Bleach Solution Research Articles

Enhancing antibacterial and flame-retardant performance of cotton fabric with an iminodiacetic acid-containing N-halamine

This research focused on preparing antibacterial and flame-retardant multifunctional cotton fabric to decrease the threat of harmful microorganism and fire, which might have huge potential application in household textiles. A water-soluble N-halamine precursor based on s-triazine (TIAPC) was synthesized by introducing iminodiacetic acid (IDA), which can chelate with metal ions to obtain flame retardancy. After coating with TIAPC, the cotton fabric was chlorinated in dilute bleach solution and chelated in metal salt solution to achieve antibacterial and flame-retardant properties. The surface morphology and chemical state of TIAPC-coated cotton fabric were characterized by FT-IR, XPS, SEM and EDX. The chlorinated TIAPC-coated cotton fabric displayed high-efficacy and rapid bactericidal effect against S. aureus and E. coli O157: H7 with 100% bacterial reduction in 1 min. Meanwhile, the chelated TIAPC-modified cotton fabric presented good thermal stability and char-forming capability. The hydrophobic property of modified cotton fabric was greatly improved after chlorination. Besides, this multifunctional coating had little effect on the cytotoxicity, tensile strength, air permeability, whiteness and drape of cotton fabric.

Chemo-mechanical modeling of static fatigue of high density polyethylene in bleach solution

High density polyethylene (HDPE) is increasingly used in infrastructure applications with a design service lifetime of several decades. In many cases, the HDPE member is exposed to a corrosive environment, such as in pipes carrying potable water, where the dissolved bleach selectively attacks the loosely packed amorphous phase of the polymer. The failure mechanism of HDPE transitions from a ductile to a brittle mode as the corrosion level increases. This leads to subcritical crack propagation, which deteriorates the load capacity of the structure. In this study, we develop a coupled chemo-mechanical model to simulate stress corrosion cracking (SCC) in HDPE members exposed to a bleach solution. The mechanical response of the polymer is described by a constitutive model that separately considers the individual deformation and damage behaviors of the amorphous and the crystalline phases. The model accounts for the intermolecular deformation and homogeneous void growth in the crystalline and amorphous phases, along with the resistance of the entangled network and craze damage in the amorphous phase. The embrittlement due to corrosion is captured by relating the constitutive parameters of amorphous phase to the molecular weight of the polymer. The diffusion and chemical reaction of bleach are described by a reduced order kinetics model that links the extent of polymer oxidation to the reduction of the molecular weight. The material constitutive model and diffusion–reaction model are combined in a single finite element (FE) code to investigate the SCC behavior of double edge notched HDPE specimens. The simulation yields the stress-life curves and fracture kinetics under different environments. The predicted stress-life curve qualitatively matches the measured stress-life data of polymer pipes. It is shown that the stress-life curve exhibits different regimes corresponding to distinct failure mechanisms, as indicated by the stress and strain distributions in the specimen.

Estimation of the Biological Activity of Some Commercial Bleaching Solutions (Hypochlorites) on Pathogenic Bacteria

Hypochlorites, the active ingredients in bleach, are an extremely useful chemical that have been used sincethe 18th century as a disinfectant.Hypochlorite solutions are in general strong oxidizing agents. The studyincluded of five species of hypochlorite solutions widely used as commercial bleaching solutions (Shoof,Oroplus, Alwazir , Lamoa and Fas) and their concentrations were confirmed chemically by potentiometrictitration methods previously and applicate their ability and efficiency against two types of bacteria (E.coliand Staphylococcus arueus) which are isolated from human infected sample in general Heat hospital /Iraq.The results revealed that all bleaching solutions have anti-bacterial influence against two species of bacteriaand more successful against Staphylococcus aureus than the E.coli especially with Alwazir solution givehigh significant difference compared with other solutions ,also the outcomes showed sensitivity of bacteriaenhanced with concentrations of bleaching solutions. The study indicates the fast reduction rate in the 30Sreaction showed the immediate efficiency of Hypochlorites. Finally the current study suggest and encourageto use hypochlorite solutions as antiseptics and disinfectants to killing species of bacteria which proved theirefficiency during this study

