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2006 Volume 24 Issue 5
2006, 24(5): 441-447
Abstract:
Twokindsofwater-solublemetallophthalocyanines,binuclearcobaltphthalocyanine(Co2Pc2)andbinuclearferricphthalocyanine(Fe2Pc2),weresynthesizedthroughphenylanhydride-urearouteandcharacterizedbyelementalanalysisandFT-IRspectra.Binuclearmetallophthalocyaninederivatives(Mt2Pc2)wereimmobilizedonsilkfibersandmodifiedviscosefiberstoconstructbioactivefibersofmimicenzyme.Mt2Pc2wasusedastheactivecenterofbioactivefibers,viscoseandsilkfibersasthemicroenvironments.Thecatalyticoxidationabilityofbioactivefibersonthemalodorsofmethanthiolandhydrogensulfidewasinvestigatedatroomtemperature.Theexperimentalresultsindicatedthatthecatalyticactivityofsuchbioactivefiberswascloselycorrelativetothetypesofbioactivefibersandsubstrates.
Twokindsofwater-solublemetallophthalocyanines,binuclearcobaltphthalocyanine(Co2Pc2)andbinuclearferricphthalocyanine(Fe2Pc2),weresynthesizedthroughphenylanhydride-urearouteandcharacterizedbyelementalanalysisandFT-IRspectra.Binuclearmetallophthalocyaninederivatives(Mt2Pc2)wereimmobilizedonsilkfibersandmodifiedviscosefiberstoconstructbioactivefibersofmimicenzyme.Mt2Pc2wasusedastheactivecenterofbioactivefibers,viscoseandsilkfibersasthemicroenvironments.Thecatalyticoxidationabilityofbioactivefibersonthemalodorsofmethanthiolandhydrogensulfidewasinvestigatedatroomtemperature.Theexperimentalresultsindicatedthatthecatalyticactivityofsuchbioactivefiberswascloselycorrelativetothetypesofbioactivefibersandsubstrates.
2006, 24(5): 463-471
Abstract:
Inthisstudy,electrorheological(ER)behaviorofsuspensionspreparedfrom3.0and9.0mdiatomiteparticulate,dispersedininsulatingsiliconeoil(SO)mediumwasinvestigated.Sedimentationstabilitiesofsuspensions(c=5wt%)preparedusingthesediatomitepowdersweredeterminedtobe32days(d=3m)and24days(d=9m),respectively.ERactivityofallthesuspensionswasobservedtoincreasewithincreasingelectricfieldstrength,concentrationanddecreasingshearrate.Shearstressofdiatomitesuspensionsincreasedlinearlywithincreasingconcentrationsoftheparticlesandwiththeappliedelectricfieldstrength.Electricfieldviscosityofallthesuspensionsdecreasedsharplywithincreasingshearrateandparticlesize,showingatypicalshearthinningnon-Newtonianvisco-elasticbehavior.EffectsofhightemperatureandpolarpromoterontoERactivityofdiatomite/SOsystemwerealsoinvestigated.
Inthisstudy,electrorheological(ER)behaviorofsuspensionspreparedfrom3.0and9.0mdiatomiteparticulate,dispersedininsulatingsiliconeoil(SO)mediumwasinvestigated.Sedimentationstabilitiesofsuspensions(c=5wt%)preparedusingthesediatomitepowdersweredeterminedtobe32days(d=3m)and24days(d=9m),respectively.ERactivityofallthesuspensionswasobservedtoincreasewithincreasingelectricfieldstrength,concentrationanddecreasingshearrate.Shearstressofdiatomitesuspensionsincreasedlinearlywithincreasingconcentrationsoftheparticlesandwiththeappliedelectricfieldstrength.Electricfieldviscosityofallthesuspensionsdecreasedsharplywithincreasingshearrateandparticlesize,showingatypicalshearthinningnon-Newtonianvisco-elasticbehavior.EffectsofhightemperatureandpolarpromoterontoERactivityofdiatomite/SOsystemwerealsoinvestigated.
2006, 24(5): 473-482
Abstract:
In this paper, we proposed a method to determine the nucleation effect of pre-existing crystals on crystallization of the second block in double crystalline block copolymers, which is usually covered by the suppression effect. The nucleation mechanism of poly(ethylene oxide) (PEO) block from the pre-crystallized polyethylene (PE) block in poly(ethylene-co-butene)-b-poly(ethylene glycol) (EmEOn) diblock copolymers was investigated under variable crystallization environments. The crystallization environment for the PEO block was altered by cooling at different cooling rates or successive self-nucleation (SSN) to the PE block. It was found that the presence of nucleation effect is strongly dependent on composition of the block copolymers. The crystallization temperature (Tc) of PEO block in E174EO90 increases as cooling rate applied to the PE block decreases, indicating that PE block can nucleate the crystallization of PEO block and more perfect PE crystals have stronger nucleation effect. In E182EO41 crystallization of the PEO block is confined, shown by the disappearance of self-nucleation domain, and the PE block has no nucleation effect on the crystallization of PEO block. Double crystallization peaks are observed for the PEO block in E182EO41 and the intensity of the crystallization peak at higher temperature increases as the PE crystals become more perfect. After exclusion of homogeneous nucleation mechanism, the higher temperature crystallization peak of the PEO block in E182EO41 is tentatively ascribed to surface nucleation.
