Green Synthesis of Silver Nanoparticles and Study of Their Antimicrobial Properties

One of the major disadvantages of polymers when used in food-contact applications is that they are very susceptible to microbial attack. On the other hand, silver nanoparticles have received increased attention as novel antimicrobial agents. Therefore, the introduction of silver nanoparticles into conventional polymers results in new materials with improved properties. In this investigation, colloidal silver nanoparticles using an environmentally friendly procedure were synthesized. An aqueous solution of AgNO₃ was used as a silver precursor with ‘green’ reducing agents either different types of honey, or β-d-glucose. In the first case, different pH values, as well as the addition of poly(ethylene glycol), PEG were studied, while in the latter, the effect of reduction time in the presence of PEG with various average molecular weights was examined. Properties of the nanoparticles were measured using X-Ray diffraction, UV–Vis and FTIR spectroscopy. Using honey it seems that spherical particles are produced with the smaller average particle size obtained at pH 8.5. Use of honey has the advantage of being a natural product, although its main drawback is that its composition varies and it cannot be predefined to result in reproducible results. Use of β-d-glucose results in stable silver nanoparticles with small average particle size after 24 h reduction. The addition of low molecular weight PEG seems to be beneficial in the production of stable nanoparticles. Finally, the antimicrobial activity of the nanoparticles produced was investigated at different concentrations on both Gram positive and negative bacteria, such as Bacillus cereus, Bacillus subtilis, Escherichia coli and Staphylococcus aureus.     

Antibacterial and Catalytic Performance of Green Synthesized Silver Nanoparticles Embedded in Crosslinked PVA Sheet

Journal of Polymers and the Environment - In this research work, a green method of using Saussurea costus extract for the synthesis of silver nanoparticles (AgNPs) is developed. Analysis of the...     

Synthesis of Silver Nanoparticles Through Orange Peel Powder for Antibacterial Composite Filler Applications

Journal of Polymers and the Environment - Environmental concerns and the positive aspects of biowaste materials gained the attention of researchers to use them as filler materials in fabricating of...     

Green Synthesis and Characterization of Silver Nanoparticles Using Elaeagnus angustifolia Bark Extract and Study of Its Antibacterial Effect

Journal of Polymers and the Environment - Nowadays, many chemical methods have been proposed for the synthesis of silver nanoparticles, but green synthesis has received more attention due to its...     

Properties of Biocomposite Films From PLA and Thermally Treated Wood Modified with Silver Nanoparticles Using Leaf Extracts of Oriental Sweetgum

Journal of Polymers and the Environment - The technological, thermal, and antimicrobial properties of biocomposite films produced from polylactic acid (PLA) and thermally treated wood flour with in...     

Microfibrillated Cellulose-Silver Nanocomposite Based PVA Hydrogels and Their Enhanced Physical,Mechanical and Antibacterial Properties

Journal of Polymers and the Environment - Modification of cellulose with silver nanoparticles produces various nanocomposites with significantly developed properties. This work aims to prepare a...     

Injectable Methylcellulose and Hyaluronic Acid Hydrogel Containing Silver Nanoparticles for Their Effective Anti-microbial and Wound Healing Activity After Fracture Surgery

Journal of Polymers and the Environment - Currently, the synthesis of silver nanoparticles (AgNPs) was utilized for various life-saving biomedical applications. Herein, we report the synthesis and...     

Formulation and Evaluation of Matrix Type Transdermal Patch Containing Silver Nanoparticles

This research aimed to prepare the silver nanoparticles (AgNPs)-loaded antimicrobial wound dressing patch using ethyl cellulose as a matrix membrane and diethyl phthalate as a plasticizer. The polymer suspension was homogeneously mixed with plasticizer, and then added to the colloidal AgNPs suspension. This mixture was poured into Petri dish and subsequently dried in a hot air oven at 80?±?2 °C for 10 h. The minimum inhibition concentration of the colloidal AgNPs suspension was 2.5 µg/ml. The AgNPs-loaded antimicrobial wound dressing patch was evaluated for physical properties by differential scanning calorimeter, X-ray diffraction, scanning electron microscope, and in vitro study. The antimicrobial wound dressing patch did not exhibit any interaction between the matrix membrane and AgNPs. The AgNPs were evenly dispersed in the patch. The patch could control the release of silver at 102.98?±?4.11% over 12 h. Although the AgNPs-loaded antimicrobial wound dressing patches can be easily prepared by the simple method, in future studies antimicrobial wound dressing patch will be developed by employing different types of film forming agents.     

Preparation of Water-Insoluble Antibacterial Materials with Surface-Grafted Material PSt/SiO<Subscript>2</Subscript> and Their Antibacterial Activity

Styrene (St) was graft-polymerized onto the surfaces of micro-sized silica gel particles, and the surface-grafted composite particles PSt/SiO₂ were obtained. With the surface-grafted composite particles PSt/SiO₂ as a starting material, water-insoluble antibacterial materials with quaternary ‘onium’ salt-type were synthesized via two polymer reaction steps. The grafted polystyrene was first chloromethylated, resulting in grafted particles CMPS/SiO₂, and then quaterisation (QN) and quaternary phosphonium reaction (QP) were conducted with triethylamine, tri-n-butylamine and triphenyl phosphine as reagents, respectively. Two kinds of water-insoluble antibacterial materials, QN-PSt/SiO₂ and QP-PSt/SiO₂ were prepared. Their antibacterial property was mainly investigated by using Escherichia coli (E. coli) as a model bacterium and by adopting colony count method. The relationship between the chemical structure of the antibacterial group and antimicrobial activity for the water-insoluble antibacterial materials was studied in detail, and their antibacterial mechanism was investigated by TTC-dehydrogenase activity determination and extracellular DNA and RNA measurement methods. The experimental results show that QN-PSt/SiO₂ and QP-PSt/SiO₂ possess strong antibacterial activity. The main factors affecting the antibacterial ability of the water-insoluble materials are the chemical structure of the antibacterial groups, the bound density of the antibacterial groups on the surface of the water-insoluble antibacterial materials as well as the pH value of the medium. QP-PSt/SiO₂ has stronger antibacterial activity than QN-PSt/SiO₂; the QN-PSt/SiO₂ prepared with tri-n-butylamine has stronger antibacterial activity than that prepared with triethylamine; the water-insoluble material with higher bound density of the antibacterial groups has stronger antibacterial ability; as the pH value of the medium is over the isoelectric point of E. coli, the antibacterial ability is strengthened with the increase of pH value.     

