Exploring the Effect Mechanism of Alkyl Chain Lengths on the Tribological Performance of Ionic Liquids.

In this work, four kinds of imidazole phosphate ionic liquids (ILs) with different anionic and cationic alkyl chain lengths were synthesized. The physicochemical properties and tribological performance of ILs were evaluated. The experimental results revealed that the tribological properties of ILs were positively correlated with the cationic chain length and negatively correlated with the anionic chain length. The effect mechanism can be summarized in two aspects: on the one hand, anions with shorter alkyl chain lengths possess stronger adsorption performance and better film forming ability on the friction pair surfaces, which makes the ILs form more robust and stable lubricating film; on the other hand, ILs with longer cationic alkyl chain lengths possess milder tribo-chemical reactions, which can effectively enhance the tribological performance and decrease the corrosion wear.

Wine consumers' subjective responses to wine mouthfeel and understanding of wine body.

Wine mouthfeel is considered important for wine quality by experts, while consumers understanding of mouthfeel and the role of wine body in their wine choice is unknown. One experiment determined the influence of intrinsic wine mouthfeel on consumers' wine liking and emotions, and the other, how consumers understand the term wine body. The first experiment used a 2 astringency level×2 body level experimental design. The samples were base wine with; nothing added (control), added xanthan gum (for increased body), added grape seed extract (GSE, for increased astringency), and with both added xanthan gum and GSE. The consumer taste trial (n=112) indicated that wine with increased body did not influence wine liking and emotions; while increased astringency decreased liking and elicited more intense negative emotions. The second experiment examined consumers' knowledge of wine body through an online survey (n=136). Consumers described wine body most frequently using words such as flavour, fullness, and strength. Wine body was therefore understood by consumers predominantly as a holistic multi-sensory perception of flavour. Wine flavour was indicated by consumers to be the most important factor driving purchase decisions followed by balance of flavours and wine body. It is crucial that wine professionals carefully communicate wine characteristics to consumers to prevent possible misunderstandings such as the meaning of wine body and as a result better meet consumer expectations. In future, the term body may benefit from a clearer definition for academic research as well as industry.