Biocidal Materials Research Articles

Experiments and Modeling for Biocidal Effects of Explosives

AbstractThis paper reports an experimental and modelling study of the biocidal effect of an energetic mixture which is detonated in a closed chamber containing an initial spore distribution. The resulting spore neutralization efficiency is recorded as a function of measured detonation and combustion performance. We also report the results of a range of numerical modelling studies carried out to aid the interpretation of these experiments and to guide future developments. We find that the current energetic mixture (aluminum powder which is shock dispersed by detonation of a central high explosive core) gives variable combustion efficiency. The Al powder ignites on impact with the walls. In the modelling we match the recorded quasi‐static pressures in each experiment and compare predicted spore neutralization with measured values. Using a critical spore temperature for neutralization of 670 K gives a good match to the experiments. We report how neutralization efficiency varies with changes to this temperature. The coupled experimental and modelling approach allows us to suggest requirements for future biocidal energetic materials.

Release of Polymeric Biocides from Synthetic Matrices for Marine Biofouling Applications

Marine biofouling is a natural phenomenon representing one of the greatest problems in marine technology (navigation, aquaculture nets, etc). To circumvent these problems, antifouling paints or coatings, i.e. matrices containing biocidal species, are used to protect the submerged surfaces and objects. Polymers containing quaternary phosphonium or quaternary ammonium groups are promising biocidal materials. Such a biocidal polymeric material is the polymeric salt PSSAmC16 formed between the polystyrene sulfonate anion and the cetyltrimethylammonium cation. When embedded into a paint or a polymeric matrix, the cation of PSSAmC16 is gradually dissolved in the surrounding water through an ion exchange mechanism, offering the biocidal protection of the surface. In the present work, the release of PSSAmC16 from the synthetic polymeric matrix poly(methyl methacrylate), PMMA, was evaluated, as a function of the contact time with the surrounding aqueous environment. The PSSAmC16 content in the matrix varied from 0 up to 40% (wt/wt), while aqueous NaCl solutions with a salt concentration up to 2 M were investigated. The release of the polymeric biocidal was quantified through Total Organic Carbon (TOC) and Total Nitrogen (TN) measurements. Both methods reveal that the major part of the polymeric biocidal is released within a few days, while release increases with the PSSAmC16 content and it is enhanced by the salinity.

Aggregation of cationic p-phenylene ethynylenes on Laponite clay in aqueous dispersions and solid films

Previous studies of cationic p-phenylene ethynylenes oligomers (OPEs) have revealed strong antimicrobial activity and strong photophysical changes upon their aggregation that can be utilized for sensing various chemicals and biomolecules. In this article, the adsorption of two types of OPEs with different placement of charged groups onto the synthetic clay Laponite is studied, and the changes to photophysical properties, photochemical degradation efficiency, and biocidal effectiveness are determined. In addition to solution-phase studies, the material and biocidal properties of solid films formed from the OPE-Laponite complex were assessed. The results of this study suggest that OPEs aggregate on Laponite and induce aggregation between Laponite discs, leading to drastic changes to their photophysical and material properties. Solid OPE-Laponite films were shown to have fair resistance to dissolution in aqueous solution compared with Laponite alone, and adhesion and minor killing of both Gram-negative and Gram-positive bacteria on the surface was observed. The results of this study give insight into controlling the colloidal phases of Laponite via molecular aggregation, may be useful for development of sensors and biocides involving Laponite as a scaffold, and lead to further control over slow-release and surface interactions of biocidal materials.

Synthesis and antibacterial activity of versatile substrate-coated biocidal material via catechol chemistry

We report a potential coating material showing durable and significant antimicrobial activity for preserving the surfaces of a broad range of materials. The structure of the prepared antimicrobial adhesive material features a catechol moiety of dopamine hydrochloride conjugated to 4-bromobutanoyl chloride as an adhesive material. Antimicrobial properties against a wide range of microorganism species are achieved by quaternizing a long hydrophobic chain (N,N'-dimethyldecylamine) onto 3,4-dihydroxyphenylalanine (Dopa) to afford the prepared material (Dopa-decyl). The successful formation of Dopa-decyl is confirmed by hydrogen nuclear magnetic resonance (1H-NMR) and attenuated total reflectance-infrared (ATR-IR) measurements. The chemical composition of the quaternized adhesive material (Dopa-decyl) is characterized by X-ray photoelectron spectroscopy (XPS). Investigation of the antimicrobial activity of the Dopa-decyl-coated film against both gram-positive Staphylococcus aureus (S. aureus) and gram-negative Escherichia coli (E. coli) stains reveals a highly efficient antimicrobial effect under both normal and extreme stress conditions due to the biocidal effect of the quaternized amine when the materials are applied on the surface of various substrates. Copyright © 2014 John Wiley & Sons, Ltd.

