为了进一步提高二氧化钛（ TiO2）的反射率，采用乳液法结合溶胶 -凝胶法，以聚乙二醇（PEG）为相分离诱导剂，制备了内部具有不连续多孔结构的 TiO2微球。考察了 PEG的添加量对 TiO2微球内部孔径大小的影响。研究结果表明： TiO2微球内部的孔径随 PEG的用量增加而增大。基于溶胶-凝胶转变和相分离过程，详细介绍了多孔 TiO2微球的形成机理。当 PEG的添加量为 9.0%时，所制备的多孔 TiO2微球在近红外区的积分平均反射率为 84.9%，比常见钛白粉提高了 5.4%。
For improving reflectivity of titanium dioxide，porous titania（TiO2） micro. spheres with incontinuous multicavities were prepared via emulsion process accompanied bysol-gel reaction in the presence of polyethylene glycol（PEG）as phase separation inducer.Theeffect of the addition amount of PEG on internal pore size of TiO2 microspheres were studied.The results showed that the size of cavities inside microsphere increased gradually with in.creasing the amount of PEG.The cavity formation mechanism of porous TiO2 microspheres wasexplained in detail based on sol-gel transition and phase separation.When the mass ratios of PEG to tetrabutyl titanate was 9.0%，the average integrated reflectance of the prepared porous TiO2 microspheres in the near-infrared region was 84.9%，which was 5.4% higher than that of conventional titania.
[1]HANYL，TAYLOR J E，PISELLO A L. Toward mitigating urban heat island effects：investigating the thermal-energy impact of bio-inspired retro-reflective building envelopesin dense urban settings[J].[J].Energy and Buildings, 2015, 102:380-389
[2]杨茜，徐国跃，谭淑娟，等.二氧化钛涂层热反射性能影响因素研究[J].涂料工业, 2018, 48(3):64-68
[3]CAI H，MU W，LIU W，et al. Sol-gel synthesis highly porous titanium dioxide microspheres with cellulose nanofibrils-based aerogel templates[J].[J].Inorganic ChemistryCommunications, 2015, 51:71-74
[4]KAWASHITA M，TANAKA Y，UENO S，et al. In vitro apatite formation and drug loading release of porousTiO2 microspheres prepared by sol -gel processing withdifferent SiO2 nanoparticle contents[J].[J].Materials Science Engineering C, 2015, 50:317-323
[5]DINGGJ，ZHU Y J，QI C，et al.Porous microspheres ofamorphous calcium phosphate：block copolymer templated microwave-assisted hydrothermal synthesis and applicationin drug delivery[J].Journal of Colloid and Interface Science, 2015, 443(9):72-79
[6]PANJ，YIN Y，GAN M，et al. Fabrication and evaluation of molecularly imprinted multi-hollow microspheres adsorbentswith tunable inner pore structures derived from templatingPickering double emulsions[J].[J].Chemical Engineering Journal, 2015, 266:299-308
[7]WEIY，WANG Y，ZHANG H，et al. A novel strategy for thepreparation of porous microspheres and its application inpeptide drug loading[J].[J].J Colloid Interface Sci, 2016, 478:46-53
[8]TANG C，LIU L，LI Y，et al. Aerosol spray assisted assembly of TiO2 mesocrystals into hierarchical hollow microspheres with enhanced photocatalytic performance[J].[J].Applied Catalysis B：Environmental, 2017, 201:41-47
[9]CAIWW，YANG H，GUO X Z.A facile one-step route tosynthesize titania hollow microspheres with incontinuousmulticavities[J].Chinese Chemical Letters, 2014, 25(3):441-446
[10]GUOXZ，HAO G S，Xie Y，et al.Preparation of porouszirconia microspheres via emulsion method combined withphase separation[J].Journal of Sol-Gel Science and Technology, 2015, 76(3):651-657
[11]YANG H，XIE Y，HAO G S，et al.Preparation of porousalumina microspheres via an oil-in-water emulsion methodaccompanied by a sol-gel process[J].New Journal of Chemistry, 2016, 40(1):589-595
[12]ZHANG Q，WU F，YANG H，et al.Preparation and dielectric properties of(Ca061，Nd0. 26)TiO3 nanoparticles bya sol-gel method[J].Journal of Materials Chemistry, 2008, 18(44):5339-5343
[13]NAKANISHI K. Pore structure control of silica gels basedon phase separation[J].[J].Journal of Pourous Materials, 1997, 4:67-112
[14]NAKANISHI K，TANAKA N. Sol-gel with phase sepa-ration. Hierarchically porous materials optimized for high-performance liquid chromatography separations[J].[J].Accounts ofChemical Research, 2007, 40:863-873
[15]ROSS W D.Theoretical light-scattering power of TiO2 microviods[J].Industrial & Enginrrring Chemistry ProductResearch and Development, 1974, 13(1):45-49
[16]DIENEROWITZ M，MAZILU M，DHOLAKIA K.Optical manipulation of nanoparticles：a review[J].Journal of Nanophotonics, 2008, 2(1):269-270
