tannins and melamine

5-Hydroxymethylfurfural (HMF) is a promising bio-derived platform chemical with a broad scope of application, for example, in the production of solvents, fuels, polymers, or adhesives. The wood and foundry industries are among the largest adhesive users and currently both rely to a large extent on the use of fossil-based binders, such as by using formaldehyde as a crosslinker in many commercial adhesive systems. The industry is thus looking for suitable alternatives to replace fossil-based chemicals. HMF and its derivatives are considered to be key renewable reactants in adhesive systems. The core of this Review is the critical evaluation of the potential of HMF and its derivatives in adhesive systems. The technological performance was assessed in the fields of wood-based materials, sand casting and composites. As an overall conclusion, HMF and its derivatives have a high application potential in alternative adhesives. Clearly, further research is needed to improve the performance and produce economically competitive adhesives.

Topics: Adhesives; Cross-Linking Reagents; Formaldehyde; Furaldehyde; Glass; Hydrolysis; Industry; Sand; Solvents; Sucrose; Tannins; Triazines; Wood

Topics: Environmental Restoration and Remediation; Hydrophobic and Hydrophilic Interactions; Microscopy, Electron, Scanning; Nanoparticles; Nanostructures; Nanotechnology; Petroleum Pollution; Photoelectron Spectroscopy; Plant Oils; Polyphenols; Silicon Dioxide; Silver; Solvents; Tannins; Triazines; Water

Melamine toxicity has recently attracted worldwide attention as it causes renal failure and the death of humans and animals. Therefore, developing a simple, fast and sensitive method for the routine detection of melamine is the need of the hour. Herein, we have developed a selective colorimetric method for the detection of melamine in milk samples based upon in-situ formation of silver nanoparticles (AgNPs) via tannic acid. The AgNPs thus formed were characterized by UV-Visible spectrophotometer, transmission electron microscope (TEM), zetasizer and dynamic light scattering (DLS). The AgNPs were used to detect melamine under in vitro condition and in raw milk spiked with melamine. Under optimal conditions, melamine could be selectively detected in vitro within the concentration range of 0.05-1.4μM with a limit of detection (LOD) of 0.01μM, which is lower than the strictest melamine safety requirement of 1ppm. In spiked raw milk, the recovery percentage range was 99.5-106.5% for liquid milk and 98.5-105.5% for powdered milk. The present method shows extreme selectivity with no significant interference with other substances like urea, glucose, glycine, ascorbic acid etc. This assay method does not utilize organic cosolvents, enzymatic reactions, light sensitive dye molecules and sophisticated instrumentation, thereby overcoming some of the limitations of the other conventional methods.

Topics: Animals; Colorimetry; Food Contamination; Limit of Detection; Metal Nanoparticles; Milk; Silver; Tannins; Triazines