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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 department of {3. science and engineering, college of chemistry and molecular engineering, Peking university, beijing 100871, {13.. department of chemistry, 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 department of {3. science and engineering college of chemistry and molecular engineering Peking university beijing 100871,{13., 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

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 department of {3. science & engineering college of chemistry & molecular engineering, Peking university beijing 100871, {13. department of chemistry, 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 department of {3. science & engineering college of chemistry & molecular engineering Peking university beijing 100871,{13., 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

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 department of polymer {3. 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

FLUORESCENCE AND ELECTROCHEMICAL BEHAVIOR OF DANSYL-SHELLED PAMAM DENDRIMERS:EFFECT OF DENDRITIC ARCHITECTURE

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FLUORESCENCE AND ELECTROCHEMICAL BEHAVIOR OF DANSYL-SHELLED ...

Polaron interfacial entropy as a route to high thermoelectric performance in DAE-doped PEDOT:PSS films

Third East Asian polymer Conference

作者： Bing-bing Wang. Xin Zhang, Xin-ru Jia, Ling Yang, Yan Ji polymer science, college of {3. and molecular engineering, Pkeing university yen wei {3. department, drexel university, {13., PA 19104 usa

Poly (amidoamine) dendrimer G1, G2, G3. G4, and G5 were peripherally modified by reacting -NH2 groups with dansyl chloride (PAMAM-DNS G1, 2, 3. 4and 5). For comparison, G0 PAMAM dendrimer was modified with the same ch...

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National science Review 2024年第3期11卷 259-270页

作者： Jiajia Zhang Caichao Ye Genwang wei Liang Guo Yuhang Cai Zhi Li Xinzhi Wu Fangyi Sun Qikai Li Yupeng Wang Huan Li Yuchen Li Shuaihua Wang wei Xu Xuefeng Guo Wenqing Zhang weishu Liu department of Materials science and engineering Southern University of Science and Technology Academy for Advanced Interdisciplinary Studies and Guangdong Provincial Key Laboratory of Computational science and Material Design Southern University of Science and Technology department of Mechanical and Energy engineering Southern University of Science and Technology beijing National Laboratory for molecular sciences Key Laboratory of Organic Solids Institute of Chemistry Chinese Academy of Sciences college of chemistry and molecular {3. National Biomedical Imaging Centre Peking University Guangdong Provincial Key Laboratory of Functional Oxide Materials and Devices Southern University of Science and Technology

Enhancing the thermoelectric transport properties of conductive polymer materials has been a long-term challenge, in spite of the success seen with molecular doping strategies. However, the strong coupling between the thermopower and the electrical conductivity limits thermoelectric performance. Here, we use polaron interfacial occupied entropy engineering to break through this intercoupling for a PEDOT:PSS(poly（3.4-ethylenedioxythiophene）-poly（4-styrenesulfonate）) thin film by using photochromic diarylethene（DAE） dopants coupled with UV-light modulation. With a 10-fold enhancement of the thermopower from 13.5 μV K-1to 13..4 μV K-1and almost unchanged electrical conductivity, the DAE-doped PEDOT:PSS thin film achieved an extremely high power factor of 521.28 μW m-1K-2from an original value of 6.78 μW m-1K-2. The thermopower was positively correlated with the UV-light intensity but decreased with increasing temperature, indicating resonant coupling between the planar closed DAE molecule and PEDOT. Both the experiments and theoretical calculations consistently confirmed the formation of an interface state due to this resonant coupling. Interfacial entropy engineering of polarons could play a critical role in enhancing the thermoelectric performance of the organic film.

关键词： thermoelectric PEDOT: PSS interfacial occupied entropy resonant coupling UV-light modulation

The Nano Research Young Innovators Awards in bio-inspired nanomaterials

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Nano Research 2024年第2期17卷 417-425页

作者： Jun Chen Shuotao Wang department of Bioengineering University of CaliforniaLos AngelesLos AngelesCA 90095USA Key Laboratory of Bio-inspired Materials and Interfacial science Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China

Nano Research Young Innovators(NR45)Awards are designed to acknowledge and celebrate the achievements of young researchers under 45 years of *** individuals have made significant contributions to the field of nanoscience and *** the inaugural NR45 Awards in 2018,the journal's editorial board has recognized over a hundred innovators specializing in nanobiotechnology,nano energy,two-dimensional materials,and *** focus of the 2023.NR45 Awards is on bioinspired nanomaterials,acknowledging thirty-three outstanding young innovators for their extraordinary contributions in developing these materials with applications spanning clean energy,human healthcare,monitoring,and disease treatments,as shown in *** extend our heartfelt congratulations to all the 3. NR45 Awardees in 2023.

关键词： journal materials contributions

Recent insights on iron based nanostructured electrocatalyst and current status of proton exchange membrane fuel cell for sustainable transport

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Journal of Energy chemistry 2022年第6期31卷 466-489,I0013页

作者： Mohamedazeem M.Mohideen Adiyodi Veettil Radhamani Seeram Ramakrishna yen wei Yong Liu beijing Key Laboratory of Advanced Functional polymer Composites College of Materials Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China department of Physics and Nanotechnology SRM Institute of Science and TechnologyKattankulathur 603203India Center for Nanofibers and Nanotechnology National University of SingaporeSingapore 1157Singapore department of chemistry Key Lab of Bioorganic Phosphorus Chemistry&Chemical BiologyTsinghua UniversityBeijing 100084China

Bridging the performance gap of the electrocatalyst between the rotating disk electrode(RDE) and membrane electrode assembly(MEA) level testing is the key to reducing the total cost of proton exchange membrane fuel cell(PEMFC) vehicles. Presently, platinum metal accounts for ~42% of the total cost of the PEMFC vehicles for usage in the cathode catalyst layer, where the sluggish oxygen reduction reaction(ORR) occurs. An alternative to the platinum catalyst, the Fe-N-C catalyst has attracted considerable interest for PEMFC due to its cost-effectiveness and high catalytic activity towards ORR. However, the excellent ORR activity of Fe-N-C obtained from RDE studies rarely translates the same performance into MEA operating conditions. Such a performance gap is mainly attributed to the lack of atomic-level understanding of Fe-N-C active sites and their ORR mechanism. Besides, unless the cost of expensive electrocatalyst is reduced, the total operation cost of the PEMFC vehicles remains constant. Therefore,developing highly efficient Fe-N-C catalysts from academic and industrial perspectives is critical for commercializing PEMFC vehicles. Here, the scope of the review is three-fold. First, we discussed the atomiclevel insights of Fe-N-C active sites and ORR mechanism, followed by unraveling the different iron-based nanostructured ORR electrocatalysts, including oxide, carbide, nitride, phosphide, sulfide, and singleatom catalysts. And then we bridged their ORR catalytic performance gap between the RDE and MEA tests for real operating conditions of PEMFC vehicles. Second, we focused on bridging the cost barriers of PEMFC vehicles between capital, operation, and end-user. Finally, we provided the path to achieve sustainable development goals by commercializing PEMFC vehicles for a better world.

关键词： Proton exchange membrane fuel cell(PEMFC) Active sites Iron-based nanostructure Sustainable development goals