简介:Thebovinehydroxyapatite(BHA)wasappliedtopreparebiologicaltissueengineeringscaffoldsbythemethodofextrusionfreeforming.Toachievethisgoal,BHAwereaddedtosodiumalginate(SA)solutiontoformaslurrysysteminappropriateproportion.Theresultingmixtureswerefabricatedtobeakindofcontrollableandporousscaffoldsfollowedwithcross-linkingin5%calciumchloride(CaCl2)solutionfor24h.Afterthat,thescaffoldsweresinteredinairat1000,1100,1200and1300℃for5h.Scanningelectronmicroscopy(SEM)andX-raydiffraction(XRD)studieswereperformedonthescaffoldstoanalyzeitsmicrostructureandconstituent.Toexploretheeffectofsinteringtemperatureonscaffolds,thecompressivestrength,volumeshrinkageandwaterabsorptivityofBHA-SAcompositescaffoldsaftersinteringwereinvestigated.TheresearchtestsindicatedthefeasibilityofapplyingBHApowderto3Dprinting.Besides,thescaffoldssinteredinarespectivelylowertemperaturepossessmuchmoreporesandperformedhigherwaterabsorptivity,whichmeansbettercellularaffinity.Andscaffoldssinteredbetween1100and1200℃presentshighercompressivestrength.
简介:Er^3+-dopedSrBi4Ti4O15-Bi4Ti3O12(SBT-BIT-xEr^3+,x=0.00,0.05,0.10,0.15and0.20)inter-growthceramicsweresynthesizedbythesolid-statereactionmethod.Structural,electricalandup-conversionpropertiesofSBT-BIT-xEr^3+wereinvestigated.Allsamplesshowedasinglephaseoftheorthorhombicstructure.RamanspectroscopyindicatedthattheEr^3+substitutionforBi^3+atAsitesofthepseudo-perovskitelayerincreasesthelatticedistortionofSBT-BIT-xEr^3+ceramics.ThesubstitutionofBi^3+byEr^3+leadstoadecreaseofdielectriclosstanδandanincreaseofconductivityactivationenergy.Piezoelectricconstantd33wasslightlyimproved,butdielectricconstantwasdecreasedwiththeEr^3+doping.TheSBT-BIT-xEr^3+ceramicwithx=0.15exhibitstheoptimizedelectricalbehavior(d33~17pC/N,tanδ~0.83%).Moreover,twobrightgreen(532and548nm)andonered(670nm)emissionbandswereobservedunderthe980nmexcitation.Optimizedemissionintensitywasalsoobtainedwhenx=0.15fortheSBT-BIT-xEr^3+ceramic.Therefore,thiskindofceramicsoughttobepromisingcandidatesformultifunctionaloptoelectronicapplications.
简介:Theyolk-shellLaMnO3perovskitemicrosphereswerefabricatedbyanovel,simpleandmildsofttemplateapproach.Aseriesoftemplate-P123concentrations(0-6.12mmol·L^-1)wereemployedtooptimizethemostcompletespheres.WhentheconcentrationofP123is3.0mmol·L^-1,theobtainedyolk-shellmicrosphereswithadiameterof200-700nmwereconstructedbynanoparticles.Thepossibleformationmechanismoftheyolk-shellmicrosphereswasrevealedstepbystepviaXRD,SEM,TEM,EDSandHRTEM.MoleculesofP123weresuitablymixedwithsolventsfordoubleshelledvesiclesthroughself-assembly,whichinteractedwithmetalcomplexestoformP123-metalvesicles.AftertheremovalofP123andcitricacidbycalcinationat700℃,theyolk-shellLaMnO3microsphereswiththrough-channelswereobtained.Through-channelsonthesurfacewereduetocitricacidandthesolidcorewasattributedtotheshrinkofinnervesicles.Preparedyolk-shellmicrospheresamplespossessedalargersurfaceareaandahighermaximumNOconversionvalueof78%at314℃forNOoxidation,comparedwithsampleswithouttheyolk-shellstructure.
简介:Three-dimensional-printed(3D-P)titaniumimplantsdisplaymanyadvantages,suchasdesignflexibility,higherefficiency,thecapabilitytoeasilyconstructcomplexorcustomizedstructures,etc.,andisbelievedtopotentiallyreplacetraditionalimplants.However,thebiologicalperformanceofthe3D-Ptitaniumsurfacehasnotbeeninvestigatedsystematically.Herein,weanalyzedthesurfacecharacteristicsof3D-PTi6AI4Vimplantsandevaluatedthebiologicalresponsesofbonemarrowderivedmesenchymalstromalcells(BMSCs)tothe3D-Psurfaceinvitro.Moreover,afterimplantationintotheratfemoralcondylefor3and6weeks,theosseointegrationperformaneewasevaluated.Theresultsshowedthe3D-PTi6Al4Vimplantpresenteddistinctfluctuantmacroscaleroughsurfaceandrelativelybetterhydrophilicitywhichenhancedtheadhesion,proliferation,osteogenicdifferentiationandangiogeneticfactorexpressionofBMSCs.Moreover,theinvivoosseointegrationperformancewasalsobetterthanthatofthecontrolgroupattheearlystage.Thepresentstudysuggestedthe3D-Ptitaniumalloyisapromisingcandidatetobeusedasimplantmaterial.
简介:AdditivelymanufacturedTi-6Al-4Vlatticestructureshavefoundimportantnicheapplications.However,theyoftenshowinsufficientcompressiveductilityorinsufficientstructuralintegrity.Inthisstudy,abatchof45octahedralTi-6Al-4Vlatticestructureswasmanufacturedinthreedifferentstrutdiameters(0.5,1.0,1.5mm)byselectiveelectronbeammelting(SEBM).Theinfluenceofpost-SEBMannealingonthecompressivedeformationcharacteristicsofthelatticestructurewasinvestigated.Theas-builtTi-6AI-4Vlatticesfragmentedwhenthecompressivestrainreached13%-23%dependingonstrutdiameter.Annealingat950℃(Ptransustemperature:995℃)onlyslightlyimprovedthecompressiveductilityofthelatticestructures.However,annealingat1050℃(p-annealing)fundamentallychangedthecompressivedeformationmodeofthelatticestructures.Theresultantcompressivestress-straincurvewasfeaturedbyalongsmoothplateauandnofactureoccurredevenaftersignificantdensificationofthelatticestructurehadtakenplace(>50%ofcompressivestrain).