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Supramolecular motifs in dynamic covalent PEG-hemiaminal organogels.

Fox CH, ter Hurrne GM, Wojtecki RJ, Jones GO, Horn HW, Meijer EW, Frank CW, Hedrick JL, García JM - Nat Commun (2015)

Bottom Line: Under specific network synthesis conditions, these materials exhibited self-healing behaviour.This work reports on both the molecular-level detail of hemiaminal crosslink junction formation as well as the macroscopic behaviour of hemiaminal dynamic covalent network (HDCN) elastomeric organogels.These materials have potential applications as elastomeric components in printable materials, cargo carriers and adhesives.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, Stanford University, 443 via Ortega, Stanford, California 94305, USA.

ABSTRACT
Dynamic covalent materials are stable materials that possess reversible behaviour triggered by stimuli such as light, redox conditions or temperature; whereas supramolecular crosslinks depend on the equilibrium constant and relative concentrations of crosslinks as a function of temperature. The combination of these two reversible chemistries can allow access to materials with unique properties. Here, we show that this combination of dynamic covalent and supramolecular chemistry can be used to prepare organogels comprising distinct networks. Two materials containing hemiaminal crosslink junctions were synthesized; one material is comprised of dynamic covalent junctions and the other contains hydrogen-bonding bis-hemiaminal moieties. Under specific network synthesis conditions, these materials exhibited self-healing behaviour. This work reports on both the molecular-level detail of hemiaminal crosslink junction formation as well as the macroscopic behaviour of hemiaminal dynamic covalent network (HDCN) elastomeric organogels. These materials have potential applications as elastomeric components in printable materials, cargo carriers and adhesives.

No MeSH data available.


Mechanical testing of organogels prepared under different conditions.(a) Hysteresis curves for H/H, H/L, and L/H HDCNs. (b) Hysteresis curves for three load/unload cycles, L/H HDCN. (c) Hysteresis curves for three load/unload cycles, H/L HDCN. (d) Hysteresis curves for three load/unload cycles, H/H HDCN.
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f4: Mechanical testing of organogels prepared under different conditions.(a) Hysteresis curves for H/H, H/L, and L/H HDCNs. (b) Hysteresis curves for three load/unload cycles, L/H HDCN. (c) Hysteresis curves for three load/unload cycles, H/L HDCN. (d) Hysteresis curves for three load/unload cycles, H/H HDCN.

Mentions: Figure 4 shows the hysteresis behaviour of HDCN organogels synthesized under specific reaction conditions. Dynamic mechanical analysis (DMA) results are presented in Fig. 6 and Supplementary Fig. 14. Images of stretched HDCN gels are provided in Supplementary Fig. 14. HDCN gels were linearly deformed at a rate of 0.1 (mm mm−1) per minute over a strain range within the elastic deformation regime (<60% strain). All HDCN gels exhibited elastomeric behaviour when strained <0.6 mm mm−1; the hysteresis curves indicate that no residual strain was present in the network after each test. All gels exhibited hysteresis behaviour, and the energy dissipated by the load–unload cycles was measured by calculating the area between the load–unload curves.


Supramolecular motifs in dynamic covalent PEG-hemiaminal organogels.

Fox CH, ter Hurrne GM, Wojtecki RJ, Jones GO, Horn HW, Meijer EW, Frank CW, Hedrick JL, García JM - Nat Commun (2015)

Mechanical testing of organogels prepared under different conditions.(a) Hysteresis curves for H/H, H/L, and L/H HDCNs. (b) Hysteresis curves for three load/unload cycles, L/H HDCN. (c) Hysteresis curves for three load/unload cycles, H/L HDCN. (d) Hysteresis curves for three load/unload cycles, H/H HDCN.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4518264&req=5

f4: Mechanical testing of organogels prepared under different conditions.(a) Hysteresis curves for H/H, H/L, and L/H HDCNs. (b) Hysteresis curves for three load/unload cycles, L/H HDCN. (c) Hysteresis curves for three load/unload cycles, H/L HDCN. (d) Hysteresis curves for three load/unload cycles, H/H HDCN.
Mentions: Figure 4 shows the hysteresis behaviour of HDCN organogels synthesized under specific reaction conditions. Dynamic mechanical analysis (DMA) results are presented in Fig. 6 and Supplementary Fig. 14. Images of stretched HDCN gels are provided in Supplementary Fig. 14. HDCN gels were linearly deformed at a rate of 0.1 (mm mm−1) per minute over a strain range within the elastic deformation regime (<60% strain). All HDCN gels exhibited elastomeric behaviour when strained <0.6 mm mm−1; the hysteresis curves indicate that no residual strain was present in the network after each test. All gels exhibited hysteresis behaviour, and the energy dissipated by the load–unload cycles was measured by calculating the area between the load–unload curves.

Bottom Line: Under specific network synthesis conditions, these materials exhibited self-healing behaviour.This work reports on both the molecular-level detail of hemiaminal crosslink junction formation as well as the macroscopic behaviour of hemiaminal dynamic covalent network (HDCN) elastomeric organogels.These materials have potential applications as elastomeric components in printable materials, cargo carriers and adhesives.

View Article: PubMed Central - PubMed

Affiliation: Department of Chemical Engineering, Stanford University, 443 via Ortega, Stanford, California 94305, USA.

ABSTRACT
Dynamic covalent materials are stable materials that possess reversible behaviour triggered by stimuli such as light, redox conditions or temperature; whereas supramolecular crosslinks depend on the equilibrium constant and relative concentrations of crosslinks as a function of temperature. The combination of these two reversible chemistries can allow access to materials with unique properties. Here, we show that this combination of dynamic covalent and supramolecular chemistry can be used to prepare organogels comprising distinct networks. Two materials containing hemiaminal crosslink junctions were synthesized; one material is comprised of dynamic covalent junctions and the other contains hydrogen-bonding bis-hemiaminal moieties. Under specific network synthesis conditions, these materials exhibited self-healing behaviour. This work reports on both the molecular-level detail of hemiaminal crosslink junction formation as well as the macroscopic behaviour of hemiaminal dynamic covalent network (HDCN) elastomeric organogels. These materials have potential applications as elastomeric components in printable materials, cargo carriers and adhesives.

No MeSH data available.