Synthesis of mesoporous silica nanoparticles with a lychee-like morphology and dual pore arrangement and its application towards biomimetic activity via functionalization with copper(II) complex

Abstract

Abstract This work represents the pioneering synthesis of Lychee-like Mesoporous Silica Nanoparticles (LMSN) using a Modified Liquid Template Corrosion (MLTC) method using ethanolamine as a base medium. In this method, the emulsion system containing a cationic surfactant, water, ethylacetate (EA), Tetraethyl orthosilicate (TEOS) was used along-with monoethanolamine under basic conditions. EA was used as the co-template and a swelling agent in the formation of lamellar micelles from spherical and cylindrical micelles. When ethyl acetate (EA) was added to cetyltrimethylammonium bromide (CTAB) and water, initially an oil/water (O/W) mixture was formed due to the formation of lamellar micelles and microemulsion droplets. On addition of ethanolamine, the EA becomes readily hydrolyzed. Then the microemulsion droplets after being corroded serve as templates for the synthesis of mesoporous silica. This method may help us in designing novel nanomaterials in addition to the conventional strategies. The current explorations may afford newer promises towards the well-regulated architecture of silica-based novel materials. The material was then functionalizsed with a novel Schiff base Copper(II) complex and used as a biomimetic catalyst for phenoxazinone synthase mimicking activity which proved to be an efficient one with appreciable yields and good catalytic reusability with negligible leaching. The synthesized materials were characterized by Scanning Electron Microscopy, Energy Dispersive X-Ray analysis(EDAX), Transmission Electron Microscopy, Infrared spectroscopy, X-ray diffraction, nitrogen sorption analyses, 13C CP MAS NMR spectroscopy, TGA, Electron Spin Resonance(ESR) analysis, and ICP-OES studies. A lot more applications could be also anticipated for this morphology.