ОЦЕНКА БЕЗОПАСНОСТИ ПРИМЕНЕНИЯ ПОЛИМЕРНОГО МАТЕРИАЛА «ПЕНОПЛЕКС» В ЖИВОТНОВОДСТВЕ

The article presents data on veterinary and sanitary and hygienic assessment of the polymer material «Penoplex». The above material is made of Styrofoam and used in many areas of production, including to reduce heat loss of livestock facilities. Cattle and pig manure was used as a contact medium with the material under study. The duration of contact with the material (exposure) was 30 days. To study the resistance of the material to disinfectants, we used: 10 % sodium hydroxide solution (80 °C); 5 % solution of soda ash (70 °C); clarified solution of bleach containing 3 % active chlorine; 40 % solution of formaldehyde; 2 % solution of hydrogen peroxide. Studies of samples of the polymer material «Penoplex» for resistance to animal secretions and disinfectants have shown that the polymer material is resistant to them. During the experiment and after its completion, the «Penoplex» material had no visually visible changes on the outer layer. The used disinfectants and the model environment did not violate the structure of the polymer material «Penoplex». A slight change in the color of the «Penoplex» was found on the 20th day of exposure to 10 % solution of sodium hydroxide with temperature of 70 °C. For sanitary and bacteriological evaluation of «Penoplex», the disk method was used. Discs with a diameter of 10 mm were prepared from the material under study; wood discs were used as a control. Studies have found that Penoplex has no effect on sanitary-indicative microorganisms and is neutral in relation to their growth, which indicates the absence of release of substances from it into the environment that can delay or stimulate the growth of test cultures. The veterinary and sanitary and hygienic assessment of the polymer material «Penoplex» is the basis to recommend it for use in the construction of livestock buildings and inclusion as an addition to the current «List of polymer materials and structures permitted for use in the construction and technological equipment of livestock facilities» in the prescribed manner.

Determining the most effective common household disinfection method to reduce the microbial load on domestic dishcloths: a pilot study

The domestic dishcloth has been shown to be the most contaminated item in the domestic kitchen, reported to contain up to 108 bacteria for up to 48 hours. Their smooth texture and large surface area allow bacteria to be transferred to kitchen surfaces easily, presenting a greater risk of cross-contamination and potentially contributing to foodborne illness. The purpose of this pilot study was to determine the most effective method to decrease the aerobic colony count (ACC) present on contaminated dishcloths. Dishcloths were inoculated in a beef slurry for 48 hours at room temperature. Contaminated dishcloths were subjected to 1-minute treatments of 10% bleach solution, lemon juice, vinegar, tap water, and microwaving. Serial dilutions were plated and incubated at 37°C overnight. Three replicates were produced, and 95% confidence intervals were calculated. Although treatments of 10% bleach solution and vinegar showed reduced ACC growth, no growth was identified after microwaving dishcloths for 1 minute on high power. There was no significant difference identified between the tap water and lemon juice treatments. Given that this is the first study conducted directly comparing different disinfection methods for dishcloths, microwaving dishcloths on high power for 1 minute can be recommended to disinfect domestic dishcloths and reduce cross-contamination within the home.

Redox-based colorimetric sensing of H2O2 after removal of antioxidants with ABTS radical oxidation

Monitoring and determining H2O2 in many industries, treatment plants and biochemical media is important because of its harmful effects even at low concentrations. This work proposes a redox-based colorimetric sensor for the determination of hydrogen peroxide in the presence of antioxidants which are known interferents causing positive errors. On the other hand, the widely used peroxidase-based methods are interfered by enzyme inhibitors. The proposed method consists of two stages, namely antioxidant removal and H2O2 determination. In the first step, antioxidants were removed simply using ABTS radical (ABTS+) oxidant produced by persulfate. After antioxidant elimination, H2O2 in samples was determined by using the CUPRAC colorimetric sensor. The CUPRAC reagent, copper (II)-neocuproine (Cu(II)-Nc), immobilized on a Nafion persulfonate membrane was used for sensor preparation. The light blue Cu(II)-Nc was reduced by H2O2 to the yellow-orange colored Cu(I)-Nc chelate on the sensor, and the absorbance increase at 450 nm was recorded. The LOD and the LOQ values obtained for H2O2 were 0.33 and 1.10 µM, respectively. The proposed assay was validated in terms of linearity, additivity, precision and recovery. The H2O2 contents of spiked food extracts, synthetic serum and certain commercial products (i.e. food sterilization solution, whitening toothpaste and hair bleaching solution) were found to be comparable to the results of peroxidase-ABTS and titanyl sulfate reference assays. In addition, peroxide-type explosive triacetone triperoxide (TATP) was successfully determined in the presence of amine-type antioxidants. The proposed simple and low-cost assay is not inhibited by environmental agents (heavy metals, pesticides, sulfhydryl agents, etc.) adversely affecting enzymatic methods. It is additionally insensitive to turbidity and colored components of complex samples.

