Synthesis of metallic nanoparticles using plant extracts.

Nanotechnology is the creation, manipulation and use of materials at the nanometre size scale (1 to 100 nm). At this size scale there are significant differences in many material properties that are normally not seen in the same materials at larger scales. Although nanoscale materials can be produced using a variety of traditional physical and chemical processes, it is now possible to biologically synthesize materials via environment-friendly green chemistry based techniques. In recent years, the convergence between nanotechnology and biology has created the new field of nanobiotechnology that incorporates the use of biological entities such as actinomycetes algae, bacteria, fungi, viruses, yeasts, and plants in a number of biochemical and biophysical processes. The biological synthesis via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. The aim of this review is to provide an overview of recent trends in synthesizing nanoparticles via biological entities and their potential applications.

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Green Synthesis of Metallic Nanoparticles via Biological Entities

Nanoparticles exhibit unique properties that enable them to find potential applications in various fields. Accordingly, significant research attention is being given to the development of novel strategies for the synthesis of nanoparticles. Among these, biological route of nanoparticle synthesis has been portrayed as an efficient, low-cost and environmental friendly technique. Biological materials such as bacteria, fungi, yeast, algae and plant have been reported to possess high bioreduction ability to synthesize various size and shape of metallic nanoparticles. Of these biomaterials, this review focuses on plant-mediated biosynthesis of metallic nanoparticles. The biomolecules present in the plants such as terpenoids, flavones, ketones, aldehydes, proteins, amino acids, vitamins, alkaloids, tannins, phenolics, saponins, and polysaccharides play a vital role in reduction of metals. A systematic comparison of literature, based on the bioreduction capacity of various plant biomass/extract towards various metals under different experimental conditions, is also provided. Various instrumental techniques utilized to characterize nanoparticles are also discussed. Finally, this review also highlights the application of biosynthesized nanoparticles in different fields such as medicine, agriculture, catalytic, cosmetic and food. Thus, this article reviews the achievements and current status of plant-mediated biosynthesis, and hopes to provide insights into this exciting research frontier.

Plant-mediated biosynthesis of metallic nanoparticles: A review of literature, factors affecting synthesis, characterization techniques and applications

Advanced nanomaterials in oil and gas industry: Design, application and challenges

The invention relates to new processes for the preparation of antireflective coatings and coated substrates, as well as articles produced by these processes. These coatings can include one or more layers made of materials which form nano-structured and/or nano-porous surfaces. The process can include applying a cross-linkable hard coat to a substrate, partially curing or cross-linking the hard coat, and then applying a second coat carried by a solvent or mixture of solvents capable of swelling the partially cured hard coat. The second coat is then cross-linked and grafted to the hard coat to produce a durable coated substrate with antireflective properties.

Method of preparing nano-structured surface coatings and coated articles

It was surprisingly found that when a suitable binder including a suitable filler is used during the high temperature treatment of a curing process, the coating materials of the invention change in such a manner that electrically conducting reactive layers are formed that allow welding and especially spot welding together with the metal substrate even after treatment at temperatures of more than 800 °C.

Coating material for protecting metals, especially steel, from corrosion and/or scaling, method for coating metals and metal element

The invention relates to a method for producing a microstructured surface relief by applying a coating composition to a substrate. Said coating composition is thixotropic or acquires thixotropic properties on the substrate when pretreated. According to the invention, an embossing device is used to emboss the surface relief into the applied thixotropic coating composition, and the coating composition hardens after removing the embossing device. The substrates which are obtained by using this method and which are provided with a microstructured surface relief are particularly suited for optical, electronic, micromechanical and/or antisoiling applications.

Method for producing a microstructured surface relief by embossing thixotropic layers

The invention relates to a method for producing a coating material as well as the use of said coating material. The aim of the invention is to devise a method for producing a novel coating material which allows scratch-resistant coatings to be produced and can also be used as coating powder. Said aim is achieved by reacting one or more organic molecules, oligomers, or polymers comprising at least one functional group with one or more silanes comprising at least one functional organic group on an organic side chain in order to form a covalent bond between the organic molecule, oligomer, or polymer and the silane such that a polymolecular silane is obtained which can be directly cured using a catalyst. Surprisingly, reacting (optionally slightly pre-crosslinked) organically functionalized silanes, e.g. silanes having an NCO functionalization, with suitable reaction partners has shown that a novel class of compounds can be produced which can be used as a coating material, e.g. in the form of coating powders, high solid binders, or 100 percent resins.

Method for the production of a coating material

A process for the production of nano-structured mouldings and coatings comprises (a) preparation of a free-flowing material containing nano-scale inorganic solid particles (I) with polymerisable and/or polycondensable organic surface groups, (b1) pouring the material into a mould or (b2) coating it onto a substrate, and (c) polymerisation and/or polycondensation of the surface groups to give a hardened moulding or coating. Also claimed are (i) nano-structured mouldings obtained by this process, (ii) a process for the production of highly scratch- resistant coatings on plastic substrates, and (iii) substrates coated with a nano-structured layer made by process (ii).

Production of nano-structured mouldings and coatings

A composition for producing a protective coat against scaling on metallic surfaces. The composition includes, as binders, hydrolysates/condensates of at least one silane or a silicone resin binder and also, further, at least one metallic filler.

Stefan Sepeur

Papers

Coating material for protecting metals, especially steel, from corrosion and/or scaling, method for coating metals and metal element

Method for producing a microstructured surface relief by embossing thixotropic layers

Method for the production of a coating material

Production of nano-structured mouldings and coatings

Method for coating metal surfaces