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syntheses of amphiphilic biodegradable copolymers of poly(ethyl ethylene phosphate) and poly(3-hydroxybutyrate) for drug delivery

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science china Chemistry 2009年第7期52卷 961-968页

作者： CHENG Jing1 & WANG Jun2.1 department of polymer science and {2., university of science and technology of china, hefei 2.002., china 2.hefei national laboratory for physical sciences at {12., school of Life sciences, university of science and technology of china, hefei 2.002., china department of polymer science and {2. University of Science and Technology of China Hefei 230026 China hefei national {2. for physical sciences at microscale School of Life Sciences University of Science and Technology of China Hefei 230027 China

Biodegradable and amphiphilic triblock copolymers poly(ethyl ethylene phosphate)-poly(3-hydroxybutyrate)-poly(ethyl ethylene phosphate) (PEEP-b-PHB-b-PEEP) have been successfully synthesized through ring-opening polymerization. The structures are confirmed by gel permeation chromatography and NMR analyses. Crystallization investigated by X-ray diffraction reveals that the block copolymer with higher content of poly(ethyl ethylene phosphate) (PEEP) is more amorphous, showing decreased crystallizability. The obtained copolymers self-assemble into biodegradable nanoparticles with a coreshell micellar structure in aqueous solution, verified by the probe-based fluorescence measurements and transmission electronic microscopy (TEM) observation. The hydrophobic poly(3-hydroxybutyrate) (PHB) block serves as the core of the micelles and the micelles are stabilized by the hydrophilic PEEP block. The size and size distribution are related to the compositions of the copolymers. Paclitaxel (PTX) has been encapsulated into the micelles as a model drug and a sustained drug release from the micelles is observed. MTT assay also demonstrates that the block copolymers are biocompatible, rendering these copolymers attractive for drug delivery.

关键词： poly(3-hydroxybutyrate) polyphosphoester drug delivery polymeric nanoparticles

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Facile synthesis of dendrimer-like star-branched poly(isopropylacrylamide) via combination of click chemistry and atom transfer radical polymerization

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science china Chemistry 2010年第12期53卷 2520-2527页

作者： WAN XueJuan,XU Jian & LIU shiYong CAs Key laboratory of soft Matter Chemistry department of {2. science and engineering,hefei national laboratory for physical sciences at the microscale,university of science and technology of china,{12.,china 1. CAs Key laboratory of soft Matter Chemistry department of polymer science and {2. Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei 230026 China

We report a facile synthesis method of dendrimer-like star-branched poly(N-isopropylacrylamide) (PNIPAM) via the combination of click chemistry and atom transfer radical polymerization (ATRP) by employing the arm-first ***,the α-azido-ω-chloro-heterodifunctionalized building block,N3-PNIPAM-Cl (G0-Cl),was synthesized via ATRP by 3-azidopropyl 2.chloropropionate as the *** advantage of click chemistry,the first generation (G1) of dendrimer-like star-branched PNIPAM,G1-(Cl)3,was facilely prepared via the click coupling reaction between G0-Cl and *** the construction of second generation (G2. dendrimer-like star-branched PNIPAM,G2.(Cl)6,terminal chloride moieties of G1-(Cl)3 were first converted to azide,and then reacted with excess tripropargylamine to give G1-(alkynyl)6 ;G2.(Cl)6 was subsequently prepared via click reaction between G1-(alkynyl) 6 and *** permeation chromatography (GPC) and matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry were employed to confirm the successful construction of dendrimer-like star-branched *** unique thermal phase transition behavior of this dendrimer-like star-branched polymer in aqueous solutions was further investigated by turbidimetry and micro-differential scanning calorimetry (Micro-DsC).