Determination of color-changing effects of bleaching chemicals on some heat-treated woods

The aim of this study was to use bleaching chemicals to remove the discoloration occurring on the surface of wood after heat treatment in order to restore the natural color of the wood. For this purpose, samples prepared from Scots pine (Pinus sylvestris L.), sessile oak (Quercus petraea L.), Eastern beech (Fagus orientalis L.), and Uludağ fir (Abies bornmuelleriana Mattf.) were exposed to heat treatment at temperatures of 140 and 160 °C for time periods of 3, 5, and 7 h. Bleaching solutions S1 (NaOH + H2O2), S2 (NaSiO3 + H2O2), and S3 (H2C2O4) at a concentration of 18% were then applied to the surface of the materials and the color change was determined according to ASTM D 2244 standard. Depending on the heat treatment temperature and duration, an increase in total color change values was detected on the surfaces of the materials and the color of the samples became darker. The total color change values decreased after bleaching with the S2 solution in the heat-treated Scots pine and fir samples, with the S3 solution in the beech samples, and with the S1, S2, and S3 solutions in the oak samples. The findings showed that by using bleaching chemicals to lighten wood materials darkened after heat treatment, it is possible to obtain results close to the natural color values.

The Effect of a Biomass Increase on The Carbon Fixation Rates of A. Thaliana

Arabidopsis Thaliana, a model organism for genetic modification, was tested to discover whether or not a genetic increase in biomass affects the plant’s rate of carbon fixation. An experimental design was employed, involving the testing of the carbon fixation rates from 4 separate experimental groups, genetically modified and a control group, both sterilized and unsterilized. Sterile water and a 50% bleach solution were used for seed sterilization, and once complete, all types of seeds were given a week long cold treatment. After the cold treatment had concluded, these plants were grown on moist fertilized soil, and were watered using a glass tray. Water was added into the flat surface every 2 days, and this nourishment was absorbed by the soil through holes in 4.409 x 3.937 terracotta pots. This absorption allowed for dry soil to remoisten, ultimately providing hydration to A. Thaliana. Growth measurements of the observed largest leaf were taken each week for a 4 week growth period. Once fully grown, a procedure known as photosynthetic flotation was used to uncover carbon fixation rates between the experimental groups, involving 0.5 cm leaf disks rising in a bicarbonate solution as carbon dioxide was converted to oxygen. The faster the leaf disk rose, the more rapidly carbon dioxide was fixated. Overall, data gathered from this experiment showed little difference between carbon fixation rates of biomass genetic modification and a control group, causing for this genetic modification only being able to be used to combat overpopulation with larger food being produced, but not that of reversing climate change. However, there was a significant gap in terms of the time to rise of leaf disks between sterilized and unsterilized groups, revealing that a more specific study in regards to this variable must be conducted.

Fecal Sample Collection Method for Wild Birds-Associated Microbiome Research: Perspectives for Wildlife Studies.

Simple SummaryThis paper describes an easy-to-build box for the noninvasive collection of feces from wild birds or small wild animals (up to 1 kg), including a plastic storage box, a plastic tray, and a vinyl-coated hardware cloth. This method could minimize potential contamination and allow for cross-study comparisons on gut microbiomes for wildlife medicine, conservation, ecology, and evolutionary biology.Gut microbial communities play important roles in host health, modulating development, nutrient acquisition, immune and metabolic regulation, behavior and diseases. Wildlife microbiome studies and host–microbe interaction and exploration might be an important goal for evolutionary biology, conservation, and ecology. Therefore, collection and sampling methods must be considered before choosing a microbiome-based research plan. Since the fecal microbial community reflects the true gut community better than that of cloacal swab samples and only few nondestructive methods have been described, we propose an easy-to-build box for a noninvasive fecal collection method. The main components of the collection box include a plastic storage box, a plastic tray, a vinyl-coated hardware cloth, and a 10% bleach solution. In the plastic box, the tray is positioned under the raised grate, where the bird is placed, to reduce the risk of contamination of the fecal samples. This procedure could simplify handling and processing phases in wild birds or other animals. It might represent a cheap and useful method for research studies, wildlife rescue center activities, veterinary practices, and conservation practitioners.

First Report of Sclerotinia sclerotiorum Causing Strawberry Fruit Rot in Florida.

