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Chinese Journal of polymer science 2000年第2期18卷 149-153页

作者： Xiao-ping Chen kun-yuan qiu department of polymer science and engineering, college of chemistry, peking university, {3. 100871, china peking Univ Coll Chem Dept Polymer Sci & Engn Beijing 100871 Peoples R China

'Living'/controlled radical polymerization of ethyl methacrylate (EMA) was carried out with a 2,2'-azobisisobutyronitrile (AIBN)/ferric chloride (FeCl_3./triphenylphosphine (PPh_3. initiation system at 85℃. Thc numberaverage molecular weight (M_n) increases linearly with monomer conversion and the rate of polymerization is first order withrespect to monomer concentration. The M_w of PEMA ranges from 3.00 to 17600 and the polydispersity indices are quitenarrow (1.09～1.22). The conversion can reach up to～100% and M_w of the polymers obtained is close to that designed. Thepolymerization mechanism belongs to the reverse atom transfer radical polymerization (ATRP). The polymer was end-functionalized by chlorine atom, which acts as a macroinitiator to proceed extension polymerization in the presence ofCuBr/bipy catalyst system via an ATRP process. The presence of ω-chlorine in the PEMA obtained was identified by ~1H-NMR spectrum.

关键词： 'Living'/controlled radical polymerization Reverse ATRP Ethyl methacrylate AIBN/FeCl_3.PPh_3 Bulk polymerization

A NOVEL PHOTO-INITIATING SYSTEM FOR ATOM TRANSFER RADICAL polymerIZATION OF STYRENE

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Chinese Journal of polymer science 2001年第5期19卷 441-445页

作者： Shu-hui Qin Dong-qi Qin kun-yuan qiu department of polymer science and engineering college of chemistry and Molecular engineering{3. beijing 100871, china beijing Univ Dept Polymer Sci & Engn Coll Chem & Mol Engn Beijing 100871 Peoples R China

A novel photo-induced initiating system, 2,2-dimethoxy-2-phenylacetophenone (DMPA)/ferric tri(NN-diethyldithiocarbamate) [Fe(DC)(3.], was developed and used for the atom transfer radical polymerization (ATRP) of styrene in toluene. The polymerization proceeds with DMPA as photo-initiator, Fe(DC)(3. as catalyst and DC as a reversible transfer group, while the halogen and ligands are free. Well-defined PSt was prepared and the polymerization mechanism revealed by end group analysis belongs to a reverse ATRP. Block copolymer was prepared by using thus obtained PSt as macroinitiator and Fe(DC)(2) as catalyst under UV light irradiation via a conventional ATRP process.

关键词： photo atom transfer radical polymerization living radical polymerization well-defined polystyrene block copolymer

SYNTHESIS AND BIOTECHNOLOGICAL APPLICATIONS OF VINYL polymerINORGANIC HYBRID AND MESOPOROUS MATERIALS

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Chinese Journal of polymer science 2000年第1期18卷 1-7页

作者： Yen Wei kun-yuan qiu {3. of chemistry, Drexel university, Philadelphia, Pennsylvania 19104, USA {3. of polymer science and engineering, peking university, beijing 100871, china Drexel Univ Dept Chem Philadelphia PA 19104 USA peking Univ Dept Polymer Sci & Engn Beijing 100871 Peoples R China

We describe the sol-gel synthesis of a new family of organic-inorganic hybrid materials, in which various vinyl polymers are covalently bonded to and uniformly distributed in inorganic oxide matrices. The materials can be tailored to have both good toughness and hardness while maintaining excellent optical transparency. Doping the sol-gel metal oxides with optically active compounds such as D-glucose results in new optical rotatory composite materials. Removal of the dopant compounds from the composites affords mesoporous oxide materials; which represents a new, nonsurfactant-templated route to mesoporous molecular sieves. We have successfully immobilized a series of enzymes and other bioactive agents in mesoporous materials. Catalytical activities of the enzyme encapsulated in mesoporous materials were found to be much higher than those encapsulated in microporous materials.

