News Flash  

Sep. 2016: Second Workshop on Hierarchical Materials in Erlangen: RV with invited lecture on transport properties of hierarchical porous solids.

Sep. 2015: IUPAC has established the task group "Diffusion in nanoporous solids" involving us as the active members.

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Sep. 2015Our work on diffusion in hollow core-shell nanoparticles just appeared in Langmuir.

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Seminars  

R. Valiullin: Mesoporous materials -- Perspectives revealed by fluids confined in their pore spaces
Mo, 27.06.2016, 17:15–18:00
Universität Hamburg, Fachbereich Chemie, Martin-Luther-King-Platz 6, Hörsaal C

October 21-23, 2015
R. Valiullin: NMR Cryoporometry: From fundamentals to application
Workshop: Methods of Porosimetry and Applications (HZDR Dresden-Rossendorf)

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Among different experimental techniques, NMR cryoporometry provides unique options to probe various details of solid-liquid equilibria in porous solids. In particular, by applying specially designed nuclear magnetic relaxation filters, the phase composition of confined matter and its evolution upon temperature changes can directly be probed. In our work, we use this technique to study freezing and melting transitions of fluids confined to mesoporous host materials. These materials include ones with ordered and disordered pore structures, such as random porous glasses, ordered silicas, or nano-structured mesoporous silicon. With the experimental conditions under which our studies are performed, freezing closely resembles the process of layer-by-layer crystal growth. The kinetics of this process is essentially determined by the pore structure and the thermodynamic conditions with the occurrence of a multitude of metastable configurational states. Melting is controlled by similar mechanisms, but can appear more intricate. Due to their complexity, the analysis of the experimental data obtained on melting in freezing in confined spaces require the application of teoretical models capturing the microscopic details of solid-liquid equilibria. In our work, we base our analysis on the Kosel-Stranski crystal growth model, which we have recently adopted for confined fluids.

  1. D Kondrashova and R Valiullin. Freezing and Melting Transitions under Mesoscalic Confinement: Application of the Kossel–Stranski Crystal-Growth Model. J. Phys. Chem. C 119(8):4312-4323, 2015. BibTeX

    @article{2015,
    	author = "Kondrashova, D. and Valiullin, R.",
    	title = "Freezing and Melting Transitions under Mesoscalic Confinement: Application of the Kossel–Stranski Crystal-Growth Model",
    	journal = "J. Phys. Chem. C",
    	volume = 119,
    	number = 8,
    	pages = "4312-4323",
    	year = 2015
    }
    
  2. D Kondrashova and R Valiullin. Improving structural analysis of disordered mesoporous materials using NMR cryoporometry. Microporous Mesoporous Mat. 178:15-19, 2013. BibTeX

    @article{2013,
    	author = "Kondrashova, D. and Valiullin, R.",
    	title = "Improving structural analysis of disordered mesoporous materials using NMR cryoporometry",
    	journal = "Microporous Mesoporous Mat.",
    	volume = 178,
    	pages = "15-19",
    	year = 2013
    }
    
  3. D Kondrashova, M Dvoyashkin and R Valiullin. Structural characterization of porous solids by simultaneously monitoring the low-temperature phase equilibria and diffusion of intrapore fluids using nuclear magnetic resonance. New J. Phys. 13:015008, 2011. BibTeX

    @article{2011,
    	author = "Kondrashova, D. and Dvoyashkin, M. and Valiullin, R.",
    	title = "Structural characterization of porous solids by simultaneously monitoring the low-temperature phase equilibria and diffusion of intrapore fluids using nuclear magnetic resonance",
    	journal = "New J. Phys.",
    	volume = 13,
    	pages = 015008,
    	year = 2011
    }
    
  4. D Kondrashova, C Reichenbach and R Valiullin. Probing pore connectivity in random porous materials by scanning freezing and melting experiments. Langmuir 26:6380-6385, 2010. BibTeX

    @article{2010,
    	author = "Kondrashova, D. and Reichenbach, C. and Valiullin, R.",
    	title = "Probing pore connectivity in random porous materials by scanning freezing and melting experiments",
    	journal = "Langmuir",
    	volume = 26,
    	pages = "6380-6385",
    	year = 2010
    }
    
  5. M Dvoyashkin, A Khokhlov, R Valiullin and J Kärger. Freezing of fluids in disordered mesopores. J. Chem. Phys. 129:154702-6, 2008. BibTeX

    @article{2008,
    	author = "Dvoyashkin, M. and Khokhlov, A. and Valiullin, R. and Kärger, J.",
    	title = "Freezing of fluids in disordered mesopores",
    	journal = "J. Chem. Phys.",
    	volume = 129,
    	pages = "154702-6",
    	year = 2008
    }
    
  6. A Khokhlov, R Valiullin, J Kärger, F Steinbach and A Feldhoff. Freezing and melting transitions of liquids in mesopores with ink-bottle geometry. New J. Phys. 9:272, 2007. BibTeX

    @article{2007,
    	author = "Khokhlov, A. and Valiullin, R. and Kärger, J. and Steinbach, F. and Feldhoff, A.",
    	title = "Freezing and melting transitions of liquids in mesopores with ink-bottle geometry",
    	journal = "New J. Phys.",
    	volume = 9,
    	pages = 272,
    	year = 2007
    }
    

 
   
© Rustem Valiullin, 2006-2013