dc.contributor |
Háskóli Íslands |
dc.contributor |
University of Iceland |
dc.contributor.author |
Ghosh, Dipankar |
dc.contributor.author |
Mulvee, Matthew T. |
dc.contributor.author |
Damodaran, Krishna Kumar |
dc.date.accessioned |
2020-03-23T15:08:09Z |
dc.date.available |
2020-03-23T15:08:09Z |
dc.date.issued |
2019-09-25 |
dc.identifier.citation |
Ghosh, D.; Mulvee, M.T.; Damodaran, K.K. Tuning Gel State Properties of Supramolecular Gels by Functional Group Modification. Molecules 2019, 24, 3472. |
dc.identifier.issn |
1420-3049 |
dc.identifier.uri |
https://hdl.handle.net/20.500.11815/1644 |
dc.description |
Publisher's version (útgefin grein) |
dc.description.abstract |
The factors affecting the self-assembly process in low molecular weight gelators (LMWGs) were investigated by tuning the gelation properties of a well-known gelator N-(4-pyridyl)isonicotinamide (4PINA). The N—H···N interactions responsible for gel formation in 4PINA were disrupted by altering the functional groups of 4PINA, which was achieved by modifying pyridyl moieties of the gelator to pyridyl N-oxides. We synthesized two mono-N-oxides (INO and PNO) and a di-N-oxide (diNO) and the gelation studies revealed selective gelation of diNO in water, but the two mono-N-oxides formed crystals. The mechanical strength and thermal stabilities of the gelators were evaluated by rheology and transition temperature (Tgel) experiments, respectively, and the analysis of the gel strength indicated that diNO formed weak gels compared to 4PINA. The SEM image of diNO xerogels showed fibrous microcrystalline networks compared to the efficient fibrous morphology in 4PINA. Single-crystal X-ray analysis of diNO gelator revealed that a hydrogen-bonded dimer interacts with adjacent dimers via C—H···O interactions. The non-gelator with similar dimers interacted via C—H···N interaction, which indicates the importance of specific non-bonding interactions in the formation of the gel network. The solvated forms of mono-N-oxides support the fact that these compounds prefer crystalline state rather than gelation due to the increased hydrophilic interactions. The reduced gelation ability (minimum gel concentration (MGC)) and thermal strength of diNO may be attributed to the weak intermolecular C—H···O interaction compared to the strong and unidirectional N—H···N interactions in 4PINA. |
dc.description.sponsorship |
We thank the University of Iceland Research Fund and the Science Institute for funding. D.G. thanks the University of Iceland for the Doctoral Research and Teaching Assistantship grant. We thankfully acknowledge Jonathan Steed, Durham University, Durham, UK for rheology experiments, Sigurjur Sveinn Jonsson, ISOR-Iceland for X-ray powder diffraction analysis, and Sigridur Jonsdottir, University of Iceland for NMR and mass spectroscopy. We thank Rannís Iceland for granting an infrastructure grant for a single-crystal X-ray diffractometer. |
dc.format.extent |
3472 |
dc.language.iso |
en |
dc.publisher |
MDPI AG |
dc.relation.ispartofseries |
Molecules;24(19) |
dc.rights |
info:eu-repo/semantics/openAccess |
dc.subject |
Hydrogel |
dc.subject |
LMWGs |
dc.subject |
N-oxides |
dc.subject |
Pyridyl amides |
dc.subject |
Structural modification |
dc.subject |
Efnafræði |
dc.title |
Tuning Gel State Properties of Supramolecular Gels by Functional Group Modification |
dc.type |
info:eu-repo/semantics/article |
dcterms.license |
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited |
dc.description.version |
Peer Reviewed |
dc.identifier.journal |
Molecules |
dc.identifier.doi |
10.3390/molecules24193472 |
dc.relation.url |
https://www.mdpi.com/1420-3049/24/19/3472/pdf |
dc.contributor.department |
Raunvísindastofnun (HÍ) |
dc.contributor.department |
Science Institute (UI) |
dc.contributor.school |
Verkfræði- og náttúruvísindasvið (HÍ) |
dc.contributor.school |
School of Engineering and Natural Sciences (UI) |