JOURNAL OF APPLIED POLYMER SCIENCE
·
2016
·Vol. 134
·期 12
·
IF 1.866
Qing Zhang,Wan-Xia Huang,Gan-Ji Zhong
Poly(methyl methacrylate) grafted silica (SiO 2 -g-PMMA) was synthesized via in situ suspension polymerization. To achieve better uniform dispersion, hexadecyltrimethylammonium bromide (CTAB) was introduced into xylene to manipulate SiO 2 aggregation. SiO 2 -g-PMMA or SiO 2 was incorporated into PMMA matrix by in situ polymerization to prepare PMMA-based nanocomposites. The effect of CTAB amount, in the range 0–35 wt %, on the modification was evaluated by DLS, TGA, and FTIR. Furthermore, morphology, optical, mechanical, and thermal properties of PMMA nanocomposites was characterized by SEM, UV–vis, DMA, and TGA. Owing to surface functionalization, SiO 2 -g-PMMA exhibited far more excellent compatibility and dispersion in matrix compared with SiO 2 . Surface hardness and thermal properties of nanocomposites were enhanced significantly under the premise in high transparency. It is expected that transparent nanocomposites with promising scratch-resistance could have wide applications, such as airplane shielding window and daily furniture. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134 , 44612.
研究领域:
材料科学
·
聚合物化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
·
2024
·
IF 3.5
Le Fu,Wenjun Yu,Bohan Wang,Ying Deng
Extensive efforts have been devoted to investigate the distribution of dopants in ceramics. However, one critical question remained barely explored, which is the redistribution of dopants between amorphous and crystalline phases during fast sintering of ceramics. Here we address this gap by observing the redistribution of five selected dopants (Y, Ce, Yb, Hf, and Ta) in ZrO 2 –SiO 2 nanoceramics during sintering. We designed two groups of experiments: In group one, dual-phase amorphous particles were sintered with multicomponent crystalline ones. The former particles were ZrO 2 –SiO 2 glass, whereas the latter ones consisted of ZrO 2 solid-solution nanocrystallites (SSNCs) embedded in an oxide glass containing Zr, Si, Y, Ce, Hf, Yb, and Ta. In group two, dual-phase crystalline particles were sintered with multicomponent amorphous ones. The former particles were composed of ZrO 2 nanocrystallites (NCs) embedded in an amorphous SiO 2 matrix, whereas the latter ones were oxide glass containing Zr, Si, Y , Ce, Hf, Yb, and Ta. Redistribution of the dopants from the glass to ZrO 2 NCs occurred in the two groups, that is, the five dopants migrated from the glass matrix into the ZrO 2 NCs, forming ZrO 2 SSNCs. The redistribution of the dopants not only increased the configuration entropy of the ZrO 2 NCs but also benefited the network structure integrity of SiO 2 glass. The dopant redistribution process was driven by the minimization of the studied material's free energy. The reported results are important for understanding the redistribution behaviors of dopants and are expected to provide new insights to design new ceramics via the multielement co-doping strategy.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2019
·
IF 5.128
Lina Han,Weiguo Ren,Bing Wang,Xingxing He,Lingjun Ma,Qihuang Huo,Jiancheng Wang,Weiren Bao,Liping Chang
In this work, a novel method is introduced to activate coal gangue (CG) for extraction of Si and Al species. The activation experiments were carried out using a stainless steel tube reactor (17 mL) and an autoclave reactor (1000 mL). Firstly, CG was activated by supercritical water added with alkali. It was found that the kaolinite phase of raw CG could be transformed into cancrinite, sodalite and kalsilite by using NaOH, Na 2 CO 3 and KOH as activators, respectively. Secondly, silica (SiO 2 ) and alumina (Al 2 O 3 ) were prepared by acid and alkali combination method. The extraction rates of Al 3+ and Si 4+ from the activated CG using KOH as activator were as high as 78.9% and 69.2%, respectively. The purity of SiO 2 and Al 2 O 3 products were 96.2% and 99.3%, respectively. The as-synthesized SiO 2 both from 17 mL and 1000 mL reactor exhibited very high specific surface areas of 710.0 m 2 ·g −1 and 872.8 m 2 ·g −1 , respectively. In addition, the SiO 2 after hydrophobic modification displayed excellent absorption selectivity for xylene.
