A biosensor based on microbial lipase immobilized on lamellar zinc hydroxide-decorated gold nanoparticles for carbendazim determination

We report an enzymatic biosensor based on the microbial lipase Ceratobasidium sp.2 immobilized on lamellar zinc hydroxynitrate decorated gold nanoparticles and then incorporated into carbon paste with multi-walled carbon nanotubes (CNTs).

Development and preparation of oxide mixture-based pigments for anticorrosion paints

Purpose The aim of the work is to develop an anticorrosion pigment based on an oxide mixture with lamellar particles. The pigments are prepared from lamellar zinc, zinc oxide and magnetite by calcination. An alkaline earth carbonate is added when embedding a third cation in the lattice of the ferrite that forms the envelope of the lamellar zinc. The properties of the pigments are tested both in the powdered state and when embedded in an epoxy-ester system using different pigment volume concentrations (PVC). Design/methodology/approach The properties of paints containing synthesised oxide mixture-based pigments at various volume concentrations and with the Q factor – Q = PVC/CPVC = 0.65 – were examined (where CPVC is critical pigment volume concentration). A series of isometric ferrite pigments were also synthesised for a comparison. Paints of both types with PVC = 10, 15 and 20 per cent were formulated. Steel panels coated with the paints were subjected to corrosion and mechanical tests. Findings The oxide mixtures with lamellar particles were subjected to particle size analysis and found to make up a broad distribution curve. Electron microscopy photographs confirmed that the oxide mixture pigments contained lamellar particles with a surface layer. A high anticorrosion effect was achieved owing to the combination of different oxide types. Research limitations/implications The properties of the oxide mixtures with lamellar particles are described. Their particle distribution curves can be obtained by particle size analysis methods with a view to obtaining additional information on the status and properties of the pigment particles that may be useful in the development of better paints/coating materials. Practical implications Oxide mixtures with lamellar particles can be used in paints protecting construction steel. Originality/value The composition of the prepared oxide mixture-based pigments is novel. Each oxide acts by its own anticorrosion mechanism and the final beneficial effect is due to their concerted action.

Surfactant-directed syntheses of mesostructured zinc imidazolates: formation mechanism and structural insights

A detailed study on the formation mechanism, local and long-range structures of surfactant-directed lamellar zinc imidazolates is presented.

Preparation and Characterization of Inorganic Zinc-Rich Coatings Based on Geopolymers

In this work, a high performance, environmentally friendly and waterborne inorganic zinc-rich coating based on geopolymer was developed and applied as protective coating of steel substrate. The geopolymer was the main ingredient of the zinc-rich paint (ZRP), and the zinc powder and additives were added to geopolymer to prepare ZRP. The corrosion protection behaviors of ZRP with different kinds of zinc powder and various zinc contents were characterized by electrochemical protection performance test. The results showed that coatings with 55 wt% spherical zinc powder and 25 wt% lamellar zinc powder exhibited good corrosion resistance mainly because of the cathodic protection and barrier effect.

New Synthesis Method of the Lamellar Zinc Phosphate and its Electrochemical Corrosion Inhibitions

A new synthesis method namely hydrolysis precipitation was used to prepare Zn3(PO4)2•4H2O. Structural characteristics of products were investigated by X-ray Diffraction, scanning electron microscope and chemical analysis. The electrochemical corrosion inhibitions of title zinc phosphate were studied by electrochemical impedance of coating immersion test. The results show that the obtained product is a highly crystalline, micronized and lamellar Zn3(PO4)2•4H2O. Comparing with commercial zinc phosphate, the synthesized lamellar microcrystalline product has excellent anticorrosive property and dispersibility.