关键词： vinyl polymer-inorganic hybrid materials mesoporous materials sol-gel process biotech-nological applications

SYNTHESIS OF HYBRID MESOPOROUS POLYSTYRENE-SILICA MATERIALS WITH NON-SURFACTANT CITRIC ACID AS TEMPLATE VIA SOL-GEL PROCESS

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Chinese Journal of polymer science 2002年第6期20卷 565-572页

作者： Jie Bai Jin-yu Zheng kun-yuan qiu Yen Wei {3. of polymer science & engineering college of chemistry & Molecular engineering, peking university beijing 100871, china {3. of {13., Drexel university, Philadelphia, PA 19104, USA peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Drexel Univ Dept Chem Philadelphia PA 19104 USA

Hybrid mesoporous polystyrene-silica materials were successfully prepared through HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and triethoxysilyl-functionalized polystyrene obtained via atom transfer radical polymerization (ATRP) of styrene, in the presence of citric acid (CA) as non-surfactant template or pore-forming agent and followed by ethanol extraction to remove template molecules. The materials were characterized by infrared spectroscopy OR), N-2 adsorption-desorption measurements, powder X-ray diffraction (XRD), thermogravimetric analysis (TGA) and transmission electron microscopy (TEM). The results indicate that the materials prepared with 50 wt%-60 wt% template contents have average pore sizes of 2-3.nm and large surface areas (ca. 886 m(2)/g) as well as high pore volumes (ca. 0.53.cm(3./g). The mesoporosity arises from interconnected channels and pores with disordered arrangements. The pore diameters and pore volumes increase as the template content is increased. The pore diameters show a little change upon heating at 200degreesC overnight. However, the materials do not have good hydrothermal stability.

关键词： atom transfer radical polymerization hybrid material mesoporous polystyrene silica

SYNTHESIS AND CHARACTERIZATION OF STRUCTURALLY WELL-DEFINED polymer-INORGANIC HYBRID NANOPARTICLES VIA ATRP

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Chinese Journal of polymer science 2002年第3期20卷 261-267页

作者： Jie Bai Jie-bin Pang kun-yuan qiu Yen Wei {3. of polymer science & engineering college of chemistry & Molecular engineering peking university beijing 100871, china {3. of {13. Drexel university Philadelphia, PA 19104 USA peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Drexel Univ Dept Chem Philadelphia PA 19104 USA

Atom transfer radical polymerization (ATRP) using cuprous chloride/2,2'-bipyridine (bipy) was applied to graft polymerization of styrene on the surface of silica nanoparticles to synthesize polymer-inorganic hybrid nanoparticles, 2-(4Chloromethylphenyl) ethyltriethoxysilane (CTES) was immobilized on the surface of silica nanoparticles through condensation reaction of the silanol groups on silica with triethoxysilane group of CTES. Then ATRP of St was initiated by this surface-modified silica nanoparticles bearing benzyl chloride groups, and formed PSt graft chains on the surface of silica nanoparticles. The thickness of the graft chains increased with reaction time. End group analysis confirmed the occurrence of ATRP. Thermal analysis indicated that thermal stabilization of these resulting hybrid nanoparticles also increases with polymerization conversion. The results above show that this 'grafting from' reaction could be used for the preparation of polymer-inorganic hybrid nanoparticles with controlled structure of the polymer's end groups.

关键词： atom transfer radical polymerization polymer-inorganic hybrid nanoparticles 2-(4-chloromethylphenyl)ethyltriethoxysilane surface-modification

SYNTHESIS OF MESOPOROUS POLY(STYRENE-co-MALEIC ANHYDRIDE)/SILICA HYBRID MATERIALS VIA A NONSURFACTANT-TEMPLATED SOL-GEL PROCESS

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Chinese Journal of polymer science 2000年第5期18卷 469-472页

作者： Jie-bin Pang kun-yuan qiu Yen Wei {3. of polymer science and engineering, college of chemistry and Molecular engineering, peking university, beijing 100871, china. {3. of {13., Drexel university, Philadelphia, Pennsylvania 19104, USA. peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Drexel Univ Dept Chem Philadelphia PA 19104 USA

Mesoporous poly(styrene-co-maleic anhydride)/silica hybrid materials have been prepared. The synthesis was achieved by the HCl-catalyzed sol-gel reactions of tetraethyl orthosilicate (TEOS) and styrene-maleic anhydride copolymer in the presence of 3.aminopropyl triethoxysilane (APTES) as a coupling agent and citric acid as a nonsurfactant template or pore-forming agent, followed by ethanol extraction. Characterization results from nitrogen sorption isotherms and powder X-ray diffraction indicate that polymer-modified mesoporous materials with large specific surface areas (e.g. 900 m(2)/g) and pore volumes (e.g. 0.6 cm(3./g) could be prepared. As the citric acid concentration is increased, the specific surface areas, pore volumes and pore diameters of the hybrid materials increase.

