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ANTI-BIOFOULING BY DEGRADATION OF POLYMERS

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Chinese Journal of Polymer Science 2012年第3期30卷 337-342页

作者： Chun-feng Ma hong-jun yang 张广照 Faculty of Materials Science and Engineering South China University of TechnologyGuangzhou 510640Chin Hefei National Laboratory for Physical Sciences at Microscale Department of Chemical PhysicsUniversity of Science and Technology of ChinaHefei 230026China

Copolymers of methyl methacrylate （MMA） and acrylate terminated poly（ethylene oxide-co-ethylene carbonate）（PEOC） macromonomer （PEOCA） were synthesized, and the degradation of the polymers was investigated by use of quartz crystal microbalance with dissipation （QCM-D）. It is shown that the polymeric surface exhibits degradation in seawater depending on the content of the side chains. Field tests in seawater show that the surface constructed by the copolymer can effectively inhibit marine biofouling because it can be self-renewed due to degradation of the copolymer.

关键词： Anti-biofouling Degradation Poly(ethylene carbonate) Poly(ethylene oxide).

A family of novel bifunctional organocatalysts:Highly enantioselective alcoholysis of meso cyclic anhydrides and its application for synthesis of the key intermediate of P2X_7 receptor antagonists

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Chinese Chemical Letters 2013年第7期24卷 553-558页

作者： hong-jun yang Fang-jun Xiong Jie Li Fen-Er Chen Department of Chemistry Fudan University Institute of Biomedical Science Fudan University

A family of novel squaramides/sulfamides based on 1,2-alkamine was developed as chiral bifunctional catalysts to promote the asymmetric alcoholysis of meso cyclic anhydrides. The hemiesters were obtained in high yield with up to 93% ee. The usefulness of this methodology was demonstrated in the asymmetric synthesis of the key intermediate of P2X7 receptor antagonists.

关键词： Asymmetric alcoholysis Bifunctional organocatalyst Cyclic anhydrides P2X7 receptor antagonists Sulfamides

Synthesis and fluorescence properties of CdTe:Eu3+ nanocrystals and core-shell SiO2-coated CdTe:Eu3+ nanospheres

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Rare Metals 2019年第10期38卷 989-995页

作者： jun-Fang Gao jun-hong yang Xiao-Yong Zhang jun Zhao Xing-Wang Liu Bing-Feng Shi Key Laboratory of Materials Physical Chemistry Baotou Teachers CollegeBaotou 014000China Institute of Chemistry Northeast Normal UniversityChangchun 130000China

Eu3+ doped-CdTe(CdTe:Eu3+)nanocrystals were prepared via a facile hydrothermal method,and Eu3+ was successfully incorporated into the crystal lattice of CdTe and measured by X-ray powder diffraction(XRD),transmission electron microscopy(TEM),ultraviolet-visible(UV-Vis) absorption spectroscopy and fluorescence *** CdTe:Eu^3+ nanocrystals still have a cubic crystal structure,and the corresponding XRD peaks of CdTe:Eu3+nanocrystals shift to larger angles compared with those of pure *** CdTe:Eu3+ nanocrystals are monodisperse and the particles size is about 2-4 *** with pure CdTe,the CdTe:Eu^3+ nanocrystals have larger band gap and thus exhibit blueshift in the emission spectra,which could be accounted for by the energy transfer between Eu^3+ and *** enhance the stability and functionality of CdTe:Eu3+nanocrystals,the CdTe:Eu3+nanocrystals were coated with SiO2 and the core-shell SiO2-coated CdTe:Eu3+nanocrystals(CdTe:Eu^3+@SiO2) were prepared via microemulsion *** results show that CdTe:Eu3+nanocrystals are uniformly dispersed in the shell,and CdTe:Eu3+@SiO2 nanospheres are uniformly spherical with an average diameter of about 75 *** fluorescence emission of CdTe:Eu3+@SiO2(567 nm) shows a blueshift compared with that of CdTe:Eu^3+nanocrystals(632 nm),possibly because of altered surface properties after SiO2 ***:Eu^3+and CdTe:Eu^3+@SiO2 with tunable photoluminescence are potentially useful in fabricating optical and bioimaging devices.

