简介:SAPO-34,asilicoaluminophosphatezeolite,hasbeensynthesizedbythehydrothermalmethodwiththeadditionofdifferentmolecularweightsofpolyethyleneglycol(PEG),andhasbeencharacterizedwithXRD,SEM,N2adsorption-desorption,FT-IR,andNH3temperatureprogrammeddesorption(NH3-TPD).WestudiedSAPO-34asacatalystinthemethanol-to-olefins(MTO)reaction,inafixed-bedreactor.TheresultsshowthatthechainlengthofPEGhasagreatinfluenceontheparticlesizeandmorphologyofSAPO-34.PEGactsasinhibitorinthecrystallizationprocess.WiththeincreaseofthechainlengthofPEGusedinthesynthesis,fromarelativemolecularweightof400-6000,themorphologyofSAPO-34changesgraduallyfromcubictonanoplate-likeandthenchangestocubicagain.Theparticlesizedecreasesmarkedlyatfirstandthenincreasestosomeextent.ThecatalyticstabilityintheMTOreactionalsoincreasesfirstandthendecreases,withallthecatalystshavingalmostthesameselectivitytoolefins.WhenthesampleissynthesizedwithPEG800,theparticlesbecomenanoplate-likewithathicknessof46nmonaverage,andthecatalyticstabilityisappreciablyprolonged,whichisattributedtotheshorterdiffusionpathsofthereactantsinthezeolite.
简介:文章以聚乙二醇2000衍生化二硬脂酿嶙脂酰乙醇胺(PEG2000-DSPE)为载体,采用薄膜分散法制备前列地尔(PGE1)肢束,评价其制剂学性质;并对其大鼠体内分布及金黄地鼠微循环血管药理作用进行研究.实验结果表明PGE1胶束在大鼠体内生物利用度和各组织含药量方面均高于PGE1注射剂;PGE1肢束对微血管作用强于PGE1注射剂,可显著降低血压、维持管径和血流速度并增强微血管自律运动.
简介:摘要:本文采用微波水热法合成PEG-MoS2纳米球材料,研究发现PEG-MoS2生物毒性小,生物相容性好,在近红外区有很强的光吸收,可作为一种新型的纳米光热试剂。
简介:以漆酚(U)、环氧氯丙烷(ECH)、聚乙二醇(PEG)为原料制备一系列漆酚基乳化剂(UE).用IR、^1H-NMR对UE的结构进行表征,用吊片法测定UE水溶液的表面张力,并研究了UE的溶解性、乳化性、起泡高度等性能.结果表明:UE仍然保留了漆酚分子的不饱和长侧链;所制得的UE均溶于水且都能较好地降低水溶液的表面张力,随着亲水基团PEG分子量的增大,UE降低表面张力的能力降低;PEG分子量对UE的起泡能力影响不大,但对UE乳化自油的能力影响较大,当PEG的分子量为1.0×10^3时,所制得的UE10的乳化能力最强.