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
CERAMICS INTERNATIONAL
·
2023
·
IF 5.2
Baolu Shi,Zhiliang Zhou,Yu Chen,Xinqiao Wang,Baosheng Xu
SiO 2 aerogels have an inherent optical transparency, but there is a hydrophilic defect and high transparency and hydrophobicity seem impossible to achieve at the same time. In order to realize the practical application value of highly transparent aerogel, our study used hexamethyldisilazane (HMDS) as the hydrophobic agent to improve the hydrophobicity of the prepared highly transparent SiO 2 aerogels. We investigated the effects of HMDS concentration and modification duration on SiO 2 aerogels through the chemical liquid method. Results showed that the concentration and modification time of HMDS have no significant effect on the microstructure and properties of highly transparent SiO 2 aerogels, which maintained uniform microstructure, low thermal conductivity , good thermal stability and contact angles were all above 136°. Hydrophobic and highly transparent SiO 2 aerogels hold great potential for use as observation windows in the aerospace applications, building thermal management, and transparent coating.
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
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Mo Zou,Jingzhi Chen,Zhaoyang Wei,Weiwei Lei,Jun You,Jie Liu,Qunchao Zhang,Dean Shi
Core-shell particles with rigid core and soft rubber shell have been proven to be effective in strengthening and toughening polymers simultaneously when the rubber shell thickness is controlled within a critical range. However, the critical value of the so-called thickness-to-diameter ratio τ (the ratio of the rubber shell thickness to the rigid core diameter) obtained in the previous work are all from polymer blends containing core–shell particles with monodispersed particle size. Does the critical τ value still exist in the core–shell toughening system with polydisperse particle sizes? Is it possible to produce core–shell particles with polydisperse particle sizes but the same τ value? In this paper, the post-emulsification method is first reported to prepare core–shell particles with polydisperse SiO 2 particles as the rigid core and ethylene–vinyl acetate copolymer grafted maleic anhydride (EVA- g -MAH) as the rubber shell, in which the thickness of the rubber shell can be well controlled and tuned via varying the feeding weight ratio of SiO 2 and EVA- g -MAH. The τ value is only determined by the weight ratio of SiO 2 and rubber, and has nothing to do with the SiO 2 particle size. A series of polyamide 6 (PA6)/SiO 2 @EVA core–shell toughening systems are prepared via melt blending process. It is proved the existence of the critical τ value ( τ cbd ) above which brittle-ductile transition happens in the core–shell toughening system with polydisperse core–shell particle sizes. The value of τ cbd is 0.069 in PA6/SiO 2 @EVA core–shell toughening system.
研究领域:
材料科学
·
聚合物工程
✓ 已验证
DOI
高影响因子
JOURNAL OF RARE EARTHS
·
2020
·
IF 3.104
Xiaowei Lv,Wenyi Huang,Xingcheng Ding,Jiangwei He,Qiumei Huang,Jialin Tan,Hao Cheng,Jun Feng,Lijun Li
In this study, Fe 3 O 4 @SiO 2 @ZnO:La microspheres were successfully prepared. The microspheres have the advantages of both ZnO doped with La and the Fe 3 O 4 @SiO 2 structure such that the former improves the photocatalytic activity of ZnO and the latter can be reused. The X-ray diffraction (XRD), a field emission scanning electron microscope (SEM), a field emission transmission electron microscope (TEM), X-ray photoelectron spectroscopy (XPS), and a vibrating sample magnetometer (VSM) were used to characterize Fe 3 O 4 @SiO 2 @ZnO:La microspheres. Methyl orange was used as the model molecule to study the effect of the Zn 2+ concentration and the doping amount of La on the photocatalytic activity of Fe 3 O 4 @SiO 2 @ZnO:La microspheres. Results show that in the synthesis of Fe 3 O 4 @SiO 2 @ZnO:La microspheres, photocatalytic activity of the microspheres is enhanced first and weakened later with the increase of Zn 2+ concentration. In the La doping process, the photocatalytic activity of Fe 3 O 4 @SiO 2 @ZnO:La microspheres is enhanced with the increase in the La doping amount. The magnetic photocatalysts not only have high photocatalytic activity, but also can be reused. After being reused five times, the photocatalyst's degradation rate of methyl orange is still as high as 81%, which shows that magnetic photocatalysts have prospective wider applications in photocatalytic degradation of dye wastewater.