In this paper, we proposed a method to determine the nucleation effect of pre-existing crystals on crystallization of the second block in double crystalline block copolymers, which is usually covered by the suppression effect. The nucleation mechanism of poly(ethylene oxide) (PEO) block from the pre-crystallized polyethylene (PE) block in poly(ethylene-co-butene)-b-poly(ethylene glycol) (EmEOn) diblock copolymers was investigated under variable crystallization environments. The crystallization environment for the PEO block was altered by cooling at different cooling rates or successive self-nucleation (SSN) to the PE block. It was found that the presence of nucleation effect is strongly dependent on composition of the block copolymers. The crystallization temperature (Tc) of PEO block in E174EO90 increases as cooling rate applied to the PE block decreases, indicating that PE block can nucleate the crystallization of PEO block and more perfect PE crystals have stronger nucleation effect. In E182EO41 crystallization of the PEO block is confined, shown by the disappearance of self-nucleation domain, and the PE block has no nucleation effect on the crystallization of PEO block. Double crystallization peaks are observed for the PEO block in E182EO41 and the intensity of the crystallization peak at higher temperature increases as the PE crystals become more perfect. After exclusion of homogeneous nucleation mechanism, the higher temperature crystallization peak of the PEO block in E182EO41 is tentatively ascribed to surface nucleation.
2006, 24(5): 489-496
Abstract:
Lowmolecularweightpoly(glycidylmethacrylate)s(PGMAs)werepreparedbyphotopolymerizationinethylacetate,withbenzophenone(BP)asphotoinitiator,andtriethylamine(TEA)ashydrogendonor.TheexistenceofsemipinacoldormantendgroupsinPGMAwasconfirmedbyFT-IRand1H-NMR,andthecontentofthesemipinacoldormantgroupswasdeterminedquantitativelyby1H-NMRmeasurement.Theeffectsofvariousfactors,suchasreactiontime,BPconcentrationandmonomerconcentrationonthesynthesisofthepolymerswereinvestigatedsystematically.ThemolecularweightsofthepolymerswerealsoinvestigatedwithGPC.ItisshownthatincreasingBPconcentrationanddecreasingirradiationtimeandmonomerconcentrationledtoasignificantdecreaseofthemolecularweights.
Lowmolecularweightpoly(glycidylmethacrylate)s(PGMAs)werepreparedbyphotopolymerizationinethylacetate,withbenzophenone(BP)asphotoinitiator,andtriethylamine(TEA)ashydrogendonor.TheexistenceofsemipinacoldormantendgroupsinPGMAwasconfirmedbyFT-IRand1H-NMR,andthecontentofthesemipinacoldormantgroupswasdeterminedquantitativelyby1H-NMRmeasurement.Theeffectsofvariousfactors,suchasreactiontime,BPconcentrationandmonomerconcentrationonthesynthesisofthepolymerswereinvestigatedsystematically.ThemolecularweightsofthepolymerswerealsoinvestigatedwithGPC.ItisshownthatincreasingBPconcentrationanddecreasingirradiationtimeandmonomerconcentrationledtoasignificantdecreaseofthemolecularweights.
2006, 24(5): 497-502
Abstract:
The effects of pH, initial concentration and temperature on the adsorption of phenol by chitosan are investigated in this paper. The isothermal data was applied to Langmuir linear and the Freundlich linear isotherm equation, and the thermodynamic parameters (?DH, DG, ?DS) were calculated according to the values of binding Langmuir constant, KL. Results indicated that the adsorption between chitosan and phenol was significantly physical in nature, the negative ?H constant at lower temperature confirmed that more phenol was adsorbed by chitosan at lower temperature. The kinetics of the sorption process of phenol on chitosan was investigated using the pseudo-first order and pseudo-second order kinetics, and results showed that the second order equation model provided the best correlation with the experimental results.
