Synthesis and antimicrobial activity of biocidal polymer–montmorillonite nanocomposites

Abstract

The bioactive agents p-hydroxymethylbenzoate, 2,4-dihydroxymethylbenzoate and methylsalicylate were reacted with polyoxyalkylene (D 230 -2000 )-montmorillonite (MMT) intercalated nanocomposites. D 230 -2000 -MMT were prepared by an ion exchange process of Na-MMT and-NH 3 + groups in polyoxyalkylene amine hydrochloride of three different molecular masses (D 230 , D 400 and D 2000 ). The results of X-ray analysis and transmission electron microscopy show that D 2000 -MMT/phydroxymethylbenzoate is an exfoliated nanocomposite, whereas in D 230 -MMT/p-hydroxymethylbenzoate, D 230 -MMT/2,4dihydroxymethylbenzoate, D 230 -MMT/methylsalicylate and D 400 -MMT/p-hydroxymethylbenzoate, having lower molecular mass and polymer loading, the MMT rearranges in an intercalated and flocculated structure. The amount of intercalated polymer and interaction between polymer and layered silicate were determined using thermogravimetric analysis and Infrared spectroscopy. The antimicrobial activities of the nanocomposites were qualitatively and quantitatively assessed by agar diffusion tests and minimal inhibitory concentration values against a Gram-negative bacterium (Escherichia coli NCIM 2065), a Gram-positive bacterium (Bacillus subtilis ATCC) and fungi (Candida albicans SC5314 and Cryptococcus neoformans). The D 2000 -MMT/p-hydroxymethylbenzoate nanocomposite strongly inhibits the growth of all the micro-organisms tested. The diameter of the inhibition zone varies according to the type of micro-organism tested. The effect of nanocomposite concentration on morphology, respiration and release of calcium, potassium and sodium ions of the test micro-organisms was examined.

Photophysical and antibacterial properties of complex systems based on smectite, a cationic surfactant and methylene blue

“…A lot of attention has been paid to hybrid systems based on smectites as carriers of antimicrobially-active substances. These include systems with sulfonamides [4], tetracyclines [5], sulfathiazoles [6], quaternary alkylammonium and alkylphosphonium ions [7,8], or biocidal polymers [9]. General antibacterial and antifungal properties have been observed for colloids based on montmorillonite and the photosensitizer methylene blue (MB) [10].…”

High-performance flexible epoxy/ZnO nanocomposites with enhanced mechanical and thermal properties

“…The effects of inorganic fillers on the properties of the composites depend on the concentration and inter‐particle distance , shape, type of particles, filler size, the fraction surface characteristics, and degree of dispersion . Several nanoparticles, including nano alumina , carbon nanotubes , calcium carbonate , montmorillonite , silica , nanoclay , graphite nanofiber and some metal oxides , have been reported to promote the electrical properties, mechanical properties, thermal stability, and flame retardancy of the polymer matrix. Among several of metal oxide fillers, zinc oxide (ZnO) nanostructures have been received more attention, because of the unique physical properties as well as their low cost and extensive applications in diverse areas .…”

Polyamide‐montmorillonite nanocomposites as a drug delivery system: Preparation, release of 1,3,4‐oxa(thia)diazoles, and antimicrobial activity

“…These nanocomposites were expected to achieve in situ release for colon rectal therapy . In addition, the bioactive agents, vanillin, P ‐hydroxymethylbenzoate, 2,4‐dihydroxymethyl benzoate, and methyl salicylate incorporated into polyoxypropylenediamine were tested for their antimicrobial activities. The inhibition effect depends on molecular weight of polymer and morphology of the resulting nanocomposites.…”