Transformation of tributyltin in zebrafish eleutheroembryos (Danio rerio).

Organotin compounds are highly versatile group of organometallic chemicals used in industrial and agricultural applications. Their endocrine-disrupting effects are well known and their extensive uses as biocide materials, e.g., in antifouling paints, for many years have led to serious environmental problems. So far, attention has mainly been given to tributyltin pollution in water, sediments, and marine organisms because of its highly toxic effects and high accumulation levels at very low concentrations. In this study, we will focus on the conversion of tributyltin after it is absorbed by zebrafish eleutheroembryos, presented here as an alternative model to adult fish for describing bioconcentration. A simplified analytical extraction procedure based on the use of an assisted ultrasonic probe and derivatization by ethylation, followed by gas chromatography with a flame photometric detector (GC-FPD) is proposed. This classical methodology for organotin determination has been validated by inductively coupled plasma mass spectrometry (ICP-MS) and Zeeman graphite furnace atomic absorption spectrometry (ZGF-AAS) in terms of total tin content. The speciation analysis results show that zebrafish eleutheroembryos absorb high amounts of tributyltin and convert it into monobutyltin and likely in inorganic tin.

Antimicrobial activity of cobalt imidazolate metal–organic frameworks

Two cobalt imidazolate metal–organic frameworks were evaluated as a bactericidal material against the growth of the Gram-negative bacteria Pseudomonas putida and Escherichia coli.Under the most unfavourable conditions, within the exponential growth phase and in the culture media for both microorganisms, the growth inhibition reached over 50% for concentrations of biocidal material in the 5–10mgL−1 range. The release of metal gives excellent durability with the antibacterial effect persisting after 3months. Both cobalt-based materials can be prepared with simple, cheap and easily accessible commercial ligands, leading to a more affordable possible future application as antimicrobial materials.

Simple and efficient synthesis with theoretical calculations of novel N-halamine monomers

Hydantoins represent a group of compounds which over the past few years has attracted great attention because of their diverse biological activities. The synthetic methods for 5,5-dimetyhyl hydantoin (well-known biocidal material) available in literature are particularly difficult, and the yield of the synthesis after purification does not exceed 40%. On the other hand, styrene-type monomers containing spirohydantoin moieties were successfully synthesized by N-alkylation reaction. A simple and efficient preparation of N-chlorinated (N-halamine) monomers is presented, and the experimental data are supported by DFT calculations.

Molecularly Doped Metals

The many millions of organic, inorganic, and bioorganic molecules represent a very rich library of chemical, biological, and physical properties that do not show up among the approximately 100 metals. The ability to imbue metals with any of these molecular properties would open up tremendous potential for the development of new materials. In addition to their traditional features and their traditional applications, metals would have new traits, which would merge their classical virtues such as conductivity and catalytic activity with the diverse properties of these molecules. In this Account, we describe a new materials methodology, which enables, for the first time, the incorporation and entrapment of small organic molecules, polymers, and biomolecules within metals. These new materials are denoted dopant@metal. The creation of dopant@metal yields new properties that are more than or different from the sum of the individual properties of the two components. So far we have developed methods for the doping of silver, copper, gold, iron, palladium, platinum, and some of their alloys, as well as Hg-Ag amalgams. We have successfully altered classical metal properties (such as conductivity), induced unorthodox properties (such as rendering a metal acidic or basic), used metals as heterogeneous matrices for homogeneous catalysts, and formed new metallic catalysts such as metals doped with organometallic complexes. In addition, we have created materials that straddle the border between polymers and metals, we have entrapped enzymes to form bioactive metals, we have induced chirality within metals, we have made corrosion-resistant iron, we formed efficient biocidal materials, and we demonstrated a new concept for batteries. We have developed a variety of methods for synthesizing dopant@metals including aqueous homogeneous and heterogeneous reductions of the metal cations, reductions in DMF, electrochemical entrapments, thermal decompositions of zerovalent metal carbonyls, and dissolution during amalgam formation. The structures of these dopant@metal materials indicate that metals entrap the organic molecules within their agglomerated nanocrystals. As a result, these materials are porous, making the dopant accessible for chemical reactions, in particular for catalysis. We have prepared these materials in a variety of forms, including powder, granules, pressed discs, thin films, thick films, sub-micrometer particles, and nanometric particles decorating ceramic nanofibers. Entrapment and adsorption are very different processes. If entrapped, water-soluble molecules cannot be extracted, but the same molecules, if adsorbed, are easily washed away. Likewise, most of the special properties that we have observed, such as major improvements or changes in catalytic activity, completely different thermal gravimetric analysis behavior, and more, are observed only in the entrapped cases.

