Does drying affect gel networks?

The properties of low molecular weight gels are determined by the underlying, self-assembled network. To access information on the network, it is common for techniques to be used that require the gel to be dried, such as transmission electron microscopy or scanning electron microscopy. The implicit assumption is that this drying has no bearing on the data collected. Here, we discuss the validity of this assumption

Multicomponent low molecular weight gelators

Low molecular weight gelators (LMWG) self-assemble in solution into one-dimensional objects such as fibres or tapes. The entanglement of these fibres or tapes results in the formation of a network and a gel. In general, LMWG are investigated as single component systems. However, there are significant potential opportunities from mixed LMWG systems, which are rarely investigated. Here, we discuss the potential of multicomponent systems, and critically discuss the challenges

Scrolling for gels

No abstract available

A low molecular weight hydrogel with unusual gel aging

We describe a dipeptide hydrogel with unusual aging characteristics. Over time, a transformation from a turbid gel to a transparent gel occurs which is initiated from the air–water interface. Here, we investigate this transition and discuss the implications of this aging on the bulk properties of the gel

Pathway dependence in redox driven metal–organic gels

Pathway dependence is common in self‐assembly. Here, we show the importance of pathway dependence for redox‐driven gels by constructing a Fe(II)/Fe(III) redox‐based metal‐organic gel system. We show that in situ oxidation of the Fe(II) ions at different rates results in conversion of a Fe(II)‐gel into a Fe(III)‐organic gel, which controls the material properties such as gel stiffness, gel strength, and an unusual swelling behaviour. The rate of formation of Fe(III) ions determines the extent of intermolecular interactions and so whether gelation or precipitation occurs

Supramolecular nanostructures

No abstract available

Photoresponsive gelators

Low molecular weight gels can be responsive to a range of external stimuli. The use of light as an external stimulus to modify gels is of particular interest for a number of reasons. Light is a non-invasive trigger. For example, using light it is possible to spatially target a specific area of the gel leading to patterned gel surfaces. Here, we review the different approaches that have been used to form low molecular weight gels that respond to ligh

Controlling the assembly and properties of low-molecular-weight hydrogelators

Low-molecular-weight gels are formed by the self-assembly of small molecules into fibrous networks that can immobilize a significant amount of solvent. Here, we focus on our work with a specific class of gelator, the functionalized dipeptide. We discuss the current state of the art in the area, focusing on how these materials can be controlled. We also highlight interesting and unusual observations and unanswered questions in the field

Probing the self-assembled structures and pKa of hydrogels using electrochemical methods

The surface chemistry of the aggregated structures that form the scaffold in self-assembled hydrogels - their charge, hydrophobicity and ion-binding dynamics - play an important role in determining the gel properties and the gel’s suitability for specific applications. However, there are limited methods available for the study of this surface chemistry. Here, we show that electrochemical techniques can be used to measure the surface chemical properties of the self-assembled aggregates structures and also to determine the pKa of the gelators. We also provide a method to quickly determine whether a functionalised-dipeptide will form either a gel or not. This method has scope for use in use in high-throughput screening and further complex pH-triggered self-assembled gelation systems

Chemically fuelled self-regulating gel-to-gel transition

Artificial self‐regulating materials can be prepared by exploiting fuel‐driven pathways. Dynamic covalent bonds are formed and broken reversibly under mild reaction conditions. Herein, we utilise this concept to programme a system that can undergo a fuel‐driven self‐regulated gel‐to‐gel transition. The reaction between the gelator and the fuel resulted in a change in chemical structure of the gelator that initially causes a transition from a solution to gel state by co‐assembly. With time, the intermediate complex collapses, re‐forming the gelator structure. However, the gel does not collapse. This method allows us to prepare gels with improved mechanical strength. Unlike conventional gel‐to‐gel transitions, exploitation of dynamic covalent chemistry provides an opportunity to access materials that cannot be prepared directly under similar final conditions