Controlled Self‐Assembly—Synthetic Tunability and Covalent Capture of Nanoscale Gel Morphologies

Coates, Ian A.; Smith, David K.

doi:10.1002/chem.200900858

Cited by 33 publications

(17 citation statements)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…These experiments testified that the formation of ultrasound‐induced fibers needs enough energy to overcome a high energy barrier 3. 17 A force balance involving the thermal and ultrasound treatments operates on the various morphologies of the gels, so a proper temperature is important to obtain the desired gel. Table 1 indicates the different states of 1 a and 1 b and the effect of temperature changes in the thermal, ultrasound, and thermal–ultrasound processes.…”

Section: Resultsmentioning

confidence: 99%

Sonication‐Triggered Instantaneous Gel‐to‐Gel Transformation

Liu

et al. 2010

Chemistry A European J

125

View full text Add to dashboard Cite

Two new peptide-based isomers containing cholesterol and naphthalic groups have been designed and synthesized. We found that the position of L-alanine in the linker could tune the gelation properties and morphologies. The molecule with the L-alanine residue positioned in the middle of the linker (1b) shows better gelation behavior than that with L-alanine directly linked to the naphthalimido moiety (1a). As a result, a highly thermostable organogel of 1b with a unique core-shell structure was obtained at high temperature and pressure in acetonitrile. Moreover, the gels of 1a and 1b could undergo an instantaneous gel-to-gel transition triggered by sonication. Ultrasound could break the core-shell microsphere of 1b and the micelle structure of 1a into entangled fibers. By studying the mechanism of the sonication-triggered gel-to-gel transition process of these compounds, it can be concluded that ultrasound has a variety of effects on the morphology, such as cutting, knitting, unfolding, homogenizing, and even cross-linking. Typically, ultrasound can cleave and homogenize pi-stacking and hydrophobic interactions among the gel molecules and then reshape the morphologies to form a new gel. This mechanism of morphology transformation triggered by sonication might be attractive in the field of material storage and controlled release.

show abstract

Section: Resultsmentioning

confidence: 99%

Sonication‐Triggered Instantaneous Gel‐to‐Gel Transformation

Liu

et al. 2010

Chemistry A European J

125

View full text Add to dashboard Cite

show abstract

“…While marked volume transitions in supramolecular gels are reported only occasionally, transitions between fibres and thicker ribbons or tapes are common. 17,51,[141][142][143][144][145] The dimensions of a polymer lamella were shown by Armon et al to dictate the pitch, curvature and diameter of the resulting fibre, with wider and thinner sheets producing more condensed, tubular helices and higher elastic energies. 127 Thermal treatment can lead to morphological changes by inducing growth or shrinkage of lamellae and shifting the optimal balance between stretching and bending deformations.…”

Section: Swelling Effectsmentioning

confidence: 99%

Gels with sense: supramolecular materials that respond to heat, light and sound

2016

View full text Add to dashboard Cite

. (2016) 'Gels with sense : supramolecular materials that respond to heat, light and sound.', Chemical society reviews., 45 (23). pp. 6546-6596. Further information on publisher's website:https://doi.org/10.1039/C6CS00435KPublisher's copyright statement:Additional information: Use policyThe full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that:• a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.Please consult the full DRO policy for further details. Advances in the field of supramolecular chemistry have made it possible, in many situations, to reliably engineer soft materials to address a specific technological problem. Particularly exciting are "smart" gels that undergo reversible physical changes on exposure to remote, non-invasive environmental stimuli. This review explores the development of gels which are transformed by heat, light and ultrasound, as well as other mechanical inputs, applied voltages and magnetic fields. Focusing on small-molecule gelators, but with reference to organic polymers and metal-organic systems, we examine how the structures of gelator assemblies influence the physical and chemical mechanisms leading to thermo-, photo-and mechano-switchable behaviour. In addition, we evaluate how the unique and versatile properties of smart materials may be exploited in a wide range of applications, including catalysis, crystal growth, ion sensing, drug delivery, data storage and biomaterial replacement.

show abstract

“…It is known that control over heating and cooling can modify gel morphology. 33 These experiments therefore clearly demonstrate the dynamic nature of self-assembled hybrid nanomaterials held together solely by non-covalent interactions, highlighting their ability to reorganise in response to simple stimuli. The data would imply that in order to keep the gold nanoparticles on the gel fibres under heating conditions, it would be necessary to enhance (or rigidify) the interaction between gelator building blocks (e.g.…”

Section: Dynamic Behaviour Of Gelator : Gnp Hybrid Nanomaterialsmentioning

confidence: 94%

Hierarchical assembly—dynamic gel–nanoparticle hybrid soft materials based on biologically derived building blocks

Coates

Smith

2010

J. Mater. Chem.

View full text Add to dashboard Cite

This article reports the interaction between cysteine-functionalised organogelators and gold nanoparticles. It is clearly demonstrated by transmission electron microscopy that for these gelators, where S-Au interactions can form, the nanoparticles align directly on top of, inside, and along the gel fibres. On the other hand, for a tryptophan functionalised gelator, which cannot form direct interactions with gold nanoparticles, the nanoparticles tend instead to simply cluster loosely around the fibrillar objects as a consequence of sample drying effects. Dependent on the ligand initially present as a stabiliser on the nanoparticle surface, some rearrangement of the nanoparticles on exposure to the gelator and sonication conditions can be observed. On thermal treatment, the nanoparticle-doped xerogel undergoes significant rearrangement: the gel fibres become smaller in diameter and the gold nanoparticles undergo enlargement by Ostwald ripening. This demonstrates how supramolecular nanohybrid assembled materials can evolve in response to stimulus as a consequence of the noncovalent interactions which underpin them, and their resulting dynamic nature.

show abstract

Controlled Self‐Assembly—Synthetic Tunability and Covalent Capture of Nanoscale Gel Morphologies

Abstract: Tuning structures: We report a synthetically simple yet structurally rich gelator that self-assembles through hydrogen bonding under different cooling regimes into different nanoscale morphologies (see figure), which can be covalently captured and stabilised by alkene metathesis.

Cited by 33 publications

References 35 publications

Sonication‐Triggered Instantaneous Gel‐to‐Gel Transformation

Sonication‐Triggered Instantaneous Gel‐to‐Gel Transformation

Gels with sense: supramolecular materials that respond to heat, light and sound

Hierarchical assembly—dynamic gel–nanoparticle hybrid soft materials based on biologically derived building blocks

Contact Info

Product

Resources

About