Quaternary Trimethyl Chitosan Chloride Capped Bismuth Nanoparticles with Positive Surface Charges: Catalytic and Antibacterial Activities

Abstract

Quaternary trimethyl chitosan-stabilized bismuth nanoparticles (QTMC-BiNPs) with positive surface charges were uniquely synthesized and fully characterized. In the synthesis, Quaternary Trimethyl Chitosan (QTMC), a water-soluble derivative of chitosan (CTS) was prepared using two-step reductive methylation. The new biopolymeric functionalized ligand was further used as capping agent for the synthesis of QTMC-BiNPs which was applied as antibacterial and catalytic agents. The reaction was carried out at room temperature without the use of energy consuming or high-cost instruments. The QTMC and nanocomposites were characterized by proton nuclear magnetic resonance ( 1 H NMR), attenuated total reflection Fourier-transform infrared, UV-visible, X-ray diffraction, X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopic techniques. The topology and morphology of the composites were examined with scanning electron microscopy and high-resolution transmission electron microscopy. Thermogravimetric and differential thermal gravimetric analysis were also conducted. The degree of quaternization and degree of dimethylation values of 63.33 and 11.75%, respectively obtained for QTMC confirmed that the main product is a quaternary derivative. The average particle size of QTMC-BiNPs was evaluated to be between 30 and 45 nm. The QTMC-BiNPs revealed clear and uniform lattice fringes with an estimated interplanar d-spacing of 0.32 nm confirming the formation of highly crystalline nanocomposites. A further insight into the antibacterial activities of this nanomaterial were carefully examined on Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) using resazurin based microdilution method for Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration (MBC). The obtained results revealed that both bacteria pathogens were effectively inhibited/killed by the QTMC-BiNPs at very low concentrations. The MIC of 15.63 and 125 lg/mL were recorded against E. coli and S. aureus, respectively while the MBC of 31.25 and 500.00 lg/mL were estimated against E. coli and S. aureus, respectively. An extensive evaluation of the catalytic capability of the nanocomposites towards the reduction of 4-nitrophenol to 4-aminophenol was also carried out with highly promising result.Keywords Chitosan Á Quaternary trimethyl chitosan Á Bismuth nanoparticles Á Antibacterial activity Á Catalytic activity

Compressed Hydrogen-Induced Synthesis of Quaternary Trimethyl Chitosan-Silver Nanoparticles with Dual Antibacterial and Antifungal Activities

“…QTMC was prepared using two steps of reductive methylation of CTS as described in our previous work . The typical preparation involved dissolving 2.0 g of CTS and 4.8 g of sodium iodide as a catalyst in 80.0 mL of N -methyl-2-pyrrolidinone (NMP) as the base.…”

“…QTMC was prepared using two steps of reductive methylation of CTS as described in our previous work. 43 The typical preparation involved dissolving 2.0 g of CTS and 4.8 g of sodium iodide as a catalyst in 80.0 mL of N-methyl-2-pyrrolidinone (NMP) as the base. This was first measured in a 500 mL double-necked round-bottom flask mounted on a water bath at 60 °C and stirred continuously until complete dissolution of CTS was observed.…”

“…44,45 On the other hand, the solubility of QTMC in water was investigated and compared to that of ordinary CTS according to our previous study. 43 In brief, 100 mg of CTS and QTMC solid samples were suspended in 10 mL of double distilled water and stirred at 25 °C for 6 h to produce a saturated solution, after which the insoluble polymer was collected by gravity filtration, washed with acetone, and dried under vacuum at 40 °C overnight. The following formula was used to calculate the percentage saturation solubility (eq 1).…”

Bismuth Nanoparticles Supported on Biobased Chitosan as Sustainable Catalysts for the Selective Hydrogenation of Nitroarenes

“…Indeed, it has been applied to many organic reactions such as protection and deprotection reactions, Friedel–Crafts reactions, epoxide opening, ring-opening polymerization, cycloaddition reactions, oxidations, allylations, Diels–Alder reactions, and others. ,− Among these catalysts, bismuth triflate [Bi­(OTf) 3 ] showed a high reactivity for the ring-opening polymerization of ε-caprolactone even at low temperatures . In spite of its remarkable properties, immobilization of Bi on solid supports for heterogeneous catalysis has been only seldom reported. − Consequently, we set out to graft Bi on biomass-derived chitosan and to study their catalytic properties. Chitosan was selected due to its abundance, the presence of OH and NH 2 groups ready to chelate the metal, , and its easy formulation in micrometer-thick films and porous microspheres .…”

Biopolymer-Mushroom Nanofiber Composite Xerogel Film: Bio-Base-Mediated Green, Chemically Resistant, Edible, and Printable Films

“…13,14 Chitosan, the (1−4)-2-amino-2-deoxy-β-D-glucan possesses −NH 2 on its polymeric chain, which provides unique chemical and physical properties to this biopolymer. 15,16 Both of these biopolymers possess excellent film-forming abilities. However, some drawbacks, such as low flexibility in the case of chitosan film and inferior water resistance of the alginate films, become barriers to their use in packaging applications.…”