关键词： dendrimer-like branched ATRP click chemistry

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REACTION MECHANIsM OF BENZOPHENONE-PHOTOINITIATED CROssLINKING OF POLYETHYLENE

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Chinese Journal of polymer science 2002年第4期20卷 291-307页

作者： Bao-jun Qu state Key laboratory of Fire science and department of {2. science and engineering university of science and technology of china hefei 2.002. china Univ sci & Technol china State Key Lab Fire Sci Hefei 230026 Peoples R China Univ sci & Technol china Dept Polymer Sci & Engn Hefei 230026 Peoples R China

The radical intermediates, the crosslink microstructures, and the reaction mechanism of benzophenone (BP)-photoinitiated crosslinking of low-density polyethylene (LDPE) and model compounds (MD) have been reviewed in detail. The spin-trapping electron spin resonance (EsR) spectra obtained from the LDPE/BP systems with spin-trap agents show that two kinds of polymer radical intermediates are mainly formed: tertiary carbon and secondary carbon radicals. The spin-trapping EsR studies of MD/BP systems give further evidence that photocrosslinking reactions of PE predominantly take place a sites of tertiary carbon, secondary carbon, and especially allylic carbon when available. The high resolution C-13-NMR spectra obtained from LDPE and MD systems show that the crosslink microstructures have H- and Y-type links and that their concentrations are of the same order. The fluorescence, EsR, C-13 and H-1-NMR spectra from the PE and MD systems demonstrate that the main photoreduction product of BP (PPB) is benzpinacol formed by the recombination of two diphenylhydroxymethyl (K-.) radical intermediates. Two new PPB products: an isomer of benzpinacol with quinoid structure, 1-phenylhydroxymethylene-4-diphenylhydroxymethyl-2.5-cyclobexadiene and three kinds of alpha-alkyl-benzhydrols have been detected and identified. These results provide new experimental evidence for elucidating the reaction mechanism in the BP-photoinitiated crosslinking of polyethylene.

关键词： photocrosslinking mechanism polymer radical intermediates crosslink microstructures photolytic products of benzophenone polyethylene model compound

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Formation of hyperbranched polymers in atom transfer radical copolymerization of MMA and DVB

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science china Chemistry 2010年第12期53卷 2440-2451页

作者： sUN Miao & PAN CaiYuan CAs Key laboratory of soft Matter Chemistry department of {2. science and engineering,university of science and technology of china,hefei 2.002.,china 1. CAs Key laboratory of soft Matter Chemistry department of polymer science and {2. University of Science and Technology of China Hefei 230026 China

Hyperbranched poly(methyl methacrylate)s (HPMMAs) have been successfully prepared by atom transfer radical copolymerization of MMA and divinylbenzene (DVB).Kinetic study shows complete consumption of the initiator in 0.5 h,and relatively low polymerization rate when DVB content in the feed was *** analyzing MALDI-TOF spectra of the resulting copolymers,the linear A n B (n=0,1,2.3) oligomers were formed in 0.5 h of polymerization,and then the oligomers reacted each other to form dimers,further reactions produced *** sEC and NMR spectroscopies were used to trace the polymerization,and the results demonstrate that small amount of the branching reactions occur in the initial polymerization,and the branched polymers are significantly generated past a certain conversion depending upon the feed *** the content of DVB in the monomer mixture can increase the pendent vinyl groups of the linear oligo-inimers,leading to gelation at low MMA conversion.

关键词： atom transfer radical polymerization branching divinylbenzene hyperbranched polymers mechanism

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Recent progress in polymer/layered double hydroxide nanocomposites

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Progress in Natural science:Materials International 2006年第6期16卷 573-579页

作者： DING Peng, CHEN Wei and QU Baojun (state Key laboratory of Fire science and department of {2. science and engineering, university of science and technology of china, hefei 2.002., china) [a] state Key laboratory of Fire science and department of {2. engineering University of Science and Technology of china Hefei China

New developments in the studies of nanocomposites based on polymer matrixes and layered double hydroxides (LDHs) in recent years are reviewed combining our relative research work, among which the synthesis techniques, the physicochemical characterizations, and the improved material properties are especially discussed. The possible application of polymer/LDH nanocomposites is also proposed.

关键词： nanocomposite layered double hydroxide synthesis characterization structure property.