关键词： CdTe:Eu^3+nanocrystals Doping Core-shell SiO2 Fluorescent properties

Synthesis,characterization and optical studies on Sm2+-doped CdSe nanocrystals:a blueshift and fixed emission with high quantum yields

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Rare Metals 2019年第11期38卷 1097-1104页

作者： jun-hong yang jun-Fang Gao Sheng-Li Yong Xue-Lin Ma Li-Jing Liu Department of Chemistry Baotou Teachers’ College

CdSe:Sm nanocrystals(NCs) were synthesized by a water phase method,and their structures,shapes and optical properties were further characterized.X-ray diffraction(XRD) analysis suggested that both the CdSe and CdSe:Sm NCs contained(111),(220) and(311) lattice planes in the zinc blende structure overlapped with the(002),(110) and(112) lattice planes in the wurtzite structure,and the diameters were about 4.2,3.3 and 2.3 nm for CdSe,CdSe:Sm(8%) and CdSe:Sm(10%) NCs,*** of the CdSe:Sm NCs were monodispersed and uniform spherical *** CdSe:Sm(10%) NCs prepared with different reaction times exhibited constant absorption spectra at 430 nm and a fixed emission peak at581 *** with those of pure CdSe NCs,the fluorescence emission of CdSe:Sm(10%) NCs blueshifted 20-36 nm,and the absorption peak initially redshifted and then blueshifted with the prolongation of reaction *** addition,the Sm^2+ doping decreased the fluorescence lifetime and increased the quantum yields(QYs) of CdSe *** QYs of CdSe:Sm NCs increased initially and then decreased with the increase in the amount of doped Sm2+.The initial pH and charge compensator concentration also exhibited significantly enhanced fluorescence emission of CdSe:Sm NCs.

关键词： CdSe:Sm NCs Doping Optical properties Blueshift QYs

A new C_(21)-steroidal glycoside from Cynanchum stauntonii

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Chinese Chemical Letters 2007年第4期18卷 415-417页

作者： Mei hong Fu Zhu Ju Wang hong jun yang Mayila Maimai Jing Fang Li Ying Tang Lan yang Institute of Traditional Chinese Materia Medica Chinese Academy of Medical Sciences Beijing 100700 China

A new C21-steroidal glycoside with two known compounds were isolated from the root of Cynanchum Stauntonii. Based on the spectral analysis, including MS, 1H NMR, 13C NMR, DEPT, 1H-1H COSY, 13C-1H COSY, HMQC and HMBC, their chemical structures were determinated as glaucogenin-C 3-O-α-L-cymaropyranosyl-（1→ 4）-β-o-digitoxopyranosyl-（1→4）-β-D-canaropyranoside （1）, stigmasterol （2） and ursolic acid （3）.

关键词： Cynanchum stauntonii C21-steroidal glycoside

Optimization of operation conditions for extracting lithium ions from calcium chloride-type oil field brine

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International Journal of Minerals,Metallurgy and Materials 2012年第4期19卷 290-294页

作者： hong-jun yang Qing-hai Li Bing Li Feng-qin Guo Qing-fen Meng Wu Li Qinghai Institute of Salt Lakes Chinese Academy of Sciences Xining 810008 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Fundamental Department Qinghai University Xining 81 O016 China

AI（OH）3 was prepared to extract lithium ions from calcium chloride-type oil field brine. The influences of four factors, namely temperature, Al3＋/Li＋ molar ratio, OH-/Al3＋ molar ratio, and contact time between AI（OH）3 and the brine, on the yield of lithium ions were investigated. It is found that their optimal values are 35℃, 4.5, 2.6, and 6 h, respectively. In the course of the experiment, the apparent pH value was observed. The results reveal that the apparent pH value has no remarkable influence on the yield of lithium ions. Meanwhile, the effects of the concentrations of calcium ions and magnesium ions in the brine on lithium recovery were studied. The results indicate that cal- cium ions have minor negative influence on the yield of lithium ions under optimal conditions, and magnesium ions slightly influence the yield of lithium ions.

