Abstract:Various polybenzimidazole (PBI)-based ion-exchange films were prepared and thoroughly characterized by Fourier transform infrared (FT-IR) spectroscopy, proton conductivity, and water uptake for possible use as fuel cell membranes. Upon the increase in the flexibility of the PBI-based polymer films (e.g., poly(oxyphenylene benzimidazole) (OPBI) and sulfonated OPBI (s-OPBI)), the membranes exhibited slightly improved proton conductivity, but significantly increased dimensional changes. To reduce the dimensional changes (i.e., increase the stability), the cross-linking of the polymer films (e.g., cross-linked OPBI (c-OPBI) and sulfonated c-OPBI (sc-OPBI)) was accomplished using phosphoric acid. Interestingly, the sc-OPBI membrane possessed a greatly increased proton conductivity (0.082 S/cm), which is comparable to that of the commercially available Nafion membrane (0.09 S/cm), while still maintaining slightly better properties regarding the dimensional change and water uptake than those of the Nafion membrane.
Digital technologies have redefined how people use audio media, especially for the millennial audience segment. Faced with the challenge from streaming music, many broadcast radio stations have launched their own mobile apps to compete with the new audio services such as Spotify. Guided by the uses and gratifications conceptual framework, this study employed a national survey to investigate millennials’ perceptions of the substitutability and complementarity of broadcast radio, its apps, and music streaming services. The results showed that while radio listeners perceived broadcast radio and its apps as similar products, they regarded music streaming services as distinct from the two. In addition, this study examined motivators behind the diverse perceptions and identified information, escapism, entertainment, and socialization as important. The results suggest that radio stations should take advantage of the mobile technology and offer unique values through their apps, rather than duplicate the offline consumption experience.
This study investigates the factors affecting the cord-cutting behavior of media consumers. Adopting the frameworks of diffusion of innovations, uses and gratifications theory (U&G), channel repertoire, and media usage/segmentation, we conducted an online survey of 860 respondents in the United States to examine the use, perception, and motivation of cord-cutting behavior among three different consumer segments: cord-cutters, cord-loyalists, and cord-couplers. The results show that cord-cutting is predicted by eudaimonic and exploration motivators, perceived compatibility and complementarity, and age.
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