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Preparation and rheological behaviors of PA6/SiO2 nanocompiste

WEI Shanshan, LIU Yuejun, LI Xianggang, HUANG Yugang, WANG Xiayu, ZHANG Ping

《化学科学与工程前沿（英文）》 2007年第1卷第4期页码 332-337 doi: 10.1007/s11705-007-0060-2

摘要： The polyamide 6 (PA6)/SiO nanocomposites were prepared by in situ polymerization and the rheological behaviors were investigated. The morphology of resultant materials was characterized by scanning electron microscopy (SEM) and the rheological behaviors were characterized by capillary rheometer. The results showed that the SiO particle size was around 50 nm and the particles dispersed evenly in PA6 matrix. The nanocomposites were pesudoplastic fluids and the apparent viscosities of nanocomposites increased initially and then decreased with the increase in nano-SiO content at the same temperature. The non-Newtonian indexes of nanocomposites were smaller than those of pure PA6. With the increase in nano-SiO content the apparent viscous activation energies of nanocomposites increased initially and then decreased. The rheological behaviors revealed that there were strong interactions between PA6 macromolecule chains and nano-SiO particles.

关键词： polyamide temperature rheological activation pesudoplastic

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Hydrogenation of furfuryl alcohol to tetrahydrofurfuryl alcohol on NiB/SiO2 amorphous alloy catalyst

SONG Yun, LI Wei, ZHANG Minghui, TAO Keyi

《化学科学与工程前沿（英文）》 2007年第1卷第2期页码 151-154 doi: 10.1007/s11705-007-0028-2

摘要： NiB/SiO amorphous alloy catalyst was prepared by power electroless plating method and characterized by induction coupled plasma (ICP), Brunauer Emmett Teller method (BET), transmission electron microscope (TEM) and X-ray diffraction (XRD) techniques. The catalytic performance of NiB/SiO was investigated for the hydrogenation of furfuryl alcohol (FA) to tetrahydrofurfuryl alcohol (THFA). The effects of operational conditions, such as reaction temperature, pressure, and stirring rate were carefully studied. The proper conditions were determined as the following: pressure 2.0 MPa, temperature 120?C and stirring rate 550 r/min. A typical result with FA conversion of 99% and THFA selectivity of 100% was obtained under such conditions, which was close to that over Raney Ni.

关键词： following Brunauer electroless temperature transmission

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一种提高超疏水木材机械稳定性的方法

王成毓,刘峰

《中国工程科学》 2014年第16卷第4期页码 79-82

摘要：本文将聚乙烯醇（PVA）与二氧化硅（SiO₂）复合，通过滴涂法在木材表面形成一层有机-无机复合薄膜，之后对薄膜进行疏水改性，制得了一种机械稳健性较好的超疏水木材。

关键词：超疏水机械稳定性 PVA/SiO2 木材表面

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超疏水SiO2/PS 薄膜于木材表面的构建

张明,王成毓

《中国工程科学》 2014年第16卷第4期页码 83-86

摘要：

通过溶胶-凝胶法一步合成疏水性且具备独特形貌的二氧化硅粒子，联合聚苯乙烯以滴涂的方式于木材表面仿生合成了稳定性超疏水薄膜。经处理后的木材表面与水的静态接触角为153°，滚动角小于5°。通过扫描电子显微镜照片观察到该复合涂层拥有微米/亚微米的二维等级粗糙结构，该结构协同低表面能物质共同决定超疏水性木材的成功制得。此外，进一步研究了超疏水性木材表面的稳定性和耐久性。结果表明，该超疏水性木材于水、腐蚀性液体（酸液/碱液）、常见有机溶剂中以及一些常见条件下仍保留超疏水特性，为未来木材材料的应用领域扩展提供了有利条件。

关键词：超疏水木材表面滴涂法复合薄膜

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Preparation and properties of nano SiO2 core-shell structured additives and their nanocomposite with

KE Yangchuan, SUN Mingzhuo, SONG Yanxin, YANG GuangFu

《化学科学与工程前沿（英文）》 2007年第1卷第1期页码 76-80 doi: 10.1007/s11705-007-0016-6

摘要： To improve the performance of traditional nucleation additives and their compatibility with other additives, as well as to solve complex problems in practical applications, SiO precursors were reactively grafted in situ with the symmetrical hydroxyl groups of the nucleation agents. With this approach, the dissymmetrical part of the nucleation agents plays an important role. As a result, the prepared composite additive the nanoparticle precursor (NPP0) produces excellent results. The NPP0-PP composite has a transparency of over 93%, haze lower than 15%, and a heat distortion temperature (HDT) of 142?C, which is more than the 110?C of the pure PP matrix. In addition, it maintains over 90% of the mechanical properties with a deformation coefficient less than 1%. This indicates a strong nanoeffect.

