Ultrasonication-enhanced gelation properties of a versatile amphiphilic formamidine-based gelator exhibiting both organogelation and hydrogelation abilities

  1. Bachl, J. 3
  2. Sampedro, D. 1
  3. Mayr, J. 3
  4. Díaz Díaz, D. 3
  1. 1 Universidad de La Rioja
    info

    Universidad de La Rioja

    Logroño, España

    ROR https://ror.org/0553yr311

  2. 2 Instituto de Química Avanzada de Cataluña
    info

    Instituto de Química Avanzada de Cataluña

    Barcelona, España

    ROR https://ror.org/03srn9y98

  3. 3 University of Regensburg
    info

    University of Regensburg

    Ratisbona, Alemania

    ROR https://ror.org/01eezs655

Revista:
Physical Chemistry Chemical Physics

ISSN: 1463-9076

Año de publicación: 2017

Volumen: 19

Número: 34

Páginas: 22981-22994

Tipo: Artículo

DOI: 10.1039/C7CP03529B SCOPUS: 2-s2.0-85028630425 WoS: WOS:000408671600037 GOOGLE SCHOLAR

Otras publicaciones en: Physical Chemistry Chemical Physics

Resumen

We describe the preparation of a novel amphiphilic gelator built from a formamidine core, which is able to form a variety of physical organogels and hydrogels at concentrations ranging from 15 to 150 mg mL-1. Interestingly, ultrasound treatment of isotropic solutions (i.e., gel-precursor) resulted in a remarkable enhancement of the gelation kinetics as well as the gelation scope and characteristic gel properties (e.g., critical gelation concentration, gel-to-sol transition temperature, viscoelastic moduli) in comparison to the heating-cooling protocol typically used to obtain supramolecular gels. Thermoreversibility, thixotropy, injectability and multistimuli responsiveness are some of the most relevant functionalities of these gels. Electron microscopy imaging revealed the formation of entangled networks made of fibers of nanometer diameters and micrometer lengths, with different morphological features depending on the solvent. Insights into the driving forces for molecular aggregations were obtained from FTIR, NMR, PXRD and computational studies. The results suggest a major stabilization of the fibers through additive N-H⋯O hydrogen bonds, in combination with hydrophobic interactions, over π-π stacking interactions. © 2017 the Owner Societies.