Colloid and Polymer Science

, Volume 295, Issue 10, pp 1773–1785 | Cite as

Radical polymerization of capillary bridges between micron-sized particles in liquid bulk phase as a low-temperature route to produce porous solid materials

  • Katharina HaufEmail author
  • Kamran Riazi
  • Norbert Willenbacher
  • Erin Koos
Original Contribution


We present a generic and versatile low-temperature route to produce macroporous bodies with porosity and pore size distribution that are adjustable in a wide range. Capillary suspensions, where the minor fluid is a monomer, are used as precursors. The monomer is preferentially located between the particles, creating capillary bridges, resulting in a strong, percolating network. Thermally induced polymerization of these bridges at temperatures below 100 °C for less than 5 h and subsequent removal of the bulk fluid yields macroscopic, self-supporting solid bodies with high porosity. This process is demonstrated using methyl methacrylate and hydroxyethylmethacrlyate with glass particles as a model system. The produced poly(methyl methacrylate) (PMMA) had a molecular weight of about 500,000 g/mol and dispersity about three. Application specific porous bodies, including PMMA particles connected by PMMA bridges, micron-sized capsules containing phase change material with high inner surface, and porous graphite membranes with high electrical conductivity, are also shown.


Membranes Microparticles Microscopy (electron, fluorescence) Phase-change materials Rheological properties 1H-NMR Capillary bridges Capillary suspensions Poly(methyl methacrylate) Radical polymerization 



The authors would like to thank Jonas Keller and Christoph Pfeifer for fruitful discussions, as well as Carolyn Benner for contributing of physical properties of Micronal PCM materials and Frank Schultz and Stefanie Stadler from Freudenberg Technology Innovation SE for μ-Tomography images. Furthermore, we would like to thank Volker Zibat from LEM for SEM and 3M for providing glass hollow spheres iM16K, as well as BASF SE for providing the Micronal DS particles and Altuglas International for providing the PMMA particles. Additionally, we would like to acknowledge financial support from the European Research Council under the European Union’s Seventh Framework Program (FP/2007-2013)/ERC Grant Agreement no. 335380.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no competing interests.

Supplementary material

396_2017_4149_Fig11_ESM.gif (190 kb)
ESM 1:

Glass spheres iM16K OTES (hydrophobic) as received with attached nanoparticles (GIF 189 kb)

396_2017_4149_MOESM1_ESM.tif (951 kb)
High Resolution Image (TIFF 951 kb)
396_2017_4149_Fig12_ESM.gif (308 kb)
ESM 2:

Glass spheres iM16K (hydrophilic) as received with attached nanoparticles (GIF 308 kb)

396_2017_4149_MOESM2_ESM.tif (951 kb)
High Resolution Image (TIFF 951 kb)
396_2017_4149_Fig13_ESM.gif (71 kb)
ESM 3:

μ-CT image of a solid porous sample made of 40 vol % hollow glass spheres with 6 vol % MMA at 82 °C for 2.5 h. (GIF 71 kb)

396_2017_4149_MOESM3_ESM.tif (347 kb)
High Resolution Image (TIFF 347 kb)
396_2017_4149_Fig14_ESM.gif (30 kb)
ESM 4:

Example for SEC analysis of the molecular weight distribution for a bridge sample extracted after polymerization of a capillary suspension with 40 vol % solid fraction and 6 vol % MMA at 84 °C for 5 h with 15 mg/ml BPO. (GIF 29 kb)

396_2017_4149_MOESM4_ESM.tif (416 kb)
High Resolution Image (TIFF 415 kb)
396_2017_4149_Fig15_ESM.gif (133 kb)
ESM 5:

The atomic composition of both the neck and the particle surface of porous materials made of hydrophilic glass spheres (Φsolid = 40 vol %) and HEMA as secondary phase (ΦHEMA = 4 vol %) using Energy-dispersive X-ray spectroscopy (EDX) in the ESEM-mode. The samples were polymerized in paraffin oil with 15 mg BPO/ml HEMA at 82 °C for 2.5 h and afterwards extracted with hexane. (GIF 133 kb)

396_2017_4149_MOESM5_ESM.tif (1.2 mb)
High Resolution Image (TIFF 1210 kb)
396_2017_4149_Fig16_ESM.gif (65 kb)
ESM 6:

