A polyether diol poly[3-bromomethyl-3-tridecafluorooctyloxymethyloxetane]glycol(PFBOX 3) was prepared in 91% yield from ring opening polymerization of 3-bromomethyl-3-tridecafluorooctyloxymethyloxetane 2 which was der...A polyether diol poly[3-bromomethyl-3-tridecafluorooctyloxymethyloxetane]glycol(PFBOX 3) was prepared in 91% yield from ring opening polymerization of 3-bromomethyl-3-tridecafluorooctyloxymethyloxetane 2 which was derived from 3,3-dibromomethyloxetane 1 and 1H,1H,2H,2H-perfluorooctanol.The waterborne fluorinated polyurethane FPU was thus obtained by condensed polymerization of PFBOX 3 with isophoronediisocyanate(IPDI).The structure of FPU was characterized by Fourier transform infrared spectrometer(FTIR).FPU showed good thermal stability under 300℃.The surface properties of FPU were studied by applied on cotton fabric.The treated fabric surface showed excellent water repellent property as the contact angle reached 147°.On the other hand,the surface showed slightly oil repellent property as the contact angle for nujol droplet was 126°.展开更多
Novel, fully degradable brush polymers with polycarbonate backbones and polylactide side chains were prepared by a three-step reaction that included the terpolymerization of cyclohexene oxide （CHO） and benzyl glycid...Novel, fully degradable brush polymers with polycarbonate backbones and polylactide side chains were prepared by a three-step reaction that included the terpolymerization of cyclohexene oxide （CHO） and benzyl glycidyl ether （BGE） with CO2, hydrogenation of the resultant terpolymers to afford the terpolymers with 1,2-glycerol carbonate units and the 1,8-diazabicyclo[5.4.0]undec-7-ene （DBU） mediated ring-opening polymerization of lactide on the polycarbonate backbone. The brush copolymer bearing polylactide （PLA） chains from racemic lactide （rac-LA） has a single glass-transition temperature of 58.5 ℃, whereas the copolymers with （L）-PLA side chains exhibited a melting enthalpy at 135.8 ℃ with AHm=25.04 J/g and were further shown by a WAXD study to be a typical semicrystalline polymer with sharp diffraction peaks at 20 values of 16.7° and 18.9°.展开更多
We report here our results on the investigation of the chain dynamics of poly(acrylic acid) in aqueous solution. The concentration of poly(acrylic acid) was approximately 3.8×10^(-4) mol/L, two orders of magnitud...We report here our results on the investigation of the chain dynamics of poly(acrylic acid) in aqueous solution. The concentration of poly(acrylic acid) was approximately 3.8×10^(-4) mol/L, two orders of magnitude higher than that reported in the literature. The p H value of the solution was 3.9, and the hydrogen bonds between the intrinsic and ionized carboxylic acid groups formed dynamic networks, which captured aggregation-induced emission-active molecules(a tetra-quaternary ammonium modified tetraphenylethene derivative) inside the polymer coils and induced fluorescence emission. The hydrogen bonds can be classified as intra- or intermolecular; both can be probed based on the emission change of the tetra-quaternary ammonium modified tetraphenylethene probes. The effects of different external stimuli on the polymer chain dynamics were investigated using different metal cations(including Na^+, Li^+, Zn^(2+), Ni^(2+), Ca^(2+), and Co^(2+)), different cation concentrations(1×10^(-6) to 4×10^(-4) mol/L), different poly(acrylic acid) molecular weights(5, 240, and 450 k Da), and different copolymers. The experimental results indicate that the long poly(acrylic acid) chains(high molecular weight) tend to form dense globular coils and exclude the probe molecules outside, which are robust and unsusceptible to water-soluble metal cations. However, the shorter poly(acrylic acid) chains tend to form intermolecular hydrogen bonds, which are helpful in capturing more probe molecules inside the networks, thus inducing stronger emission. Because of the dual functions of forming hydrogen bonds with carboxylic groups and acting as an acceptor of protons from the carboxylic acid group to form cationic species, copolymerization with acrylate amide [poly(acrylic acid)-co-poly(acrylamide)] can greatly affect the chain dynamics of poly(acrylic acid) segments, which is reflected by the drastically decreased emission intensity from the fluorescent probes.展开更多
