二氧化硅空心微球是由模板/溶胶-凝胶法制备的,其中模板选用的是阳离子型聚苯乙烯(PS),前驱体采用的是正硅酸乙酯(TEOS).二氧化硅空心微球的空腔大小由PS模板的尺寸决定,所以通过改变聚合反应的参数(单体、引发剂、稳定剂、分散介质的极性),可以制得粒径范围在0.71～1.80μm的二氧化硅空心微球.改变TEOS的浓度为0.4～0.8mmol/L,可以得到壁厚为20～60nm的二氧化硅空心微球.空心微球的粒径和壁厚将会影响粉体的堆积密度,而这同样会影响到以二氧化硅空心微球为原料制备的材料的热导率及强度.
Hollow silica spheres were synthesized by template/Sol-Gel approach,using cationic polystyrene (PS) as template and tetraethoxysilane (TEOS) as precursor.The void size of hollow silica sphere was decided by the diameter of their PS templates.Hollow silica spheres with controllable size between 0.71 μm and 1.8 μm were obtained by varying the parameters of polymerization (the monomer,the initiator,the stabilizer and the polarity of the dispersion medium).The shell thickness of hollow silica spheres could be easily changed in the range of 20 nm to 60 nm by changing the TEOS concentration from 0.4 mmo/L to 0.8 mmol/L.Both the size and shell thickness of hollow silica spheres have effects on their bulk density,the thermal conductivity and strength of materials.
参考文献
| [1] | Deng Z,Chen M,Zhou S,et al.A novel method for the fabrication of monodisperse hollow silica spheres.Langmuir,2006,22(14):6403-6407. |
| [2] | Chen M,Wu L M,Zhou S X,et al.A method for the fabrication of monodisperse hollow silica spheres.Advanced Materials,2006,18(6):801 806. |
| [3] | Corcos F,Bourgeat-Lami E,Novat C,et al.Poly(styrene-b-ethylene oxide) copolymers as stabilizers for the synthesis of silica-poly-styrene core-shell particles.Colloid & Polymer Science,1999,277(12):1142-1151. |
| [4] | Lu Y,McLellan J,Xia Y N.Synthesis and crystallization of hybrid spherical colloids composed of polystyrene cores and silica shells.Langmuir,2004,20(8):3464-3470. |
| [5] | Zhong Z Y,Yin Y D,Gates B,et al.Preparation of mesoscale hollow spheres of TiO2 and SnO2 by templating against crystalline arrays of polystyrene beads.Advanced Materials,2000,12(3):206-209. |
| [6] | Lee J,Hong C K,Choe S,et al.Synthesis of polystyrene/silica composite particles by soap-free emulsion polymerization using positively charged colloidal silica.Journal of Colloid and Interface Science,2007,310(1):112-120. |
| [7] | Tissot I,Reymond J P,Lefebvre F,et al.SiOH-functionalized polystyrene latexes.A step toward the synthesis of hollow silica nanoparticles.Chemistry of Materials,2002,14(3):1325-1331. |
| [8] | Bertling J,blomer J,Kummel R.Hollow microspheres.Chemical Engineering & Technology,2004,27(8):829-837. |
| [9] | Barbe C,Bartlett J,Kong L G,et al.Silica particles:a novel drug-delivery system.Advanced Materials,2004,16(21):1959-1966. |
| [10] | Tavman I H.Effective thermal conductivity of granular porous materials.International Communications in Heat and Mass Transfer,1996,23(2):169-176. |
| [11] | Fiedler T,Hosseini S M H,Belova I V,et al.A refined finite element analysis on the thermal conductivity of perforated hollow sphere structures.Computational Materials Science,2009,47(2):314-319. |
| [12] | Hass D D,Prasad B D,Glass D E,et al.Reflective coating on fibrous insulation for reduced head heat transfer.NASA,1997. |
| [13] | Korb L J,Morant C A,Calland R M,et al.The shuttle orbiter thermal protection system.American Ceramic Society Bulletin,1981,60(11):1188-1193. |
| [14] | Rohsenow W.Basic Mannual for Heat Transfer.1992. |
| [15] | Hong J,Hong C K,Shim S E.Synthesis of polystyrene microspheres by dispersion polymerization using poly(vinyl alcohol) as a steric stabilizer in aqueous alcohol media.Colloids and Surfaces a-Physicochemical and Engineering Aspects,2007,302(1/2/3):225-233. |
| [16] | Hong J,Lee J,Rhym Y M,et al.Polyelectrolyte-assisted synthesis of polystyrene microspheres by dispersion polymerization and the subsequent formation of silica shell.Journal of Colloid and Interface Science,2010,344(2):410-416. |
| [17] | Zhang X,Shen S H,Fan L Y.Uniform polystyrene particles by dispersion polymerization in different dispersion medium.Polymer Bulletin,2008,61(1):19-26. |
| [18] | Zhang F,Cao L,Yang W T.Preparation of monodisperse and anioncharged polystyrene microspheres stabilized with polymerizable sodium styrene sulfonate by dispersion polymerization.Macromolecular Chemistry and Physics,2010,211(7):744-751. |
| [19] | Paine A J,Luymes W,McNulty J.Dispersion polymerization of styrene in polar solvents.6.Influence of reaction parameters on particle size and molecular weight in poly(N-vinylpyrrolidone)stabilized reactions.Macromolecules,1990,23(12):3104-3109. |
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