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Rheologica Acta

, Volume 49, Issue 3, pp 285–298 | Cite as

Interfacially active particles in droplet/matrix blends of model immiscible homopolymers: Particles can increase or decrease drop size

  • Prachi Thareja
  • Kevin Moritz
  • Sachin S. VelankarEmail author
Original Contribution

Abstract

Particles have been shown to adsorb at the interface between immiscible homopolymer melts and to affect the morphology of blends of those homopolymers. We examined the effect of such interfacially active particles on the morphology of droplet/matrix blends of model immiscible homopolymers. Experiments were conducted on blends of polydimethylsiloxane and 1,4-polyisoprene blended in either a 20:80 or 80:20 weight ratio. The effects of three different particle types, fluoropolymer particles, iron particles, and iron oxyhydroxide particles, all at a loading of 0.5 vol.%, were examined by rheology and by direct flow visualization. Particles were found to significantly affect the strain recovery behavior of polymer blends, increasing or decreasing the ultimate recovery, slowing down or accelerating the recovery kinetics, and changing the dependence of these parameters on the applied stress prior to cessation of shear. These rheological observations were found to correlate reasonably well with particle-induced changes in drop size. The particles can both increase as well as decrease the drop size, depending on the particle type, as well as on which phase is continuous. The cases in which particles cause a decrease in drop size are analogous to the particle stabilization of “Pickering emulsions” well-known from the literature on oil/water systems. We hypothesize that cases in which particles increase drop size are analogous to the “bridging–dewetting” mechanism known in the aqueous foam literature.

Keywords

Polymer blends Pickering emulsions Strain recovery Interfacial tension Compatibilizers 

Notes

Acknowledgements

We thank Rhodia Silicones and Kuraray America for providing the PDMS and PI homopolymers, respectively. We are grateful to Elementis Inc., Dyneon Corp., and Prof. Phule (University of Pittsburgh) for making particles available for this research. This research was supported by a CAREER grant CBET- 0448845 from the National Science Foundation, USA.

