Hollow spherical micro/meso-porous silica structure by nanospherical sacrificial polystyrene templates

Abstract

In this study, spherical polystyrene (PS) nanoparticles having a negative surface charge were synthesized by polymerization of a miniemulsion containing styrene monomer, normal hexadecane (HD) as hydrophobic agent, sodium dodecyl sulfate (SDS) as anionic emulsifier, sodium bicarbonate (NaHCO₃) as buffer, and water soluble potassium persulfate (KPS) as initiator. The effects of three important parameters (surfactant, cosurfactant, and initiator) on particle size and size distribution were contemporaneously investigated. The particle size and size distribution was measured using dynamic light scattering (DLS). Transmission electron microscopy (TEM) images were also taken from the corresponding latexes to confirm the results. The produced polystyrene particles were coated by silica via sol-gel process in which tetraethyl orthosilicate (TEOS) precursor, ethanol, hydrochloric acid, and water were employed to carry out hydrolyzation/condensation process. Using ultra-high speed centrifugation, a closely packed assembly of particles resulted which were subjected to calcination process to form hallow spherical micro/meso-porous silica structure. The average pore diameters of the micro and meso pores were 2–3 nm and 25–30 nm, respectively, as determined by nitrogen sorption isotherms. The specific surface of the porous sample was also measured by Brunauer, Emmett, and Teller (BET) method to be 554.74 m²/g that is well suited for catalyst support applications. In the end, the produced catalyst support was used to form ziegler-natta catalyst. By using the produced catalyst via prepolymerization and slurry polymerization at 70℃, polypropylene was polymerized from propylene.

Keywords

Micro/meso-porous silica structure sacrificial template polystyrene nanoparticles miniemulsion polymerization

Get full access to this article

View all access options for this article.

References

Rouquerol

Avnir

Fairbridge

. Recommendations for the characterization of porous solids. Pure Appl Chem 1994; 66: 1739–1758.

Lou

XWD

Archer

Yang

. Hollow micro-/nanostructures: synthesis and applications. Adv Mater 2008; 20: 3987–4019.

Wang

Angelatos

Caruso

. Template synthesis of nanostructured materials via layer-by-layer assembly. Chem Mater 2008; 20: 848–858.

Lee

Park

Song

. Nanoreactor framework of a Au@SiO₂ yolk/shell structure for catalytic reduction of p-Nitrophenol. Adv Mater 2008; 20: 1523–1528.

Sun

Liu

. Use of carbonaceous polysaccharide microspheres as templates for fabricating metal oxide hollow spheres. Chem Eur J 2008; 12: 2039–2047.

Kalajahi

Haddadi-Asl

Mamaqani

. Study of kinetics and properties of polystyrene/silica nanocomposites prepared via in situ free radical and reversibleaddition-fragmentation chain transfer polymerizations. Scientia Iranica 2012; 19: 2004–2011.

Kongsinlark

Garry

Prasassarakich

. Synthesis of monodispersedpolyisoprene–silica nanoparticles via differential microemulsion polymerization and mechanical properties of polyisoprenenanocomposite. Chem Eng J 2012; 193–194: 215–226.

Min

Wan

Liu

. Novel hollow sub-microspheres with movable Au nanoparticles and excessive Pt nanoparticles in core and silica as shell. Mater Chem Phys 2008; 111: 364–367.

Lou

Wang

Yuan

. Template-free synthesis of SnO₂ hollow nanostructures with high lithium storage capacity. Adv Mater 2012; 18: 2325–2329.

10.

Ikeda

Harada

. Fabrication of hollow carbon nanospheres encapsulating platinum nanoparticles using a photocatalytic reaction. Adv Mater 2012; 19: 597–601.

11.

Song

Gao

. Synthesis, characterization, and optical properties of well-defined N-doped, hollow silica/titania hybrid microspheres. Langmuir 2012; 23: 11850–11856.

12.

Han

Jang

Kim

. Simple synthesis of hollow tin dioxide microspheres and their application to lithium-ion battery anodes. Adv Func Mater 2012; 15: 1845–1850.

13.

Wang

Zhang

Wang

. Synthesis of hollow mesoporous silica microspheres through surface sol–gel process on polystyrene-co-poly(4-vinylpyridine) core–shell microspheres. Micropor Mesopor Mater 2011; 139: 1–7.

14.

Hong

Lee

Rhym

. Polyelectrolyte-assisted synthesis of polystyrene microspheres by dispersion polymerization and the subsequent formation of silica shell. J Colloid Interf Sci 2010; 344: 410–416.