Nanoparticles: Their potential toxicity,waste and environmental management

This literature review discusses specific issues related to handling of waste containing nanomaterials. The aims are (1) to highlight problems related to uncontrolled release of nanoparticles to the environment through waste disposal, and (2) to introduce the topics of nanowaste and nanotoxicology to the waste management community. Many nanoparticles used by industry contain heavy metals, thus toxicity and bioaccumulation of heavy metals contained in nanoparticles may become important environmental issues. Although bioavailability of heavy metals contained in nanoparticles can be lower than those present in soluble form, the toxicity resulting from their intrinsic nature (e.g. their size, shape or density) may be significant. An approach to the treatment of nanowaste requires understanding of all its properties – not only chemical, but also physical and biological. Progress in nanowaste management also requires studies of the environmental impact of the new materials. The authors believe Amara’s law is applicable to the impact of nanotechnologies, and society might overestimate the short-term effects of these technologies, while underestimating the long-term effects. It is necessary to have basic information from companies about the level and nature of nanomaterials produced or emitted and about the expectation of the life cycle time of nanoproducts as a basis to estimate the level of nanowaste in the future. Without knowing how companies plan to use and store recycled and nonrecycled nanomaterials, development of regulations is difficult. Tagging of nanoproducts is proposed as a means to facilitate separation and recovery of nanomaterials.     

Impact of Silver Nanoparticles Synthesized by Irradiated Polyvinylpyrrolidone on Spodoptera littoralis Nucleopolyhedrosis Virus Activity

Journal of Polymers and the Environment - A Green nanomaterial synthesis could be considered as an alternative bio-controller source of insect pest management as well as saving the environment....     

Ultrastructural, Morphological, and Antifungal Properties of Micro and Nanoparticles of Chitosan Crosslinked with Sodium Tripolyphosphate

Recent studies have demonstrated the antibacterial effect of micro and nanoparticles of chitosan (CS) crosslinked with sodium tripolyphosphate (TPP), and incorporating metallic ions, bringing that the size, shape, and zeta potential are related to the antimicrobial potential. However, there are few studies on the antifungal activity and the effect of TPP on the antimicrobial potential. Micro and nanoparticles were prepared from CS by ionotropic gelation with TPP, and structurally characterized by transmission and scanning electron spectroscopy, and Fourier transformed infrared spectroscopy. Depending on the concentration of CS and TPP, spherical particles were obtained from 80 nm to 20 μm. Subsequently, particles were evaluated for their antifungal potential against Aspergillus parasiticus assessing radial growth, spore germination, and morphological changes. An increase in the antifungal potential compared with CS in solution was observed, inhibiting the development of the fungus causing clear morphological changes in both, hyphae and spores. Particle size and the availability of functional groups of CS/TPP (amino group and phosphate), suggest a possible synergistic effect between CS and TPP.     

Development and Analysis of Silver Nano Particle Influenced PVA/Natural Particulate Hybrid Composites with Thermo-Mechanical Properties

Journal of Polymers and the Environment - Owing to develop the utilization of biowaste materials and minimize the usage of plastic materials, Orange peel Powder (OPP) biowaste is chosen as filler...     

Improving the Antibacterial Activity of Curcumin Loaded Nanoparticles in Wastewater Treatment by Enhancing Permeability and Sustained Release

Journal of Polymers and the Environment - In this research, the antibacterial effect of curcumin entrapped in polymeric nanoparticles (mPEG-PCL/curcumin) on resistant bacteria were investigated....     

Green Synthesis of Silver Nanoparticles Using Exopolysaccharides Produced by Bacillus anthracis PFAB2 and Its Biocidal Property

Journal of Polymers and the Environment - Nowadays when control of environmental toxicity is a matter of concern, the focus of the researchers is to find an eco-friendly process. Considering the...     

Physicochemical and Antibacterial Evaluation of Poly (Vinyl Alcohol)/Guar Gum/Silver Nanocomposite Films for Food Packaging Applications

Journal of Polymers and the Environment - In this study, we prepared Poly (vinyl alcohol) (PVA)/Guar gum (GG) based nanocomposite films with a different weight ratio of silver nanoparticles (AgNPs)...     

铝片包裹氯化银置换法回收银

将含银废液中的Ag+转化为Ag Cl,再用铝片包裹Ag Cl固体,在Na2CO3溶液中采用置换法回收银。考察了各反应条件对Ag Cl还原为银的转化率的影响。实验结果表明,适宜的反应条件为:Na2CO3溶液质量分数20%,反应温度40℃,反应时间20 h,不搅拌静置反应。在此适宜的反应条件下,Ag Cl还原为银的转化率为95.32%。     

Effect of the Fe2O3/TiO2 Nanoparticles on the Structural,Mechanical, Electrical Properties and Antibacterial Activity of the Biodegradable Chitosan/Polyvinyl Alcohol Blend for Food Packaging

Journal of Polymers and the Environment - As the request for ready-made food grows, it’s more important than ever to develop effective antimicrobial food packaging materials to assure...