English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Zendy Plus

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Zendy Tools

Zendy Open

A new methodology based on pyrene excimer fluorescence (PEF) was applied to quantitatively measure the actual level of intermolecular association between ethylene–propylene (EP) copolymers in toluene in the presence of wax, an intrinsic component of engine oils. EP copolymers are commonly used as viscosity index improvers (VIIs) in engine oils. Unfortunately, waxes in engine oils thicken the oil and are suspected of associating with VIIs at low temperature. In this study, four EP copolymers were maleated to yield EP-MA and then fluorescently labeled with 1-pyrenemethylamine to yield Py-EP. Successful maleation and pyrene labeling were confirmed by Fourier transform infrared (FTIR) and UV–vis absorption spectroscopy. The solution behavior of the EP copolymers in the presence of wax was characterized by PEF, which was used to quantitatively measure the molar fraction of intermolecular interactions (finter) between EP copolymers in the absence or presence of wax. The fraction finter was determined through th...

Using Pyrene Excimer Fluorescence To Probe the Interactions between Viscosity Index Improvers and Waxes Present in Automotive Oil