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Cement mortar with enhanced flexural strength and durability-related properties using

Qing LIU, Renjun LIU, Qiao WANG, Rui LIANG, Zongjin LI, Guoxing SUN

《结构与土木工程前沿（英文）》 2021年 第15卷 第1期   页码 99-108 doi: 10.1007/s11709-021-0721-0

摘要： The low flexural strength and high brittleness of cementitious materials impair their service life in building structures. In this study, we developed a new polymer-modified mortar by polymerization of acrylamide (AM) monomers during the cement setting, which enhanced the flexural and durable performances of mortars. The mechanical properties, micro-and-pore structures, hydrated products, interactions between cement hydrates and polyacrylamide (PAM), and durability-related properties of the mortars were investigated comprehensively. Mortars with 5% PAM exhibited the best performance in terms of flexural strength among all the mixtures. The mechanical strength of cement pastes modified by polymerization of AM monomers was significantly superior to those modified by PAM. The chemical interactions between the polymer molecules and cement hydrates together with the formation of polymer films glued the cement hydrates and polymers and resulted in an interpenetrating network structure, which strengthened the flexural strength. Reductions in porosity and calcium hydroxide content and improvement in capillary water absorption were achieved with the addition of PAM. Finally, the chloride resistance was significantly enhanced with the incorporation of PAM.

关键词： acrylamide     in situ polymerization     interaction     porosity     durability    

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Development and application of ex-situ presulfurization technology for hydrotreating catalysts in China

Yulan GAO, Xiangchen FANG, Zhenmin CHENG

《化学科学与工程前沿（英文）》 2011年 第5卷 第3期   页码 287-296 doi: 10.1007/s11705-010-0529-2

摘要： The development and application of ex-situ presulfurization (EPRES) technology for hydrotreating catalysts has been reviewed in the present article. The studies in laboratory scale and commercial practice indicated that the adoption of the EPRES catalyst in industrial application can significantly enhance the degree of presulfurization of metal oxide components, shorten the start-up period, and effectively reduce the environmental impact as well as the danger of start-up procedure in industrial hydrotreating unit. This catalyst has been proved to be versatile for different types of hydrogenation reactions. Different types of active site models are also discussed for better understanding the nature of presulfurized catalysts.

关键词： ex-situ presulfurization     in situ presulfurization     hydrotreating catalyst     sulfur utilization ratio    

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Gas phase ethylene polymerization over SiO

Liuzhong LI, Aiyou HAO, Ruihua CHENG, Boping LIU

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 89-95 doi: 10.1007/s11705-010-0558-x

摘要： Although an important industrial catalyst for producing high density polyethylene, the SiO -supported organosilyl chromate UCC S-2 catalyst has not been fully investigated compared with the SiO -supported oxo chromium Phillips catalyst. In this work, gas phase ethylene polymerization by S-2 catalysts (Cat-1, Cat-2, and Cat-3) was carried out in a high-speed stirred-autoclave reactor. The effects of temperature, time, and pressure on kinetics, activity, and product properties were studied. All kinetics were typical built-up types with slow decay. Compared to the simple physical mixtures of Cat-1 and Cat-2, Cat-3 showed higher activity and its product had a broader molecular weight distribution, indicating new active species induced during blending of Cat-1 and Cat-2 in -hexane. The innovation by a simple catalyst technology created a new application to meet market demands.

关键词： UCC S-2 catalyst     Al-alkyl co-catalyst     gas-phase ethylene polymerization     high density polyethylene    

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Surface modification of biomaterials by photochemical immobilization and photograft polymerization to

