A structural development of an organogel explored by synchrotron time-resolved small-angle X-ray scattering

Lamellar-cubic transition of a dihydrazide derivative and its effect on the gel stability

N,N'-Bis(4-n-alkyloxybenzoyl)hydrazine (4D16) was demonstrated to show three different aggregates, i.e. a crystalline cubic phase and two kinds of lamellar structure with layer spacings of 34.20 Å (termed the L1 structure) and 40.85 Å (L2 structure) depending on the type of solvents. Lamellar (L1)-crystalline cubic transition during heating was confirmed for 4D16 showing the L1 structure. 4D16 organogels in cyclohexane and benzene exhibited either a mixture of the L1 structure and the crystalline cubic phase or only one of the two structures. 4D16 gels prepared at a higher concentration or a lower incubation temperature consisted of more lamellar L1 structures compared to those obtained at a lower concentration or a higher incubation temperature. Annealing of the as-prepared 4D16 gels at certain temperatures for different time periods caused gradual lamellar L1-cubic transition, and thus increased the content of the cubic phase in the gels, which showed lower Tgel compared to those of the as-prepared ones. The existence of the cubic phase in 4D16 gels in cyclohexane and benzene destabilized the gels.

Speed versus stability – structure–activity effects on the assembly of two-component gels

Modifying the peripheral peptides dramatically changes the time required for gelation under ambient conditions, whilst an enthalpy–entropy balance means that as the temperature increases, the thermal stability of the gels is very similar.

Systematic modifications of alkane-based molecular gelators and the consequences to the structures and properties of their gels

Structural development of simple molecular gelators based on n-alkanes and the properties of their complex gels.

The past, present, and future of molecular gels. What is the status of the field, and where is it going?

A Perspective is presented on the history and current understanding of molecular gels and the factors that must be considered to characterize them. The abilities of the most important structural, dynamic, and rheological tools available currently to provide the information necessary to follow the formation of a molecular gel from its initial sol phase and then to define it at different distance and time scales are discussed. Approaches to determining a priori when a molecule will gelate a selected liquid, as well as possible methodologies for overcoming current limitations in understanding molecular gels, are presented. Finally, some of the many potential and realized applications for these materials are enumerated.