关键词： deformation coefficient distortion temperature excellent NPP0-PP traditional nucleation

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新型磷系阻燃剂四苯基双酚A二磷酸酯阻燃ABS的应用研究

徐晓楠,卢林刚,陈南,殷全明,王大为

《中国工程科学》 2010年第12卷第2期页码 62-69

摘要： pkHRR最大分别下降50.11 %和55.58 %，TTI延长35 s ，FGI最大降幅为64.32 %，6 min内的SEA升幅为20.52 %，600 ℃时成炭率为11.15 %；采用BDP/NP/纳米SiO₂ =20 %/5 %/7 %时，材料的冲击性能上升了20.00 %，LOI达到31.20 %，UL94阻燃性能达到V-0级，av-HRR和pkHRR分别下降了49.45 ％和58.09

关键词： BDP ABS APP SiO2 阻燃烟

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Electrochemical performance of thermally-grown SiO

X. D. HUANG, X. F. GAN, Q. A. HUANG, J. Z. YANG

《能源前沿（英文）》 2018年第12卷第2期页码 225-232 doi: 10.1007/s11708-018-0556-0

摘要： Direct integration of lithium-ion battery (LIB) with electronic devices on the same Si substrate can significantly miniaturize autonomous micro systems. For achieving direct integration, a barrier layer is essential to be inserted between LIB and the substrate for blocking Li diffusion. In this paper, the feasibility of thermal SiO film as the barrier layer is investigated by electrochemical characterization and X-ray photoelectron spectroscopy (XPS). Due to the negligible side reactions of thermal SiO with electrolyte, the solid electrolyte interphase (SEI) layer formed on the surface of the barrier layer is thin and the SEI content mainly consists of hydrocarbon together with slight polyethylene oxide (PEO), Li PO F , and Li CO . Although 8-nm thermal SiO effectively prevents the substrate from alloying with Li , the whole film changes to Li silicate after electrochemical cycling due to the irreversible chemical reactions of SiO with electrolyte. This degrades the performance of the barrier layer against the electrolyte penetration, thus leading to the existence of Li (in the form of F-Si-Li) and solvent decompositions (with the products of hydrocarbon and PEO) near the barrier layer/substrate interface. Moreover, it is found that the reaction kinetics of thermal SiO with electrolyte decrease significantly with increasing the SiO thickness and no reactions are found in the bulk of the 30-nm SiO film. Therefore, thermal SiO with an appropriate thickness is a promising barrier layer for direct integration.

关键词： autonomous micro system direct integration barrier layer thermal SiO₂ film X-ray photoelectron spectroscopy (XPS)

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Effect of thermal pretreatment on the surface structure of PtSn/SiO

Guozhen Xu, Jian Zhang, Shengping Wang, Yujun Zhao, Xinbin Ma

《化学科学与工程前沿（英文）》 2016年第10卷第3期页码 417-424 doi: 10.1007/s11705-016-1583-1

摘要： The effect of thermal pretreatment on the active sites and catalytic performances of PtSn/SiO catalyst in acetic acid (AcOH) hydrogenation was investigated in this article. The catalysts were characterized by N physical adsorption, X-ray diffraction, transmission electron microscopy, pyridine Fourier-transform infrared spectra, and H -O titration on its physicochemical properties. The results showed that Pt species were formed primarily in crystalline structure and no PtSn alloy was observed. Meanwhile, with the increment of thermal pretreatment temperature, Pt dispersion showed a decreasing trend due to the aggregation of Pt particles. Simultaneously, the amount of Lewis acid sites was remarkably influenced by such thermal pretreatment owning to the consequent physicochemical property variation of Sn species. Interestingly, the catalytic activity showed the similar variation trend with that of Lewis acid sites, confirming the important roles of Lewis acid sites in AcOH hydrogenation. Moreover, a balancing effect between exposed Pt and Lewis acid sites was obtained, resulting in the superior catalytic performance in AcOH hydrogenation.

