Breathable and Flexible Dual‐Sided Nonwovens with Adjustable Infrared Optical Performances for Smart Textile

Qiang Gao,Seema Agarwal,Markus Retsch,Bernd A F Kopera,Tobias Lauster,Andreas Greiner

doi:10.1002/adfm.202108808

Qiang Gao, Seema Agarwal + Show 4 more

Open Access

https://doi.org/10.1002/adfm.202108808

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Abstract

AbstractMaintaining constant body temperature is the most basic function of textiles. However, traditional fabrics irradiate a massive amount of thermal energy to the ambient environment due to the high emissivity of the materials used for textiles. This phenomenon weakens the thermal function, causing vast thermal energy loss by dissipation as infrared (IR) irradiation. To improve thermal comfort and reduce extra energy consumption, smart thermal management textiles must maintain constant body temperature by regulating IR irradiation from the human body or by compensating heat losses by joule heating. Here, a smart dual‐sided nonwovens’ preparation procedure and properties for use as a textile with this combination of properties are shown. The nonwoven combines a high porosity with high IR reflectance and low IR emittance. The nonwoven is adjustable from reflective to emissive when turned inside out. It is consequently permeable to air and vapor and simultaneously mitigates thermal heat losses with radiation. In addition, low sheet resistance and superior flexibility make it possible to use them in flexible electronics and wearable devices. It can be further equipped with a porous Joule heating layer adding active control to the personal thermal comfort.

Highlights

Traditional fabrics irradiate a massive amount of thermal energyThousands of years ago, our ancestors to the ambient environment due to the high emissivity of the materials used for textiles
A thermoplastic polyurethane (TPU) solution was filtered through the PI/AgNW nonwoven network under light vacuum with the intention to bond AgNW networks strongly onto the PI nonwoven by residual TPU acting as glue between the two
In PI/TPU/AgNW-25 with fewer AgNWs, stretching just over 10% leads to a break in electrical percolation due to the fracture of AgNW networks leading to the loss of conductivity

Summary

Introduction

Our ancestors to the ambient environment due to the high emissivity of the materials used for textiles. Short electrospun fibers constructed polymeric sponge is an excellent thermal insulator with very high thermal resistance thanks to its super-high porosity.[11] when some electrically conductive materials such as graphene and carbon nanotube,[12] electrically conductive polymer,[13] and metal nanowire[14] were incorporated, these polymeric materials could change their electrical property from non-conductive to conductive, even highly conductive, which often used to prepare wearable devices, such as sensor and triboelectric nanogenerator.[15] Recently, silver nanowire (AgNW) has been established as a promising electrically conductive material applied to prepare various kinds of electronic devices such as smart sensors[16] for monitoring physiological indexes, transparent touch screens,[17] and nanogenerator for energy-harvesting and storage.[18] AgNW is known for its ultralow IR emissivity, thanks to the low emissivity of bulk silver (≈0.02). The prepared PI/AgNW nonwoven is appropriate for flexible electronics and smart wearable devices and for other applications like for example sensor devices and energy devices for future use

Result and Discussion

Conclusion

Findings

Experimental Section

Data Availability Statement