Confocal image of 35 vol % PMMA particles and 3 vol % MMA in glycerine-water-bulk (60/40 wt %). The confocal image is a flattened image with a depth of 25.1 μm. (GIF 64 kb)

396_2017_4149_MOESM6_ESM.tif (429 kb)
High Resolution Image (TIFF 428 kb)
396_2017_4149_Fig17_ESM.gif (77 kb)
ESM 7:

Confocal image of 35 vol % Micronal particles and 3 vol MMA in glycerine-water-bulk (60/40 wt %). (GIF 76 kb)

396_2017_4149_MOESM7_ESM.tif (458 kb)
High Resolution Image (TIFF 458 kb)
396_2017_4149_Fig18_ESM.gif (171 kb)
ESM 8:

Graphite particles (GIF 170 kb)

396_2017_4149_MOESM8_ESM.tif (443 kb)
High Resolution Image (TIFF 443 kb)


  1. 1.
    Kumar R, Bhattacharjee B (2003) Porosity, pore size distribution and in-situ strength of concrete Cem Concr Res 33(1):155–164. doi: 10.1016/S0008-8846(02)00942-0 CrossRefGoogle Scholar
  2. 2.
    Babu CHA, Rao MP, Ratna JV (2010) Controlled-porosity osmotic pump tablets-an overview J Pharm Res Health Care 2(1):114–126Google Scholar
  3. 3.
    Tunón Å, Börjesson E, Frenning G, Alderborn G (2003) Drug release from reservoir pellets compacted with some excipients of different physical properties Eur J Pharm Sci 20(4–5):469–479. doi: 10.1016/j.ejps.2003.09.009 CrossRefGoogle Scholar
  4. 4.
    Tunón Å, Gråsjö J, Alderborn G (2003) Effect of intragranular porosity on compression behaviour of and drug release from reservoir pellets Eur J Pharm Sci 19(5):333–344. doi: 10.1016/S0928-0987(03)00106-4 CrossRefGoogle Scholar
  5. 5.
    Ulbricht M (2006) Advanced functional polymer membranes Polymer 47(7):2217–2262. doi: 10.1016/j.polymer.2006.01.084 CrossRefGoogle Scholar
  6. 6.
    Dittmann J, Koos E, Willenbacher N (2013) Ceramic capillary suspensions: novel processing route for macroporous ceramic materials J Am Ceram Soc 96(2):391–397. doi: 10.1111/jace.12126 Google Scholar
  7. 7.
    Maurath J, Dittmann J, Schultz N, Willenbacher N (2015) Fabrication of highly porous glass filters using capillary suspension processing Sep Purif Technol 149:470–478. doi: 10.1016/j.seppur.2015.06.022 CrossRefGoogle Scholar
  8. 8.
    Lee M, Park JK, Lee HS, Lane O, Moore RB, McGrath JE, Baird DG (2009) Effects of block length and solution-casting conditions on the final morphology and properties of disulfonated poly(arylene ether sulfone) multiblock copolymer films for proton exchange membranes Polymer 50(25):6129–6138. doi: 10.1016/j.polymer.2009.10.023 CrossRefGoogle Scholar
  9. 9.
    Vankelecom IFJ (2002) Polymeric membranes in catalytic reactors Chem Rev 102(10):3779–3810. doi: 10.1021/cr0103468 CrossRefGoogle Scholar
  10. 10.
    Tabatabaei SH, Carreau PJ, Ajji A (2008) Microporous membranes obtained from polypropylene blend films by stretching J Memb Sci 325(2):772–782. doi: 10.1016/j.memsci.2008.09.001 CrossRefGoogle Scholar
  11. 11.
    Lee SY, Park SY, Song HS (2006) Lamellar crystalline structure of hard elastic HDPE films and its influence on microporous membrane formation Polymer 47(10):3540–3547. doi: 10.1016/j.polymer.2006.03.070 CrossRefGoogle Scholar
  12. 12.
    Tabatabaei SH, Carreau PJ, Ajji A (2009) Microporous membranes obtained from PP/HDPE multilayer films by stretching J Memb Sci 345(1–2):148–159. doi: 10.1016/j.memsci.2009.08.038 CrossRefGoogle Scholar
  13. 13.
    Stropnik C, Germic L, Zerjal B (1996) Morphology variety and formation mechanisms of polymeric membranes prepared by wet phase inversion J Appl Polym Sci 61(10):1821–1830. doi: 10.1002/(SICI)1097-4628(19960906)61:10<1821::AID-APP24%3C3.0.CO;2-3 CrossRefGoogle Scholar
