Binder driven self-assembly of metal-organic cubes towards functional hydrogels

Abstract

The process of assembling astutely designed, well-defined metal-organic cube (MOC) into hydrogel by using a suitable molecular binder is a promising method for preparing processable functional soft materials. Here, we demonstrate charge-assisted H-bonding driven hydrogel formation from Ga3+-based anionic MOC ((Ga8(ImDC)12)12−) and molecular binders, like, ammonium ion (NH4+), N-(2-aminoethyl)-1,3-propanediamine, guanidine hydrochloride and β-alanine. The morphology of the resulting hydrogel depends upon the size, shape and geometry of the molecular binder. Hydrogel with NH4+ shows nanotubular morphology with negative surface charge and is used for gel-chromatographic separation of cationic species from anionic counterparts. Furthermore, a photo-responsive luminescent hydrogel is prepared using a cationic tetraphenylethene-based molecular binder (DATPE), which is employed as a light harvesting antenna for tuning emission colour including pure white light. This photo-responsive hydrogel is utilized for writing and preparing flexible light-emitting display.

Investigation of the Mechanism Behind Conductive Fluorescent and Multistimuli‐responsive Li+‐enriched Metallogel Formation

“…In order to establish the metallogel as true gel phase material and to explore its viscoelastic properties, we performed detailed rheological experiments over freshly prepared metallogel (2.6 % w/v). Strain sweep experiment shows that in response to applied shear strain, the storage modulus (G’) was found to be ∼1 order magnitude higher than loss modulus (G’’) upto 4% strain value and beyond this value, they crossed each other which indicates the phase transition from gel to sol phase (Figure ) . When the metallogel was subjected to dynamic shear stress, G’ was found to be ∼1 order magnitude higher than G’’ up to yield stress of 2.4 Pa, supporting the metallogel as true gel phase material, upon further application of shear stress beyond the yield stress point both G’ and G” cross each other, indicating the deformation of the gel network (Figure ) .…”

“…Strain sweep experiment shows that in response to applied shear strain, the storage modulus (G’) was found to be ∼1 order magnitude higher than loss modulus (G’’) upto 4% strain value and beyond this value, they crossed each other which indicates the phase transition from gel to sol phase (Figure ) . When the metallogel was subjected to dynamic shear stress, G’ was found to be ∼1 order magnitude higher than G’’ up to yield stress of 2.4 Pa, supporting the metallogel as true gel phase material, upon further application of shear stress beyond the yield stress point both G’ and G” cross each other, indicating the deformation of the gel network (Figure ) . Dynamic frequency sweep measurements show that the predominantly unchanged behavior of the storage modulus (G’) and the loss modulus (G’’) within the applied frequency range (0.1 to 100 rad −1 at 25 °C) advocates the elastic nature of the metallogel (Figure ).…”

Charge-Transfer Regulated Visible Light Driven Photocatalytic H2 Production and CO2 Reduction in Tetrathiafulvalene Based Coordination Polymer Gel

“…To this end, developing soft hybrid materials such as coordination polymer gel (CPGs), assembled by the low molecular weight gelator (LMWG) based linker and suitable metal ions, could be an excellent design approach in the realm of photocatalysis. [36][37][38][39] Such hierarchical soft nano-brous materials 40,41 can facilitate the facile diffusion of reactants to the active sites and thus, will have the potential to overcome the low charge mobility and also ease e cient electron transfer between the different components. [42][43][44] These arti cial hybrid synthetic systems can mimic the intricate functioning of natural photosystem and can eventually show impressive H 2 evolution from water [45][46][47][48] or CO 2 reduction.…”

Self-assembly behaviors of perylene- and naphthalene-crown macrocycle conjugates in aqueous medium

“…Thanks to the development of supramolecular chemistry, the ordered structures could be obtained through programmed self-assembly coupled with covalent chemical synthesis [7]. In fact, supramolecular technology has shown great importance in various kinds of functional materials, including natural protein complexes [8–10], hydrogels [11–13], carbon-based materials [14–17], self-healing materials [18–23], and composite materials [24–26]. Moreover, several new proof-of-concept applications of supramolecular assemblies are also of increasing interest, specifically in the fields of energy generation and storage [27], water treatment and environmental remediation [28–29], and healthcare and biomedical engineering [30–32].…”