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Green analytical methods and principles of green analytical chemistry
No full textThe chemical field, in previous years, has worked through a linear process, and this type of trend caused large waste volume and accumulation, leading to the current crisis of pollution and the environment. In the last century, industrial activity has been growing up so fast, but on the other hand, this has caused quite a few environmental problems, such as leading the search for new approaches that are about more eco-friendly chemical research and ecological engineering. In this scenario, starting in early 1990 with the birth of green chemistry (GC), a continuous improvement in greenness research has been observed, which nowadays reaches green analytical chemistry (GAC) and green sample preparation (GSP). All these principles, concepts, and tools are widely used to make the different methods greener, with a reduced environmental impact and reduced waste production. In this chapter, these points will be considered and analyzed to better highlight how chemistry, and particularly analytical chemistry, can help in this process
Social media e comunicazione scientifica nelle università. Il caso dei piccoli atenei italiani
No full textGreen chemistry and green analytical chemistry
No full textSince 1996, the importance of green chemistry (GC) increased, thanks to 10 principles that require minimizing of waste, of hazardous solvents and quantity of solvents, energy consumption etc. GC was born due to increase in pollution with the aim of safeguarding the environment and the operator. Thus, years later green analytical chemistry (GAC) was born, sectoring GC principles in analytical field. In addition, GAC had, and still has, a big impact on daily work. For this reason index that “quantify” the greenness of a procedure were born and someone most used are explicated in this chapter. Chapter starts with a general view on green and GAC trends, following with an in-depth analysis of them, principle by principle, there is also a scale of solvents, which can be helpful for scientist to choice the right one. Later, GAC principles are analyzed and there are some examples of most used index, with a focus on their growth and specificity, and this part can be helpful to understand how to read a GAC index
Exploring beer culture dissemination and quality perception through different media: the craft beer experience
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Stability and tribological properties of oil-in-water emulsions stabilized with native corn starch and olive leaves phenolic extracts
No full textIn this work, the tribological behaviour of o/w model emulsions stabilized by native corn starch particles in association with a surface-active olive leaf phenolic extract (OLE) was studied. Preliminarily, starch particles were submitted to a high-pressure homogenization pre-treatment and were then separated, by sedimentation, into small (<5 μm, centered on 2.5 μm) and large (<50 μm, centered on 17 μm) particles. Oil-in-water emulsions (10 % dispersed phase, w/v) were prepared using native corn starch particles in the presence of OLE as an emulsifier and characterized for particle size, microstructure and tribological behaviour. OLE and starch particles were both needed for system structuration, providing stability with different mechanisms. OLE triggered oil droplet formation acting as a low molecular weight emulsifier, while starch particles played a different role in the stabilization of the emulsions based on their size: the small starch particles provide stability by adsorbing onto the o/w interface, while the large particles provide stability by forming an interconnected network in the continuous phase, which embedded OLE-stabilized oil droplets. The tribological study showed that emulsions stabilized by small particles showed higher friction coefficients. In these emulsions, the stable emulsion droplets provided particle lubrication. In emulsions stabilized by large particles, lower friction coefficients were observed, which was due to the low stability of the oil droplets. The oil droplets could easily coalesce under flow, causing the formation of an oil film, which was more efficient in lowering the friction coefficient than the oil droplets stabilized with smaller particles. Such findings demonstrated that the size of starch particles played an important role in the stabilization mechanism of the emulsions as well as of their lubrication properties, and can be used to control different properties of emulsions
