Thixotropic Twin-Dendritic Organogelators

Authors

  • Virgil Percec Prof. Dr.,

    1. Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA, Fax: (+1) 215-573-7888
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  • Mihai Peterca Dr.,

    1. Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA, Fax: (+1) 215-573-7888
    2. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104-6396, USA
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  • Michael E. Yurchenko Dr.,

    1. Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA, Fax: (+1) 215-573-7888
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  • Jonathan G. Rudick Dr.,

    1. Roy & Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, PA 19104-6323, USA, Fax: (+1) 215-573-7888
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  • Paul A. Heiney Prof. Dr.

    1. Department of Physics and Astronomy, University of Pennsylvania, Philadelphia, PA 19104-6396, USA
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Abstract

Twin-dendritic organogelators have been prepared through selective functionalization of N-(3-aminopropyl)-1,3-propanediamine (APPDA) with self-assembling dendrons by using 1,1′-carbonyldiimidazole (CDI). Subsequent modification of the APPDA linker provided an additional degree of structural diversity by which to tailor the gelator self-assembly in bulk or in the gel state. These compounds are able to gel cyclohexane, toluene, n-butyl acetate, ethyl acetate, dichloromethane, and tetrahydrofuran. 3,4-Disubstituted apical branching units provided the most efficient organogelators and show a propensity to form thixotropic gels, wherein the gel recovers its elasticity after being subjected to shear. Structural and retrostructural analysis of the twin-dendritic organogelators reveals the bulk structural characteristics to be indicative of the subsequent gel properties. Diverse self-organized arrays were identified in bulk and all are able to form gels, thus indicating the role of quasiequivalence in mediating self-assembly in the gel state. Furthermore, we have found that porous columnar mesophases provide a strategy by which to prepare thixotropic gels. We demonstrate the importance of weak lateral hydrogen bonding within a column stratum versus hydrogen bonding along the length of the column for forming porous columnar mesophases and, by extension, thixotropic gels.

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