References

  1. Ashby NP, Binks BP, Paunov VN (2004) Bridging interaction between a water drop stabilised by solid particles and a planar oil/water interface. Chem Comm (4): 436–437Google Scholar
  2. Binks BP (2002) Particles as surfactants—similarities and differences. Curr Opin Colloid Interface Sci 7:21–41CrossRefGoogle Scholar
  3. Binks BP, Horozov TS (2006) Colloidal particles at liquid interfaces. Cambridge University Press, CambridgeCrossRefGoogle Scholar
  4. Cheng HL, Velankar SS (2008) Film climbing of particle-laden interfaces. Colloid Surf A 315:275–284CrossRefGoogle Scholar
  5. Cheng HL, Velankar SS (2009) Interfacial jamming of particle-laden interfaces studied in a spinning drop tensiometer. Langmuir 25:4412–4420CrossRefPubMedGoogle Scholar
  6. Datta S, Lohse DJ (1996) Polymeric compatibilizers. Hanser, MunichGoogle Scholar
  7. Denkov ND, Marinova KG (2006) Antifoam effects of solid particles, oil drops, and oil-solid compounds in aqueous foams. In: Binks BP, Horozov TS (eds) Colloidal particles at liquid interfaces. Cambridge University Press, CambridgeGoogle Scholar
  8. Dickinson E (2006) Interfacial particles in food emulsions and foams. In: Binks BP, Horozov TS (eds) Colloidal particles at liquid interfaces. Cambridge University Press, CambridgeGoogle Scholar
  9. Elias L, Fenouillot F, Majeste JC, Cassagnau P (2007) Morphology and rheology of immiscible polymer blends filled with silica nanoparticles. Polymer 48:6029–6040CrossRefGoogle Scholar
  10. Elias L, Fenouillot F, Majeste JC, Martin G, Cassagnau P (2008) Migration of nanosilica particles in polymer blends. J Polym Sci Polym Phys 46:1976–1983. doi: 10.1002/polb.21534 CrossRefGoogle Scholar
  11. Fenouillot F, Cassagnau P, Majeste JC (2009) Uneven distribution of nanoparticles in immiscible fluids: Morphology development in polymer blends. Polymer 50:1333–1350. doi: 10.1016/j.polymer.2008.12.029 CrossRefGoogle Scholar
  12. Garrett PR (1993) Mode of action of antifoams. In: Garrett PR (ed) Defoaming. Marcel Dekker, New YorkGoogle Scholar
  13. Graebling D, Muller R, Palierne JF (1993) Linear viscoelastic behavior of some incompatible polymer blends in the melt. Interpretation of data with a model of emulsion of viscoelastic liquids. Macromolecules 26:320–329Google Scholar
  14. Gramespacher H, Meissner J (1995) Reversal of recovery direction during creep recovery of polymer blends. J Rheol 39:151–160CrossRefADSGoogle Scholar
  15. Gubbels F, Jerome R, Teyssie P, Vanlathem E, Deltour R, Calderone A, Parente V, Bredas JL (1994) Selective localization of carbon-black in immiscible polymer blends—a useful tool to design electrical conductive composites. Macromolecules 27:1972–1974CrossRefADSGoogle Scholar
  16. Hong JS, Namkung H, Ahn KH, Lee SJ, Kim C (2006) The role of organically modified layered silicate in the breakup and coalescence of droplets in PBT/PE blends. Polymer 47:3967–3975CrossRefGoogle Scholar
  17. Horozov TS, Binks BP (2006) Particle-stabilized emulsions: a bilayer or a bridging monolayer? Angew Chemie Int Ed 45:773–776CrossRefGoogle Scholar
  18. Kitade S, Ichikawa A, Imura N, Takahashi Y, Noda I (1997) Rheological properties and domain structures of immiscible polymer blends under steady and oscillatory shear flows. J Rheol 41:1039–1060CrossRefADSGoogle Scholar
  19. Kosaric N, Cairns WL, Gray NCC (1987) Microbial deemulsifiers. In: Kosaric N, Cairns WL, Gray NCC (eds) Biosurfactants and biotechnology, vol 25. Marcel Dekker, New York, pp 247–321Google Scholar
  20. Macosko CW, Guegan P, Khandpur AK, Nakayama A, Marechal P, Inoue T (1996) Compatibilizers for melt blending: premade block copolymers. Macromolecules 29:5590–5598CrossRefADSGoogle Scholar
  21. Martin JD (2007) The efof surface-active block copolymers on two-phase flow. PhD thesis, Chemical Engineering, University of Pittsburgh, PittsburghGoogle Scholar
  22. Martin JD, Velankar SS (2007) Effects of compatibilizer on immiscible polymer blends near phase inversion. J Rheol 51:669–692CrossRefADSGoogle Scholar
  23. Milner ST, Xi H (1996) How copolymers promote mixing of immiscible homopolymers. J Rheol 40:663–687CrossRefADSGoogle Scholar
  24. Mizrahi J, Barnea E (1970) Effects of solid additives on the formation and separation of emulsions. Br Chem Eng 15:497–503Google Scholar
  25. Pugh RJ (1996) Foaming, foam films, antifoaming and defoaming. Adv Colloid Interface Sci 64:67–142CrossRefGoogle Scholar
  26. Ray SS, Pouliot S, Bousmina M, Utracki LA (2004) Role of organically modified layered silicate as an active interfacial modifier in immiscible polystyrene/polypropylene blends. Polymer 45:8403–8413CrossRefGoogle Scholar
  27. Si M, Araki T, Ade H, Kilcoyne ALD, Fisher R, Sokolov JC, Rafailovich MH (2006) Compatibilizing bulk polymer blends by using organoclays. Macromolecules 39:4793–4801CrossRefADSGoogle Scholar
  28. Stancik EJ, Fuller GG (2004) Connect the drops: using solids as adhesives for liquids. Langmuir 20:4805–4808CrossRefPubMedGoogle Scholar
  29. Sumita M, Sakata K, Asai S, Miyasaka K, Nakagawa H (1991) Dispersion of fillers and the electrical conductivity of polymer blends filled with carbon black. Polymer Bull 25:266–271CrossRefGoogle Scholar
  30. Thareja P (2008) Study of particles at fluid/fluid interfaces. PhD Thesis, Chemical Engineering, University of Pittsburgh, PittsburghGoogle Scholar
  31. Thareja P, Velankar SS (2007) Particle-induced bridging in immiscible polymer blends. Rheol Acta 46:405–412CrossRefGoogle Scholar
  32. Thareja P, Velankar S (2008a) Rheology of immiscible blends with particle-induced drop clusters. Rheol Acta 47:189–200CrossRefGoogle Scholar
  33. Thareja P, Velankar SS (2008b) Interfacial activity of particles at PI/PDMS and PI/PIB interfaces: analysis based on Girifalco-Good theory. Colloid Polym Sci 286:1257–1264CrossRefGoogle Scholar
  34. Tucker CL, Moldenaers P (2002) Microstructural evolution in polymer blends. Ann Rev Fluid Mech 34:177–210CrossRefMathSciNetADSGoogle Scholar
  35. Van Hamme JD, Singh A, Ward OP (2003) Recent advances in petroleum microbiology. Microbiol Mol Biol Rev 67:503–549CrossRefPubMedGoogle Scholar
  36. Van Puyvelde P, Velankar S, Moldenaers P (2001) Rheology and morphology of compatibilized polymer blends. Curr Opin Colloid Interface Sci 6:457–463CrossRefGoogle Scholar
  37. Vermant J, Cioccolo G, Nair KG, Moldenaers P (2004) Coalescence suppression in model immiscible polymer blends by nano-sized colloidal particles. Rheol Acta 43:529–538CrossRefGoogle Scholar
  38. Vinckier I, Mewis J, Moldenaers P (1996) Relationship between rheology and morphology of model blends in steady shear flow. J Rheol 40:613–632CrossRefADSGoogle Scholar
  39. Vinckier I, Moldenaers P, Mewis J (1999) Elastic recovery of immiscible blends 1. Analysis after steady state shear flow. Rheol Acta 38:65–72CrossRefGoogle Scholar
  40. Wang J, Velankar S (2006a) Strain recovery of model immiscible blends without compatibilizer. Rheol Acta 45:297-304CrossRefGoogle Scholar
  41. Wang J, Velankar S (2006b) Strain recovery of model immiscible blends: effects of added compatibilizer. Rheol Acta 45:741–753CrossRefGoogle Scholar
  42. Zaikin AE, Zharinova EA, Bikmullin RS (2007) Specifics of localization of carbon black at the interface between polymeric phases. Polym Sci, Ser A 49:328–336CrossRefGoogle Scholar

Copyright information

© Springer-Verlag 2009

Authors and Affiliations

  • Prachi Thareja
    • 1
  • Kevin Moritz
    • 1
  • Sachin S. Velankar
    • 1
    Email author
  1. 1.Department of Chemical EngineeringUniversity of PittsburghPittsburghUSA

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