To yield cholinesterase（ChE） from prokaryotic expression, the ChE gene that belongs to Daphnia magna was amplified by reverse transcription-polymerase chain reaction（RT-PCR） using forward primer 5＇-CCCYGGNGCSAT G...To yield cholinesterase（ChE） from prokaryotic expression, the ChE gene that belongs to Daphnia magna was amplified by reverse transcription-polymerase chain reaction（RT-PCR） using forward primer 5＇-CCCYGGNGCSAT GATGTG-3＇ and reverse primer 5＇-GYAAGTTRGCCCAATATCT-3＇. To express the gene, one sequence of the amplified DNA, which was able to encode a putative protein containing two conserved carboxylesterase domains, was connected to the prokaryotic expression vector PET-29a（＋）. The recombinant vector was transformed into Escherichia coil BL21（DE3）. Protein expression was induced by isopropy-D-thiogalactoside. The expressed ChE was used as an immunogen to immunize BALB/c mice. The obtained antibodies were tested for their specificity towards crude enzymes from species such as Alona milleri, Macrobrachium nipponense, Bombyx mori, Chironomus kiiensis, Apis mellifera, Eisenia foetida, Brachydanio rerio, and Xenopus laevis. Results indicated that the antibodies had specificity suitable for detecting ChE in Daphnia magna. A type of indirect and non-competitive enzyme-linked immunosorbent assay（IN-ELISA） was used to test the immunoreactive content of ChE（ChE-IR） in Daphina magna. The detection limit of the IN-ELISA was found to be 14.5 ng/ml at an antiserum dilution of 1：22 000. Results from tests on Daphnia magna exposed to sublethal concentrations of triazophos indicated a maximal induction of 57.2% in terms of ChE-IR on the second day after the animals were exposed to a concentration of 2.10 μg/L triazophos. Testing on animals acclimatized to a temperature of 16 °C indicated that ChE-IR was induced by 16.9% compared with the ChE-IR content detected at 21 °C, and the rate of induction was 25.6% at 10 °C. The IN-ELISA was also used to test the stability of ChE-IR in collected samples. Repeated freezing and thawing had no influence on the outcome of the test. All these results suggest that the polyclonal antibodies developed against the recombinant ChE are as efficient as those developed against the native ChE in detecting ChE content in Daphnia magna.展开更多
基金Shanghai Municipal Scientific Committee,China (No. 08JC1400400)
文摘A polyether diol poly[3-bromomethyl-3-tridecafluorooctyloxymethyloxetane]glycol(PFBOX 3) was prepared in 91% yield from ring opening polymerization of 3-bromomethyl-3-tridecafluorooctyloxymethyloxetane 2 which was derived from 3,3-dibromomethyloxetane 1 and 1H,1H,2H,2H-perfluorooctanol.The waterborne fluorinated polyurethane FPU was thus obtained by condensed polymerization of PFBOX 3 with isophoronediisocyanate(IPDI).The structure of FPU was characterized by Fourier transform infrared spectrometer(FTIR).FPU showed good thermal stability under 300℃.The surface properties of FPU were studied by applied on cotton fabric.The treated fabric surface showed excellent water repellent property as the contact angle reached 147°.On the other hand,the surface showed slightly oil repellent property as the contact angle for nujol droplet was 126°.
基金supported by the National Natural Science Foundation of China(21134002 and 21104007)the Program for Changjiang Scholars and Innovative Research Teams in Universities(IRT13008)Xiao Bing Lu gratefully acknowledges the Chang Jiang Scholars Program(T2011056)of the Ministry of Education of China
文摘Novel, fully degradable brush polymers with polycarbonate backbones and polylactide side chains were prepared by a three-step reaction that included the terpolymerization of cyclohexene oxide （CHO） and benzyl glycidyl ether （BGE） with CO2, hydrogenation of the resultant terpolymers to afford the terpolymers with 1,2-glycerol carbonate units and the 1,8-diazabicyclo[5.4.0]undec-7-ene （DBU） mediated ring-opening polymerization of lactide on the polycarbonate backbone. The brush copolymer bearing polylactide （PLA） chains from racemic lactide （rac-LA） has a single glass-transition temperature of 58.5 ℃, whereas the copolymers with （L）-PLA side chains exhibited a melting enthalpy at 135.8 ℃ with AHm=25.04 J/g and were further shown by a WAXD study to be a typical semicrystalline polymer with sharp diffraction peaks at 20 values of 16.7° and 18.9°.