研究领域:
材料科学
·
环境科学
✓ 已验证
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Yonghong Wu,Zhihang Shang,Zhaorui Li,Wenle Zhu,Lifang Nie,Juncheng Liu
Sol-gel is one of the most economical methods to prepare antireflection films, but the low ultraviolet radiation-resistance (UV-resistance) of the sol-gel film limits its applicability in the solar industry. A SiO 2 antireflection film was prepared with sol-gel method with phenyl salicylate (PS) as the porogen. The effects of the PS addition were investigated on the microstructure, optical property and UV-resistance of the film. When the addition of PS is 1.20 g, the refractive index at 550 nm is 1.30, and the maximum transmittance is 96.30 %. The average transmittance within the 400–1100 nm range reaches its peak at 92.85 %, which is 4.35 percentage points higher than that of the blank glass. In addition, the film without PS has an average transmittance of 91.00 % after 5000 equivalent solar hours (ESHs) UV irradiation, decreasing 1.07 percent point, and has a pencil hardness of 5 H and an adhesion of grade 2 of the tape-tearing method. However, the film with 1.20 g of PS still has an average transmittance of 92.15 % after 5000 ESHs UV irradiation, decreasing only 0.7 percent point, and has a pencil hardness of 7 H and an adhesion of grade 1 of the tape-tearing method.
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 84
·44575-44582
·
IF 3.708
Peng Jing,Qin Wang,Baocang Liu,Guangran Xu,Yanbing Zhang,Jun Zhang,Gejihu De
We develop a facile layer-by-layer deposition process to create bi-functional Fe3O4@SiO2@Gd2O3:Yb,Er nanostructures composed of magnetic Fe3O4 cores, variable SiO2 mid-layers, and up-converting Gd2O3 shells. The synthetic process is well-controlled and the obtained Fe3O4@SiO2@Gd2O3:Yb,Er nanoparticles show relative monodispersity and exhibit tunable magnetic and up-conversion luminescence depending on the thickness of SiO2 mid-layers. The influences of SiO2 mid-buffer-layers on morphology, magnetism, and up-conversion luminescence are well addressed. The obtained bi-functional Fe3O4@SiO2@Gd2O3:Yb,Er nanoparticles may be potentially applicable in magnetic, fluorescent, and biological applications. The synthetic route may be employed for fabricating other multifunctional nanostructures.
研究领域:
材料科学
·
生物医学工程
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Catalysis Science & Technology
·
2025
·
IF 4.2
Yilin Zhao,Fangwei Liu,Jingbo Hu,Yang Yang,Jianzhou Wu,Shihui Zou,Jie Fan
The Mn–Na2WO4/SiO2 catalyst for oxidative coupling of methane (OCM) is highly appealing and promising but its high light-off temperature (>800 °C) hinders its industrial application. Engineering catalysts for efficient catalytic performance is attractive yet challenging. In this study, we demonstrate that the incorporation of small amounts of silver into the Mn–Na2WO4/SiO2 catalyst significantly improves its performance, achieving a C2 yield of up to 20% at 750 °C. Characterization results indicate that silver facilitates O2 activation and promotes C–H bond activation, thereby further enhancing CH4 conversion. The findings offer valuable insights into advancing the design concept of high-performance OCM catalysts.