  14. 14.
    Wienk IM, Boom RM, Beerlage MAM, Bulte AMW, Smolders CA, Strathmann H (1996) Recent advances in the formation of phase inversion membranes made from amorphous or semi-crystalline polymers J Memb Sci 113(2):361–371. doi: 10.1016/0376-7388(95)00256-1 CrossRefGoogle Scholar
  15. 15.
    Pinnau I, Freeman BD (1999) Formation and modification of polymeric membranes: overview Membr Form Modif 744:1. doi: 10.1021/bk-2000-0744.ch001 Google Scholar
  16. 16.
    Li D, Chung TS, Wang R (2004) Morphological aspects and structure control of dual-layer asymmetric hollow fiber membranes formed by a simultaneous co-extrusion approach J Memb Sci 243(1–2):155–175. doi: 10.1016/j.memsci.2004.06.014 CrossRefGoogle Scholar
  17. 17.
    Jeong BH, Hoek VEM, Yan Y, Subramani A, Huang X, Hurwitz G, Ghosh AK, Jawor A (2007) Interfacial polymerization of thin film nanocomposites: a new concept for reverse osmosis membranes J Memb Sci 294(1–2):1–7. doi: 10.1016/j.memsci.2007.02.025 CrossRefGoogle Scholar
  18. 18.
    Song Y, Sun P, Henry LL, Sun B (2005) Mechanisms of structure and performance controlled thin film composite membrane formation via interfacial polymerization process J Memb Sci 251(1–2):67–79. doi: 10.1016/j.memsci.2004.10.042 CrossRefGoogle Scholar
  19. 19.
    Freger V (2003) Nanoscale heterogeneity of polyamide membranes formed by interfacial polymerization Langmuir 19(11):4791–4797. doi: 10.1021/la020920q CrossRefGoogle Scholar
  20. 20.
    Zou L, Vidalis I, Steele D, Michelmore A, Low SP, Verberk JQJC (2011) Surface hydrophilic modification of RO membranes by plasma polymerization for low organic fouling J Memb Sci 369(1–2):420–428. doi: 10.1016/j.memsci.2010.12.023 CrossRefGoogle Scholar
  21. 21.
    Silverstein MS (2014) Emulsion-templated porous polymers: a retrospective perspective Polym 55(1):304–320. doi: 10.1016/j.polymer.2013.08.068 CrossRefGoogle Scholar
  22. 22.
    Dittmann J, Maurath J, Bitsch B, Willenbacher N (2015) Highly porous materials with unique mechanical properties from smart capillary suspensions Adv Mater 28(8):1689–1696. doi: 10.1002/adma.201504910 CrossRefGoogle Scholar
  23. 23.
    Studart AR, Gonzenbach UT, Akartuna I, Tervoort E, Gauckler LJ (2007) Materials from foams and emulsions stabilized by colloidal particles J Mater Chem 17(31):3283. doi: 10.1039/B703255B CrossRefGoogle Scholar
  24. 24.
    Yan F, Goedel WA (2004) A simple and effective method for the preparation of porous membranes with three-dimensionally arranged pores Adv Mater 16(11):911–915. doi: 10.1002/adma.200306419 CrossRefGoogle Scholar
  25. 25.
    Hemmerle A, Schröter M, Goehring L (2016) A tunable cohesive granular material Nat Publ Gr:1–12. doi: 10.1038/srep35650
  26. 26.
    Kiesow I, Marczewski D, Reinhardt L, Mühlmann M, Possiwan M, Goedel WA (2013) Bicontinuous zeolite polymer composite membranes prepared via float casting J Am Chem Soc 135(11):4380–4388. doi: 10.1021/ja311785f CrossRefGoogle Scholar
  27. 27.
    Koos E, Willenbacher N (2011) Capillary forces in suspension rheology Science 331(1994):897–900. doi: 10.1126/science.1199243 CrossRefGoogle Scholar
  28. 28.
    Bossler F, Koos E (2016) Structure of particle networks in capillary suspensions with wetting and nonwetting fluids Langmuir 32(6):1489–1501. doi: 10.1021/acs.langmuir.5b04246 CrossRefGoogle Scholar
