A two-component hydrogelator from citrazinic acid and melamine: synthesis, intriguing role of reaction parameters and iodine adsorption study

Abstract

Herein, we have implemented an intimate grinding-mixing protocol (GMP) for the synthesis of a new hydrogelator from citrazinic acid and melamine. Ground mixture upon sonication, just for few second, in a suitable solvent/mixed-solvent system finally results in a gel matrix.Citrazinic acid, is decorated with ureidopyrimidone functionality and melamine is enriched with amino-pyridine functionality. Therefore, the necessary non-covalent interactions (like hydrogen bonding and π-π stacking) become a part-and-parcel, bringing a nanofibrous gel material in existence. A thorough and complete solvent dependent gelation investigation suggests that water must be present as the sole solvent or one of the members of other mixedsolvent system to successfully result in gel formation. The gel shows entangled network morphology. Different micro-analytical studies (FTIR, Powder XRD, FESEM, TEM, Rheology etc.) have been conducted for complete characterizations of the gel sample. The gel also exhibits its stimuli responsive behaviour towards different interfering chemical parameters like pH, selective anions etc. Again, it is worth mentioning that here GMP plays a key role to strongly initiate and improvise solid state self-assembly. Different non-covalent interactions procure the suitable hydrogen-bonded motif which presumably propagates upon activation in solution phase after mild sonication favouring spontaneous formation of fibrous architectures. It was also noticed that without grinding, the solid state interactions are jeopardized and only partial gel structure prevails. Finally the available porosity in the gel framework and the enriched π-electron density within, make the gel a suitable host for adsorption of guest molecules. This information provoked us to study the reversible adsorption-desorption equilibrium of molecular iodine within the dried-gel matrix. The guest, iodine entrapment into the host occurs both from the solution and also from gas phase iodine.The complete analysis suggests that our material presents a high storage capacity of this halogen species. Therefore the study prescribes that the synthesized hydrogel material could be a suitable candidate for application in synthetic organic chemistry and would find an avenue to solve other environmental issues also.Melamine and citrazinic acid, upon solid state grinding, produced a two-component gelator

One-Pot Fabrication of Perforated Graphitic Carbon Nitride Nanosheets Decorated with Copper Oxide by Controlled Ammonia and Sulfur Trioxide Release for Enhanced Catalytic Activity

“…This is the first report, to the best of our knowledge, of the synthesis of CuO–Cu 2 O/g-C 3 N 4 by the pyrolysis of melamine in a semiclosed system, which also contained a copper precursor salt, by a one-pot method by heating in a furnace. More specifically, weighed amounts of melamine and CuSO 4 ·5H 2 O were taken in the mortar and evenly ground following the grinding–mixing protocol (GMP) 55 so as to obtain a homogenous physical mixture, which was then taken in a covered porcelain crucible. Thereafter, it was kept under heat treatment at 550 °C with a heating rate of 5 °C/min and maintained at this temperature for 4 h. A schematic representation of the process is given in Scheme 1.…”

Facile fabrication of luminescent organic dots by thermolysis of citric acid in urea melt, and their use for cell staining and polyelectrolyte microcapsule labelling

“…Thus, the resulting O-dot is a set of primary fluorophores bound by covalent or intermolecular (coordination, donor–acceptor, hydrogen) bonds, for example, forming a polymer-like structure [47], so that the particles formed can be identified as clusters of independent fluorophores [19]. Solubilization of these clusters in water leads to micellar peptization and colloidal sol formation; peptization increases with temperature and dilution.…”

Tuning the C/N Ratio of C‐Rich Graphitic Carbon Nitride (g‐C3N4) Materials by the Melamine/Carboxylic Acid Adduct Route

“…Two sharp bands at 3419 and 3472 cm À 1 show asymmetrical À NH 2 stretching, [29] while bands at 808 and 1020 cm À 1 corresponds to triazine deformation modes. [30] The typical signatures of carboxylic acid groups were observed with the C=O stretching (1720 cm À 1 ) and CÀ O stretching (region 1105 and 1200 cm À 1 ). Since acid-base reaction is expected in the mixture of the precursors, partial protonation of amine and deprotonation of carboxylic acid groups may occur.…”