关键词： thermal pretreatment acetic acid hydrogenation ethanol PtSn/SiO₂

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A novel strategy for the construction of silk fibroin–SiO composite aerogel with enhanced mechanicalproperty and thermal insulation performance

《化学科学与工程前沿（英文）》 2023年第17卷第3期页码 288-297 doi: 10.1007/s11705-022-2222-7

摘要： The practical application of silica aerogels is an enormous challenge due to the difficulties in improving both mechanical property and thermal insulation performance. In this work, silk fibroin was used as scaffold to improve the mechanical property and thermal insulation performance of silica aerogels. The ungelled SiO₂ precursor solution was impregnated into silk fibroin to prepare silk fibroin–SiO₂ composite aerogels via sol−gel method followed by freeze-drying. By virtue of the interfacial hydrogen-bonding interactions and chemical reactions between silk fibroin and silica nanoparticles, SiO₂ was well-dispersed in the silk fibroin aerogel and composite aerogels exhibited enhanced mechanical property. By increasing the loading of silk fibroin from 15 wt % to 21 wt %, the maximum compressive stress was enhanced from 0.266 to 0.508 MPa when the strain reached 50%. The thermal insulation performance of the composite aerogels was improved compared with pure silica aerogel, as evidenced that the thermal conductivity was decreased from 0.0668 to 0.0341 W∙m^‒1∙K^‒1. Moreover, the composite aerogels exhibited better hydrophobicity and fire retardancy compared to pure silica aerogel. Our work provides a novel approach to preparing silk fibroin–SiO₂ composite aerogels with enhanced mechanical property and thermal insulation performance, which has potential application as thermal insulation material.

关键词： silica aerogel silk fibroin impregnation thermal insulation mechanical property

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电沉积Zn-Fe-SiO2复合镀层研究

张英杰,范云鹰,董鹏,罗少林

《中国工程科学》 2008年第10卷第3期页码 93-96

摘要：

报告了电沉积Zn-Fe-SiO2复合镀层的研究结果，论述了电流密度、极间距、搅拌方式、阳极数量及排布方式、添加剂等对Zn-Fe-SiO2复合镀层的影响及试验所取得的技术指标试验结果表明，Zn-Fe-SiO2复合镀层工艺具有过程稳定性好，维护措施简单方便，生产的环保及安全性好等优点。

关键词：电沉积复合镀层 Zn-Fe-SiO2

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The stabilization effect of Al₂O₃ on unconventional Pb/SiO₂ catalyst

《化学科学与工程前沿（英文）》 2023年第17卷第10期页码 1423-1429 doi: 10.1007/s11705-023-2315-y

摘要： Similar to Sn, Pb located at the same group (IVA) in the periodic table of elements, can also catalyze propane dehydrogenation to propene, while a fast deactivation can be observed. To enhance the stability, the traditional carrier Al₂O₃ with a small amount, was introduced into Pb/SiO₂ catalyst in this study. It has been proved that Al₂O₃ can inhibit the reduction of PbO, and weaken the agglomeration and loss of Pb species due to its enhanced interaction with Pb species. As a result, 3Al15Pb/SiO₂ catalyst exhibits a much higher stability up to more than 150 h. In addition, a simple schematic diagram of the change of surface species on the catalyst surface after Al₂O₃ addition was also proposed.

关键词： Pb/SiO₂ Al₂O₃ propane dehydrogenation propene stability

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Application of rapid thermal processing on SiN thin film to solar cells

LI Youjie, LUO Peiqing, ZHOU Zhibin, CUI Rongqiang, HUANG Jianhua, WANG Jingxiao

《能源前沿（英文）》 2008年第2卷第4期页码 519-523 doi: 10.1007/s11708-008-0095-1

摘要： Rapid thermal processing (RTP) of SiN thin films from PECVD with low temperature was investigated. A special processing condition of this technique which could greatly increase the minority lifetime was found in the experiments. The processing mechanism and the application of the technique to silicon solar cells fabrication were discussed. A main achievement is an increase of the minority lifetime in silicon wafer with SiN thin film by about 200% after the RTP was reached. PC-1D simulation results exhibit an enhancement of the efficiency of the solar cell by 0.42% coming from the minority lifetime improvement. The same experiment was also conducted with P-diffusion silicon wafers, but the increment of minority lifetime is just about 55%. It could be expected to improve the solar cell efficiency if it would be used in silicon solar cells fabrication with the combination of laser firing contact technique.