关键词： lithium extraction oil field brine aluminium hydroxide

Polymerization Mechanism of Methyl Methacrylate Initiated by Ethyl Acetate/t-BuP_4

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Chinese Journal of Polymer Science 2019年第6期37卷 598-603页

作者： De-Yong Xia Qi-Min Jiang Wen-Yan Huang hong-jun yang Xiao-Qiang Xue Li Jiang Bi-Biao Jiang Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials School of Materials Science and Engineering Jiangsu Collaborative Innovation Center of Photovoltaic Science and Engineering Changzhou University Changzhou University Huaide College

The anionic polymerization of methyl methacrylate(MMA) was carried out using phosphazene base t-BuP_4 and ethyl acetate(EA) as the catalyst and the initiator, respectively. Gas chromatography(GC), size exclusion chromatography(SEC) measurements, and nuclear magnetic resonance(NMR) analyses were used to reveal the polymerization mechanism and to confirm the polymer structure. The results confirmed the proposed polymerization mechanism and the polymer structure, while the initiator efficiency was low. Meanwhile,the initiation by methoxy anion coming from hydrolysis of the ester bond in MMA was also observed. As a result, there is a marked deviation between the theoretical molecular weight and the measured molecular weight, and it is essential to carry out the polymerization at excessive dosage of t-BuP_4 for preparing polymers with narrow molecular weight distribution.

关键词： Phosphazene base(t-BuP4) Methyl methacrylate Ethyl acetate Anionic polymerization

Thorium isotopes ((228)Th,(230)Th,(232)Th) and applications in reconstructing the yangtze and Yellow River floods

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International Journal of Sediment Research 2013年第4期28卷 588-595页

作者： Wei-feng yang Min CHEN Xin-xing ZHANG Zhi-gang GUO Guang-xue LI Qiang MA jun-hong yang Yi-pu Huang State Key Laboratory of Marine Environmental Science Xiamen University Department of Environmental Science and Engineering Fudan University College of Marine Geo-Science Ocean University of China

In the past decades,the Hoods of the yangtze and Yellow River introduced unexpected changes of the ecological community and sedimentary dynamics in the Fast China Sea(KCS).To reconstruct the flood events in the ECS,228Th,230Th and232Th have been examined in a sediment *** specific activities of three thorium isotopes have good positive relations with line fractions(yangtze and Yellow River demonstrated that size-normalized Th recorded the two rivers’ flood *** activity ratios of thorium isotopes,i.e.230Th/232Th and228Th/232Th,also showed similar patterns to the historical river *** three periods(1740s,[840—1860s and1930- 1960s),characterized by frequent Hoods,the thorium activity ratios were fairly low and close to the yangtze and Yellow River estuary sediments,coinciding with the less oceanic228Th and230Th contributions during the flooding ***,these results support the size-normalized Th activity and thorium ratios as proxies of the river floods in coastal seas.

关键词： Thorium Yellow River yangtze River Flood East China Sea

Hybrid Copolymerization via the Combination of Proton Transfer and Ring-opening Polymerization

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Chinese Journal of Polymer Science 2020年第3期38卷 231-239,I0005页

作者： hong-jun yang Chen-Qiong Chai Yong-Kang Zuo Jin-Feng Huang Yi-Ye Song Li Jiang Wen-Yan Huang Qi-Min Jiang Xiao-Qiang Xue Bi-Biao Jiang China Jiangsu Key Laboratory of Environmentally Friendly Polymeric Materials School of Materials Science and EngineeringJiangsu Collaborative Innovation Centre of Photovoltaic Science and EngineeringChangzhou UniversityChangzhou 213164China Changzhou University Huaide College Jingjiang 214500China key Laboratory of Polymer Processing Engineering of Ministry of Education(South China University of Technology) Guangzhou 510000China

Phosphazene base,t-BuP2,was employed to catalyze the proton transfer polymerization(PTP)of 2-hydroxyethyl acrylate(HEA),and PTP was further combined with ring-opening polymerization(ROP)to exploit a new type of hybrid *** studies on homopolymerization showed that t-BuP2 was a particularly efficient catalyst for the polymerization of HEA at room temperature,giving an excellent monomer *** the polymerization,transesterification reactions were unavoidable,which increased the randomness in the structures of the resulting *** studies on copolymerization showed that t-BuP2 could simultaneously catalyze the hybrid copolymerization via the combination of PTP and ROP at 25°*** copolymerization,HEA not only provided hydroxyl groups to initiate the ROP ofε-caprolactone(CL)but also participated in the polymerization as a monomer for *** copolymer composition was approximately equal to the feed ratio,demonstrating the possibility to adjust the polymeric structure by simply changing the monomer feed *** copolymerization reaction provides a simple method for synthesizing degradable functional copolymers from commercially available ***,it is important not only in polymer chemistry but also in environmental and biomedical engineering.

关键词： Hybrid copolymerization Proton transfer Ring-opening polymerization 2-Hydroxyethyl acrylate