ABSTRACT
The direct hydrothermal conversion of waste biomass to 5-hydroxymethyl furfural (5-HMF) and levulinic acid was studied here in the presence of new biomass-derived sulfonated carbonaceous solid acid catalysts. Different cheap and waste lignocellulosic/cellulosic biomass materials (wheat straw, corn straw, cotton linter and industrial textile fluff) were used as feedstock to prepare bio-based chemicals in an eco-friendly and economical process. The yields of products were improved by optimization of reaction temperature, reaction time and catalyst type for various types of biomass. Under the optimum reaction conditions BT300S sulfonated solid acid carbonaceous catalyst has exhibited higher activity compared to commercial Amberlyst 15 thus 403.7â¯ppm 5-HMF (16.2â¯mg 5-HMF/g biomass) and 1624.8â¯ppm LA (65.6â¯mg LA/g biomass) have been generated from corn straw biomass in aqueous media at 200⯰C in 1â¯h.
Subject(s)
Acids , Furaldehyde , Biomass , Catalysis , Temperature , Zea maysABSTRACT
In this article, we report a simple, cost-effective and eco-friendly method of airbrushing for the fabrication of antibacterial composite nanofibers using Nylon-6 and silver chloride (AgCl). The Nylon-6 is a widely used polymer for various biomedical applications because of its excellent biocompatibility and mechanical properties. Similarly, silver has also been known for their antibacterial, antifungal, antiviral, and anti-inflammatory properties. In order to enhance the antibacterial functionality of the Nylon-6, composite nanofibers in combination with AgCl have been fabricated using airbrush method. The chemical functional groups and morphological studies of the airbrushed Nylon-6/AgCl composite nanofibers were carried out by FTIR and SEM, respectively. The antibacterial activity of airbrushed Nylon-6/AgCl composite nanofibers was evaluated using Gram +ve (Staphylococcus aureus) and Gram -ve (Escherichia coli) bacterial strains. The results showed that the airbrushed Nylon-6/AgCl composite nanofibers have better antibacterial activity against the tested bacterial strains than the airbrushed Nylon-6 nanofibers. Therefore, the airbrushed Nylon-6/AgCl composite nanofibers could be used as a potential antibacterial scaffolding system for tissue engineering and regenerative medicine.
Subject(s)
Anti-Bacterial Agents/chemistry , Nanofibers , Silver , Escherichia coli/drug effects , Staphylococcus aureus/drug effectsABSTRACT
BACKGROUND: Fibrous structures and synthetic polymer blends offer potential usages in making biomedical devices, textiles used in medical practices, food packaging, tissue engineering, environmental applications and biomedical arena. These products are also excellent candidates for building scaffolds to grow stem cells for implantation, to make tissue engineering grafts, to make stents to open up blood vessels caused by atherosclerosis or narrowed by blood clots, for drug delivery systems for micro- to nano-medicines, for transdermal patches, and for healing of wounds and burn care. The current study was designed to evaluate the antimicrobial activity of woven and non-woven forms of nano- and macro-scale blended polymers having biocompatible and biodegradable characteristics. METHODS: The antimicrobial activity of non-woven fibrous structures created with the combination of synthetic and biopolymer was assessed using Gram-negative, Gram-positive bacteria, such as Staphylococcus aureus, Proteus vulgaris, Escherichia coli and Enterobacter aerogenes using pour plate method. Structural evaluation of the fabricated samples was performed by Fourier transform infrared spectroscopy. RESULTS: Broad spectrum antibacterial activities were found from the tested materials consisting of polyvinyl alcohol (PVA) with chitosan and nylon-6 combined with chitosan and formic acid. CONCLUSIONS: The combination of PVA with chitosan was more bactericidal or bacteriostatic than that of nylon-6 combined with chitosan and formic acid. PVA combination with chitosan appears to be a broad-spectrum antimicrobial agent.