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synthesis and intrinsic blue fluorescence study of hyperbranched poly(ester-amide-ether)

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science china Chemistry 2010年第12期53卷 2452-2460页

作者： ZHANG Yong,FU Qi & sHI WenFang CAs Key laboratory of soft Matter Chemistry department of {2. science and engineering,university of science and technology of china,hefei 2.002.,china 1. CAs Key laboratory of soft Matter Chemistry department of polymer science and {2. University of Science and Technology of China Hefei 230026 China

A series of hyperbranched poly(ester-amide-ether)s (H-PEAEs) were synthesized via the A2.CB3 approach by the self-transesterification of ethyl ester-amide-ethers end-capped with three hydroxyl groups and ethyl ester group at two *** molecular structures were characterized with 1H NMR and FT-IR *** number average molecular weights were estimated by GPC analysis to possess bimodal wide distribution from 1.57 to *** strong inherent blue fluorescence was observed at 330 nm for excitation and 390 nm for ***,the emission intensity and fluorescence quantum yield increased along with the incorporated ether chain length,as well as almost linearly with the H-PEAE concentration in an aqueous *** comparing the fluorescence performance,the linear poly(ester-amide-ether) (L-PEAE) and hyperbranched poly(ester-amide) (H-PEA) were *** results showed that the coexistence of ether bond and carboxyl group in the molecular chain was essential for generating the strong ***,the compact backbone of H-PEAE would be propitious to the enhancement of fluorescence properties.

关键词： synthesis self-transesterification hyperbranched poly(ester-amide-ether) fluorescence property

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Adsorption and corrosion inhibition behavior of imidazole on cobalt electrodes studied by sERs and electrochemical methods

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science china Chemistry 2005年第6期48卷 497-503页

作者： GU Wei1, LIU Guokun2. REN Bin2. WU Deyin2. GU Renao1 & TIAN Zhongqun2.1. department of Chemistry, College of Chemistry and Chemical engineering, suzhou {2., suzhou 2.5006, china 2. state Key laboratory for physical Chemistry of solid surfaces and department of Chemistry, College of Chemistry and Chemical engineering, Xiamen {2., Xiamen 361005, china 1. department of Chemistry College of Chemistry and Chemical Engineering Suzhou University 215006 Suzhou China 2. state Key laboratory for physical Chemistry of solid surfaces and {2. of Chemistry College of Chemistry and Chemical Engineering Xiamen University 361005 Xiamen China

The interaction of imidazole with Co electrodes in an electrochemical system was studied by surface-enhanced Raman scattering (sERs) and electrochemical methods. The sER spectra of Co in an imidazole solution as a function of the applied potential were analyzed and the assignment of the Raman bands was made. It was found that there were three kinds of sur-face species on the Co surface in different potential regions and they were interchangeable de-pending on the potential. In a relatively negative potential region (?1.2.to ?0.9 V), imidazole was adsorbed on the surface and its orientation might change from a vertical configuration via the N-end of the pyridine ring to a tilted configuration via the C2.N3 double bond. In a more positive potential region (?0.8 to ?0.7 V), the sERs signal from the adsorbed imidazole weakened and finally disappeared, meanwhile the signal from the Co and imidazole complex strengthened gradually. At the open circuit potential (?0.6 V), we detected very strong bands from the Co ox-ides. By comparing the Tafel curves of the Co electrode in the solution without and with imidazole, we found that imidazole has a marked effect on the corrosion inhibition of the Co electrode. This result demonstrates that we may be able to reveal the complicated interaction of surface species with metal surface at the molecular level by combining the sERs and electrochemical methods.

关键词： cobalt, imidazole, inhibition, surface-enhanced Raman spectroscopy, Tafel plot.

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Porous Y_2._3 microcubes:synthesis and characterization

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Rare Metals 2011年第6期30卷 577-582页

作者： DENG Bin DING Liwen CHEN Jianjun ZHONG shengliang department of Chemistry and Life sciences Xiangnan University Chenzhou 423000 China College of Chemistry and Chemical engineering Jiangxi Normal University Nanchang 330022 China Division of Nanomaterials and Chemistry Hefei National Laboratory for Physical Sciences at Microscale University of Science and Technology of China Hefei 230026 China

In this work, a facile route using a simple solvothermal reaction and sequential heat treatment process to prepare porous Y2.3 microcubes is presented. The as-synthesized products were characterized by X-ray powder diffraction （XRD）, scanning electronic microscope （sEM）, energy dispersive spectrometer （EDs）, thermogravimetric analysis （TG）, and differential thermal analysis （DTA）. The thermal decomposition process of the Y2.3 precursor was investigated. sEM results demonstrated that the as-prepared porous Y2.3 microcubes were with an average width of about 2. μm and thickness of about 8μm. It was found that the morphology of the Y2.3 precursor could be readily tuned by varying the molar ratio of s2.2. to y3＋. Y2.3：Eu3＋（6.6%） microcubes were also prepared and their photoluminescence properties were investigated.

