying that the introduction of PEI-TA coating is in favor of the Cu 2+ adsorption. Based on the analysis of kinetic data, the kinetics of Cu 2+ adsorption is more accurately described by the pseudo-second-order model. The equilibrium data are analyzed by Langmuir and Freundlich isotherms. Results of isotherms show that the better agreement is Freundlich isotherm model with correlation coefficient of 0.9914, which suggests that the adsorption of Cu 2+ onto SiO 2 @PEI-TA is mainly a heterogeneous adsorption process. Thermodynamic analyses show that the adsorption interaction is actually a spontaneous and endothermic chemical process, which might involve the chemical chelation between Cu 2+ and functional groups (amine and carboxyl groups) on the surface of SiO 2 @PEI-TA. In addition, the Cu 2+ ions could desorb from SiO 2 @PEI-TA by using acid solution and the adsorption efficiency remains at high level after five adsorption-desorption recycles. These results provide potential applications of these novel adsorbents for the removal of heavy metal Cu 2+ from aqueous solution and also provide strong evidence to support the adsorption mechanism proposed in the study.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2014
·
IF 1.968
Yanqing Wang,Hongmei Zhang
The effect of SiO 2 nanoparticle on the conformation and activity of catalase were studied and observed by UV–vis, circular dichroism, fluorescence spectroscopy and molecular modeling methods. All the experimental data showed that the spectral changes of catalase were induced by SiO 2 nanoparticle exposure. SiO 2 nanoparticle could bind to catalase by electrostatic, hydrogen bonding and hydrophobic forces. These interactions decreased the α-helices content of catalase, which had more unfolded and more flexible structure. These structural changes did not obviously affect the solvent polarity of environment around both Trp and Tyr residues on catalase. Moreover, the activity assay indicated that SiO 2 nanoparticle was an activator for catalase activity. In a word, the biomolecular structure changes revealed by spectra provided a better understanding of the nanotoxicity and potential health effects of SiO 2 NP exposure.
研究领域:
生物化学
·
纳米毒理学
·
分子生物学
✓ 已验证
产品关联
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2014
·
IF 1.09
Zhanjun Wu,Min Wang,Zhi Wang
The mechanical and thermal properties of epoxy nanocomposites filled with 7–40 nm spherical silica particles were investigated as a function of silica loadings. Due to the ultrasonic dispersion and modification of the coupling agent, the silicon dioxide (SiO2) nanoparticles were readily dispersed in the epoxy resin with light aggregation for the loading of up to 5 wt% as determined using a scanning electron microscope (SEM). The tensile test indicated that the tensile strength and elongation at break of the nanocomposites increased by up to 23% and 31%, respectively, compared with the neat epoxy resin. The glass transition temperatures of all the epoxy nanocomposites were higher than that of the neat epoxy resin for about 35–45°C, but did not show significant changes with an increase in the silica loading. The fracture surfaces were also observed using SEM, which showed evidence of the SiO2 nanoparticle debonding.
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）