Synthesis and Characterization of Cellulose/Quaternary Phosphonium Salt

This paper investigates imparting antibacterial properties to wood pulp cellulose via introducing quaternary phosphonium salt groups in/onto the cellulose structure to get biocidal material. The 4-carboxybutyltriphenylphosphonium bromide was grafted to cellulose in an esterification at 70°C with mechanical stirring 5h.The grafted cellulose were evaluated with FTIR and 1H NMR. The product shows good antibacterial property against E. coli.

Review of Antibacterial Finishing Processes with Plasma for Cotton

Textiles are a suitable substrate for the growth of micro-organisms, especially at appropriate humidities and temperatures, when in contact with the human body. Due to the awareness that healthcare textiles enhance the quality of life, antimicrobials and antibacterial textiles have received, and continue to receive, considerable attention from researchers due to their potential to provide quality and safety benefits to many products. However, antimicrobial agents and antibacterial finishing processes have not grown in number because of possible harmful or toxic effects on humans and the environment. The application of rechargeable, safe antimicrobial agents and eco-friendly antibacterial finishing processes are being studied. This paper analyzes the disadvantages and advantages of antimicrobials and antibacterial finishing processes and finds suitable antimicrobials and antibacterial finishing processes for cotton. It is anticipated that the review will be a good resource for those who are interested in antimicrobials and biocidal textile materials, and will help to stimulate further interest in this area.

Photochemistry of “End-Only” Oligo-p-phenylene Ethynylenes: Complexation with Sodium Dodecyl Sulfate Reduces Solvent Accessibility

Cationic oligo-p-phenylene ethynylenes are very effective light-activated biocides and biosensors but degrade upon exposure to light. In this study, we explore the photochemistry of a class of "end-only" compounds from this series, which have cationic moieties on the ends of the backbone. Product characterization by mass spectrometry reveals that the photoreactivity of these molecules is higher than that of a previously studied oligomer and that the primary products of photolysis result from the addition of water or oxygen across the triple bond. In addition, a product suggesting the addition of peroxide or other reactive oxygen species across the triple bond was observed. To explore avenues by which the photodegradation of these compounds can be mitigated, the effects of complexation with sodium dodecyl sulfate micelles on their photochemistry was explored. Classical molecular dynamics simulations revealed that compounds that were protected from photolysis by SDS buried their phenylene ethynylene backbones into the interior of the micelle, protecting it from contact with water. This work has revealed a molecular basis for the protection of a novel class of light-activated biocides from irradiation that is consistent with the proposed photochemistry of these compounds. This information can be useful for developing photodegradation-resistant biocidal materials and applications for current compounds and leads to new molecular design.

Comparative Antimicrobial Activities of Aerosolized Sodium Hypochlorite, Chlorine Dioxide, and Electrochemically Activated Solutions Evaluated Using a Novel Standardized Assay

The main aim of this study was to develop a standardized experimental assay to enable differential antimicrobial comparisons of test biocidal aerosols. This study represents the first chlorine-matched comparative assessment of the antimicrobial activities of aerosolized sodium hypochlorite, chlorine dioxide, and electrochemically activated solution (ECAS) to determine their relative abilities to decontaminate various surface-associated health care-relevant microbial challenges. Standard microbiological challenges were developed by surface-associating typed Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus subtilis spores, or a clinical methicillin-resistant S. aureus (MRSA) strain on stainless steel, polypropylene, or fabric. All test coupons were subjected to 20-min biocidal aerosols of chlorine-matched (100 ppm) sodium hypochlorite, chlorine dioxide, or ECAS within a standard aerosolization chamber using a commercial humidifier under defined conditions. Biocidal treatment type and material surface had a significant effect on the number of microorganisms recovered from various material surfaces following treatment exposure. Under the conditions of the assay, the order of antimicrobial efficacy of biocidal aerosol treatment was as follows: ECAS > chlorine dioxide > sodium hypochlorite. For all biocides, greater antimicrobial reductions were seen when treating stainless steel and fabric than when treating plastic-associated microorganisms. The experimental fogging system and assay protocol designed within this study were shown capable of differentiating the comparative efficacies of multiple chlorine-matched biocidal aerosols against a spectrum of target organisms on a range of test surface materials and would be appropriate for testing other biocidal aerosol treatments or material surfaces.