基金supported by the Natural Science Foundation of Zhejiang Province(2012C32007Z4110056)the National Basic Research Program of China(2013CB834704)
文摘We report here our results on the investigation of the chain dynamics of poly(acrylic acid) in aqueous solution. The concentration of poly(acrylic acid) was approximately 3.8×10^(-4) mol/L, two orders of magnitude higher than that reported in the literature. The p H value of the solution was 3.9, and the hydrogen bonds between the intrinsic and ionized carboxylic acid groups formed dynamic networks, which captured aggregation-induced emission-active molecules(a tetra-quaternary ammonium modified tetraphenylethene derivative) inside the polymer coils and induced fluorescence emission. The hydrogen bonds can be classified as intra- or intermolecular; both can be probed based on the emission change of the tetra-quaternary ammonium modified tetraphenylethene probes. The effects of different external stimuli on the polymer chain dynamics were investigated using different metal cations(including Na^+, Li^+, Zn^(2+), Ni^(2+), Ca^(2+), and Co^(2+)), different cation concentrations(1×10^(-6) to 4×10^(-4) mol/L), different poly(acrylic acid) molecular weights(5, 240, and 450 k Da), and different copolymers. The experimental results indicate that the long poly(acrylic acid) chains(high molecular weight) tend to form dense globular coils and exclude the probe molecules outside, which are robust and unsusceptible to water-soluble metal cations. However, the shorter poly(acrylic acid) chains tend to form intermolecular hydrogen bonds, which are helpful in capturing more probe molecules inside the networks, thus inducing stronger emission. Because of the dual functions of forming hydrogen bonds with carboxylic groups and acting as an acceptor of protons from the carboxylic acid group to form cationic species, copolymerization with acrylate amide [poly(acrylic acid)-co-poly(acrylamide)] can greatly affect the chain dynamics of poly(acrylic acid) segments, which is reflected by the drastically decreased emission intensity from the fluorescent probes.
基金supported by the Zhejiang Provincial Natural Science Foundation(No.LY12B07008),China
文摘To yield cholinesterase（ChE） from prokaryotic expression, the ChE gene that belongs to Daphnia magna was amplified by reverse transcription-polymerase chain reaction（RT-PCR） using forward primer 5＇-CCCYGGNGCSAT GATGTG-3＇ and reverse primer 5＇-GYAAGTTRGCCCAATATCT-3＇. To express the gene, one sequence of the amplified DNA, which was able to encode a putative protein containing two conserved carboxylesterase domains, was connected to the prokaryotic expression vector PET-29a（＋）. The recombinant vector was transformed into Escherichia coil BL21（DE3）. Protein expression was induced by isopropy-D-thiogalactoside. The expressed ChE was used as an immunogen to immunize BALB/c mice. The obtained antibodies were tested for their specificity towards crude enzymes from species such as Alona milleri, Macrobrachium nipponense, Bombyx mori, Chironomus kiiensis, Apis mellifera, Eisenia foetida, Brachydanio rerio, and Xenopus laevis. Results indicated that the antibodies had specificity suitable for detecting ChE in Daphnia magna. A type of indirect and non-competitive enzyme-linked immunosorbent assay（IN-ELISA） was used to test the immunoreactive content of ChE（ChE-IR） in Daphina magna. The detection limit of the IN-ELISA was found to be 14.5 ng/ml at an antiserum dilution of 1：22 000. Results from tests on Daphnia magna exposed to sublethal concentrations of triazophos indicated a maximal induction of 57.2% in terms of ChE-IR on the second day after the animals were exposed to a concentration of 2.10 μg/L triazophos. Testing on animals acclimatized to a temperature of 16 °C indicated that ChE-IR was induced by 16.9% compared with the ChE-IR content detected at 21 °C, and the rate of induction was 25.6% at 10 °C. The IN-ELISA was also used to test the stability of ChE-IR in collected samples. Repeated freezing and thawing had no influence on the outcome of the test. All these results suggest that the polyclonal antibodies developed against the recombinant ChE are as efficient as those developed against the native ChE in detecting ChE content in Daphnia magna.
