There is growing demand for smart materials whose chemical structure, shape, and/or color, among other properties could be modified for use in applied packaging in the food industry, pharmacy, textiles, and so forth. These variations results from external stimuli, whether chemical, physical, and/or environmental (humidity, heat, light, and so forth), which has created promising materials for use in various areas of engineering, such as the production of ultrasensitive sensors with the capacity that the said variations are perceptible to the naked eye. The production of nanostructured sensor membranes obtained by electrospinning is one interesting alternative that has been attracting the attention of researchers in recent years. However, many studies related to the application of photosensors supported in electrospun cellulose acetate (CA) have not been found in the literature. Among the most used materials in electrospinning, CA stands out due to its wide availability and low cost that reflects in several applications. Two commercial sensitive pigments were used, a thermosensitive and a photosensitive one, in concentrations between 0 and 10% (m/v), to evaluate the best amount in the nanosensors they could be seen through naked eye. Variation on the fibers morphology was characterized by scanning electron microscopy. The stability and thermal transitions were evaluated using thermogravimetric analysis/differential thermogravimetric analysis and differential scanning calorimetry. The composition of chemical fibers was studied using FTIR-ATR. Finally, the thermal and/or UV light response was performed by qualitative test.

Crude glycerol is a low-cost biodiesel industry co-product in a ratio of 1:10 with the main product. The large quantities of crude glycerol produced affect the biodiesel and glycerol markets. Consequently, the exploration of new applications for crude glycerol becomes crucial. As the composition of crude glycerol differs significantly from that of purified glycerol, this work was focused on studying the effect of crude glycerol impurities on its polymerization, as this process, at the same reaction conditions established for the polymerization of purified glycerol, did not result in polymeric products. To identify the reason for this result, the crude glycerol was fully characterized to identify its composition. Hence, an experimental design using simulated crude glycerol was performed to study the effect of the most abundant impurities in the raw glycerol on the polymerization andthe impurities that would persist with such reaction conditions, such as soap and sodium. The response variable for the experimental design was the hydroxyl number of the reaction products. FT-IR spectroscopy was used to analyze differences among the reaction products obtained from different treatments. The presence of soap was identified as primary inhibitory factor and the bottleneck in the formation of polyglycerol via polymerization of crude glycerol. Molecular weights of the polymerization reaction products were determined and analyzed as per the MALDI-TOF technique. The identification of the effect of impurities of crude glycerol polymerization suggests new routes for using it in the production of high value-added chemicals.