RESUMEN
Constructing a synergistic effect with different structural fillers is an important strategy for improving the comprehensive properties of polymeric composites. To improve the comprehensive properties of two-component additive liquid silicon rubber (SR) materials used in electronics packaging, the synergistic effect of granular aluminum nitride (AlN) and tubular carbon nanotube (CNT)-reinforced SR nanocomposites was investigated. AlN/CNT/SR composites with different AlN/CNT ratios were fabricated with two-component additive liquid SR via the thermal curing technique, and the influence of AlN/CNT hybrid fillers on the hardness, strength, elongation at break, surface resistivity, thermal conductivity, and thermal decomposition was investigated in detail. With the incorporation of AlN/CNT hybrid fillers, the comprehensive properties of the obtained AlN/CNT/SR composites are better than those of the AlN/SR and CNT/SR composites. The synergistic thermal conductive mechanism of AlN/CNT hybrid fillers was proposed and demonstrated with the fractural surface morphology of the obtained composites. The obtained AlN/CNT/SR composites show promising applications in electronic packaging, where necessary mechanical strength, electrical insulating, thermal conductivity, and thermal stable materials are needed.
RESUMEN
China is currently the world's largest producer of food irradiation. Despite the long-standing (about 100 years) evidence supporting the safety of food irradiation, consumers' acceptance of irradiated foods remains limited. This study aimed to investigate the development of food irradiation in China and identify the barriers that keep consumers away from irradiated foods. This was accomplished by exploring the relevant policies of food irradiation, the size and distribution of irradiation facilities in China, and analyzing their relationships between consumer characteristics and the acceptance of irradiated food. To achieve these objectives, we conducted an online survey of participants from Hubei, China (N = 264). The results reveal that irradiation facilities are mainly distributed in large coastal cities such as the Bohai Bay, the Yangtze River Delta, and the Greater Bay Area. Furthermore, the study identified that consumer' acceptance of irradiated food is directly related to their level of understanding. Approximately 22% of the sampled consumers reported that they would not accept that they have consumed irradiated food and most of them (41%) stated that they would not purchase irradiated food if they were aware of buying irradiated food. Specifically, consumers expressed discomfort with consuming irradiated food under unknown circumstances. This trend is more prevalent among female, low-educated, and older consumers, with 40% of the sampled population indicating that they would not buy irradiated food. Given the strong correlation between knowledge and acceptance of irradiated foods, the study suggests that policy reform should prioritize enhancing the understanding of irradiated food, particularly among female, low-educated, and older consumers.
RESUMEN
Giving a deep insight into the microstructure, and realizing the correlation between microstructure and properties is very important to the precise construction of high-performance graphene/polymer nanocomposites (GPN). For the promising application in microstructure characterization, much attention has been focused on the effective technique of positron annihilation lifetime spectroscopy (PALS). Based on the introduction of the basic principle, this review summarized the application progress of PALS in the correlation of microstructure and properties for GPN, especially for the characterization of free volume and interfacial interaction, and the correlation of these microstructures and properties.
RESUMEN
The quantitative characterization of microstructure is most desirable for the establishment of structure-property relationships in polymer nanocomposites. In this work, the effects of graphene on the microstructure, mechanical, electrical, and thermal properties of the obtained graphene/polyethylene (PE) composites were investigated. In order to reveal the structure-performance relationship of graphene/PE composites, especially for the effects of the relative free volume fraction (fr) and interfacial interaction intensity (ß), positron annihilation lifetime spectroscopy (PALS) was employed for its quantitative description. The relative free volume fraction fr gives a good explanation of the variation for surface resistivity, melting temperature, and thermal stability, and the variation of tensile strength and thermal conductivity agree well with the results of interfacial interaction intensity ß. The results showed that fr and ß have a significant effect on the properties of the obtained graphene/PE composites, and the effect on the properties was revealed.