Yakai FENG, Haiyang ZHAO, Li ZHANG, Jintang GUO,

《化学科学与工程前沿（英文）》 2010年 第4卷 第3期   页码 372-381 doi: 10.1007/s11705-010-0005-z

摘要： Thrombus formation and blood coagulation are serious problems associated with blood contacting products, such as catheters, vascular grafts, artificial hearts, and heart valves. Recent progresses and strategies to improve the hemocompatibility of biomaterials by surface modification using photochemical immobilization and photograft polymerization are reviewed in this paper. Three approaches to modify biomaterial surfaces for improving the hemocompatibility, i.e., bioinert surfaces, immobilization of anticoagulative substances and biomimetic surfaces, are introduced. The biomimetic amphiphilic phosphorylcholine and Arg-Gly-Asp (RGD) sequence are the most effective and most often employed biomolecules and peptide sequence for improving hemocompatibility of material surfaces. The RGD sequence can enhance adhesion and growth of endothelial cells (ECs) on material surfaces and increase the retention of ECs under flow shear stress conditions. This surface modification is a promising strategy for biomaterials especially for cardiovascular grafts and functional tissue engineered blood vessels.

关键词： biomimetic amphiphilic     amphiphilic phosphorylcholine     endothelial     functional     biomaterial    

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Synthesis and bulk polymerization kinetics of monomer dehydroabietic acid-(2-acryloyloxy-ethoxy)-ethyl

Haibo ZHANG,Yanping YANG,He LIU,Jie SONG,Shibin SHANG,Zhanqian SONG

《农业科学与工程前沿（英文）》 2017年 第4卷 第1期   页码 97-105 doi: 10.15302/J-FASE-2016115

摘要： A bulk polymerization monomer dehydro- abietic acid-(2-acryloyloxy-ethoxy)-ethyl ester (DHA-DG-AC) was synthesized from dehydroabietic acid (DHA). The chemical structure of DHA-DG-AC was characterized by H NMR, C NMR, MS and FT-IR. The kinetics of the bulk polymerization of DHA-DG-AC was investigated by Differential Scanning Calorimeter (DSC). Two kinds of kinetic model (nth-order model and autocatalytic model) were used to investigate the polymerization process. The results showed that the experimental DSC curves were consistent with the computational data generated by the autocatalytic kinetic model, and the value of was 95.73 kJ·mol .

关键词： dehydroabietic acid     bulk polymerization     kinetics     autocatalytic kinetic model    

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Polyolefin-nanocomposites with special properties by in-situ polymerization

Walter Kaminsky

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 555-563 doi: 10.1007/s11705-018-1715-x

摘要：

Exceptionally strong polyolefin nanocomposites are synthesized by in-situ polymerization using soluble metallocene/methylaluminoxane (MAO) as catalysts in a two-step process. First, the soluble metallocene/MAO or other single site catalysts are absorbed on the surface of the nanofillers. Then by addition of ethene or propene, a polyolefin film is formed, covering the nanoparticles, layered silicates, or fibers. The resulting polyethylene and polypropylene nanocomposites are characterized by better physical and chemical properties such as stiffness, gas barrier properties, degradation temperatures, and crystallization rates. They show better mechanical properties than materials produced by mechanical blending. The thickness of the polyolefin can be controlled by the pressure of ethene or propene and by the polymerization time. Carbon fibers and carbon nanotubes are covered with isotactic or syndiotactic polypropylene. Because of the hydrophobic character of the carbon surface, the polymer is drawn on the fiber. This leads to a reinforced combined polymer with special properties. The crystallization temperature is 10 °C higher and therefore the crystallization rate up to 20 times faster than that of pure syndiotactic polypropylene. The form stability increases by 100% if 3 wt-% of carbon nanotubes are incorporated.

关键词： polyolefin nanocomposites     metallocenes     methylaluminoxane    

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The effect of altering crosslinker chemistry during interfacial polymerization on the performance of