研究领域:
化学工程
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·
IF 3.83
Wei Wan,Meizhen Tao,Hailin Cao,Yuqing Zhao,Junrong Luo,Jian Yang,Tai Qiu
Exploring flexible dielectrics with high dielectric constant and low loss is pertinent for many applications in electronic devices. In the present work, a non-ferroelectric polymer, polyvinyl alcohol (PVA), was used to fabricate homogeneous dielectric composite films with a relatively high dielectric constant and a low dielectric loss by using 2D nano sheets (Ti 3 C 2 T x MXene) as the filler. To limit dielectric loss, SiO 2 was coated onto the surface of MXene to provide interfacial barrier effect and suppress dielectric loss. MXene@SiO 2 /PVA composite films showed lower dielectric losses at low frequencies (from 20 Hz to ~ 10 kHz) compared with MXene/PVA composite films. MXene@SiO 2 /PVA composite films with 2.5 wt% MXene loading and 5 wt% (with respect to MXene content) SiO 2 coating had a dielectric constant of 27.2 (a 292.5% rise compared to neat PVA film) and a dielectric loss of only 0.057 (a 259.6% reduction compared to MXene/PVA composite film) at 100 Hz and room temperature (RT). In addition, this SiO 2 -coated composite film had stable dielectric properties (dielectric constant and loss change from 27.2 to 29.3 and 0.057 to 0.104, respectively) in the temperature range of RT to 60 °C. This work provides a promising way to fabricate PVA-based dielectric composites with excellent dielectric properties for practical applications in electronics.
研究领域:
材料科学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Wenchao Zhang,Liangjun Wang,Shiyu Liu,Feng Guan,Min Jiang,Yanpeng Li,Dong Yue,Jialong Li,Xiaoxu Liu,Yu Feng
It is important that the dielectric material in the electrical system be able to handle the increasing applied electric strength owing to the rising demands for power supply reliability. Based on this, in this work, Nb 2 O 5 donor doped SiO 2 (NSO) particles were synthesized by high-temperature sintering method and successfully doped into the PI matrix. The maximum E b of the composite material is 527.3 kV/mm, which is 64.2% higher than that of pure PI (321.1 kV/mm) and 34.8% higher than that of the SiO 2 /PI composite material (392.5 kV/mm) owning to the effect of donor doping on the carrier transport of the composite material. At the same time, it maintains excellent dielectric stability and lower dielectric loss even at 100 ℃. These consequences offer a new strategy for enhancing the integrated dielectric properties of polymer dielectrics in insulation fields.
研究领域:
材料科学
·
电气工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2022
·Vol. 15
·期 14
·4875
·
IF 3.748
Liguo Xu,Yanwu Chen,Peijiang Liu,Jianghua Zhan
Commercial polyolefin separators exhibit problems including shrinkage under high temperatures and poor electrolyte wettability and uptake, resulting in low ionic conductivity and safety problems. In this work, core–shell silica-polyphosphazene nanoparticles (SiO2@PZS) with different PZS layer thicknesses were synthesized and coated onto both sides of polyethylene (PE) microporous membranes to prepare composite membranes. Compared to pure silica-coated membranes and PE membranes, the PE-SiO2@PZS composite membrane had higher ionic conductivity. With the increase in the SiO2@PZS shell thickness, the electrolyte uptake, ionic conductivity and discharge capacity gradually increased. The discharge capacity of the PE-SiO2@PZS composite membrane at 8 C rate was 129 mAh/g, which was higher than the values of 107 mAh/g for the PE-SiO2composite membrane and 104 mAh/g for the PE membrane.Keywords:composite membrane;SiO2@PZS nanoparticle;lithium-ion batteries
研究领域:
材料科学
·
能源技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）