1 / 13

Nanoporous Materials Synthesis - Using Alternative Solvents

Nanoporous Materials Synthesis - Using Alternative Solvents. J. L. Anthony Research Group Department of Chemical Engineering Kansas State University. My Background. Graduate work (Notre Dame) Novel solvents (ionic liquids) Absorption (“adsorption”) of gases

ronda
Download Presentation

Nanoporous Materials Synthesis - Using Alternative Solvents

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Nanoporous Materials Synthesis - Using Alternative Solvents J. L. Anthony Research Group Department of Chemical Engineering Kansas State University

  2. My Background • Graduate work (Notre Dame) • Novel solvents (ionic liquids) • Absorption (“adsorption”) of gases • Thermodynamic solvation properties • Gas separations • Post-doctoral work (Caltech) • Materials synthesis (zeolite-like molecular sieves) • Conductive properties (fuel-cell membranes, sensors) • Current work (K-State) • Synthesis, characterization and application of nanoporous materials • Ionic liquids as solvents for materials synthesis

  3. Overall Research Objective To design microporous materials for specific applications through by control of chemical interactions at the molecular level • General Approach: • Effects of solvent characteristics on synthesis • Characterization of materials • Measurements of adsorption and ion exchange capabilities • Assessment of how physical properties change

  4. Current Projects • Application: Heavy Metal Capture • Removal of lead and mercury from water • Using zincosilicates • Characterization: Far-FTIR • Can detect differences in structure • Looking at local environments (cations, metal sites) • As-made, post-synthesis treated, collapsed, during synthesis • Synthesis: Alternative Solvents • Using ionic liquids • As structure-directing agent (have made magadiite) • As solvent/structure-directing agent • Measuring solubilities

  5. Zeolite-like Molecular Sieves Zeolite A VPI-10 • Uniform micropores (<2nm) • Uniform bulk properties Applications: Catalysts, ion exchangers, adsorbents, molecular sieves, chemical sensors, membranes / additives, coatings • Pure silica  neutral framework • Si and Al  negative framework (-1) • Si and Zn  negative framework (-2)

  6. R 4 - - R R - X + X X 3 5 + N R R R N 2 1 2 pyrrolidinium R 1 - X pyridinium R 1 - X + P R R R 4 3 2 tetra alkylphosphonium Alternative Solvents: Ionic Liquids R 1 X = PF6 BF4 (CF3SO2)2N Cl NO3 CH3CO2 CF3CO2 CF3SO3 + + N N N R R R R 4 3 R 1 2 3 imidazolium tetra alkylammonium Example: 1-n-butyl-3-methylimidazolium hexafluorophosphate [bmim][PF6] • Organic Salts • Liquid at Ambient Conditions • Negligible Vapor Pressure!! • Water Stable ILs (Wilkes and Zaworotko, 1992) • Solvent for a Variety of Industrial Reactions

  7. Alternative Solvents for Zeolites • Few organic solvents have been used (ethylene glycol, propanol, sulfolane, pyridine) • Aluminophosphate compound made using [emim][Br] and urea/choline chloride eutectic (Cooper et al., Nature, 2004) • Advantages of Ionic Liquids for Ionothermal Synthesis • Similar structure to common SDA’s • Easily tailored molecular structure while maintaining overall solvation capabilities • Potential to impart solvent characteristics on molecular sieve framework (e.g. chirality) • Potential new synthesis methods due to ionic, non volatile solvent • Thin films • Open containers • Others???

  8. Proposed Mechanism for Zeolite “Self-assembly” Current standard hydrothermal method de Moor et al., Chem.-Eur. J. (1999)

  9. Challenges for “Design” • Do not know the synthetic mechanism • Cannot “see” the steps occur In situ techniques applied: • SAXS, WAXS, USAXS • TEM • NMR • DLS • Synthetic control limited to SDA, temperature and time

  10. Tools: • Materials synthesis • Zeolites and other molecular sieves • Ionic liquids • Measurements of thermophysical properties and solvent character • *High pressure systems*

  11. Interests: • Other techniques for characterizing materials or solvent systems (spectroscopy, etc) • During synthesis • Location of adsorbed/ion exchanged compounds • Silica/ionic liquid mixtures – make gels… • Other materials – to study solvent effects • Other applications

  12. Synthesizing Zeolite-like Molecular Sieves • Synthetic Components: • Solvent (Water) • T-atoms (silica, aluminum, zinc, germanium, etc.) • Mineralizing agent (OH-, F-) • Structure-directing agent • Solution-mediated or sol-gel transformation • Hydrothermal synthesis process • Heat in teflon-lined autoclave • Time ranges from days to months

  13. Example SDA’s

More Related