简介：Forasystemofflexiblepolymermolecules,theconceptsoftwoconcentrations,namelythesegmentalandthemolecularconcentrations,havebeenproposedinthispaper.Theformerisequivalenttothevolumefraction.Thelattercanbedefinedasthenumberofthegravitycentersofmacromoleculesinaunitvolume.Thetwoconcentrationsshouldbecorrelatedwitheachotherbytheconformationalfunctionofthepolymerchainandshouldbediscussedindifferentthermodynamicequations.OnthebasisoftheseconceptsithasbeenprovedthattheFlory-Hugginsentropyofmixingshouldbetheresultofthemixing'idealgasesofthegravitycentersofmacromolecules'.Thegeneralcorrelationbetweenthefreeenergyofmixingandthescatteringfunction(structuralfactor)ofpolymerblendshasbeenstudiedbasedonthegeneralfluctuationtheory.WhentheFlory-Hugginsfreeenergyofmixingisadopted,thedeGennesscatteringfunctionofapolymerblendcanbederived.

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简介：Anewdi-functionadsorbent(JN-3)waspreparedbysulfhydrylmodified.ComparingwithAmberliteXAD-4andNDA-150,theequilibriumadsorptionforphenolontheJN-3fromaqueoussolutionswastested,perfectadsorptioncapacitywasshown.Pb2+canbealsoremovedbyJN-3becauseofthechelateinteractionbetweensulfhydrylgroupsandmetalions.Thisadsorbentcouldbeusedinremovalofcombinepollutantssuchasphenoliccompoundsandheavymetalionsfromwastestreams.

简介：Theeffectofsinteringdispersedandbulk,lowmolecularweight(Mn=50,000Da),nano-emulsionpolytetrafluoroethylene(PTFE)particlesneartheirmeltingpointisdescribed.Withthenascentparticlesconsistingofca.75nmdiameter,hexagonal,singlecrystals,sinteringat,e.g.,350℃,results,initially,inmergerofneighboringparticles,followedbyindividualmolecularmotiononthesubstrateandtheformationoffoldedchain,lamellarsinglecrystalsandspherulites,andon-edgeribbons.Itissuggestedthesestructuresdevelop,withtime,inthemesomorphic'melt'.Sinteringofthebulkresinyieldsextendedchain,bandstructures,aswellasfoldedchainlamellae;end-surfacetoend-surfacemerger,possiblybyend-to-endpolymerization,occurswithincreasingtime.