Translocation of fluorescent probes upon stretching low-density polyethylene films. Comparison between ‘free’ and covalently-attached anthryl groups

Host/Guest Simulation of Fluorescent Probes Adsorbed into Low-Density Polyethylene, 1. Excimer Formation of 1,3-Di(1-pyrenyl)propane

“…This assumption was based on previous experimental studies by X-ray diffraction, [17,18] which demonstrated that the LDPE crystalline phase was not modified by the presence of a fluorophore.…”

Fluorescence response from anthracene labeled polystyrene to study its thermal transitions

“…Due to this, changes in the free volume of a polymer matrix (for instance when a glass transition is taking place) in which the fluorophore is located should modify the number and type of interactions between the polymer and the fluorophore and, therefore, changes in the fluorescence response of it should occur [24][25][26]. J. M. Torkelson et al [21] and M. Talhavini et al [27,28] have used the fluorescence intensity from probes and labels to study temperature induced polymer relaxation processes. In those studies plots of the fluorescence intensity vs. temperature exhibited slope changes that were interpreted as co-operative influence of the polymer chain motions on the photophysical properties of the excited states of the chromophore used.…”

“…Furthermore, in most of the samples the slope changes are so weak that are not easily distinguishable. Due to this, other methods were tried as the use of intensity ratios although they do not seem to be very sensitive [28].…”

Fluorescent labels to study thermal transitions in epoxy/silica composites

“…In general, luminescent methods are based on the dependence of the f uorescent emission intensity on temperature (radiative and nonradiative constant rates) when that dependence is related to the thermal relaxation processes of the polymer [8][9][10][11][12][13][14][15]. For example, Atvars et al [12] obtained the glass transition temperature in poly(ethylacrylate) networks using anthracene as a fluore cent probe and as a label.…”

“…For example, Atvars et al [12] obtained the glass transition temperature in poly(ethylacrylate) networks using anthracene as a fluore cent probe and as a label. Furthermore, with the same method they studied the secondary relaxation processes assigned to rotation of small polymer segments [13]. However, these f uorescent methods do not eliminate the effect of intensity variations arising from external factors such as lamp intensity, optical alignment, probe location, and excitation area.…”