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SiO₂ passivation layer grown by liquid phase deposition for silicon solar cell application

Yanlin CHEN,Sihua ZHONG,Miao TAN,Wenzhong SHEN

《能源前沿（英文）》 2017年第11卷第1期页码 52-59 doi: 10.1007/s11708-016-0429-3

摘要： Surface passivation is one of the primary requirements for high efficient silicon solar cells. Though the current existed passivation techniques are effective, expensive equipments are required. In this paper, a comprehensive understanding of the SiO passivation layer grown by liquid phase deposition (LPD) was presented, which was cost-effective and very simple. It was found that the post-annealing process could significantly enhance the passivation effect of the LPD SiO film. Besides, it was revealed that both chemical passivation and field-effect passivation mechanisms played important roles in outstanding passivation effect of the LPD SiO film through analyzing the minority carrier lifetime and the surface recombination velocity of n-type and p-type silicon wafers. Although the deposition parameters had little influence on the passivation effect, they affected the deposition rate. Therefore, appropriate deposition parameters should be carefully chosen based on the compromise of the deposition rate and fabrication cost. By utilizing the LPD SiO film as surface passivation layer, a 19.5%-efficient silicon solar cell on a large-scale wafer (156 mm × 156 mm) was fabricated.

关键词： Si solar cell passivation SiO₂ liquid phase deposition carrier lifetime

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Preparation of Ni/SiO catalyst in ionic liquids for hydrogenation

FAN Qingming, LIU Yingxin, ZHENG Yifan, YAN Wei

《化学科学与工程前沿（英文）》 2008年第2卷第1期页码 63-68 doi: 10.1007/s11705-008-0013-4

摘要： A series of silica supported nickel catalysts were prepared from nickel nitrate and tetraethyl orthosilicate by the sol-gel method with the imidazolium type ionic liquids as solvents. The catalysts were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Their catalytic performances for the selective hydrogenation of cinnamaldehyde to hydrocinnamaldehyde were investigated. The results show that the Ni/SiO catalyst prepared with 1-(2-hydroxyethyl)-3-methyl-imidazole tetrafluoroborate ionic liquid as solvent exhibits the highest catalytic activity for the reaction. Under the optimal conditions of catalyst dosage (based on the mass of cinnamaldehyde used) 10%, reaction pressure 2 MPa, temperature 373 K and reaction time 2 h, the conversion of cinnamaldehyde and the selectivity to hydrocinnamaldehyde can reach 97.6% and 98.8%, respectively.

关键词： dispersive conversion catalytic 2-hydroxyethyl catalytic activity

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Theoretical and experimental study on the fluidity performance of hard-to-fluidize carbon nanotubes-based CO2

《化学科学与工程前沿（英文）》 2022年第16卷第10期页码 1460-1475 doi: 10.1007/s11705-022-2159-x

摘要： Carbon nanotubes-based materials have been identified as promising sorbents for efficient CO₂ capture in fluidized beds, suffering from insufficient contact with CO₂ for the high-level CO₂ capture capacity. This study focuses on promoting the fluidizability of hard-to-fluidize pure and synthesized silica-coated amine-functionalized carbon nanotubes. The novel synthesized sorbent presents a superior sorption capacity of about 25 times higher than pure carbon nanotubes during 5 consecutive adsorption/regeneration cycles. The low-cost fluidizable-SiO₂ nanoparticles are used as assistant material to improve the fluidity of carbon nanotubes-based sorbents. Results reveal that a minimum amount of 7.5 and 5 wt% SiO₂ nanoparticles are required to achieve an agglomerate particulate fluidization behavior for pure and synthesized carbon nanotubes, respectively. Pure carbon nanotubes + 7.5 wt% SiO₂ and synthesized carbon nanotubes + 5 wt% SiO₂ indicates an agglomerate particulate fluidization characteristic, including the high-level bed expansion ratio, low minimum fluidization velocity (1.5 and 1.6 cm·s^–1), high Richardson−Zakin index (5.2 and 5.3 > 5), and low Π value (83.2 and 84.8 < 100, respectively). Chemical modification of carbon nanotubes causes not only enhanced CO ₂ uptake capacity but also decreases the required amount of silica additive to reach a homogeneous fluidization behavior for synthesized carbon nanotubes sorbent.

关键词： CO₂ capture CNT-based sorbents fluidization SiO₂ nanoparticles fluidized bed reactors