Enhanced IR Radiative Cooling of Silver Coated PA Textile

Design, Characterization, and Evaluation of Textile Systems and Coatings for Sports Use: Applications in the Design of High-Thermal Comfort Wearables

Exposure to high temperatures during indoor and outdoor activities increases the risk of heat-related illness such as cramps, rashes, and heatstroke (HS). Fatal cases of HS are ten times more common than serious cardiac episodes in sporting scenarios, with untreated cases leading to mortality rates as high as 80%. Enhancing thermal comfort can be achieved through heat loss in enclosed spaces and the human body, utilizing heat transfer mechanisms such as radiation, conduction, convection, and evaporation, which do not require initial energy input. Among these, two primary mechanisms are commonly employed in the textile industry to enhance passive cooling: radiation and conduction. The radiation approach encompasses two aspects: (1) reflecting solar spectrum (SS) wavelengths and (2) transmitting and emitting in the atmospheric window (AW). Conduction involves dissipating heat through materials with a high thermal conductivity. Our study focuses on the combined effect of these radiative and conductive approaches to increase thermal energy loss, an area that has not been extensively studied to date. Therefore, the main objective of this project is to develop, characterize, and evaluate a nanocomposite polymeric textile system using electrospinning, incorporating graphene oxide (GO) nanosheets and titanium dioxide nanoparticles (TiO2 NPs) within a recycled polyethylene terephthalate (r-PET) matrix to improve thermal comfort through the dissipation of thermal energy by radiation and conduction. The textile system with a 5:1 molar ratio between TiO2 NPs and GO demonstrates 89.26% reflectance in the SS and 98.40% transmittance/emittance in the AW, correlating to superior cooling performance, with temperatures 20.06 and 1.27 °C lower than skin temperatures outdoors and indoors, respectively. Additionally, the textile exhibits a high thermal conductivity index of 0.66 W/m K, contact angles greater than 120°, and cell viability exceeding 80%. These findings highlight the potential of the engineered textiles in developing high-performance sports cooling fabrics, providing significant advancements in thermal comfort and safety for athletes.

Photonic structures in radiative cooling

Radiative cooling is a passive cooling technology without any energy consumption, compared to conventional cooling technologies that require power sources and dump waste heat into the surroundings. For decades, many radiative cooling studies have been introduced but its applications are mostly restricted to nighttime use only. Recently, the emergence of photonic technologies to achieves daytime radiative cooling overcome the performance limitations. For example, broadband and selective emissions in mid-IR and high reflectance in the solar spectral range have already been demonstrated. This review article discusses the fundamentals of thermodynamic heat transfer that motivates radiative cooling. Several photonic structures such as multilayer, periodical, random; derived from nature, and associated design procedures were thoroughly discussed. Photonic integration with new functionality significantly enhances the efficiency of radiative cooling technologies such as colored, transparent, and switchable radiative cooling applications has been developed. The commercial applications such as reducing cooling loads in vehicles, increasing the power generation of solar cells, generating electricity, saving water, and personal thermal regulation are also summarized. Lastly, perspectives on radiative cooling and emerging issues with potential solution strategies are discussed.

Polypyrrole/reduced graphene oxide composites coated zinc anode with dendrite suppression feature for boosting performances of zinc ion battery

Metallic zinc (Zn) anode has been received a great promise for aqueous rechargeable zinc-ion batteries (ZIBs) due to its intrinsic safety, low cost, and high volumetric capacity. However, the dendrite formation regarding the surface corrosion is the critical problems to achieve the high performance and the long lifespans of ZIBs. Here, we purpose the facile cyclic voltammetry deposition of polypyrrole/reduced graphene oxide (PPy/rGO) composites coated onto Zn 3D surface as Zn anode for ZIBs. As results, the deposited PPy/rGO layer demonstrates the homogeneous distribution covering onto Zn surface, effectively suppressing the formation of dendrite. Additionally, a symmetric cell of the PPy/rGO coated Zn remarkably enhances an electrochemical cycling with a low voltage hysteresis for zinc plating/stripping, which is superior to the pristine Zn cell. In addition, the deposited layer of PPy/rGO on Zn effectively improves the reactivity of electrochemically active surface area and the intrinsic electronic configurations, participating in extraction/intercalation of Zn²⁺ ions and leading to enhance ZIBs performance. The coin cell battery of Zn-PPy/rGO//MnO₂ can deliver a high initial discharge capacity of 325 mAh/g at 0.5A/g with a good cycling stability up to 50% capacity retention after 300 cycles. Thus, these achieved results of Zn-PPy/rGO//MnO₂ battery with dendrite-free feature effectively enhance the life-performance of ZIBs and open the way of the designed coating composite materials to suppress dendrite issues.