The effects of pH, initial concentration and temperature on the adsorption of phenol by chitosan are investigated in this paper. The isothermal data was applied to Langmuir linear and the Freundlich linear isotherm equation, and the thermodynamic parameters (?DH, DG, ?DS) were calculated according to the values of binding Langmuir constant, KL. Results indicated that the adsorption between chitosan and phenol was significantly physical in nature, the negative ?H constant at lower temperature confirmed that more phenol was adsorbed by chitosan at lower temperature. The kinetics of the sorption process of phenol on chitosan was investigated using the pseudo-first order and pseudo-second order kinetics, and results showed that the second order equation model provided the best correlation with the experimental results.
2006, 24(5): 503-513
Abstract:
Twooxetane-derivedmonomers,3-(2-cyano-ethoxy)methyl-and3-(methoxy-(triethylenoxy))methyl-3′-methyloxetane(COXandMTOX),werepreparedfrom3-hydroxymethyl-3-methyloxetane.Theirhomo-andco-polymerizationinsolutionwerecarriedoutbythecationicring-openingpolymerizationwithBF3•Et2Oand1,4-butanediolasco-initiator.ThemolecularweightandmolecularweightdistributionweredeterminedusingGPCsoastorevealthecompetitionandinterchangebetweenactivechainend(ACE)andactivatedmonomer(AM)mechanismintheprocess.ThereactivityratiosofthetwomonomerswerecalculatedaccordingtoKelen-Tudosusing1H-NMRanalysis.Theinfluenceoffunctionalsidechainsinthemonomersonthecopolymerizationbehaviorswasdiscussedinvirtueofthereactivityratiodata.WhendopedwithlithiumsaltLiTFSI,theionconductivityofthehomopolymerofMTOXreached10-3.58S/cmat30℃and10-2.73S/cmat80℃,respectively,showingitspotentialtobeusedaspolymerelectrolyteforlithiumionbattery.
Twooxetane-derivedmonomers,3-(2-cyano-ethoxy)methyl-and3-(methoxy-(triethylenoxy))methyl-3′-methyloxetane(COXandMTOX),werepreparedfrom3-hydroxymethyl-3-methyloxetane.Theirhomo-andco-polymerizationinsolutionwerecarriedoutbythecationicring-openingpolymerizationwithBF3•Et2Oand1,4-butanediolasco-initiator.ThemolecularweightandmolecularweightdistributionweredeterminedusingGPCsoastorevealthecompetitionandinterchangebetweenactivechainend(ACE)andactivatedmonomer(AM)mechanismintheprocess.ThereactivityratiosofthetwomonomerswerecalculatedaccordingtoKelen-Tudosusing1H-NMRanalysis.Theinfluenceoffunctionalsidechainsinthemonomersonthecopolymerizationbehaviorswasdiscussedinvirtueofthereactivityratiodata.WhendopedwithlithiumsaltLiTFSI,theionconductivityofthehomopolymerofMTOXreached10-3.58S/cmat30℃and10-2.73S/cmat80℃,respectively,showingitspotentialtobeusedaspolymerelectrolyteforlithiumionbattery.
2006, 24(5): 515-528
Abstract:
Thinfilmsofincompatiblepolymerblendscanformavarietyofstructuresduringpreparationandsubsequentannealingprocess.Forthepolymerblendsystemconsistingofpolystyreneandpoly(styrene-co-p-bromo-styrene),i.e.,PS/PBrxS,itscompatibilitycouldbeadjustedbyvaryingthedegreeofbrominationandthemolecularweightofbothcomponentscomprised.Inthispaper,surfacechemicalcompositionsofthecastandtheannealingfilmswereinvestigatedbyX-rayphotoelectronspectroscopy(XPS)andcontactanglemeasurement;meanwhile,surfacetopographicalchangesarefollowedbyatomicforcemicroscopy(AFM).Inaddition,substantialattentionwaspaidtotheeffectofannealingonthemorphologicvariationsinducedbyphaseseparationand/ordewettingofthethinfilm.Moreover,theinfluencesofthemolecularweight,Mw,aswellasthebrominateddegree,x%,onthesamplesurfaceareexploredsystematically,andthecorrespondingobservationsareexplainedinvirtueoftheFlory-Hugginstheory,alongwiththedewettingofthepolymerthinfilm.
Thinfilmsofincompatiblepolymerblendscanformavarietyofstructuresduringpreparationandsubsequentannealingprocess.Forthepolymerblendsystemconsistingofpolystyreneandpoly(styrene-co-p-bromo-styrene),i.e.,PS/PBrxS,itscompatibilitycouldbeadjustedbyvaryingthedegreeofbrominationandthemolecularweightofbothcomponentscomprised.Inthispaper,surfacechemicalcompositionsofthecastandtheannealingfilmswereinvestigatedbyX-rayphotoelectronspectroscopy(XPS)andcontactanglemeasurement;meanwhile,surfacetopographicalchangesarefollowedbyatomicforcemicroscopy(AFM).Inaddition,substantialattentionwaspaidtotheeffectofannealingonthemorphologicvariationsinducedbyphaseseparationand/ordewettingofthethinfilm.Moreover,theinfluencesofthemolecularweight,Mw,aswellasthebrominateddegree,x%,onthesamplesurfaceareexploredsystematically,andthecorrespondingobservationsareexplainedinvirtueoftheFlory-Hugginstheory,alongwiththedewettingofthepolymerthinfilm.