During the 2019-2020 Florida strawberry season (October to April), a strawberry (Fragaria × ananassa) fruit rot was observed in two fields (Plant City and Wimauma, FL) with up to 5% incidence on short-day cultivars SensationTM Florida127, and Florida Brilliance. Symptoms on pink and ripe fruit consisted of softening, discoloration, watery rot with white fuzzy mycelium, and initial sclerotium formation. Diseased tissue was placed on General Isolation (GI) medium (Amiri et al. 2018) and incubated at 25°C under a 12-h photoperiod. A fungus producing spreading cottony white colonies with dark sclerotia near the outer edges of the plates was consistently isolated. One isolate from each cultivar field (20-51 and 20-55) was selected for identification and pathogenicity tests. Apothecial production was induced following the protocol of Li and Rollins (2009), and apothecia (n=30) had an average diameter of 4.5 (3.5 to 7.2) mm. Sclerotia were 3.6 (2.5 to 6.2) mm by 4.5 (3.1 to 5.9) mm (n=30) in size. Dimensions of asci were 130.2 (115.1 to 160.5) μm by 8.5 (6.2 to 13.1) μm (n=30), and those of ascospores were 12.2 (10.8 to 14.6) μm by 6.8 (5.7 to 8.1) μm (n=30). Based on these morphological features, the pathogen was tentatively identified as Sclerotinia sclerotiorum (Lib.) de Bary (Maas 1998). DNA was extracted from the same two isolates using the FastDNA kit (MP Biomedicals, Solon, OH), and the ribosomal internal transcribed spacer (ITS) region was amplified using the primers ITS1 and ITS4 (White et al. 1990). Sequences were deposited in GenBank (accession nos. MT378215 and MT378216). BLASTn searches revealed that isolates 20-51 and 20-55 were 99.62% identical (526 / 528 bp) to S. sclerotiorum CBS 499.50 (MH856725.1). Immature pink fruit of SensationTM 'Florida127' were harvested, surface disinfested in bleach solution (0.08% NaClO) for 90 sec, rinsed twice with deionized water, then placed into styrofoam egg cartons inside clean plastic boxes (30x24x7 cm) containing 150 ml of sterile deionized water to maintain moisture, and kept at 25°C with a 12-h photoperiod. Ascospores and sclerotia were used for inoculation tests with three repetitions in an egg carton containing 12 fruit each per isolate and inoculation method. The experiment was repeated once. Fruit were inoculated by placing 20 μl of a 1 × 106 ascospores/mL suspension or a single sclerotium on the upper half of the fruit. Controls were included, by placing 20 μl of sterile DI water or fruit with no sclerotia. Evaluations were done 6, 10, and 15 days after inoculation (DAI). Control fruit remained healthy, while inoculated fruit developed symptoms of softening and discoloration. For ascospore inoculation, disease incidence was 55 (± 5) and 78% (± 4), for 6 and 15 DAI, respectively, whereas for sclerotia inoculation incidence was 100% 6 DAI. Morphologically identical fungi to the original isolates were re-isolated from the diseased fruit. No other fruit decay fungi were observed. S. sclerotiorum has been previously reported causing strawberry fruit rot in Washington state in the United States, England, Israel, and Scotland (Alcorn 1966; Maas 1998; McLean 1957). It has also been listed in the indices of plant diseases from Florida, North Carolina, and California as causing crown rot (Farr and Rossman 2020). To our knowledge, this is the first report of S. sclerotiorum causing strawberry fruit rot in Florida. The pathogen is an aggressive necrotroph with prolonged survival and affects several vegetable crops grown in Florida (Paret et al. 2018). Because only the strawberry beds are fumigated, sclerotia remaining in the alleys could serve as inoculum sources. Currently, the disease is rare and of minor significance to strawberry production. However, efforts should be implemented to monitor its occurrence and spread.

What can a dentist and dental sleep apnea researcher do under COVID-19 lockdown?

Citation:Tanaka Y, Almeida FR. What can a dentist and dental sleep apnea researcher do under COVID-19 lockdown? J Clin Sleep Med. 2020;16(9):1641–1643.

