High Throughput H2s Detection Using Colorimetric And Fluorescence Methods During Wine Fermentation

High Throughput H2S Detection Using Colorimetric and Fluorescence Methods During Wine Fermentation

Bonding of heterogeneous substrates, specifically polymers, is an important requirement for industries involved with the manufacture and use of products such as adhesives, coatings, and medical devices. Attempts at bonding via welding, chemical treatment, and use of adhesives are often hindered by the hydrophobic nature and chemical inertness of polymers, with many applications requiring prior surface treatment to improve compatibility between substrates. One way to modify a polymer surface is plasma treatment. This can be effective at producing hydroxyl groups on the surface of polymers which provide reactive sites for surface modification. However, plasma treatment alone cannot successfully bring together two heterogeneous substrates, a silane tethering agent is also required to chemically bond the hydroxylated surfaces with each other. In this project, the main aim was the heterogeneous bonding of elastomers to the surface of various thermoplastics by plasma treatment and using functional silanes as an intermediate between the two substrates. Specifically, polydimethylsiloxane (PDMS) would be bonded to polycarbonate (PC), polypropylene (PP), and nylon with the help of vinyl, glycidoxy, and amino-functionalised silane coupling agents. Alongside this, chemical treatment of PDMS was attempted in order to permanently produce a hydrophilic surface. This was carried out by bulk modification with polyethylene glycol, a well-known hydrophilic polymer. Fourier-transform infrared spectroscopy (FTIR) and water contact angle were used to determine the hydrophilic nature of the surface as well as observe the introduction of hydroxyl, aldehyde, and carboxylic groups upon plasma treatment. Surface morphology of the plasma-and silane-treated substrates was investigated through Atomic Force Microscopy (AFM) and Scanning Electron Microscopy (SEM). Density functional theory (DFT) calculations were employed to optimise ground state structures and frequencies to identify bond strength between the silane linkers and plasma-treated polymers. These characterisation techniques led to the successful demonstration of heterogeneous bonding between the thermoplastics and PDMS, as well as establishing a simple method to produce PDMS that can retain its hydrophilicity for over one week.

Factors Affecting Formation of Volatile Sulfur Compounds in Wines

Understanding Wine Chemistry

Wine chemistry inspires and challenges with its complexity, and while this is intriguing, it can also be a barrier to further understanding. The topic is demystified in Understanding Wine Chemistry, Special Mention awardee in the 2018 OIV awards, which explains the important chemistry of wine at the level of university education, and provides an accessible reference text for scientists and scientifically trained winemakers alike. Understanding Wine Chemistry: Summarizes the compounds found in wine, their basic chemical properties and their contribution to wine stability and sensory properties Focuses on chemical and biochemical reaction mechanisms that are critical to wine production processes such as fermentation, aging, physiochemical separations and additions Includes case studies showing how chemistry can be harnessed to enhance wine color, aroma, flavor, balance, stability and quality. This descriptive text provides an overview of wine components and explains the key chemical reactions they undergo, such as those controlling the transformation of grape components, those that arise during fermentation, and the evolution of wine flavor and color. The book aims to guide the reader, who perhaps only has a basic knowledge of chemistry, to rationally explain or predict the outcomes of chemical reactions that contribute to the diversity observed among wines. This will help students, winemakers and other interested individuals to anticipate the effects of wine treatments and processes, or interpret experimental results based on an understanding of the major chemical reactions that can occur in wine.