关键词： yttrium oxide yttrium sulfate solvothermal synthesis porous material

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synthesis of Perfluorinated Oxetane and surface Properties of Its Cationic UV Cured Coating as a Reactive Additive

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Chemical Research in Chinese Universities 2012年第3期28卷 550-554页

作者： ZHAN Fu,ZHANG Yong and sHI Wen-fang * CAs Key laboratory of soft Matter Chemistry,department of {2. science and engineering,university of science and technology of china,hefei 2.002.,P.R.china Univ sci & Technol china Dept Polymer Sci & Engn CAS Key Lab Soft Matter Chem Hefei 230026 Peoples R China

Perfluorinated oxetane(F-OXE) was synthesized via the ring-opening reaction of epoxy-functionalized oxetane with 2.(perfluorooctyl)ethanol under base-catalysis,and characterized by FTIR and 1 H NMR *** synthesized F-OXE was mixed with a commercial cationic UV curable resin,UVR6110,as a reactive additive at different mass fractions,and UV-irradiation cured in the presence of triphenylsulphonium hexafluoroantimonate as a cationic *** surface property study of cured films indicated that both hydrophobicity and oleophobicity were effectively enhanced by the addition of a small amount of *** contact angles of water and 1-bromonaphthalene on the surface of the cured film with 1.0%(mass fraction) F-OXE loading increased from 72.o to 106o and from 0o to 76o,respectively,compared with those on the surface of the film without F-OXE *** surface tension of UVR6110-F-OXE cured film decreased greatly from 55.6 mN/m of referenced film to 2..9 mN/*** results from X-ray photoelectron spectroscopy analysis confirm the migration and aggregation effect of perfluoroalkyl group to the surface of cured *** 1%(mass fraction) addition of F-OXE,the relative content of fluorine greatly increased from 0.70%(mass fraction) in the interior of the cured film to 36.73%(mass fraction) at the surface of the cured film,whereas those of carbon and oxygen decreased from 73.2.% to 40.96% and from 2..00% to 2..30%,respectively.

关键词： Cationic UV curing Oxetane Perfluoroalkyl Water and oil repellence

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Controlled free radical polymerization of styrene initiated from the alkoxyamine-functionalized silicon surface

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science china Chemistry 2005年第5期48卷 449-458页

作者： CHEN Zhijun1, ZHOU sikai1, LU Wenzhong1, FANG shaoming1, JIANG Xiqun2.& YANG Changzheng2.1. College of Materials and Chemical engineering, Zhengzhou university of Light Industry, Zhengzhou 450002. {2. 2. laboratory of Mesoscopic Material science and department of polymer science & engineering, College of Chemistry & Chemical engineering, Nanjing university, Nanjing 2.0093, {2. 1. College of Materials and Chemical engineering Zhengzhou University of Light Industry 450002 Zhengzhou China 2. laboratory of Mesoscopic Material science and department of {2. science & engineering College of Chemistry & Chemical Engineering Nanjing University 210093 Nanjing China

We describe a new method of fabricating a brush-like polystyrene layer anchored on the surface of the silicon substrate, which involves three steps, namely (i) the attachment of 3-methacryloxypropyltrimethoxysilane onto the silicon surface; (ii) the reaction of vinyl moiety at another extremity of the anchored 3-methacryloxypropyltrimethoxysilane to 4-Hydroxyl-2. 2. 6, 6-tetramethyl-1-piperidinyloxy (HTEMPO?) catalyzed by azobisisobutyronitrile (AIBN); (iii) living free radical grafting polymerization of styrene in the presence of HTEMPO?. The controllable living free radical polymerization permits accurate control of both the molecular weight and the polydispersity. X-photoelectron spectroscopy measurement proved that the alkoxyamine initiator layer forms on the silicon surface. XPs and Ellipsometry measurements showed that the poly-styrene chains were covalently anchored onto the silicon surface. The thickness of the grafted polymer layer can be accurately manipulated by altering the polymerization time. The new method allows synthesizing random copolymer and block copolymers by the sequential growth of monomers from the substrate surface.

关键词： polymer brush, controlled living free radical polymerization, thickness, atomic force microscopy, 3-methacryloxypropyltrimethoxysilane.

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