《化学科学与工程前沿（英文）》 2023年 第17卷 第12期   页码 2025-2036 doi: 10.1007/s11705-023-2356-2

摘要： Chemistry of the polyamide active layer of a desalination membrane is critical in determining both its physical and chemical properties. In this study, we designed and fabricated three novel membranes with different active layers using the crosslinkers: terephthaloyl chloride, isophthaloyl chloride, and trimesoyl chloride. The crosslinkers were reacted with an aqueous solution of an aliphatic tetra-amine. Because these crosslinkers differ in their structures and crosslinking mechanisms during interfacial polymerization, the resultant membranes also possess different structural properties. The water contact angle of the fabricated membranes also varies; the water contact angles of 4A-3P-TPC@PSF/PET, 4A-3P-TMC@PSF/PET, and 4A-3P-IPC@PSF/PET, are 68.9°, 65.6°, and 53.9°, respectively. Similarly, the desalination performance of resultant membranes also showed variations, with 4A-3P-TPC@PSF/PET, 4A-3P-IPC@PSF/PET, and 4A-3P-TMC@PSF/PET having a permeate flux of 17.14, 25.70, and 30.90 L·m−2·h−1, respectively, at 2.5 MPa. The 4A-3P-TPC@PSF/PET membrane exhibited extensive crosslinking with aliphatic linear amine, and cationic dye rhodamine B, MgCl2, and amitriptyline rejection rates of 98.6%, 92.7% and 80.9%, respectively. The 4A-3P-TMC@PSF/PET membrane showed mediocre performance, while 4A-3P-IPC@PSF/PET membrane showed even lower performance, with a 35% rejection of methyl orange dye.

关键词： acid chlorides     covalent crosslinking     desalination     linear aliphatic amine     micropollutant removal     thin film composite membranes    

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in industrial-wastewater pre-treatment: role of residual aluminum hydrolyzed species with different polymerization

《环境科学与工程前沿（英文）》 2023年 第17卷 第6期 doi: 10.1007/s11783-023-1675-3

摘要：

● Medium poly Al salts dominated the PAC residual salts with a rational dosage.

关键词： Coagulation/flocculation     Hydroxyl-aluminum     Hydrolysis reaction     Reactor performance     Activated sludge property     Surface properties    

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Synthesis of crystals and particles by crystallization and polymerization in droplet-based microfluidic

Jingtao WANG, Jin ZHANG, Junjie HAN,

《化学科学与工程前沿（英文）》 2010年 第4卷 第1期   页码 26-36 doi: 10.1007/s11705-009-0292-4

摘要： The recent advances in crystallization and polymerization assisted by droplet-based microfluidics to synthesize micro-particles and micro-crystals are reviewed in this paper. Droplet-based microfluidic devices are powerful tools to execute some precise controls and operations on the flow inside microchannels by adjusting fluid dynamics parameters to produce monodisperse emulsions or multiple-emulsions of various materials. Major features of this technique are producing particles of monodispersity to control the shape of particles in a new level, and to generate droplets of diverse materials including aqueous solutions, gels and polymers. Numerous microfluidic devices have been employed to generate monodisperse droplets of range from nm to μm, such as T junctions, flow-focusing devices and co-flow or cross-flow capillaries. These discrete, independently controllable droplets are ideal microreactors to be manipulated in the channels to synthesize the nanocrystals, protein crystals, polymer particles and microcapsules. The generated monodisperse particles or crystals are to meet different technical demands in many fields, such as crystal engineering, encapsulation and drug delivery systems. Microfluidic devices are promising tools in the synthesis of micron polymer particles that have diverse applications such as the photonic materials, ion-exchange and chromatography columns, and field-responsive rheological fluids. Processes assisted by microfluidic devices are able to produce the polymer particles (including Janus particles) with precise control over their sizes, size distribution, morphology and compositions. The technology of microfluidics has also been employed to generate core-shell microcapsules and solid microgels with precise controlled sizes and inner structures. The chosen “smart” materials are sensitive to an external stimulus such as the change of the pH, electric field and temperature. These complex particles are also able to be functionalized by encapsulating nanoparticles of special functions and by attaching some special groups like targeting ligands. The nucleation kinetics of some crystals like KNO was investigated in different microfluidic devices. Because of the elimination of the interactions among crystallites in bulk systems, using independent droplets may help to measure the nucleation rate more accurately. In structural biology, the droplets produced in microfluidic devices provide ideal platforms for protein crystallization on the nanoliter scale. Therefore, they become one of the promising tools to screen the optimal conditions of protein crystallization.