关键词： mesoporous hybrid material poly(styrene-co-maleic anhydride)/silica citric acid nonsurfactant template sol-gel process

TARTARIC ACID TEMPLATED SYNTHESIS OF MESOPOROUS Ti-INCORPORATED SILICA AND ITS CATALYTIC ACTIVITY FOR THE RING-OPENING polymerIZATION OF ε-CAPROLACTONE

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Chinese Journal of polymer science 2002年第4期20卷 361-368页

作者： Jie-bin Pang Chang-ming Dong kun-yuan qiu Yen Wei {3. of polymer science and engineering college of chemistry and Molecular engineering peking university beijing 100871, china {3. of {13. Drexel university Philadelphia, Pennsylvania 19104, USA peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Drexel Univ Dept Chem Philadelphia PA 19104 USA

Ti-incorporated mesoporous silica materials with pore diameters of 3.4 nm have been prepared via the co-hydrolysis and co-condensation reactions, that is the sol-gel reactions, of titanium (IV) tetrabutoxide and tetraethylorthosilicate in the presence of tartaric acid as template, followed by extraction with ethanol to remove the templatemolecules. The materials were characterized in detail by Fourier transform infrared spectroscopy, nitrogen adsorption-desorption test, powder X-ray diffraction, transmission electron microscopy and X-ray energy dispersive spectroscopy. Theresults indicate that the Ti-containing silica materials have large specific surface areas (ca. 1200 m^2 g^(-1)) and pore volumes(ca. 0.900 cm^3.g^(-1)). The mesoporosity arises from disordered interconnecting channels or pores. The Ti-incorporated silicasexhibit catalytic activity for the ring-opening polymerization of ε-caprolactone, otherwise, the pure mesoporous silicamaterial shows no catalytic activity under the identical conditions.

关键词： Mesoporous material Ti-incorporated silica ε-Caprolactone Ring-opening polymerization Sol-gel reactions

Measurement of Monomer Reactivity Ratios of D,L-3.Methylglycolide with Glycolide or D,L-Lactide

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Chinese Chemical Letters 2000年第9期11卷 815-818页

作者： Chang Ming DONG kun yuan qiu Zhong Wei GU Xin De FENG {3. of polymer science and engineering, college of chemistry and Molecular engineering, peking university, beijing 100871 National Research Institute for Family Planning, beijing 100081 peking Univ Coll Chem & Mol Engn Dept Polymer Sci & Engn Beijing 100871 Peoples R China Natl Res Inst Family Plannning Beijing 100081 Peoples R China

For monomer reactivity ratios study, the copolymerization of D,L-3.methylglycolide (MG) with glycolide (GA) or D,L-lactide (LA) was carried out in bulk to a certain low conversion in the presence of stannous octoate at 140 degrees C. The copolymer compositions were determined by H-1 NMR spectroscopy. The monomer reactivity ratios were evaluated by Fineman-Ross method, Kelen-Tudos method and linear least-squares method. The monomer reactivity ratios of D,L-3.methylglycolide and glycolide or D,L-lactide are r(mg)= 0.73. r(ga)= 1.47; r(mg)= 1.71, r(la)= 0.92, respectively.

关键词： D,L-3.methylglycolide glycolide D,L-lactide ring-opening copolymerization monomer reactivity ratios

Recent progress on mechanisms,principles,and strategies for high-activity and high-stability non-PGM fuel cell catalyst design

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Carbon Energy 2024年第5期6卷 25-52页

作者： Yuping yuan Yun Zheng Dan Luo Weibin qiu Jiantao Wang Xin Wang Zhongwei Chen GRINM(Guangdong)Institute of New Materials Technology FoshanChina department of Chemical engineering Waterloo Institute for NanotechnologyWaterloo Institute for Sustainable EnergyUniversity of WaterlooWaterlooOntarioCanada Guangdong Provincial Key Laboratory of Nanophotonic Functional Materials and Devices School of Information and Optoelectronic Science and EngineeringSouth China Normal UniversityGuangdongChina National Power Battery Innovation Center GRINM Group Co.Ltd.BeijingChina