2006, 24(5): 529-538
Abstract:
Two kinds of polypeptides were tethered onto the surface of polypropylene microporous membrane (PPMM) through a ring opening polymerization of L-glutamate N-carboxyanhydride initiated by amino groups which were introduced by ammonia plasma and ?-aminopropyl triethanoxysilane treatments. X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (FT-IR/ATR), scanning electron microscopy (SEM), together with water contact angle measurements were used to characterize the modified membranes. XPS analyses and FT-IR/ATR spectra demonstrated that polypeptides are actually grafted onto the membrane surface. The wettability of the membrane surface increases at first and then decreases with the increase in grafting degrees of polypeptide. Platelet adhesion and murine macrophage attachment experiments reveal an enhanced hemocompatibility for the polypeptide modified PPMMs. All these results give evidence that polypeptide grafting can simultaneously improve the hemocompatibility as well as reserve the hydrophobicity for the membrane, which will provide a potential approach to improve the performance of polypropylene hollow fiber microporous membrane used in artificial oxygenator.
Two kinds of polypeptides were tethered onto the surface of polypropylene microporous membrane (PPMM) through a ring opening polymerization of L-glutamate N-carboxyanhydride initiated by amino groups which were introduced by ammonia plasma and ?-aminopropyl triethanoxysilane treatments. X-ray photoelectron spectroscopy (XPS), attenuated total reflectance Fourier transform infrared spectroscopy (FT-IR/ATR), scanning electron microscopy (SEM), together with water contact angle measurements were used to characterize the modified membranes. XPS analyses and FT-IR/ATR spectra demonstrated that polypeptides are actually grafted onto the membrane surface. The wettability of the membrane surface increases at first and then decreases with the increase in grafting degrees of polypeptide. Platelet adhesion and murine macrophage attachment experiments reveal an enhanced hemocompatibility for the polypeptide modified PPMMs. All these results give evidence that polypeptide grafting can simultaneously improve the hemocompatibility as well as reserve the hydrophobicity for the membrane, which will provide a potential approach to improve the performance of polypropylene hollow fiber microporous membrane used in artificial oxygenator.
2006, 24(5): 545-551
Abstract:
Ahypercrosslinkedpolymericadsorbent(ZH-03)foradsorbingandremovingchlorophenoliccompoundsfromtheiraqueoussolutionswasstudied,includingthestaticadsorption.TheequilibriumadsorptiondatawerefittoFreundlichadsorptionisothermicmodelstoevaluatethemodelparameters.ThermodynamicstudiesontheadsorptionofchlorophenoliccompoundsonZH-03indicatedthattherewerechemisorptiontransitionsfor2,4,6-trichlorophenolandphysicaladsorptionprocessesfor2-chlorophenoland2,6-chlorophenol,andZH-03showedthehomogeneousnatureoftheadsorbentsurface.ColumnadsorptionforchlorophenolswastewatershowstheadvantagesoftheZH-03adsorbentforadsorbingthefollowingchlorophenoliccompoundsas2-chlorophenol,2,6-dichlorophenoland2,4,6-trichlorophenol.SodiumhydroxidewasusedfordesorptingchlorophenolsfromZH-03andshowedexcellentperformance.
Ahypercrosslinkedpolymericadsorbent(ZH-03)foradsorbingandremovingchlorophenoliccompoundsfromtheiraqueoussolutionswasstudied,includingthestaticadsorption.TheequilibriumadsorptiondatawerefittoFreundlichadsorptionisothermicmodelstoevaluatethemodelparameters.ThermodynamicstudiesontheadsorptionofchlorophenoliccompoundsonZH-03indicatedthattherewerechemisorptiontransitionsfor2,4,6-trichlorophenolandphysicaladsorptionprocessesfor2-chlorophenoland2,6-chlorophenol,andZH-03showedthehomogeneousnatureoftheadsorbentsurface.ColumnadsorptionforchlorophenolswastewatershowstheadvantagesoftheZH-03adsorbentforadsorbingthefollowingchlorophenoliccompoundsas2-chlorophenol,2,6-dichlorophenoland2,4,6-trichlorophenol.SodiumhydroxidewasusedfordesorptingchlorophenolsfromZH-03andshowedexcellentperformance.