关键词： core-shell     monodisperse     nucleation     Microfluidic     different technical    

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Evolution of humic substances in polymerization of polyphenol and amino acid based on non-destructive

Jianmei Zou, Jianzhi Huang, Huichun Zhang, Dongbei Yue

《环境科学与工程前沿（英文）》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1297-y

摘要： Abstract • Humification evolution was identified with non-destructive characterization method. • Humification process from precursors to fulvic and humic acid was confirmed. • MnO2 alone had limited oxidation ability to form HA. • MnO2 played a key role as a catalyst to transform FA to HA in the presence of O2. • MnO2 could affect the structure of the humification products. Abiotic humification is important in the formation and evolution of organic matter in soil and compost maturing processes. However, the roles of metal oxides in abiotic humification reactions under micro-aerobic remain ambiguous. The aim of this study was to use non-destructive measurement methods to investigate the role of MnO2 in the evolution of humic substances (HSs) during oxidative polymerization of polyphenol-amino acid. Our results suggested a synergistic effect between MnO2 and O2 in promoting the polymerization reaction and identified that MnO2 alone had a limited ability in accelerating the transformation of fulvic acid (FA) to humic acid (HA), whereas O2 was the key factor in the process. Two-dimensional correlation spectroscopy (2D-COS) showed that the evolution in the UV-vis spectra followed the order of 475–525 nm>300–400 nm>240–280 nm in the humification process, indicating the formation of simple organic matter followed by FA and then HA. 13C nuclear magnetic resonance (13C NMR) analysis revealed that the products under both air and N2 conditions in the presence of MnO2 had greater amounts of aromatic-C than in the absence of MnO2, demonstrating that MnO2 affected the structure of the humification products. The results of this study provided new insights into the theory of abiotic humification.

关键词： Two-dimensional correlation spectroscopy (2D-COS)     Humic substances (HSs)     Humification     Manganese dioxide     Polyphenol    

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合成橡胶化学及技术进展

武冠英

《中国工程科学》 1999年 第1卷 第3期   页码 79-85

摘要：

文章从合成橡胶的化学基础出发，叙述了合成橡胶工业二十世纪以来的过去、现状，并展望未来。着重讨论了合成化学基础及相应聚合工艺过程的进步这两方面的问题。指出合成橡胶化学基础中活性聚合、可控聚合，包括茂金属催化剂仍为近期的重点；气相聚合工艺将会得到较大的发展；高效聚合釜的研究仍是核心问题；环保问题应更受到重视。

关键词： 合成橡胶     合成化学     活性/控制聚合     气相聚合    

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反相微乳液聚合机理及模型化处理

李晓,张卫英,袁惠根

《中国工程科学》 2003年 第5卷 第1期   页码 69-73

摘要：

在阐述反相微乳液聚合液滴成核及粒子增长机理的基础上，提出了丙烯酰胺反相微乳液聚合过程的物理模式，并对反相微乳液聚合模型化处理时的关键问题作了扼要讨论。

关键词： 反相微乳液聚合     机理     模型     丙烯酰胺    

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溶液聚合合成橡胶节能技术和节能型橡胶的开发

曹湘洪,张爱民

《中国工程科学》 2001年 第3卷 第7期   页码 59-63

摘要：

总结了燕山石化溶液聚合合成橡胶节能技术和节能型橡胶的开发情况。通过改进催化体系，提高反应速度，提高反应器的生产能力，并在聚合反应器中采用带刮刀的搅拌器，同时改进聚合、凝聚、溶剂回收的部分工艺及设备，燕山石化顺丁橡胶的能耗不断下降，达到世界先进水平。溶液聚合合成橡胶凝聚过程热泵技术的工业化，使生产每吨胶可节约1MPa的低压蒸汽0.72t。橡胶溶液直接脱挥，聚丁二烯橡胶气相聚合工艺技术开发,溶聚丁苯橡胶（SSBR）、中乙烯基聚丁二烯橡胶、苯乙烯-异戊二烯-丁二烯橡胶（SIBR）、苯乙烯-丁二烯热塑性弹性体（SBS）等新型节能型合成橡胶的技术开发也在进行中，其中SSBR、SBS技术已经工业化。

