Supramolecular Assembly of pH-Sensitive Triphenylene Derived π-Gelators and Their Application as Molecular Template for the Preparation of Silica Nanotubes

Abstract

The gelation properties and mode of self-assembly of six asymmetrical hexaether triphenylene derivatives mono-functionalized with carboxylic and primary amine groups were investigated. The presence of a carboxylic and amine group attached to the triphenylene core generated stable, thermo- and pH-sensitive supramolecular π-organogels with a reversible response to both stimuli. In order to understand the gelation process, we studied the effect of the spacer length and found a different gelation scope for the acid and basic derivatives that accounts for a different supramolecular self-assembly. The presence of the basic group on the amino derivatives was used to guide and catalyze the templated in situ sol-gel polymerization of TEOS and allowed us, under controlled hydrolytic conditions, to prepare an entangled fibrillar network of silica nanotubes.

High Order in a Self‐Assembled Iridium(III) Complex Gelator Towards Nanostructured IrO2 Thin Films

“…Asian J. 2017, 12,2703 -2710 www.chemasianj.org than the relative gel phase; [52] furtherc onfirmed, in our case, by the similarities of textures observed under POMo ft he two phases ( Figure 2). For all gel concentration solutions (3 %t o 6% w/w), the PXRD patterns of the obtained xerogels are all identical.T he PXRD pattern of the xerogel issued from the 6% w/w gel phase is reported in Figure 7a sa ne xample.…”

“…the xerogel presents several additional reflection peaks of lower intensity ( Figure 7). Following the approachp erformed by Resta et al on the indexation of PXRD patterns of xerogels of triphenylene derivatives, [52] we hypothesized as econd supramolecularo rder of the Col t columnar strandst oe xplain these additional reflectionp eaks. Indeed, all new peaks can be indexedt hrough ac olumnar oblique (Col o )s ystem built up by four columns of complexes molecules arrangedi nt he Col t sub-unit system.…”

Supramolecular self-assembly and physical-gel formation in disc-like liquid crystals: a scalable predictive model for gelation and an application in photovoltaics

“…This system was then utilised as a gel electrolyte in dye sensitized solar cells (DSSCs) and it was shown that the lifetime of DSSCs can be signicantly increased due to gel formation, as a direct consequence of a reduction in solvent evaporation due to connement by the gel phase. Triphenylene HAT6 is a prototypical DLC, and while other recent studies have reported physical gel formation using functionalised DLCs, [11][12][13] the ability of use completely unmodied hexaalkyloxy-triphenylene is particularly interesting. 14 Furthermore, what makes DLCs a particularly interesting class of materials to form gels with is their inherent charge conduction capabilities as molecular wires, 15,16 self-healing 17 and low working temperatures.…”

Gels as Templates for the Syntheses of Shape-Controlled Nanostructured Materials

“…These superstructures have a unique and well defined morphology that can be used as templates for transcribing their structure into a range of inorganic and organic materials with many potential applications. Moreover, in the case of low-molecular-weight gelators (LMWGs), the successful transcription of these structures to a nanomaterial can give direct information on the morphology of the superstructure of the gel in native form, information that is otherwise difficult to obtain in a direct way [1,2].This Special Issue of Gels entitled "Gels as Templates for Transcription" presents a clear picture of the variety of approaches for the transcription of LMWG superstructures into inorganic and organic polymeric materials and is comprised of a review and three original articles. Susuki et al [3] report on the preparation of titanium dioxide nanotubes and hybrid nanotubes prepared with various metal oxides such as Ta 2 O 5 , Nb 2 O 5 , ZrO 2 , and SiO 2 by the sol-gel polymerization using a simple L-lysine-based LMWG, demonstrating that the composition ratio of hybrid nanotubes is controllable by the feed ratio of raw materials.…”

“…These superstructures have a unique and well defined morphology that can be used as templates for transcribing their structure into a range of inorganic and organic materials with many potential applications. Moreover, in the case of low-molecular-weight gelators (LMWGs), the successful transcription of these structures to a nanomaterial can give direct information on the morphology of the superstructure of the gel in native form, information that is otherwise difficult to obtain in a direct way [1,2].…”