Polymeric Hydrogelator-Based Molecular Gels Containing Polyaniline/Phosphoric Acid Systems

Abstract

To expand the range of applications of hydrogels, researchers are interested in developing novel molecular hydrogel materials that have affinities for the living body and the ability to mediate electrical signals. In this study, a simple mixing method for creating a novel composite molecular gel is employed, which combines a hydrophilic conductive polymer, a polyaniline/phosphoric acid complex, and a polymer hydrogelator as a matrix. The composite hydrogel showed an improved gel-forming ability; more effective mechanical properties, with an increased strain value at the sol–gel transition point compared to the single system, which may be sufficient for paintable gel; and a better electrochemical response, due to the electrically conducting polyaniline component. These findings demonstrate the applicability of the new composite hydrogels to new potential paintable electrode materials.

A thixotropic molecular hydrogel composite composed of polymer hydrogelator and self-doping polyaniline copolymer for electrochromic and glucose sensing applications

“…1b, the composite hydrogel, NaPPDT / PASPA 2/1 (w/w), exhibits thixotropic behaviour similar to the single component NaPPDT hydrogel. 15 a This could imply that combining NaPPDT and PASPA improves the gelation abilities of the polymer hydrogelator, NaPPDT , as previously demonstrated in composites containing a nano-disk silicate, LAPONITE®, 15 b or polyanilines 17 with NaPPDT . Since the composite hydrogels NaPPDT / PASPA with the composition 1/1 (w/w) and 1/2 (w/w) did not exhibit gel behaviour, the following measurements were performed to analyse the composite hydrogel, NaPPDT / PASPA 2/1 (w/w), only.…”

“…The results for the composite hydrogel also confirmed the gel state and the formation of a softer and more tenacious hydrogel than the corresponding NaPPDT hydrogel, which was evidenced by the shift of the value and cross point of G ′ and G ′′, as also indicated for the other NaPPDT mixed composite hydrogels. 17…”

“…This suggests that the presence of PASPA prevents aggregation of the NaPPDT polymer chains, resulting in thicker network components, as seen in other NaPPDT composite systems. 15,17 Although the freeze-dried process may influence the maintenance of the network structure as in the gel state by drying-induced aggregation and ice growth, 21 at least these SEM images reflect the differences in the network structure of the native gels.…”

Creation of Polymer Hydrogelator/Poly(Vinyl Alcohol) Composite Molecular Hydrogel Materials

“…This qualitative improvement in the composite gel network due to mixing may be the reason for the improved mechanical properties as measured by dynamic viscoelasticity described above. Although there is a concern that observation of such dried xerogel samples will show artefacts not present in the original gel-like samples due to shape changes during the drying process, it is thought that even if there are changes during the drying process, it is certain that the components have become smaller due to the mixing process as shown in our previous studies [ 19 , 20 , 21 ].…”

Creation of Molecular Gel Materials Using Polyrotaxane-Derived Polymeric Organogelator

“…As a part of our research on the fabrication of new molecular gel materials, we have investigated the fabrication and application of new polymer gelators that can form thixotropic molecular gels. We have also investigated the properties of water-soluble aromatic polyamide polymers as polymer hydrogelators [ 20 ] and their application to organic–inorganic or organic–organic composites using thixotropic base materials [ 21 , 22 , 23 , 24 ]. In this study, we designed and synthesized a polymeric organogelator containing a polyrotaxane ( PR ) structure with an octadecyl carbamate unit (urethane unit, U ), PR-U , and evaluated the mechanical properties of the obtained gel-like material by dynamic viscoelasticity measurements, as well as investigating the relationship between these properties and internal microstructure ( Scheme 1 ).…”