Gold nanoparticles as efficient antimicrobial agents for Escherichia coli and Salmonella typhi

BackgroundIt is imperative to eliminate bacteria present in water in order to avoid problems in healthy. Escherichia coli and Salmonella typhi bacteria are two common pollutants and they are developing resistance to some of the most used bactericide. Therefore new biocide materials are being tested. Thus, gold nanoparticles are proposed to inhibit the growth of these two microorganisms.ResultsGold nanoparticles were supported onto clinoptilolite, mordenite and faujasite zeolites. Content of gold in materials varied between 2.3 and 2.8 wt%. The size, dispersion and roughness of gold nanoparticles were highly dependent of the zeolite support. The faujasite support was the support where the 5 nm nanoparticles were highly dispersed. The efficiency of gold-zeolites as bactericides of Escherichia coli and Salmonella typhi was determined by the zeolite support.ConclusionsGold nanoparticles dispersed on zeolites eliminate Escherichia coli and Salmonella typhi at short times. The biocidal properties of gold nanoparticles are influenced by the type of support which, indeed, drives key parameters as the size and roughness of nanoparticles. The more actives materials were pointed out Au-faujasite. These materials contained particles sized 5 nm at surface and eliminate 90–95% of Escherichia coli and Salmonella typhi colonies.

Antibacterial and Antifungal Glass with High Biocide Performance: Increased Antimicrobial Efficiency by Acid Activation

A compound contending silver ion specimens presents biocidal properties with effect proportional to ion concentration. An efficient biocidal material can be developed by incorporating silver ions species in glasses by ionic exchange process. The reactive area and material porosity are factors that influence the ion exchange reaction efficiency. Previous studies show that the acid activation of glasses increases the absorption capacity and can also increase the exchange capacity. This paper presents preliminary results on the biocide potencial optimization of the biocide powder glass. This process was performed using hydrochloric acid. Different pH (1.00, 3.00 and 5.00), treatment time (2.0, 4.0 and 6.0 hours) and temperature (30.0, 60.0 and 90.0°C) were used in the samples development. Microbiological analysis of the samples was made by disk diffusion method in the bacteria species Echerichia coli and Staphylococcus aureus. Samples were still submitted to EDS and Atomic Absorption.

Novel application of HKUST-1 metal–organic framework as antifungal: Biological tests and physicochemical characterizations

The HKUST-1 metal–organic framework (MOF) was successfully applied as a biocidal material against representative yeast and mold. The synthesized MOF showed a strong antifungal effect against Saccharomyces cerevisiae for which the growth was completely inhibited, whereas the growth of Geotrichum candidum was reduced from 6.16 to 1.29CFUmL−1. The antifungal action was related to copper ions released into the culture medium due to a progressive degradation of the crystalline structure of the material that involved the formation of surface extra-framework Cu(I). This study shows the potential of using copper-based metal–organic frameworks for a controlled release of biologically active copper ions.

Development of Cu2+- and/or phosphonium-based polymeric biocidal materials and their potential application in antifouling paints

The synthesis and characterization of a series of biocidal polymeric materials for potential antifouling submarine applications are presented. The polymeric backbone of these materials contains anionic units, such as styrene sulfonate, and/or acrylate or maleate units. The hydrophobic/hydrophilic nature of these polymers was, furthermore, tuned through copolymerization with hydrophobic units, such as vinyl acetate or styrene. The biocidal species, Cu2+ ions and/or phosphonium cations, were incorporated through electrostatic and/or coordination interactions, depending on the nature of the polymeric backbone. It was observed that the release of Cu2+ ions in water from the Cu2+-containing materials is controlled by the hydrophobic/hydrophilic balance of the polymeric backbone. The prepared biocidal polymeric materials were incorporated into two paint formulations, based on a rosin or a vinylic matrix. The erosion properties of the biocidal paints under accelerated laboratory conditions were evaluated using scanning electron microscopy. It is found that the antifouling performance is related to the release of biocidal species. The most efficient materials are those containing Cu2+ ions or combining both Cu2+ and phosphonium cations.

