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The glass transition temperature (Tg) is an important physical parameter and signifies the reversible transition process between the glassy state and the rubbery state in polymeric materials. Herein, a simple yet reliable method, denoted as ADEtect, utilizing aggregation-induced emission luminogens (AIEgens) for Tg measurement was developed. The fluorescent images of AIEgen-doped polymer films taken at different temperatures were monitored by a camera under the same settings. By using a MATLAB program, the grayscale of the selected area in each image was calculated. This value decreased steadily with increasing the temperature, and a significant change was observed at Tg. By plotting a graph of the second derivative of relative grayscale against temperature, the Tg of a polymer can be unambiguously determined from the lowest point. The present method shows performance comparable to that of conventional DSC measurement in terms of sensitivity and reliability. Besides, it can measure multiple samples in par...

The visualization of microphase separation in immiscible polymer blends is of great academic and industrial significance as the phase-separated structures are directly associated with the properties and performances of the blend materials and ultimately influence the corresponding product quality. However, conventional techniques for detecting microphase separation are generally expensive and time-consuming with troublesome and even destructive sample preparation procedures. Complicated and highly material-dependent chemical reactions or interactions are often involved in some characterization approaches. In this work, we demonstrated a simple, fast, and powerful method for high-contrast visualization and differentiation of micrometer-sized phase separation in polymer blends using luminogens with aggregation-induced emission characteristics (AIEgens) as fluorescent probes. This method relies on the sensitive fluorescence response of AIEgens to the change of environmental rigidity and polarity and operates...

Fluorescent liquid crystals (LCs) have wide applications in optoelectronic devices. However, the synthesis of high solid-state emission efficiency LCs is difficult. On one hand, impeding the aggregation of traditional luminogens is the prerequisite for high efficiencies; on the other hand, self-organization is an inherent attribute for LCs in the mesomorphic states. Because of such irreconcilable conflict, new strategy toward efficient fluorescent LCs is highly desirable. Herein, a conceptually new approach toward high efficiency fluorescent LCs is developed. Through rational design and combination of biphenyl-containing diazides and diynes carrying tetraphenylethylene units, soluble, regioregular, and liquid crystalline polytriazoles with high solid-state emission efficiencies (up to 63.7%) are obtained. The photophysical properties of the polymers are sensitive to their molecular structures and their solid-state quantum yields decrease with increasing spacer length. The spacer length also impacts on the...

Alkyne polyhydrosilylations of 1,2-bis(4-dimethylsilanylphenyl)-1,2-diphenylethene with 4,4′-diethynylbiphenyl, bis(4-ethynyl-2-methylphenyl)dimethylsilane, 3,6-diethynyl-9-heptylcarbazole, 1,1-dimethyl-2,5-bis(4-ethynylphenyl)-3,4-diphenylsilole, and 2,5-bis(2-trimethylsilylethynyl)thiophene were mediated by Rh(PPh3)3Cl in THF in an regioselective fashion, furnishing poly(silylenevinylene)s with high molecular weights (Mw up to 36 500) and stereoregularities (E content up to 100%) in satisfactory yields. All the polymers were processable and thermally stable, losing little of their weights when heated to ≥330 °C. Whereas the polymers were weakly emissive in the solutions, they became strong emitters when aggregated in poor solvents or fabricated as thin films in the solid state, demonstrating a phenomenon of aggregation-enhanced emission. The emissions of the polymers were quenched exponentially by picric acid with quenching constant up to 8.48 × 105 L mol–1, making them as highly sensitive chemosensors ...