Assessment of PowerPlex® Fusion 5C’s ability to type degraded DNA

DNA samples collected at crime scenes are often degraded so this research focused on the ability of the Promega PowerPlex® Fusion 5C amplification kit to type both naturally and artificially degraded DNA.DNA was degraded naturally by placing equal volumes of blood on white fabric that was stored either inside, outside in a shaded area, or outside in direct sunlight. Samples were then collected every 10 days for 60 days and the DNA extracted (QIAamp® DNA Investigator). Artificially degraded samples were created by exposing extracted DNA to either UV light or 95 °C heat for varying times. DNA was also degraded artificially by placing blood samples into a 50% bleach solution for varying times prior to extraction.Following sample treatment, standard forensic DNA analysis was performed including quantification (Investigator® Quantiplex) and amplification (PowerPlex® Fusion 5C). Separation and detection were performed on an ABI 3130xl capillary electrophoresis unit and analysis was performed using GeneMapper ID v3.2.1.While the time and shade samples showed similar amounts of degradation, the samples exposed to direct sun showed more degradation. The artificially degraded samples showed more signs of degradation such as reduced overall peak height and peak height imbalance at heterozygous loci. There were also some cases where an allele that was known to be in the profile exhibited total dropout. Although there were some instances of both allelic dropout and heterozygote peak imbalance, PowerPlex® Fusion was able to reliably type degraded DNA as all alleles detected were consistent with the known donor profile. The results show that PowerPlex® Fusion is a robust kit capable of handling forensically challenged samples.

Inhibition effect of Cynara cardunculus leaf extract on corrosion of St37 steel immersed in seawater with and without bleach solution

The inhibition performance of an aqueous extract of Cynara cardunculus leaves on the corrosion of St37 steel immersed in seawater and seawater with bleach was investigated using weight loss measurements, electrochemical methods, and surface characterization techniques. It was found that the extract components acted primarily as a mixed-type inhibitor, and inhibition efficiency increased with increasing inhibitor concentration. Electrochemical impedance spectroscopy (EIS) and dynamic electrochemical impedance spectroscopy (DEIS) confirmed the formation of a protective layer on the metallic surface in both solutions. The adsorption of inhibiting molecules conformed to the Langmuir isotherm model. The thermodynamic parameter values indicated that chemisorption constituted the major contribution to the adsorption process. This result was corroborated by scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) analyses. The significant inhibition effect can be related to the large amount of phenolic compounds in the CC aqueous extract as revealed by the Fourier-transform infrared (FTIR) spectrum.

Use of chlorine solutions as disinfectant agents in health units to contain the spread of COVID-19

Objective: This study aimed to gather information available in different disinfection protocols for establishments that provide care to suspected or confirmed patients with COVID-19, to contain the spread of the virus, besides proposing different ways of preparing the bleach solution for the most varied purposes within a Health Unit. Methods: It was realized bibliographic research about disinfection protocols to contain COVID-19, as well as disinfectant agents used to inactivate the virus. Results: Many hospitals and basic health units perform disinfection in many hospitals based on disinfection protocols that are not suitable due to the insufficient amount of daily cleaning recommended, as well as the use of ineffective agents or in inadequate concentrations. Among the most used disinfectant agents chlorine solutions have been described as the most efficient and most applicable, thus, we recommend the use of solutions containing chlorine in its composition, such as commercial bleach, as well as highlight its finalities, correct way of use and application at environments that take care of patients with disease COVID-19 or suspected. Conclusion: the use of solutions containing chlorine in its composition, such as commercial bleach, is a viable alternative for disinfecting hospitals and health basic units, due to its efficiency against the coronavirus, low cost, accessibility, and greater applicability when detected by other widespread disinfectant agents.

A Practical Decontamination Framework for COVID-19 Front-line Workers Returning Home.

A Practical Decontamination Framework for COVID-19 Front-line Workers Returning Home.

Safety measures for conducting exercise oxygen consumption, VO2, tests in developing countries.

Measurements of rate of oxygen consumption (VO2) recorded during controlled exercise is used to assess cardiovascular health in test individuals. In low- or middle-income countries, where Mycobacterium tuberculosis is common and older VO2 systems are in use, three specific preventative measures should be in place to prevent the transmission of tuberculosis. These include: (1) disinfecting reusable plastic masks and rubber tubing with bleach solution; (2) limiting maximum exposure of test individuals to Cl2 gas to <1-3 ppm for a duration of ≤15 min to prevent respiratory distress; and (3) carefully inspecting for degradation of plastic VO2 masks and rubber tubing repeatedly disinfected with bleach and replace these at the first signs of deterioration.