Amidoxime copolymer beads containing Cu/Cu2O microparticles as a biocidal material for water disinfection

AbstractMacroporous crosslinked acrylonitrile‐divinylbenzene copolymer beads were synthesized by suspension polymerization technique. The beads were chemically modified to have amidoxime functional group, which was used as a solid support for anchoring copper microparticles. The copper ions loaded on the copolymer beads were reduced using strong reducing agent to have copper microparticles on the amidoxime copolymer beads. The size of copper particles formed depends upon the amount of copper ions loaded on the beads. The formation of copper microparticles on the copolymer was confirmed by instrumental analysis. The copper containing amidoxime copolymer beads were investigated for the biocidal activity. The size and the distribution of copper particles on the amidoxime copolymer beads influenced their biocidal activity. The biocidal activity was tested against two Gram‐positive bacteria, Bacillus subtilis and Staphylococcus aureus, and against two Gram‐negative bacteria, Pseudomonas aeruginosa and Escherichia coli. The beads containing copper particles showed better biocidal activity against the Gram‐negative bacteria when compared with the Gram‐positive organisms. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

Chip-calorimetry provides real time insights into the inactivation of biofilms by predatory bacteria

Control or removal of undesired biofilms has frequently been found to be quite difficult. In addition to biocidal or antibiotic chemicals or materials designed to prevent biofouling, biological control agents appear to be promising. Reports of bacterial predators eradicating biofilms or eliminating pathogens motivate a more systematic screening of biofilm-eliminating bacterial predators. Unfortunately, the analysis of the eradication process is demanding. In the present study, chip-calorimetry was applied to monitor the elimination of Pseudomonas sp. biofilms by Bdellovibrio bacteriovorus. The method uses metabolic heat as a real-time parameter for biofilm activity. The method is non-invasive, fast and convenient due to real-time data acquisition. In addition, heat-production data can reveal information about the energetics of the predator–prey interaction. The calorimetric results were validated by confocal laser scanning microscopy. The approach described may be useful for the screening of biofilm susceptibility to different predators.

Preface: Forum on Biocidal Materials & Interfaces

ADVERTISEMENT RETURN TO ISSUEEditorialNEXTPreface: Forum on Biocidal Materials & InterfacesKirk S. Schanze*View Author Information Department of Chemistry, University of Florida, Gainesville, Florida 32611, United StatesE-mail: [email protected]Cite this: ACS Appl. Mater. Interfaces 2011, 3, 8, 2807Publication Date (Web):August 24, 2011Publication History Published online24 August 2011Published inissue 24 August 2011https://doi.org/10.1021/am201056kCopyright © 2011 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views613Altmetric-Citations1LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (612 KB) Get e-AlertsSUBJECTS:Bioengineering and biotechnology,Biofilms,Biomaterials,Interfaces,Polymers Get e-Alerts

Synthesis and characterization of silver nanoparticle and graphene oxide nanosheet composites as a bactericidal agent for water disinfection

Graphene oxide (GO) nanosheets impregnated with silver nanoparticles (Ag NPs) were fabricated by the in situ reduction of adsorbed Ag+ by hydroquinone (HQ) in a citrate buffer solution. Paper-like Ag NP/GO composite materials were fabricated owing to convenient structure characterization and antibacterial tests. The Ag NP/GO composites were characterized by UV–vis spectra, transmission electron microscope, electron diffraction, Raman spectroscopy, and field emission scanning electron microscope coupled with Energy Dispersive Spectrometer. Antibacterial activity was tested using Escherichia coli and Staphylococcus aureus as model strains of Gram negative and Gram positive bacteria, respectively. The as-prepared composites exhibit stronger antibacterial activity against both. The Ag NP/GO composites performed efficiently in bringing down the count of E. coli from 106cfu/mL to zero with 45mg/L GO in water. The micron-scale GO nanosheets (lateral size) enable them to be easily deposited on porous ceramic membranes during water filtration; making them a promising biocidal material for water disinfection.