Thermal annealing behaviour and gel to crystal transition of a low molecular weight hydrogelator

Barker, Emily; Martin, Adam D.; Garvey, Christopher J.; Goh, Ching Yong; Jones, Franca; Mocerino, Mauro; Skelton, Brian W.; Ogden, Mark I.; Becker, Thomas

doi:10.1039/c6sm02431a

Cited by 24 publications

(18 citation statements)

References 46 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Indeed, although it has been widely assumed that there is a link, there are a number of examples that now specifically show that packing is different in the gel phase and crystals grown even from the same solvent. [24][25][26] As a specific example, we showed that fiber X-ray diffraction data from the gel phase did not match the crystal structure of a crystal grown directly from the gel phase. 24 In many cases, the crystals formed in one solvent are compared with a gel formed in another.…”

mentioning

confidence: 99%

Low-Molecular-Weight Gels: The State of the Art

Draper

Adams

2017

Chem

539

469

View full text Add to dashboard Cite

Low-molecular-weight gels are currently a hugely important class of materials that are attracting significant interest. These gels are formed when small molecules self-assemble into one-dimensional structures that entangle and cross-link to form a network that is capable of immobilizing the solvent. Here, we critically discuss the current state of the art and highlight two key areas where we believe there is significant untapped potential. The first is the observation that the properties of the gels are highly process dependent, which means that it is possible to access materials with very different properties from a single gelator. Second, using multiple gelators offers the opportunity to prepare materials with a high degree of information content and with a wider range of properties. We aim to spark thought and discussion on these aspects. INTRODUCTIONLow-molecular-weight gels (LMWGs), or supramolecular gels, are a fascinating and useful class of material. The gels arise from the self-assembly of small molecules into long, anisotropic structures, most commonly fibers. [1][2][3][4][5] At a sufficiently high concentration, these fibers entangle or otherwise form cross-links, leading to the network that is able to immobilize the solvent through surface tension and capillary forces. 1,2 These gels differ from permanently covalently cross-linked polymer gels because the cross-linking can be reversed by the input of energy, for example, by heating. 6 LMWGs have been around for many years but are receiving considerable current interest. 4 They are also used in industrial products, 7 although this seems rarely discussed in the academic literature.In addition to the industrial applications, many recent advances and uses are being described. [8][9][10][11][12] The specific self-assembly leading to gel formation can be exploited. For example, the fiber formation is a result of molecular stacking, meaning that the self-assembly leads to aggregates that can be suitable for optoelectronic applications. 13,14 The ready reversibility of gelation can be exploited, for example, to release cells from gels on demand in a manner that does not lead to cell death. 15 Ready gel formation by a simple trigger can also be used to allow easy and efficient gel loading. [16][17][18] Unsurprisingly, therefore, there is significant interest in these materials ( Figure 1). This is a fascinating area and in many ways holds attention because of the difficulties in probing and understanding the gels. The gels arise from assembly across many length scales, and understanding all of these is difficult. At the molecular level, the molecules must interact in a manner that leads to the formation of suitable aggregates that can eventually entangle. Thus, one-dimensional growth must be favored. From this perspective, it is very frustrating that it is often extremely difficult to predict whether a molecule will form a gel or not; indeed, gelation has been described as an empirical science. 4 Structurally similar small molecules can exhibitThe Bigger Pict...

show abstract

mentioning

confidence: 99%

Low-Molecular-Weight Gels: The State of the Art

Draper

Adams

2017

Chem

539

469

View full text Add to dashboard Cite

show abstract

“…Recent studies gave much evidence to explore the properties of gel to crystal transition for peptide, amino acid and sugar derivatives. [42][43][44][45] However, there is no literature to report the detail crystallization process of guanosine-based hydrogels. To nd out and understand the reason for the crystallization of F G d hydrogel, the visualize dynamic crystal process of F G d hydrogel has been investigated as shown in Fig.…”

Section: Resultsmentioning

confidence: 99%

Silver ions blocking crystallization of guanosine-based hydrogel for potential antimicrobial applications

Feng

Tang

et al. 2018

RSC Adv.

View full text Add to dashboard Cite

show abstract

“…[3] Since as table phase emerges at the expense of am etastable phase,g el-crystal transitions have been described to follow Ostwaldsr ule of stages, [4] as shown for other supramolecular systems. [7] Gel-crystal transitions have been reported for aw ide variety of supramolecular gelators,i ncluding sugars, [7,8] functionalized acids, [9] macrocycles, [10] and other molecules. [6] Notably,t he destabilizing gel-crystal transition is presently unavoidable by rational gelator design and has therefore invoked preventive formulation strategies.…”

Section: Introductionmentioning

confidence: 99%

Real‐Time In‐Situ Monitoring of a Tunable Pentapeptide Gel–Crystal Transition

et al. 2019

View full text Add to dashboard Cite

Supramolecular gels often become destabilizedb y the transition of the gelator into amore stable crystalline phase, but often the long timescale and sporadic localization of the crystalline phase preclude ap ersistent observation of this process.W epresent apentapeptide gel-crystal phase transition amenable for continuous visualization and quantification by common microscopic methods,a llowing the extraction of kinetics and visualization of the dynamics of the transition. Using optical microscopya nd microrheology,w es howt hat the transition is as poradic event in whichg el dissolution is associated with microcrystalline growth that follows as igmoidal rate profile.The two phases are based on b-sheets of similar yet distinct configuration. We also demonstrate that the transition kinetics and crystal morphology can be modulated by extrinsic factors,i ncluding temperature,s olvent composition, and mechanical perturbation. This work introduces an accessible model system and methodology for studying phase transitions in supramolecular gels.

show abstract

Thermal annealing behaviour and gel to crystal transition of a low molecular weight hydrogelator

Cited by 24 publications

References 46 publications

Low-Molecular-Weight Gels: The State of the Art

Low-Molecular-Weight Gels: The State of the Art

Silver ions blocking crystallization of guanosine-based hydrogel for potential antimicrobial applications

Real‐Time In‐Situ Monitoring of a Tunable Pentapeptide Gel–Crystal Transition

Contact Info

Product

Resources

About