15.

Yoon

Kim

. Template synthesis of nanostructured silica with hollow core and mesoporous shell structures. Curr Appl Phys 2006; 6: 1059–1063.

16.

Hwang

Bae

Kim

. Synthesis of silica–polystyrene core–shell nanoparticles via surface thiol-lactam initiated radical polymerization. Euro Polym J 2006; 46: 1654–1659.

17.

Zhang

Yuan

. A facile method for the fabrication of vinyl functionalized hollow silica spheres. J Colloid Interf Sci 2009; 331: 389–393.

18.

Gogotsi

Nikitin

. Nanoporous carbide-derived carbon with tunable pore size. Nat Mater 2003; 2: 591–594.

19.

Zdravkov

Čermák

Šefara

. Pore classification in the characterization of porous materials: A perspective. Cent Eur J Chem 2007; 5: 385–395.

20.

Zhu

Qiu

Terasaki

. Polystyrene bead-assisted self-assembly of microstructured silica hollow spheres in highly alkaline media. J Am Chem Soc 2001; 123: 7723–7724.

21.

Zhang

Yang

. SiO₂/Polymer hybrid hollow microspheres via double in situ miniemulsion polymerization. Macromolecules 2010; 43: 1188–1190.

22.

Ethirajan

Landfester

. Functional hybrid materials with polymer nanoparticles as templates. Chem Eur J 2010; 16: 9398–9412.

23.

Zanetti-Ramos

Lemos-Senna

Cramail

. The role of surfactant in the miniemulsion polymerization of biodegradable polyurethane nanoparticles. Mater Sci Eng C 2008; 28: 526–531.

24.

Schork

Poehlein

Wang

. Miniemulsion polymerization. Colloid Surf A Physiochem Eng Aspects 1999; 153: 39–45.

25.

Mittal V (ed.). Miniemulsion Polymerization Technology, Vol. 34. Wiley, 2011.

26.

Romio

Bernardy

Senna

. Polymeric nanocapsules via miniemulsion polymerization using redox initiation. Mater Sci Eng C 2009; 29: 514–518.

27.

Yildiz

Landfester

. Miniemulsion polymerization of styrene in the presence of macromonomeric initiators. Polymer 2008; 49: 4930–4934.

28.

Elizalde

Leal

Leiza

. Particle size distribution measurements of polymericdispersions: a comparative study. Part Part Sys Char 2000; 17: 236–243.

29.

Landfester

Bechthold

Tiarks

. Formulation and stability mechanisms of polymerizable miniemulsions. Macromolecules 1999; 32: 5222–5228.

30.

Taniguchi

Takeuchi

Kobaru

. Preparation of highly monodisperse fluorescent polymer particles by miniemulsion polymerization of styrene with a polymerizable surfactant. J Colloid Interf Sci 2008; 327: 58–62.

31.

Jeng

Dai

Chiu

. Influence of hexadecane on the formation of droplets and growth of particles for methyl methacrylate miniemulsion polymerization. J Polym Sci A Polym Chem 2006; 44: 4603–4610.

32.

Afshar

Pourmahdian

Afshar

. Synthesis of nanotemplates using miniemulsion polymerization in order to prepare mesoporous ZN-catalyst-support for catalytic polymerization of propylene , Tehran, Iran: Amirkabir University, 2009.

33.

Hecht

Wagner

Landfester

. Surfactant concentration regime in miniemulsion polymerization for the formation of MMA nanodroplets by high-pressure homogenization. Langmuir 2011; 27: 2279–2285.

34.

Wang

Zhang

. Preparation of polystyrene particles with narrow particle size distribution of γ-ray initiated miniemulsion polymerization stabilized by polymeric surfactant. Eur Polym J 2007; 43: 178–184.

35.

Jia

Tan

. Monomer emulsification and polymerization kinetics in styrene miniemulsion. Iran Polym J 2006; 15: 979–987.

36.

Choi

El-Aasser

Sudol

. Polymerization of styrene miniemulsions. J Polym Sci A Polym Chem 1985; 23: 2973–2987.

37.

Hench

West

. The sol-gel process. Chem Rev 1990; 90: 33–72.

38.

Sing

KSW

Everett

Haul

RAW

. Reporting physisorption data for gas/solid systems with special reference to the determination of surface area and porosity. Pure Appl Chem 1985; 57: 603–619.