The commercialization of a polymer membrane H2-O2 fuel cell and its widespread use call for the development of cost-effective oxygen reduction reaction(ORR)nonplatinum group metal(NPGM)***,to meet the requests for the real-world fuel cell application and replacing platinum catalysts,it still needs to address some challenges for NPGM catalysts regarding the sluggish ORR kinetics in the cathode and their poor durability in acidic *** response to these issues,numerous efforts have been made to study NPGM catalysts both theoretically and experimentally,developed these into the atomically dispersed coordinated metal-nitrogen-carbon(M-N-C)form over the past *** this review,we present a comprehensive summary of recent advancements on NPGM catalysts with high activity and *** design strategies in terms of optimizing active-site density and enhancing catalyst stability against demetalization and carbon corrosion are *** is also emphasized the importance of understanding the mechanisms and principles behind those strategies through a combination of theoretical modeling and experimental ***,further understanding the mechanisms related to the active-site structure and the formation process of the single-atom active site under pyrolysis conditions is critical for active-site *** the active-site distance is the basic principle for improving catalyst activity through increasing the catalyst active-site *** studies for the catalyst deactivation mechanism and modeling stable active-site structures provide both mechanisms and principles to improve the NPGM catalyst ***,currently remained challenges and perspectives in the future on designing high-performance atomically dispersed NPGM catalysts toward fuel cell application are discussed.

关键词： batteries electrocatalysis energy storage and conversion fuel cells

Robust Giant Octahedral[6+8]Porous Organic Cages for Efficient Ethylene/Ethane Separation

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CCS chemistry 2024年第9期6卷 2264-2274页

作者： Lijuan Feng Yan-Xi Tan El-Sayed MEl-Sayed Fenglei qiu Wenjing Wang Kongzhao Su Daqiang yuan State Key Laboratory of Structural chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002 college of chemistry Fuzhou UniversityFuzhou 350116 Chemical Refining Laboratory Refining Department Egyptian Petroleum Research InstituteNasr CityCairo 11727 university of the Chinese Academy of sciences Beijing 100049 Fujian science and Technology Innovation Laboratory for Optoelectronic Information of china Fuzhou 350108

The exploration of ethane(C_(2)H_(6))-selective porous materials for the direct production of polymer-grade ethylene(C_(2)H_(4))from a C_(2)H_(6)/C_(2)H_(4) mixture in a single energy-saving adsorption step is of utmost importance but remains a significant ***,developing robust C_(2)H_(6)-selective adsorbents with high C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity is urgently needed for industrial *** this study,we have successfully designed and synthesized two novel calix[4]resorcinarene-based porous organic cages(POCs)named CPOC-501 and *** POCs were formed via a Schiff-base reaction involving face-directed[6+8]condensation between a bowlshaped tetratopic tetraformylcalix[4]resorcinarene and triangular tritopic amine *** using single crystal X-ray crystallography revealed that both cages possess large truncated octahedral cavities with a volume of approximately 6500Å3.and 12 accessible rhombic windows with a side length of approximately 10.5Å.Furthermore,the cages exhibited excellent chemical stability under neutral,acidic,and basic conditions and high Brunauer–Emmett–Teller specific surface areas of up to 2175 m^(2) g^(−1) after *** POCs demonstrated superior adsorption capabilities for C_(2)H_(6) over C_(2)H_(4).Notably,CPOC-502 exhibited a C_(2)H_(6) capacity and C_(2)H_(6)/C_(2)H_(4) selectivity of 83.cm^(3. g^(−1) and 2.83.respectively,surpassing most of the best-performing C_(2)H_(6)-selective porous organic materials reported to ***,breakthrough experiments confirmed that both cages efficiently produced polymer-grade C_(2)H_(4)(>99.9%)directly from the C_(2)H_(6)/C_(2)H_(4) mixture,highlighting their outstanding recyclability.

关键词： C_(2)H_(6)/C_(2)H_(4)separation porous organic cages calixresorcinarene gas adsorption and separation host-guest interactions