关键词： 溶液聚合     合成橡胶     节能     节能型橡胶    

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Propagation characteristics of transient waves in low-strain integrity testing on cast-in-situ concrete

Hanlong LIU, Xuanming DING

《结构与土木工程前沿（英文）》 2009年 第3卷 第2期   页码 240-240 doi: 10.1007/s11709-009-0100-8

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Thermodynamic analysis of liquid phase in situ hydrogenation of glycerol for 1,3-propanediol synthesis

Kun OUYANG, Yu HUANG, Haoyi CHEN, Tao LI, Fahai CAO, Dingye FANG

《化学科学与工程前沿（英文）》 2011年 第5卷 第1期   页码 67-73 doi: 10.1007/s11705-010-0541-6

摘要： Based on the combination of the glycerol aqueous-phase reforming (APR) and catalytic hydrogenation of glycerol, a novel reaction system of liquid phase in situ hydrogenation of glycerol for the synthesis of 1,3-propanediol is proposed, in which hydrogen is produced from glycerol aqueous-phase reforming in the same reactor. In this new system, the glycerol is the raw material of the aqueous-phase reforming reaction; the hydrogen generated from the APR of glycerol can be quickly transformed to the in situ hydrogenation of glycerol to produce 1,3-propanediol, which can improve the selectivity of hydrogen for the APR process of glycerol. Moreover, thermodynamic calculation of the coupling processes was carried out, and standard molar enthalpies and equilibrium constants of foregoing reactions were obtained. The above calculation results indicate that the combination process is feasible for 1,3-propanediol synthesis.

关键词： glycerol     aqueous-phase reforming     1     3-propanediol     in-situ reduction    

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标题 作者 时间 类型 操作

Cement mortar with enhanced flexural strength and durability-related properties using

Qing LIU, Renjun LIU, Qiao WANG, Rui LIANG, Zongjin LI, Guoxing SUN

期刊论文

Development and application of ex-situ presulfurization technology for hydrotreating catalysts in China

Yulan GAO, Xiangchen FANG, Zhenmin CHENG

期刊论文

Gas phase ethylene polymerization over SiO

Liuzhong LI, Aiyou HAO, Ruihua CHENG, Boping LIU

期刊论文

Surface modification of biomaterials by photochemical immobilization and photograft polymerization to

Yakai FENG, Haiyang ZHAO, Li ZHANG, Jintang GUO,

期刊论文

Synthesis and bulk polymerization kinetics of monomer dehydroabietic acid-(2-acryloyloxy-ethoxy)-ethyl

Haibo ZHANG,Yanping YANG,He LIU,Jie SONG,Shibin SHANG,Zhanqian SONG

期刊论文

Polyolefin-nanocomposites with special properties by in-situ polymerization

Walter Kaminsky

期刊论文

The effect of altering crosslinker chemistry during interfacial polymerization on the performance of

期刊论文

in industrial-wastewater pre-treatment: role of residual aluminum hydrolyzed species with different polymerization

期刊论文

Synthesis of crystals and particles by crystallization and polymerization in droplet-based microfluidic

Jingtao WANG, Jin ZHANG, Junjie HAN,

期刊论文

Evolution of humic substances in polymerization of polyphenol and amino acid based on non-destructive

Jianmei Zou, Jianzhi Huang, Huichun Zhang, Dongbei Yue

期刊论文

合成橡胶化学及技术进展

武冠英

期刊论文

反相微乳液聚合机理及模型化处理

李晓,张卫英,袁惠根

期刊论文

溶液聚合合成橡胶节能技术和节能型橡胶的开发

曹湘洪,张爱民

期刊论文

Propagation characteristics of transient waves in low-strain integrity testing on cast-in-situ concrete

Hanlong LIU, Xuanming DING

期刊论文

Thermodynamic analysis of liquid phase in situ hydrogenation of glycerol for 1,3-propanediol synthesis

Kun OUYANG, Yu HUANG, Haoyi CHEN, Tao LI, Fahai CAO, Dingye FANG

期刊论文