Review on the Processing and Properties of Polymer Nanocomposites and Nanocoatings and Their Applications in the Packaging, Automotive and Solar Energy Fields

For the last decades, nanocomposites materials have been widely studied in the scientific literature as they provide substantial properties enhancements, even at low nanoparticles content. Their performance depends on a number of parameters but the nanoparticles dispersion and distribution state remains the key challenge in order to obtain the full nanocomposites' potential in terms of, e.g., flame retardance, mechanical, barrier and thermal properties, etc., that would allow extending their use in the industry. While the amount of existing research and indeed review papers regarding the formulation of nanocomposites is already significant, after listing the most common applications, this review focuses more in-depth on the properties and materials of relevance in three target sectors: packaging, solar energy and automotive. In terms of advances in the processing of nanocomposites, this review discusses various enhancement technologies such as the use of ultrasounds for in-process nanoparticles dispersion. In the case of nanocoatings, it describes the different conventionally used processes as well as nanoparticles deposition by electro-hydrodynamic processing. All in all, this review gives the basics both in terms of composition and of processing aspects to reach optimal properties for using nanocomposites in the selected applications. As an outlook, up-to-date nanosafety issues are discussed.

Physical Activity Is Associated with Attention Capacity in Adolescents

OBJECTIVE

To assess the relationships among physical activity, measured objectively, and attention capacity in European adolescents.

STUDY DESIGN

The study included 273 adolescents, aged 12.5-17.5 years, who participated in the Healthy Lifestyle in Europe by Nutrition in Adolescence Study. Participants wore a uniaxial accelerometer for 7 days to measure physical activity. The d2 Test of Attention was administered to assess attention capacity. Multivariate analyses were used to study the association of attention capacity with each measure of physical activity. Receiver operating characteristic analysis was performed to determine thresholds that best discriminate between low and good attention capacity.

RESULTS

After controlling for potential confounding variables (age, sex, body mass index, parental educational level, fat mass, aerobic fitness, and center), adolescents' attention capacity test performances were significantly and positively associated with longer time spent in moderate or moderate-to-vigorous physical activity (MVPA) in free-living conditions (P < .05). Receiver operating characteristic curve analyses revealed that the physical activity thresholds that best discriminated between low/good attention capacities were ≥41 min·day(-1) for moderate, ≥12 min·day(-1) for vigorous, and ≥58 min·day(-1) for MVPA.

CONCLUSION

These findings suggest that promoting MVPA may be have a beneficial effect on attention capacity, an important component of cognition, in adolescents.