  29. 29.
    Bossler F, Weyrauch L, Schmidt R, Koos E (2017) Influence of mixing conditions on the rheological properties and structure of capillary suspensions Colloids and Surfaces A: Physicochem Eng Aspects:1–40. doi: 10.1016/j.colsurfa.2017.01.026
  30. 30.
    Domenech T, Yang J, Heidlebaugh S, Velankar SS (2016) Three distinct open-pore morphologies from a single particle-filled polymer blend Phys Chem Chem Phys 18(6):4310–4315. doi: 10.1039/C5CP07576A CrossRefGoogle Scholar
  31. 31.
    Uemura T, Kitagawa S (2006) Polymerization in confined geometries. In: Materials Science and Technology, Wiley-VCH Verlag GmbH & Co. KGaAGoogle Scholar
  32. 32.
    Petrie RJ (2006) Polymerization in confined geometries. North Carolina State University, DissertationGoogle Scholar
  33. 33.
    de Rooij R, Potanin AA, van den Ende D, Mellema J (1993) steady shear viscosity of weakly aggregating polystyrene latex dispersions J Chem Phys 99(11):9213. doi: 10.1063/1.465537 CrossRefGoogle Scholar
  34. 34.
    Zhang J, Zhao H, Li W, Xu M, Liu H (2015) Multiple effects of the second fluid on suspension viscosity Sci Rep 5(130):16058. doi: 10.1038/srep16058 CrossRefGoogle Scholar
  35. 35.
    Domenech T, Velankar S (2014) Capillary-driven percolating networks in ternary blends of immiscible polymers and silica particles Rheol Acta 53(8):593–605. doi: 10.1007/s00397-014-0776-0 CrossRefGoogle Scholar
  36. 36.
    Velankar SS (2015) A non-equilibrium state diagram for liquid/fluid/particle mixtures Soft Matter 11:8393–8403. doi: 10.1039/C5SM01901J CrossRefGoogle Scholar
  37. 37.
    Bovey FA, Jelinski L, Mirau PA (1988) Nuclear magnetic resonance spectroscopy. ACADEMIC PRESS, San DiegoGoogle Scholar
  38. 38.
    Smith LM, Coote ML (2013) Effect of temperature and solvent on polymer tacticity in the free-radical polymerization of styrene and methyl methacrylate J Polym Sci Part A Polym Chem 51(16):3351–3358. doi: 10.1002/pola.26745 CrossRefGoogle Scholar
  39. 39.
    Matyjaszewski K (2010) Radical polymerization. Wiley, Encyclopedia of Polymer Science and Technology, pp. 359–473Google Scholar
  40. 40.
    Odian G (2004) Principles of polymerization. Wiley, New JerseyCrossRefGoogle Scholar
  41. 41.
    Moad G (2012) Radical polymerization. Elsevier, Clayton, pp. 59–118Google Scholar
  42. 42.
    Ober CK, Lok KP (1987) Formation of large monodisperse copolymer particles by dispersion polymerization Macromolecules 20(2):268–273. doi: 10.1021/ma00168a007 CrossRefGoogle Scholar
  43. 43.
    Paine AJ, Luymes W, McNulty J (1990) 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 23(12):3104–3109. doi: 10.1021/ma00214a012 CrossRefGoogle Scholar
  44. 44.
    Gibson LJ, Ashby MF (1997) Cellular solids: structure and properties. Cambridge University Press, CambridgeCrossRefGoogle Scholar

Copyright information

© Springer-Verlag GmbH Germany 2017

Authors and Affiliations

  • Katharina Hauf
    • 1
    Email author
  • Kamran Riazi
    • 2
  • Norbert Willenbacher
    • 1
  • Erin Koos
    • 1
    • 3
  1. 1.KIT—Campus Süd, Arbeitsgruppe Angewandte MechanikInstitut für Mechanische Verfahrenstechnik und MechanikKarlsruheGermany
  2. 2.Institute for Chemical Technology and Polymer Chemistry (ITCP), Karlsruhe Institute of Technology (KIT)MZEKarlsruheGermany
  3. 3.Department of Chemical Engineering (CIT)KU LeuvenLeuvenBelgium

Personalised recommendations