Due to the significant and harmful effect of the global warming on our communities, health, and climate, the usage of thermal insulation material in building is must to decrease the energy consumption and to improve energy efficiency. On the other hand, the utilization of waste and biomass resources for developing new bio-based composite materials is attracting much attention for the environmental and socioeconomics. Therefore, in this study, thermal insulation bio-based composite panels from Tetra Pak® waste and wool fiber waste with different ratios were manufactured. Likewise, other sandwich bio-based composite panels were manufactured using Tetra Pak waste as a core material with glass woven fabric and jute wove fabric as skin materials. Thermal conductivity and thermal resistance results showed a significant improvement on thermal insulation properties of the developed biocomposite panels compared to the control samples made of plain Tetra Pak®.

The global widespread of coronavirus disease 2019 (COVID-19) has caused shortage of medical face masks and led to developing of various types of cloth masks with different levels of protection and comfort to meet the market demands. Breathing comfort is a significant aspect that should be considered during the design of cloth masks along with the filtration efficiency; otherwise, the wearer will feel suffocated. In this work, different types of cotton and polyester knitted fabrics blended with spandex yarns were produced and treated with silver nanoparticles to be used as antiviral cloth masks. Scanning electron microscope, transmission electron microscope, and EDX were used to characterize the silver nanoparticles (AgNPs). Antiviral activity was assessed against SARS-CoV-2 coronavirus as well. The influence of using different fabric materials, number of layers, and hybrid layers on their air permeability and breathability were investigated to evaluate the comfortability of the cloth masks. Physiological impacts of wearing the cloth masks were evaluated by measuring oxygen saturation of hemoglobin and heart rate of the wearers while doing various activities. The results indicated that AgNPs have low cytotoxicity and considerable efficiency in inhibition of SARS-CoV-2. Adding spandex yarns with different count and ratios reduced the porosity and air permeability of the fabrics. Moreover, the combination of three hybrid layers’ mask made of polyester fabric in the outer layer with 100% cotton fabric in the inner layer showed high comfortability associated with high air permeability and breathability. Also, wearing these masks while doing activities showed no significant effect on blood oxygen saturation and heart rate of the wearers.

Improving properties of polymeric and non-polymeric fibers, for example mechanical, dimensional stability, thermal degradation, and etc. with understanding a recent theoretical investigation on the solid mechanism of single crystal growth leads to obtain fiber-based products with unusual characteristics. Similarly, high performance fibers are important engineering products and widely used due to their outstanding mechanical property along with dimensional stability. They have found extensive use as fiber reinforcement and can be utilized in many applications such as cords, ropes, performance fabrics, electronic packaging, sports equipment and fiber optics (Hearle, 2001; Kerr, Chawla and Chawla, 2005). It is well known that the highest tenacity and elastic moduli reported for such fibers are still much lower than their theoretical values. An extensive open gap between theoretical values and practical results encourage scientists to workand improve the mechanical properties. On the other hand, due to their nonconventional chemistry and instrumentation, many researches have been concentrated on reducing its production costs. Additionally, there is no single fiber chemistry that can withstand all sort of end-use conditions. The objective of this review paper is to provide a critical andconstructive analysis on current state of art high performance fiber production and modification techniques. Current problems and novel solutions were emphasized separately.