Stable N-halamine on polydopamine coating for high antimicrobial efficiency

In this paper, we report a simple method for preparing a highly effective antibacterial coating by the introduction of an N-halamine structure on a polydopamine (PDA)-based coating. The PDA-based coating includes only PDA and PDA co-deposited with polyethylenimine (PEI). The amine groups in PDA and PEI are assumed to be chlorinated and converted to N-halamine. After the simple immersion of PDA-based coatings in a dilute bleach solution, the formation of N-halamine is confirmed by iodometric titration. Compared with the original PDA-based coating, N-halamine-functionalized PDA-based coatings exhibit high antibacterial activity toward Gram-positive S. aureus and Gram-negative E. coli within a brief contact time. Notably, the PDA samples retain their oxidative chlorine content after extended storage, and ~90% of the chlorine is restorable after repeated quenching. The coatings are applicable to a wide spectrum of substrates and are stable. This study may provide a simple, effective method for the preparation of functional fibers with antibacterial activities for the clothing and textile industries.

The effect of processing medium on the 2 H/1 H of carbon-bound hydrogen in α-cellulose extracted from higher plants.

Although the 2 H/1 H ratio of the carbon-bound hydrogens (C-Hs) in α-cellulose extracted from higher plants has long been used successfully for climate, environmental and metabolic studies, the assumption that bleaching with acidified NaClO2 to remove lignin before pure α-cellulose can be obtained does not alter the 2 H/1 H ratio of α-cellulose C-Hs has nonetheless not been tested. For reliable application of the 2 H/1 H ratio of α-cellulose C-H, we processed plant materials representing different phytochemistries and photosynthetic carbon assimilation modes in isotopically contrasting bleaching media (with an isotopic difference of 273 mUr). All the isotope ratios were measured by elemental analyzer/isotope ratio mass spectrometry (EA/IRMS). Our results show that H from the bleaching medium does appear in the final pure α-cellulose product, although the isotopic alteration to the C-H in α-cellulose due to the incorporation of processing H from the medium is small if isotopically "natural" water is used to prepare the processing medium. However, under prolonged bleaching such an isotope effect can be significant, implying that standardizing the bleaching process is necessary for reliable 2 H/1 H measurement. The currently adopted method for removing lignin for α-cellulose extraction from higher plant materials with acidified NaClO2 bleaching is considered acceptable in terms of preserving the isotopic fidelity if isotopically "natural" water is used to prepare the bleaching solution.

Low-voltage thin-layer electrophoresis of inorganic anions on silica gel-G and titanium (IV) tungstate layers: separation of coexisting F−, Cl−, Br− and I−, I−, IO3− and IO4−, Fe(CN)64− and Fe(CN)63−

The electrophoretic behavior of twenty anions has been studied on silica gel-G, titanium (IV) tungstate and silica gel-G- titanium (IV) tungstate admixture layers using 0.1 M solutions of oxalic acid, citric acid, tartaric acid, succinic acid and acetic acid as background electrolyte. The mechanism of migration is explained in terms of adsorption and the solubility of various sodium or potassium salts of the anions in water. Titanium (IV) tungstate behaves only as an adsorbent and not as an ion exchanger. Being a cation exchanger, there is no exchange phenomenon occurring with anions. The migration of halides increase linearly with an increase in the bare ion radii of these ions. Differential migration of the anions on silica gel-G layers led to binary, ternary and quaternary separations of similar anions such as F− – Cl− – Br− – I−, I− – IO3− – IO4−, BrO3− – IO3− and Fe(CN)63− – Fe(CN)64−. The two cyanoferrate ions are separated from industrial waste water and from fixer and bleach solutions. The migration of anions has also been found to be in accordance with their lyotropic numbers.

Antibacterial Chitosan Hybrid Films with N-Halamine-Functionalized Graphene Oxide

Graphene, a single layer of two-dimensional carbon material, has attracted much attention due to its excellent comprehensive properties including high mechanical strength, antibacterial property, excellent thermal and electrical conductivities, high specific surface area, impermeability, etc. In this study, 3-epoxypropyl-5,5-dimethylhydantoin (GH), as a precursor of [Formula: see text]-halamine, was synthesized and attached onto graphene oxide (GO) for enhanced antibacterial activity. The synthesized GO–GH was characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS). After chlorination treatment by household bleach solution, the chlorinated graphene oxide-3-epoxypropyl-5,5-dimethylhydantoin (GO–GH–Cl) possessed great antibacterial efficacy. The synthesized GO–GH–Cl was added to chitosan (CS) solution to produce GO–GH–Cl/CS hybrid films via a solution casting method. The as-prepared antimicrobial hybrid films showed excellent antibacterial activity and could kill 100% of S. aureus and 100% of E. coli O157:H7 within 10[Formula: see text]min and 30[Formula: see text]min of contact time, respectively.