Polyionenes (PI) with stable positive charges and tunable hydrophobic spacers in the polymer backbone, are shown to be particularly efficient regarding antimicrobial properties. This effect can be modulated since it increases with the length of hydrophobic spacers, i.e., the number of methylene groups between quaternary ammoniums. Now, to further explore these properties and provide efficient antimicrobial surfaces, polyionenes should be grafted onto materials. Here a robust grafting strategy to covalently attach polyionenes is described. The method consisted in a sequential surface chemistry procedure combining polydopamine coating, diazonium-induced polymerization, and polyaddition. To the best of knowledge, grafting of PI onto surfaces is not reported earlier. All chemical steps are characterized in detail via various surface analysis techniques (FTIR, X-ray photoelectron spectroscopy, contact angle, and surface energy measurements). The antibacterial properties of polyionene-grafted surfaces are then studied through bacterial adhesion experiments consisting in enumeration of adherent bacteria (total and viable cultivable cells). PI-grafted surfaces are showed to display effective and versatile bacteriostatic/bactericidal properties associated with a proadhesive effect.

Front Cover: Polyionenes (PI) have been covalently grafted onto glass surfaces via a process combining polydopamine coating, diazonium‐induced polymerization and polyaddition. The presence of positive charges and aliphatic spacers in the PI grafted chains causes disruption of the bacterial membrane. Microbial adhesion studies demonstrated the proadhesive properties and strong bacteriostatic effect of PI grafted surfaces, particularly with a longer aliphatic spacer in the repeating unit. This is reported by Sarah Bernardi, Margareth Renault, Antoine Malabirade, Nabila Debou, Jocelyne Leroy, Jean‐Marie Herry, Morgan Guilbaud, Veronique Arluison, Marie‐Noelle Bellon‐Fontaine, Geraldine Carrot in article 2000157. Image credit to Marion Bernardi.

Despite offering many benefits to consumers, merchants, banks, and other providers, mobile payment still has not found widespread acceptance in Austria, for example, in 2015, 15% of Austrian consumers used the Internet or a mobile device for payments and 16% made contactless payments at least once a week. This study sheds light on this issue by taking a consumer perspective and investigating the factors that foster or hinder mobile payment adoption. Three popular user acceptance models were compared and in the end, a unified theory of acceptance and use of technologybased model (UTAUT2) was chosen. The developed model was composed of 12 factors (behavioral intention, utilitarian performance expectancy, hedonic performance expectancy, effort expectancy, social influence, facilitating conditions, perceived risk, perceived security, privacy concerns, trust, cost, personal innovativeness) and three moderators (age, gender, experience). The proposed model was tested using data from 158 Austrian consumers and analyzed with partial least squares structural equation modeling (PLS-SEM). The results showed that 68% of consumers’ intention to use mobile payments could be explained, making it a promising model in the mobile payment research area based on the baseline data. Perceived risk and hedonic performance expectancy are the greatest drivers with psychological risk (a lack of fit with one’s self-image) as the most important risk dimension. The results suggest that mobile payment possesses lifestyle characteristics and its usage needs to be fun in order for consumers to prefer it to cash and cards. Keywords: mobile payment adoption, unified theory of acceptance and use of technology, user acceptance models, partial least squares structural equation modeling