Search results for "Biocide"
showing 10 items of 49 documents
Novel antimicrobial ultrathin structures of zein/chitosan blends obtained by electrospinning
2009
Abstract This paper describes the formulation, morphology and biocide properties of novel antimicrobial electrospun zein based ultrathin fiber structures. From the results, it was found that the electrospun fibers of zein can turn the material into a new strong antimicrobial ultrathin-structured system due to retention of remnant amounts of trifluoroacetic acid as determined by ATR–FTIR spectroscopy. Unfortunately, this system may be considered to yield very aggressive high acidic media due to release of the strong acid, which causes the antimicrobial behavior. Nevertheless, since biocide properties are more desirable at mild acidic conditions, blending zein with the natural antimicrobial c…
The role of size and protein shells in the toxicity to algal photosynthesis induced by ionic silver delivered from silver nanoparticles
2019
Abstract Because of their biocide properties, silver nanoparticles (AgNPs) are present in numerous consumer products. The biocidal properties of AgNPs are due to both the interactions between AgNP and cell membranes and the release of dissolved silver (Ag+). Recent studies emphasized the role of different nanoparticle coatings in complexing and storing Ag+. In this study, the availability of dissolved silver in the presence of algae was assessed for three AgNPs with different silver contents (59%, 34% and 7% of total Ag), silver core sizes and casein shell thicknesses. The impact of ionic silver on the photosynthetic yield of Chlamydomonas reinhardtii was used as a proxy to estimate the amo…
Antimicrobial beeswax coated polylactide films with silver control release capacity.
2013
Although the application of silver based antimicrobial systems is a widespread technology, its implementation in areas such as food packaging is still challenging. The present paper describes the fabrication of poly(lactic acid) (PLA) coated with beeswax with controlled release properties for sustained antimicrobial performance. Release of silver ions from the polymers was monitored voltammetrically under various conditions (surface contact, immersion in various liquid media and at different pH values) throughout at least 7days. A higher release was noted with decreasing pH while surface release was much slower than the release when immersed in liquid medium. While uncoated films demonstrat…
The Essential Oil of Thymbra capitata and its Application as A Biocide on Stone and Derived Surfaces
2019
Many chemicals used nowadays for the preservation of cultural heritage pose a risk to both human health and the environment. Thus, it is desirable to find new and eco-friendly biocides that can replace the synthetic ones. In this regard, plant essential oils represent effective alternatives to synthetic substances for the preservation of historical monuments. Thymbra capitata (syn. Thymus capitatus) is a medicinal and aromatic plant growing in the Mediterranean area and endowed with important pharmacological properties related to its essential oil. Among them, the antimicrobial ones make the T. capitata essential oil an ideal candidate for industrial applications
Use of Biocides for the Control of Fungal Outbreaks in Subterranean Environments: The Case of the Lascaux Cave in France
2012
The Lascaux Cave in France suffered an outbreak of the fungus Fusarium solani in 2001. Biocides were applied for three years to control this outbreak. Four months after the initial biocide application, a new outbreak appeared in the form of black stains that progressively invaded the cave. The black stains on the ceiling and passage banks were so evident by 2007 that they became one of the caves major problems. Therefore, biocides were used again in 2008. The present study investigated the fungal communities associated with the black stains and the effectiveness of the biocides applied, by using cloning, denaturing gradient gel electrophoresis, and culture-dependent methods. A novel species…
Formulation of Mesoporous Silica Nanoparticles for Controlled Release of Antimicrobials for Stone Preventive Conservation
2020
The biotic deterioration of artifacts of archaeological and artistic interest mostly relies on the action of microorganisms capable of thriving under the most disparate environmental conditions. Thus, to attenuate biodeterioration phenomena, biocides can be used by the restorers to prevent or slow down the microbial growth. However, several factors such as biocide half-life, its wash-out because of environmental conditions, and its limited time of action make necessary its application repeatedly, leading to negative economic implications. Sound and successful treatments are represented by controlled release systems (CRSs) based on porous materials. Here, we report on the design and developm…
New biocides based on imidazolinium-functionalised hybrid mesoporous silica nanoparticles
2022
Here, we report the development of a new biocide based on hybrid mesoporous silica nanoparticles (MSN). The MSN was synthesized by condensation method in emulsion followed by grafting with two different silylated ionic liquid moieties, namely butyl imidazolinium bromide and imidazolinium propansulfonate betaine. Features of nanoparticles were characterized by Thermogravimetry, Infrared and ss-NMR Spectroscopy, and Transmission Electron Microscopy. The antibacterial properties were tested against a Gram-positive bacterial strain previously isolated from artefacts of interest in the field of Cultural Heritage. Interestingly, the hybrid material presents an antibacterial activity higher than i…
Vanadium pentoxide nanoparticles mimic vanadium haloperoxidases and thwart biofilm formation
2012
Marine biofouling—the colonization of small marine microorganisms on surfaces that are directly exposed to seawater, such as ships' hulls—is an expensive problem that is currently without an environmentally compatible solution1. Biofouling leads to increased hydrodynamic drag, which, in turn, causes increased fuel consumption and greenhouse gas emissions. Tributyltin-free antifouling coatings and paints1, 2, 3, 4 based on metal complexes or biocides have been shown to efficiently prevent marine biofouling. However, these materials can damage5 the environment through metal leaching (for example, of copper and zinc)6 and bacteria resistance7. Here, we show that vanadium pentoxide nanowires ac…
Using ATR-FTIR Spectroscopy To Design Active Antimicrobial Food Packaging Structures Based on High Molecular Weight Chitosan Polysaccharide
2007
ATR-FTIR spectroscopy has been used in this study to characterize the molecular mechanisms and kinetic processes that take place when a chitosonium acetate thin coating is put in contact with water solutions, Staphylococcus aureus solutions, microbial nutrient solutions, and with a high water activity TSA hydrogel medium to simulate the effect of direct contact with high moisture foods such as fresh meats, fish, and seafood products or beverages. The results of this work suggest that the biocide carboxylate groups that form when chitosan is cast from acetic acid solutions are being continuously evaporated from the formed film in the form of acetic acid (mechanism I) in the presence of envir…